Evaluation of novel algorithm embedded in a wearable sEMG device for seizure detection

DEFF Research Database (Denmark)

Conradsen, Isa; Beniczky, Sandor; Wolf, Peter

2012-01-01

We implemented a modified version of a previously published algorithm for detection of generalized tonic-clonic seizures into a prototype wireless surface electromyography (sEMG) recording device. The method was modified to require minimum computational load, and two parameters were trained...... on prior sEMG data recorded with the device. Along with the normal sEMG recording, the device is able to set an alarm whenever the implemented algorithm detects a seizure. These alarms are annotated in the data file along with the signal. The device was tested at the Epilepsy Monitoring Unit (EMU......) at the Danish Epilepsy Center. Five patients were included in the study and two of them had generalized tonic-clonic seizures. All patients were monitored for 2–5 days. A double-blind study was made on the five patients. The overall result showed that the device detected four of seven seizures and had a false...

One-Channel Surface Electromyography Decomposition for Muscle Force Estimation

Directory of Open Access Journals (Sweden)

Wentao Sun

2018-05-01

Full Text Available Estimating muscle force by surface electromyography (sEMG is a non-invasive and flexible way to diagnose biomechanical diseases and control assistive devices such as prosthetic hands. To estimate muscle force using sEMG, a supervised method is commonly adopted. This requires simultaneous recording of sEMG signals and muscle force measured by additional devices to tune the variables involved. However, recording the muscle force of the lost limb of an amputee is challenging, and the supervised method has limitations in this regard. Although the unsupervised method does not require muscle force recording, it suffers from low accuracy due to a lack of reference data. To achieve accurate and easy estimation of muscle force by the unsupervised method, we propose a decomposition of one-channel sEMG signals into constituent motor unit action potentials (MUAPs in two steps: (1 learning an orthogonal basis of sEMG signals through reconstruction independent component analysis; (2 extracting spike-like MUAPs from the basis vectors. Nine healthy subjects were recruited to evaluate the accuracy of the proposed approach in estimating muscle force of the biceps brachii. The results demonstrated that the proposed approach based on decomposed MUAPs explains more than 80% of the muscle force variability recorded at an arbitrary force level, while the conventional amplitude-based approach explains only 62.3% of this variability. With the proposed approach, we were also able to achieve grip force control of a prosthetic hand, which is one of the most important clinical applications of the unsupervised method. Experiments on two trans-radial amputees indicated that the proposed approach improves the performance of the prosthetic hand in grasping everyday objects.

Multichannel noninvasive human-machine interface via stretchable µm thick sEMG patches for robot manipulation

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Zhou, Ying; Wang, Youhua; Liu, Runfeng; Xiao, Lin; Zhang, Qin; Huang, YongAn

2018-01-01

Epidermal electronics (e-skin) emerging in recent years offer the opportunity to noninvasively and wearably extract biosignals from human bodies. The conventional processes of e-skin based on standard microelectronic fabrication processes and a variety of transfer printing methods, nevertheless, unquestionably constrains the size of the devices, posing a serious challenge to collecting signals via skin, the largest organ in the human body. Herein we propose a multichannel noninvasive human-machine interface (HMI) using stretchable surface electromyography (sEMG) patches to realize a robot hand mimicking human gestures. Time-efficient processes are first developed to manufacture µm thick large-scale stretchable devices. With micron thickness, the stretchable µm thick sEMG patches show excellent conformability with human skin and consequently comparable electrical performance with conventional gel electrodes. Combined with the large-scale size, the multichannel noninvasive HMI via stretchable µm thick sEMG patches successfully manipulates the robot hand with eight different gestures, whose precision is as high as conventional gel electrodes array.

An Embedded, Eight Channel, Noise Canceling, Wireless, Wearable sEMG Data Acquisition System With Adaptive Muscle Contraction Detection.

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Ergeneci, Mert; Gokcesu, Kaan; Ertan, Erhan; Kosmas, Panagiotis

2018-02-01

Wearable technology has gained increasing popularity in the applications of healthcare, sports science, and biomedical engineering in recent years. Because of its convenient nature, the wearable technology is particularly useful in the acquisition of the physiological signals. Specifically, the (surface electromyography) sEMG systems, which measure the muscle activation potentials, greatly benefit from this technology in both clinical and industrial applications. However, the current wearable sEMG systems have several drawbacks including inefficient noise cancellation, insufficient measurement quality, and difficult integration to customized applications. Additionally, none of these sEMG data acquisition systems can detect sEMG signals (i.e., contractions), which provides a valuable environment for further studies such as human machine interaction, gesture recognition, and fatigue tracking. To this end, we introduce an embedded, eight channel, noise canceling, wireless, wearable sEMG data acquisition system with adaptive muscle contraction detection. Our design consists of two stages, which are the sEMG sensors and the multichannel data acquisition unit. For the first stage, we propose a low cost, dry, and active sEMG sensor that captures the muscle activation potentials, a data acquisition unit that evaluates these captured multichannel sEMG signals and transmits them to a user interface. In the data acquisition unit, the sEMG signals are processed through embedded, adaptive methods in order to reject the power line noise and detect the muscle contractions. Through extensive experiments, we demonstrate that our sEMG sensor outperforms a widely used commercially available product and our data acquisition system achieves 4.583 dB SNR gain with accuracy in the detection of the contractions.

Electromyography Activation Levels of the 3 Gluteus Medius Subdivisions During Manual Strength Testing

DEFF Research Database (Denmark)

Otten, Roald; Tol, Johannes L; Holmich, Per

2015-01-01

deficits and guide specific rehabilitation programs. However, the optimal positions for assessing the strength and activation of these subdivisions are unknown. OBJECTIVE: The first aim was to establish which strength-testing positions produce the highest surface electromyography (sEMG) activation levels...... of the individual GM subdivisions. The second aim was to evaluate differences in sEMG activation levels between the tested and contralateral (stabilizing) leg. METHOD: Twenty healthy physically active male subjects participated in this study. Muscle activity using sEMG was recorded for the GM subdivisions in 8......STUDY DESIGN: Cross-sectional. CONTEXT: Gluteus medius (GM) muscle dysfunction is associated with overuse injury. The GM is functionally composed of 3 separate subdivisions: anterior, middle, and posterior. Clinical assessment of the GM subdivisions is relevant to detect strength and activation...

Evaluation of upper limb muscle fatigue based on surface electromyography.

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Zhou, Qianxiang; Chen, Yuhong; Ma, Chao; Zheng, Xiaohui

2011-10-01

Fatigue is believed to be a major contributory factor to occupational injuries in machine operators. The development of accurate and usable techniques to measure operator fatigue is therefore important. In this study, we used a novel method based on surface electromyography (sEMG) of the biceps brachii and the Borg scale to evaluate local muscle fatigue in the upper limb after isometric muscle action. Thirteen young males performed isometric actions with the upper limb at different force levels. sEMG activities of the biceps brachii were recorded during the actions. Borg scales were used to evaluate the subjective sensation of local fatigue of the biceps brachii after the actions. sEMG activities were analyzed using the one-third band octave method, and an equation to determine the degree of fatigue was derived based on the relationship between the variable and the Borg scale. The results showed that the relationship could be expressed by a conic curve, and could be used to evaluate muscle fatigue during machine operation.

Muscle fatigue evaluation of astronaut upper limb based on sEMG and subjective assessment

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Zu, Xiaoqi; Zhou, Qianxiang; Li, Yun

2012-07-01

All movements are driven by muscle contraction, and it is easy to cause muscle fatigue. Evaluation of muscle fatigue is a hot topic in the area of astronaut life support training and rehabilitation. If muscle gets into fatigue condition, it may reduce work efficiency and has an impact on psychological performance. Therefore it is necessary to develop an accurate and usable method on muscle fatigue evaluation of astronaut upper limb. In this study, we developed a method based on surface electromyography (sEMG) and subjective assessment (Borg scale) to evaluate local muscle fatigue. Fifteen healthy young male subjects participated in the experiment. They performed isometric muscle contractions of the upper limb. sEMG of the biceps brachii were recorded during the entire process of isotonic muscle contraction and Borg scales of muscle fatigue were collected in certain times. sEMG were divided into several parts, and then mean energy of each parts were calculated by the one-twelfth band octave method. Equations were derived based on the relationship between the mean energy of sEMG and Borg scale. The results showed that cubic curve could describe the degree of local muscle fatigue, and could be used to evaluate and monitor local muscle fatigue during the entire process.

Analysis of prosody in finger braille using electromyography.

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Miyagi, Manabi; Nishida, Masafumi; Horiuchi, Yasuo; Ichikawa, Akira

2006-01-01

Finger braille is one of the communication methods for the deaf blind. The interpreter types braille codes on the fingers of deaf blind. Finger braille seems to be the most suitable medium for real-time communication by its speed and accuracy of transmitting characters. We hypothesize that the prosody information exists in the time structure and strength of finger braille typing. Prosody is the paralinguistic information that has functions to transmit the sentence structure, prominence, emotions and other form of information in real time communication. In this study, we measured the surface electromyography (sEMG) of finger movement to analyze the typing strength of finger braille. We found that the typing strength increases at the beginning of a phrase and a prominent phrase. The result shows the possibility that the prosody in the typing strength of finger braille can be applied to create an interpreter system for the deafblind.

A Discrete-Time Algorithm for Stiffness Extraction from sEMG and Its Application in Antidisturbance Teleoperation

Directory of Open Access Journals (Sweden)

Peidong Liang

2016-01-01

Full Text Available We have developed a new discrete-time algorithm of stiffness extraction from muscle surface electromyography (sEMG collected from human operator’s arms and have applied it for antidisturbance control in robot teleoperation. The variation of arm stiffness is estimated from sEMG signals and transferred to a telerobot under variable impedance control to imitate human motor control behaviours, particularly for disturbance attenuation. In comparison to the estimation of stiffness from sEMG, the proposed algorithm is able to reduce the nonlinear residual error effect and to enhance robustness and to simplify stiffness calibration. In order to extract a smoothing stiffness enveloping from sEMG signals, two enveloping methods are employed in this paper, namely, fast linear enveloping based on low pass filtering and moving average and amplitude monocomponent and frequency modulating (AM-FM method. Both methods have been incorporated into the proposed stiffness variance estimation algorithm and are extensively tested. The test results show that stiffness variation extraction based on the two methods is sensitive and robust to attenuation disturbance. It could potentially be applied for teleoperation in the presence of hazardous surroundings or human robot physical cooperation scenarios.

[Evaluation of the electromyography activity of pelvic floor muscle during postural exercises using the Wii Fit Plus©. Analysis and perspectives in rehabilitation].

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Steenstrup, B; Giralte, F; Bakker, E; Grise, P

2014-12-01

The aim of this work was to evaluate the effect of postural awareness by using the Wii Fit Plus© on the quality of the baseline (automatic) activity of the pelvic floor muscles (PFM) measured by intravaginal surface electromyography (sEMG). Four healthy continent female subjects, all able to perform a voluntary contraction, undertook 2 sets of 3 various exercises offered by the software Wii Fit Plus© using the Wii balance board© (WBB): one set without any visual control and the second set with postural control and sEMG visual feedback. Simultaneously, we recorded the sEMG activity of the PFM. Mean baseline activity of PFM in standing position at start was 2.87 mV, at submaximal voluntary contraction the sEMG activity raised at a mean of 14.43 mV (7.87-21.89). In the first set of exercises on the WBB without any visual feedback, the automatic activity of the PFM increased from 2.87 mV to 8.75 mV (7.96-9.59). In the second set, with visual postural and sEMG control, mean baseline sEMG activity even raised at 11.39 mV (10.17-11.58). Among women able of a voluntary contraction of PFM, visualisation of posture with the help of the WBB and of sEMG activity of the PFM during static and dynamic Wii Fit Plus© activities, may improve the automatic activation of the PFMs. 4. Copyright © 2014 Elsevier Masson SAS. All rights reserved.

Surface electromyography as a screening method for evaluation of dysphagia and odynophagia

Science.gov (United States)

Vaiman, Michael; Eviatar, Ephraim

2009-01-01

Objective Patients suspected of having swallowing disorders, could highly benefit from simple diagnostic screening before being referred to specialist evaluations. The article analyzes various instrumental methods of dysphagia assessment, introduces surface electromyography (sEMG) to carry out rapid assessment of such patients, and debates proposed suggestions for sEMG screening protocol in order to identify abnormal deglutition. Data sources Subject related books and articles from 1813 to 2007 were obtained through library search, MEDLINE (1949–2007) and EMBASE (1975–2007). Methods Specifics steps for establishing the protocol for applying the technique for screening purposes (e.g., evaluation of specific muscles), the requirements for diagnostic sEMG equipment, the sEMG technique itself, and defining the tests suitable for assessing deglutition (e.g., saliva, normal, and excessive swallows and uninterrupted drinking of water) are presented in detail. SEMG is compared with other techniques in terms of cost, timing, involvement of radiation, etc. Results According to the published data, SEMG of swallowing is a simple and reliable method for screening and preliminary differentiation among dysphagia and odynophagia of various origins. This noninvasive radiation-free examination has a low level of discomfort, and is simple, time-saving and inexpensive to perform. The major weakness of the method seems to be inability for precise diagnostic of neurologically induced dysphagia. Conclusion With standardization of the technique and an established normative database, sEMG might serve as a reliable screening method for optimal patient management but cannot serve for proper investigation of neurogenic dysphagia. PMID:19232090

An ICA-EBM-Based sEMG Classifier for Recognizing Lower Limb Movements in Individuals With and Without Knee Pathology.

Science.gov (United States)

Naik, Ganesh R; Selvan, S Easter; Arjunan, Sridhar P; Acharyya, Amit; Kumar, Dinesh K; Ramanujam, Arvind; Nguyen, Hung T

2018-03-01

Surface electromyography (sEMG) data acquired during lower limb movements has the potential for investigating knee pathology. Nevertheless, a major challenge encountered with sEMG signals generated by lower limb movements is the intersubject variability, because the signals recorded from the leg or thigh muscles are contingent on the characteristics of a subject such as gait activity and muscle structure. In order to cope with this difficulty, we have designed a three-step classification scheme. First, the multichannel sEMG is decomposed into activities of the underlying sources by means of independent component analysis via entropy bound minimization. Next, a set of time-domain features, which would best discriminate various movements, are extracted from the source estimates. Finally, the feature selection is performed with the help of the Fisher score and a scree-plot-based statistical technique, prior to feeding the dimension-reduced features to the linear discriminant analysis. The investigation involves 11 healthy subjects and 11 individuals with knee pathology performing three different lower limb movements, namely, walking, sitting, and standing, which yielded an average classification accuracy of 96.1% and 86.2%, respectively. While the outcome of this study per se is very encouraging, with suitable improvement, the clinical application of such an sEMG-based pattern recognition system that distinguishes healthy and knee pathological subjects would be an attractive consequence.

Design of sEMG assembly to detect external anal sphincter activity: a proof of concept.

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Shiraz, Arsam; Leaker, Brian; Mosse, Charles Alexander; Solomon, Eskinder; Craggs, Michael; Demosthenous, Andreas

2017-10-31

Conditional trans-rectal stimulation of the pudendal nerve could provide a viable solution to treat hyperreflexive bladder in spinal cord injury. A set threshold of the amplitude estimate of the external anal sphincter surface electromyography (sEMG) may be used as the trigger signal. The efficacy of such a device should be tested in a large scale clinical trial. As such, a probe should remain in situ for several hours while patients attend to their daily routine; the recording electrodes should be designed to be large enough to maintain good contact while observing design constraints. The objective of this study was to arrive at a design for intra-anal sEMG recording electrodes for the subsequent clinical trials while deriving the possible recording and processing parameters. Having in mind existing solutions and based on theoretical and anatomical considerations, a set of four multi-electrode probes were designed and developed. These were tested in a healthy subject and the measured sEMG traces were recorded and appropriately processed. It was shown that while comparatively large electrodes record sEMG traces that are not sufficiently correlated with the external anal sphincter contractions, smaller electrodes may not maintain a stable electrode tissue contact. It was shown that 3 mm wide and 1 cm long electrodes with 5 mm inter-electrode spacing, in agreement with Nyquist sampling, placed 1 cm from the orifice may intra-anally record a sEMG trace sufficiently correlated with external anal sphincter activity. The outcome of this study can be used in any biofeedback, treatment or diagnostic application where the activity of the external anal sphincter sEMG should be detected for an extended period of time.

Robust Features Of Surface Electromyography Signal

Science.gov (United States)

Sabri, M. I.; Miskon, M. F.; Yaacob, M. R.

2013-12-01

Nowadays, application of robotics in human life has been explored widely. Robotics exoskeleton system are one of drastically areas in recent robotic research that shows mimic impact in human life. These system have been developed significantly to be used for human power augmentation, robotics rehabilitation, human power assist, and haptic interaction in virtual reality. This paper focus on solving challenges in problem using neural signals and extracting human intent. Commonly, surface electromyography signal (sEMG) are used in order to control human intent for application exoskeleton robot. But the problem lies on difficulty of pattern recognition of the sEMG features due to high noises which are electrode and cable motion artifact, electrode noise, dermic noise, alternating current power line interface, and other noise came from electronic instrument. The main objective in this paper is to study the best features of electromyography in term of time domain (statistical analysis) and frequency domain (Fast Fourier Transform).The secondary objectives is to map the relationship between torque and best features of muscle unit activation potential (MaxPS and RMS) of biceps brachii. This project scope use primary data of 2 male sample subject which using same dominant hand (right handed), age between 20-27 years old, muscle diameter 32cm to 35cm and using single channel muscle (biceps brachii muscle). The experiment conduct 2 times repeated task of contraction and relaxation of biceps brachii when lifting different load from no load to 3kg with ascending 1kg The result shows that Fast Fourier Transform maximum power spectrum (MaxPS) has less error than mean value of reading compare to root mean square (RMS) value. Thus, Fast Fourier Transform maximum power spectrum (MaxPS) show the linear relationship against torque experience by elbow joint to lift different load. As the conclusion, the best features is MaxPS because it has the lowest error than other features and show

Robust Features Of Surface Electromyography Signal

International Nuclear Information System (INIS)

Sabri, M I; Miskon, M F; Yaacob, M R

2013-01-01

Nowadays, application of robotics in human life has been explored widely. Robotics exoskeleton system are one of drastically areas in recent robotic research that shows mimic impact in human life. These system have been developed significantly to be used for human power augmentation, robotics rehabilitation, human power assist, and haptic interaction in virtual reality. This paper focus on solving challenges in problem using neural signals and extracting human intent. Commonly, surface electromyography signal (sEMG) are used in order to control human intent for application exoskeleton robot. But the problem lies on difficulty of pattern recognition of the sEMG features due to high noises which are electrode and cable motion artifact, electrode noise, dermic noise, alternating current power line interface, and other noise came from electronic instrument. The main objective in this paper is to study the best features of electromyography in term of time domain (statistical analysis) and frequency domain (Fast Fourier Transform).The secondary objectives is to map the relationship between torque and best features of muscle unit activation potential (MaxPS and RMS) of biceps brachii. This project scope use primary data of 2 male sample subject which using same dominant hand (right handed), age between 20–27 years old, muscle diameter 32cm to 35cm and using single channel muscle (biceps brachii muscle). The experiment conduct 2 times repeated task of contraction and relaxation of biceps brachii when lifting different load from no load to 3kg with ascending 1kg The result shows that Fast Fourier Transform maximum power spectrum (MaxPS) has less error than mean value of reading compare to root mean square (RMS) value. Thus, Fast Fourier Transform maximum power spectrum (MaxPS) show the linear relationship against torque experience by elbow joint to lift different load. As the conclusion, the best features is MaxPS because it has the lowest error than other features and

The correlation between surface electromyography and bite force of mastication muscles in Asian young adults.

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Yen, Cheng-I; Mao, Shih-Hsuan; Chen, Chih-Hao; Chen, Chien-Tzung; Lee, Ming-Yih

2015-05-01

Mastication function is related to mandible movement, muscle strength, and bite force. No standard device for measuring bite force has been developed. A linear relationship between electromyographic activity and bite force has been reported by several investigators, but data on the reliability of this relationship remain limited in Asian young adults. The purpose of this study was to develop a clinically applicable, reliable, quantitative, and noninvasive system to measure the kinetic mastication function and observe the correlation between surface electromyography (sEMG) and bite force. The study group consisted of 41 young healthy adults (24 men and 17 women). Surface electromyography was used to evaluate bilateral temporalis and masseter muscle activities, and an occlusal bite force system was used concurrently to measure the bite force during maximal voluntary biting. Bilateral symmetry was compared, and the correlation between EMG and bite force was calculated. The sEMG signals were 107.7±55.0 μV and 106.0±56.0 μV (P=0.699) on right and left temporalis muscles and 183.7±86.2 μV and 194.8±94.3 μV (P=0.121) on right and left masseter muscles, respectively. The bite force was 5.0±3.2 kg on the right side and 5.7±4.0 kg on the left side (P=0.974). A positive correlation between sEMG and bite force was observed. The correlation coefficient between the temporalis muscle and bite force was 0.512, and that between the masseter muscle and bite force was 0.360. No significant difference between the bilateral electromyographic activities of the temporalis and masseter muscles and bilateral bite force was observed in young healthy adults in Taiwan. A positive correlation between sEMG signals and bite force was noted. By combining sEMG and bite force, we developed a clinically applicable, quantitative, reliable, and noninvasive system for evaluating mastication function by using characteristics of biofeedback.

Effects of 2 ankle destabilization devices on electromyography measures during functional exercises in individuals with chronic ankle instability.

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Donovan, Luke; Hart, Joseph M; Hertel, Jay

2015-03-01

Randomized crossover laboratory study. To determine the effects of ankle destabilization devices on surface electromyography (sEMG) measures of selected lower extremity muscles during functional exercises in participants with chronic ankle instability. Ankle destabilization devices are rehabilitation tools that can be worn as a boot or sandal to increase lower extremity muscle activation during walking in healthy individuals. However, they have not been tested in a population with pathology. Fifteen adults with chronic ankle instability participated. Surface electromyography electrodes were located over the anterior tibialis, fibularis longus, lateral gastrocnemius, rectus femoris, biceps femoris, and gluteus medius. The activity level of these muscles was recorded in a single testing session during unipedal stance with eyes closed, the Star Excursion Balance Test, lateral hops, and treadmill walking. Each task was performed under 3 conditions: shod, ankle destabilization boot, and ankle destabilization sandal. Surface electromyography signal amplitudes were measured for each muscle during each exercise for all 3 conditions. Participants demonstrated a significant increase, with moderate to large effect sizes, in sEMG signal amplitude of the fibularis longus in the ankle destabilization boot and ankle destabilization sandal conditions during the unipedal eyes-closed balance test, the Star Excursion Balance Test in the anterior and posteromedial directions, lateral hops, and walking, when compared to the shod condition. Both devices also resulted in an increase in sEMG signal amplitudes, with large effect sizes of the lateral gastrocnemius, rectus femoris, biceps femoris, and gluteus medius during the unipedal-stance-with-eyes-closed test, compared to the shod condition. Wearing ankle destabilization devices caused greater muscle activation during functional exercises in individuals with chronic ankle instability. Based on the magnitude of the effect, there were

Muscle conduction velocity, surface electromyography variables, and echo intensity during concentric and eccentric fatigue.

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Gonzalez-Izal, Miriam; Lusa Cadore, Eduardo; Izquierdo, Mikel

2014-03-01

Concentric (CON) and eccentric (ECC) contractions may involve different mechanisms related to changes in sarcolemma status and the consequent alteration of action potential transmission along muscle fibers. Muscle conduction velocity (CV), surface electromyography signal (sEMG), muscle quality, and blood lactate concentrations were analyzed during CON and ECC actions. Compared with ECC, the CON protocol resulted in greater muscle force losses, blood lactate concentrations, and changes in sEMG parameters. Similar reductions in CV were detected in both protocols. Higher echo intensity values were observed 2 days after ECC due to greater muscle damage. The effects of the muscle damage produced by ECC exercise on the transmission of action potentials along muscle fibers (measured as the CV) may be comparable with the effects of hydrogen accumulation produced by CON exercise (related to greater lactate concentrations), which causes greater force loss and change in other sEMG variables during CON than during ECC actions.

Exercise muscle fatigue detection system implementation via wireless surface electromyography and empirical mode decomposition.

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Chang, Kang-Ming; Liu, Shing-Hong; Wang, Jia-Jung; Cheng, Da-Chuan

2013-01-01

Surface electromyography (sEMG) is an important measurement for monitoring exercise and fitness. A wireless Bluetooth transmission sEMG measurement system with a sampling frequency of 2 KHz is developed. Traditional muscle fatigue is detected from the median frequency of the sEMG power spectrum. The regression slope of the linear regression of median frequency is an important muscle fatigue index. As fatigue increases, the power spectrum of the sEMG shifts toward lower frequencies. The goal of this study is to evaluate the sensitivity of empirical mode decomposition (EMD) quantifying the electrical manifestations of the local muscle fatigue during exercising in health people. We also compared this method with the raw data and discrete wavelet transform (DWT). Five male and five female volunteers participated. Each subject was asked to run on a multifunctional pedaled elliptical trainer for about 30 minutes, twice a week, and there were a total of six recording times for each subject with a wireless EMG recording system. The results show that sensitivity of the highest frequency component of EMD is better than the highest frequency component of DWT, and raw data.

Time-varying surface electromyography topography as a prognostic tool for chronic low back pain rehabilitation.

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Hu, Yong; Kwok, Jerry Weilun; Tse, Jessica Yuk-Hang; Luk, Keith Dip-Kei

2014-06-01

Nonsurgical rehabilitation therapy is a commonly used strategy to treat chronic low back pain (LBP). The selection of the most appropriate therapeutic options is still a big challenge in clinical practices. Surface electromyography (sEMG) topography has been proposed to be an objective assessment of LBP rehabilitation. The quantitative analysis of dynamic sEMG would provide an objective tool of prognosis for LBP rehabilitation. To evaluate the prognostic value of quantitative sEMG topographic analysis and to verify the accuracy of the performance of proposed time-varying topographic parameters for identifying the patients who have better response toward the rehabilitation program. A retrospective study of consecutive patients. Thirty-eight patients with chronic nonspecific LBP and 43 healthy subjects. The accuracy of the time-varying quantitative sEMG topographic analysis for monitoring LBP rehabilitation progress was determined by calculating the corresponding receiver-operating characteristic (ROC) curves. Physiologic measure was the sEMG during lumbar flexion and extension. Patients who suffered from chronic nonspecific LBP without the history of back surgery and any medical conditions causing acute exacerbation of LBP during the clinical test were enlisted to perform the clinical test during the 12-week physiotherapy (PT) treatment. Low back pain patients were classified into two groups: "responding" and "nonresponding" based on the clinical assessment. The responding group referred to the LBP patients who began to recover after the PT treatment, whereas the nonresponding group referred to some LBP patients who did not recover or got worse after the treatment. The results of the time-varying analysis in the responding group were compared with those in the nonresponding group. In addition, the accuracy of the analysis was analyzed through ROC curves. The time-varying analysis showed discrepancies in the root-mean-square difference (RMSD) parameters between the

A more precise, repeatable and diagnostic alternative to surface electromyography

DEFF Research Database (Denmark)

Harrison, Adrian P

2018-01-01

Acoustic myography (AMG) enables a detailed and accurate measurement of those muscles involved in a particular movement and is independent of electrical signals between the nerve and muscle, measuring solely muscle contractions, unlike surface electromyography (sEMG). With modern amplifiers....../coordination (E-score), spatial summation (S-score) and temporal summation (T-score). It is concluded that modern AMG units have the potential to accurately assess patients with neuromuscular and musculoskeletal complaints in hospital clinics, home monitoring situations as well as sports settings....

Surface electromyography and ultrasound evaluation of pelvic floor muscles in hyperandrogenic women.

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Vassimon, Flávia Ignácio Antonio; Ferreira, Cristine Homsi Jorge; Martins, Wellington Paula; Ferriani, Rui Alberto; Batista, Roberta Leopoldino de Andrade; Bo, Kari

2016-04-01

High levels of androgens increase muscle mass. Due to the characteristics of hyperandrogenism in polycystic ovary syndrome (PCOS), it is plausible that women with PCOS may have increased pelvic floor muscle (PFM) thickness and neuromuscular activity levels compared with controls. The aim of this study was to assess PFM thickness and neuromuscular activity among hyperandrogenic women with PCOS and controls. This was an observational, cross-sectional, case-control study evaluating PFM by ultrasound (US) and surface electromyography (sEMG) in nonobese women with and without PCOS. Seventy-two women were divided into two groups: PCOS (n = 33) and controls (n = 39). PFM thickness during contraction was assessed by US (Vingmed CFM 800). Pelvic floor muscle activity was assessed by sEMG (MyoTrac Infinit) during contractions at different time lengths: quick, and 8 and 60 s. Descriptive analysis, analysis of variance (ANOVA), and Student's t test were used for statistical analyses. There were no significant differences in PFM sEMG activity between PCOS and controls in any of the contractions: quick contraction (73.23 mV/ 71.56 mV; p = 0.62), 8 s (55.77 mV/ 54.17 mV; p = 0.74), and 60 s (49.26 mV/ 47.32 mV; p = 0.68), respectively. There was no difference in PFM thickness during contractions evaluated by US between PCOS and controls (12.78 mm/ 13.43 mm; p =  .48). This study did not find statistically significant differences in pelvic floor muscle thickness or in muscle activity between PCOS women and controls.

Reproducibility of 3D kinematics and surface electromyography measurements of mastication.

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Remijn, Lianne; Groen, Brenda E; Speyer, Renée; van Limbeek, Jacques; Nijhuis-van der Sanden, Maria W G

2016-03-01

The aim of this study was to determine the measurement reproducibility for a procedure evaluating the mastication process and to estimate the smallest detectable differences of 3D kinematic and surface electromyography (sEMG) variables. Kinematics of mandible movements and sEMG activity of the masticatory muscles were obtained over two sessions with four conditions: two food textures (biscuit and bread) of two sizes (small and large). Twelve healthy adults (mean age 29.1 years) completed the study. The second to the fifth chewing cycle of 5 bites were used for analyses. The reproducibility per outcome variable was calculated with an intraclass correlation coefficient (ICC) and a Bland-Altman analysis was applied to determine the standard error of measurement relative error of measurement and smallest detectable differences of all variables. ICCs ranged from 0.71 to 0.98 for all outcome variables. The outcome variables consisted of four bite and fourteen chewing cycle variables. The relative standard error of measurement of the bite variables was up to 17.3% for 'time-to-swallow', 'time-to-transport' and 'number of chewing cycles', but ranged from 31.5% to 57.0% for 'change of chewing side'. The relative standard error of measurement ranged from 4.1% to 24.7% for chewing cycle variables and was smaller for kinematic variables than sEMG variables. In general, measurements obtained with 3D kinematics and sEMG are reproducible techniques to assess the mastication process. The duration of the chewing cycle and frequency of chewing were the best reproducible measurements. Change of chewing side could not be reproduced. The published measurement error and smallest detectable differences will aid the interpretation of the results of future clinical studies using the same study variables. Copyright © 2015 Elsevier Inc. All rights reserved.

Stretchable human-machine interface based on skin-conformal sEMG electrodes with self-similar geometry

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Dong, Wentao; Zhu, Chen; Hu, Wei; Xiao, Lin; Huang, Yong'an

2018-01-01

Current stretchable surface electrodes have attracted increasing attention owing to their potential applications in biological signal monitoring, wearable human-machine interfaces (HMIs) and the Internet of Things. The paper proposed a stretchable HMI based on a surface electromyography (sEMG) electrode with a self-similar serpentine configuration. The sEMG electrode was transfer-printed onto the skin surface conformally to monitor biological signals, followed by signal classification and controlling of a mobile robot. Such electrodes can bear rather large deformation (such as >30%) under an appropriate areal coverage. The sEMG electrodes have been used to record electrophysiological signals from different parts of the body with sharp curvature, such as the index finger, back of the neck and face, and they exhibit great potential for HMI in the fields of robotics and healthcare. The electrodes placed onto the two wrists would generate two different signals with the fist clenched and loosened. It is classified to four kinds of signals with a combination of the gestures from the two wrists, that is, four control modes. Experiments demonstrated that the electrodes were successfully used as an HMI to control the motion of a mobile robot remotely. Project supported by the National Natural Science Foundation of China (Nos. 51635007, 91323303).

Detection of compensatory balance responses using wearable electromyography sensors for fall-risk assessment.

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Nouredanesh, Mina; Kukreja, Sunil L; Tung, James

2016-08-01

Loss of balance is prevalent in older adults and populations with gait and balance impairments. The present paper aims to develop a method to automatically distinguish compensatory balance responses (CBRs) from normal gait, based on activity patterns of muscles involved in maintaining balance. In this study, subjects were perturbed by lateral pushes while walking and surface electromyography (sEMG) signals were recorded from four muscles in their right leg. To extract sEMG time domain features, several filtering characteristics and segmentation approaches are examined. The performance of three classification methods, i.e., k-nearest neighbor, support vector machines, and random forests, were investigated for accurate detection of CBRs. Our results show that features extracted in the 50-200Hz band, segmented using peak sEMG amplitudes, and a random forest classifier detected CBRs with an accuracy of 92.35%. Moreover, our results support the important role of biceps femoris and rectus femoris muscles in stabilization and consequently discerning CBRs. This study contributes towards the development of wearable sensor systems to accurately and reliably monitor gait and balance control behavior in at-home settings (unsupervised conditions), over long periods of time, towards personalized fall risk assessment tools.

Hand Motion Classification Using a Multi-Channel Surface Electromyography Sensor

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Dong Sun

2012-01-01

Full Text Available The human hand has multiple degrees of freedom (DOF for achieving high-dexterity motions. Identifying and replicating human hand motions are necessary to perform precise and delicate operations in many applications, such as haptic applications. Surface electromyography (sEMG sensors are a low-cost method for identifying hand motions, in addition to the conventional methods that use data gloves and vision detection. The identification of multiple hand motions is challenging because the error rate typically increases significantly with the addition of more hand motions. Thus, the current study proposes two new methods for feature extraction to solve the problem above. The first method is the extraction of the energy ratio features in the time-domain, which are robust and invariant to motion forces and speeds for the same gesture. The second method is the extraction of the concordance correlation features that describe the relationship between every two channels of the multi-channel sEMG sensor system. The concordance correlation features of a multi-channel sEMG sensor system were shown to provide a vast amount of useful information for identification. Furthermore, a new cascaded-structure classifier is also proposed, in which 11 types of hand gestures can be identified accurately using the newly defined features. Experimental results show that the success rate for the identification of the 11 gestures is significantly high.

Hand motion classification using a multi-channel surface electromyography sensor.

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Tang, Xueyan; Liu, Yunhui; Lv, Congyi; Sun, Dong

2012-01-01

The human hand has multiple degrees of freedom (DOF) for achieving high-dexterity motions. Identifying and replicating human hand motions are necessary to perform precise and delicate operations in many applications, such as haptic applications. Surface electromyography (sEMG) sensors are a low-cost method for identifying hand motions, in addition to the conventional methods that use data gloves and vision detection. The identification of multiple hand motions is challenging because the error rate typically increases significantly with the addition of more hand motions. Thus, the current study proposes two new methods for feature extraction to solve the problem above. The first method is the extraction of the energy ratio features in the time-domain, which are robust and invariant to motion forces and speeds for the same gesture. The second method is the extraction of the concordance correlation features that describe the relationship between every two channels of the multi-channel sEMG sensor system. The concordance correlation features of a multi-channel sEMG sensor system were shown to provide a vast amount of useful information for identification. Furthermore, a new cascaded-structure classifier is also proposed, in which 11 types of hand gestures can be identified accurately using the newly defined features. Experimental results show that the success rate for the identification of the 11 gestures is significantly high.

Classification of Anticipatory Signals for Grasp and Release from Surface Electromyography

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Siu, Ho Chit; Shah, Julie A.; Stirling, Leia A.

2016-01-01

Surface electromyography (sEMG) is a technique for recording natural muscle activation signals, which can serve as control inputs for exoskeletons and prosthetic devices. Previous experiments have incorporated these signals using both classical and pattern-recognition control methods in order to actuate such devices. We used the results of an experiment incorporating grasp and release actions with object contact to develop an intent-recognition system based on Gaussian mixture models (GMM) and continuous-emission hidden Markov models (HMM) of sEMG data. We tested this system with data collected from 16 individuals using a forearm band with distributed sEMG sensors. The data contain trials with shifted band alignments to assess robustness to sensor placement. This study evaluated and found that pattern-recognition-based methods could classify transient anticipatory sEMG signals in the presence of shifted sensor placement and object contact. With the best-performing classifier, the effect of label lengths in the training data was also examined. A mean classification accuracy of 75.96% was achieved through a unigram HMM method with five mixture components. Classification accuracy on different sub-movements was found to be limited by the length of the shortest sub-movement, which means that shorter sub-movements within dynamic sequences require larger training sets to be classified correctly. This classification of user intent is a potential control mechanism for a dynamic grasping task involving user contact with external objects and noise. Further work is required to test its performance as part of an exoskeleton controller, which involves contact with actuated external surfaces. PMID:27792155

A frequency and pulse-width co-modulation strategy for transcutaneous neuromuscular electrical stimulation based on sEMG time-domain features

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Zhou, Yu-Xuan; Wang, Hai-Peng; Bao, Xue-Liang; Lü, Xiao-Ying; Wang, Zhi-Gong

2016-02-01

Objective. Surface electromyography (sEMG) is often used as a control signal in neuromuscular electrical stimulation (NMES) systems to enhance the voluntary control and proprioceptive sensory feedback of paralyzed patients. Most sEMG-controlled NMES systems use the envelope of the sEMG signal to modulate the stimulation intensity (current amplitude or pulse width) with a constant frequency. The aims of this study were to develop a strategy that co-modulates frequency and pulse width based on features of the sEMG signal and to investigate the torque-reproduction performance and the level of fatigue resistance achieved with our strategy. Approach. We examined the relationships between wrist torque and two stimulation parameters (frequency and pulse width) and between wrist torque and two sEMG time-domain features (mean absolute value (MAV) and number of slope sign changes (NSS)) in eight healthy volunteers. By using wrist torque as an intermediate variable, customized and generalized transfer functions were constructed to convert the two features of the sEMG signal into the two stimulation parameters, thereby establishing a MAV/NSS dual-coding (MNDC) algorithm. Wrist torque reproduction performance was assessed by comparing the torque generated by the algorithms with that originally recorded during voluntary contractions. Muscle fatigue was assessed by measuring the decline percentage of the peak torque and by comparing the torque time integral of the response to test stimulation trains before and after fatigue sessions. Main Results. The MNDC approach could produce a wrist torque that closely matched the voluntary wrist torque. In addition, a smaller decay in the wrist torque was observed after the MNDC-coded fatigue stimulation was applied than after stimulation using pulse-width modulation alone. Significance. Compared with pulse-width modulation stimulation strategies that are based on sEMG detection, the MNDC strategy is more effective for both voluntary muscle

Implementation of a Surface Electromyography-Based Upper Extremity Exoskeleton Controller Using Learning from Demonstration

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Arenas, Ana M.; Sun, Tingxiao

2018-01-01

Upper-extremity exoskeletons have demonstrated potential as augmentative, assistive, and rehabilitative devices. Typical control of upper-extremity exoskeletons have relied on switches, force/torque sensors, and surface electromyography (sEMG), but these systems are usually reactionary, and/or rely on entirely hand-tuned parameters. sEMG-based systems may be able to provide anticipatory control, since they interface directly with muscle signals, but typically require expert placement of sensors on muscle bodies. We present an implementation of an adaptive sEMG-based exoskeleton controller that learns a mapping between muscle activation and the desired system state during interaction with a user, generating a personalized sEMG feature classifier to allow for anticipatory control. This system is robust to novice placement of sEMG sensors, as well as subdermal muscle shifts. We validate this method with 18 subjects using a thumb exoskeleton to complete a book-placement task. This learning-from-demonstration system for exoskeleton control allows for very short training times, as well as the potential for improvement in intent recognition over time, and adaptation to physiological changes in the user, such as those due to fatigue. PMID:29401754

Implementation of a Surface Electromyography-Based Upper Extremity Exoskeleton Controller Using Learning from Demonstration

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Ho Chit Siu

2018-02-01

Full Text Available Upper-extremity exoskeletons have demonstrated potential as augmentative, assistive, and rehabilitative devices. Typical control of upper-extremity exoskeletons have relied on switches, force/torque sensors, and surface electromyography (sEMG, but these systems are usually reactionary, and/or rely on entirely hand-tuned parameters. sEMG-based systems may be able to provide anticipatory control, since they interface directly with muscle signals, but typically require expert placement of sensors on muscle bodies. We present an implementation of an adaptive sEMG-based exoskeleton controller that learns a mapping between muscle activation and the desired system state during interaction with a user, generating a personalized sEMG feature classifier to allow for anticipatory control. This system is robust to novice placement of sEMG sensors, as well as subdermal muscle shifts. We validate this method with 18 subjects using a thumb exoskeleton to complete a book-placement task. This learning-from-demonstration system for exoskeleton control allows for very short training times, as well as the potential for improvement in intent recognition over time, and adaptation to physiological changes in the user, such as those due to fatigue.

Diagnostic accuracy of the electromyography parameters associated with anterior knee pain in the diagnosis of patellofemoral pain syndrome.

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Ferrari, Deisi; Kuriki, Heloyse Uliam; Silva, Cristiano Rocha; Alves, Neri; Mícolis de Azevedo, Fábio

2014-08-01

To assess the diagnostic accuracy of the surface electromyography (sEMG) parameters associated with referred anterior knee pain in diagnosing patellofemoral pain syndrome (PFPS). Sensitivity and specificity analysis. Physical rehabilitation center and laboratory of biomechanics and motor control. Pain-free subjects (n=29) and participants with PFPS (n=22) selected by convenience. Not applicable. The diagnostic accuracy was calculated for sEMG parameters' reliability, precision, and ability to differentiate participants with and without PFPS. The selected sEMG parameter associated with anterior knee pain was considered as an index test and was compared with the reference standard for the diagnosis of PFPS. Intraclass correlation coefficient, SEM, independent t tests, sensitivity, specificity, negative and positive likelihood ratios, and negative and positive predictive values were used for the statistical analysis. The medium-frequency band (B2) parameter was reliable (intraclass correlation coefficient=.80-.90), precise (SEM=2.71-3.87 normalized unit), and able to differentiate participants with and without PFPS (Ppain showed positive diagnostic accuracy values (specificity, .87; sensitivity, .70; negative likelihood ratio, .33; positive likelihood ratio, 5.63; negative predictive value, .72; and positive predictive value, .86). The results provide evidence to support the use of EMG signals (B2-frequency band of 45-96 Hz) of the vastus lateralis and vastus medialis muscles with referred anterior knee pain in the diagnosis of PFPS. Copyright © 2014 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.

Validity and Reliability of Surface Electromyography Measurements from a Wearable Athlete Performance System

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Scott K. Lynn, Casey M. Watkins, Megan A. Wong, Katherine Balfany, Daniel F. Feeney

2018-06-01

Full Text Available The Athos ® wearable system integrates surface electromyography (sEMG electrodes into the construction of compression athletic apparel. The Athos system reduces the complexity and increases the portability of collecting EMG data and provides processed data to the end user. The objective of the study was to determine the reliability and validity of Athos as compared with a research grade sEMG system. Twelve healthy subjects performed 7 trials on separate days (1 baseline trial and 6 repeated trials. In each trial subjects wore the wearable sEMG system and had a research grade sEMG system’s electrodes placed just distal on the same muscle, as close as possible to the wearable system’s electrodes. The muscles tested were the vastus lateralis (VL, vastus medialis (VM, and biceps femoris (BF. All testing was done on an isokinetic dynamometer. Baseline testing involved performing isometric 1 repetition maximum tests for the knee extensors and flexors and three repetitions of concentric-concentric knee flexion and extension at MVC for each testing speed: 60, 180, and 300 deg/sec. Repeated trials 2-7 each comprised 9 sets where each set included three repetitions of concentric-concentric knee flexion-extension. Each repeated trial (2-7 comprised one set at each speed and percent MVC (50%, 75%, 100% combination. The wearable system and research grade sEMG data were processed using the same methods and aligned in time. The amplitude metrics calculated from the sEMG for each repetition were the peak amplitude, sum of the linear envelope, and 95th percentile. Validity results comprise two main findings. First, there is not a significant effect of system (Athos or research grade system on the repetition amplitude metrics (95%, peak, or sum. Second, the relationship between torque and sEMG is not significantly different between Athos and the research grade system. For reliability testing, the variation across trials and averaged across speeds was 0.8%, 7

Surface electromyography based muscle fatigue detection using high-resolution time-frequency methods and machine learning algorithms.

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Karthick, P A; Ghosh, Diptasree Maitra; Ramakrishnan, S

2018-02-01

Surface electromyography (sEMG) based muscle fatigue research is widely preferred in sports science and occupational/rehabilitation studies due to its noninvasiveness. However, these signals are complex, multicomponent and highly nonstationary with large inter-subject variations, particularly during dynamic contractions. Hence, time-frequency based machine learning methodologies can improve the design of automated system for these signals. In this work, the analysis based on high-resolution time-frequency methods, namely, Stockwell transform (S-transform), B-distribution (BD) and extended modified B-distribution (EMBD) are proposed to differentiate the dynamic muscle nonfatigue and fatigue conditions. The nonfatigue and fatigue segments of sEMG signals recorded from the biceps brachii of 52 healthy volunteers are preprocessed and subjected to S-transform, BD and EMBD. Twelve features are extracted from each method and prominent features are selected using genetic algorithm (GA) and binary particle swarm optimization (BPSO). Five machine learning algorithms, namely, naïve Bayes, support vector machine (SVM) of polynomial and radial basis kernel, random forest and rotation forests are used for the classification. The results show that all the proposed time-frequency distributions (TFDs) are able to show the nonstationary variations of sEMG signals. Most of the features exhibit statistically significant difference in the muscle fatigue and nonfatigue conditions. The maximum number of features (66%) is reduced by GA and BPSO for EMBD and BD-TFD respectively. The combination of EMBD- polynomial kernel based SVM is found to be most accurate (91% accuracy) in classifying the conditions with the features selected using GA. The proposed methods are found to be capable of handling the nonstationary and multicomponent variations of sEMG signals recorded in dynamic fatiguing contractions. Particularly, the combination of EMBD- polynomial kernel based SVM could be used to

Validity and Reliability of Surface Electromyography in the Assessment of Primary Muscle Tension Dysphonia.

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Khoddami, Seyyedeh Maryam; Talebian, Saeed; Izadi, Farzad; Ansari, Noureddin Nakhostin

2017-05-01

The study aims to evaluate the reliability and the discriminative validity of surface electromyography (sEMG) in the assessment of patients with primary muscle tension dysphonia (MTD). The study design is cross-sectional. Fifteen patients with primary MTD (mean age: 34.07 ± 10.99 years) and 15 healthy volunteers (mean age: 34.53 ± 10.63 years) were included. All participants underwent evaluation of sEMG to record the electrical activity of the thyrohyoid and cricothyroid muscles. The outcome measures were the root mean square (RMS), activity peak, duration, and time to the peak activity, which were obtained during /a/ and /i/ prolongation for test-retest reliability. The test-retest reliability was good to excellent for the RMS and peak activity measures (intraclass correlation coefficient [agreement] [ICC agreement ] = 0.49-0.98). The reliability for the activity duration was poor to excellent (ICC agreement  = 0.19-0.9). Poor test-retest reliability was found for the time to peak measure (ICC agreement  = 0.15-0.37). The standard error of measurement for all sEMG measures was between 0.41 and 2.05. The smallest detectable change (SDC) was calculated between 1.13 and 5.66. The highest SDC values were obtained for the peak and the lowest SDCs were documented for the duration (5.66 and 1.13, respectively). All sEMG measures were not able to discriminate between the MTD patients and healthy subjects (P > 0.05). The sEMG is a reliable tool to measure the RMS, the peak activity, and the activity duration in primary MTD. However, it is not able to discriminate the patients with primary MTD from healthy subjects. Copyright © 2017 The Voice Foundation. Published by Elsevier Inc. All rights reserved.

Deep Learning with Convolutional Neural Networks Applied to Electromyography Data: A Resource for the Classification of Movements for Prosthetic Hands.

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Atzori, Manfredo; Cognolato, Matteo; Müller, Henning

2016-01-01

Natural control methods based on surface electromyography (sEMG) and pattern recognition are promising for hand prosthetics. However, the control robustness offered by scientific research is still not sufficient for many real life applications, and commercial prostheses are capable of offering natural control for only a few movements. In recent years deep learning revolutionized several fields of machine learning, including computer vision and speech recognition. Our objective is to test its methods for natural control of robotic hands via sEMG using a large number of intact subjects and amputees. We tested convolutional networks for the classification of an average of 50 hand movements in 67 intact subjects and 11 transradial amputees. The simple architecture of the neural network allowed to make several tests in order to evaluate the effect of pre-processing, layer architecture, data augmentation and optimization. The classification results are compared with a set of classical classification methods applied on the same datasets. The classification accuracy obtained with convolutional neural networks using the proposed architecture is higher than the average results obtained with the classical classification methods, but lower than the results obtained with the best reference methods in our tests. The results show that convolutional neural networks with a very simple architecture can produce accurate results comparable to the average classical classification methods. They show that several factors (including pre-processing, the architecture of the net and the optimization parameters) can be fundamental for the analysis of sEMG data. Larger networks can achieve higher accuracy on computer vision and object recognition tasks. This fact suggests that it may be interesting to evaluate if larger networks can increase sEMG classification accuracy too.

Deep Learning with Convolutional Neural Networks Applied to Electromyography Data: A Resource for the Classification of Movements for Prosthetic Hands

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Atzori, Manfredo; Cognolato, Matteo; Müller, Henning

2016-01-01

Natural control methods based on surface electromyography (sEMG) and pattern recognition are promising for hand prosthetics. However, the control robustness offered by scientific research is still not sufficient for many real life applications, and commercial prostheses are capable of offering natural control for only a few movements. In recent years deep learning revolutionized several fields of machine learning, including computer vision and speech recognition. Our objective is to test its methods for natural control of robotic hands via sEMG using a large number of intact subjects and amputees. We tested convolutional networks for the classification of an average of 50 hand movements in 67 intact subjects and 11 transradial amputees. The simple architecture of the neural network allowed to make several tests in order to evaluate the effect of pre-processing, layer architecture, data augmentation and optimization. The classification results are compared with a set of classical classification methods applied on the same datasets. The classification accuracy obtained with convolutional neural networks using the proposed architecture is higher than the average results obtained with the classical classification methods, but lower than the results obtained with the best reference methods in our tests. The results show that convolutional neural networks with a very simple architecture can produce accurate results comparable to the average classical classification methods. They show that several factors (including pre-processing, the architecture of the net and the optimization parameters) can be fundamental for the analysis of sEMG data. Larger networks can achieve higher accuracy on computer vision and object recognition tasks. This fact suggests that it may be interesting to evaluate if larger networks can increase sEMG classification accuracy too. PMID:27656140

Novel Feature Modelling the Prediction and Detection of sEMG Muscle Fatigue towards an Automated Wearable System

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Mohamed R. Al-Mulla

2010-05-01

Full Text Available Surface Electromyography (sEMG activity of the biceps muscle was recorded from ten subjects performing isometric contraction until fatigue. A novel feature (1D spectro_std was used to extract the feature that modeled three classes of fatigue, which enabled the prediction and detection of fatigue. Initial results of class separation were encouraging, discriminating between the three classes of fatigue, a longitudinal classification on Non-Fatigue and Transition-to-Fatigue shows 81.58% correct classification with accuracy 0.74 of correct predictions while the longitudinal classification on Transition-to-Fatigue and Fatigue showed lower average correct classification of 66.51% with a positive classification accuracy 0.73 of correct prediction. Comparison of the 1D spectro_std with other sEMG fatigue features on the same dataset show a significant improvement in classification, where results show a significant 20.58% (p < 0.01 improvement when using the 1D spectro_std to classify Non-Fatigue and Transition-to-Fatigue. In classifying Transition-to-Fatigue and Fatigue results also show a significant improvement over the other features giving 8.14% (p < 0.05 on average of all compared features.

Detection of surface electromyography recording time interval without muscle fatigue effect for biceps brachii muscle during maximum voluntary contraction.

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Soylu, Abdullah Ruhi; Arpinar-Avsar, Pinar

2010-08-01

The effects of fatigue on maximum voluntary contraction (MVC) parameters were examined by using force and surface electromyography (sEMG) signals of the biceps brachii muscles (BBM) of 12 subjects. The purpose of the study was to find the sEMG time interval of the MVC recordings which is not affected by the muscle fatigue. At least 10s of force and sEMG signals of BBM were recorded simultaneously during MVC. The subjects reached the maximum force level within 2s by slightly increasing the force, and then contracted the BBM maximally. The time index of each sEMG and force signal were labeled with respect to the time index of the maximum force (i.e. after the time normalization, each sEMG or force signal's 0s time index corresponds to maximum force point). Then, the first 8s of sEMG and force signals were divided into 0.5s intervals. Mean force, median frequency (MF) and integrated EMG (iEMG) values were calculated for each interval. Amplitude normalization was performed by dividing the force signals to their mean values of 0s time intervals (i.e. -0.25 to 0.25s). A similar amplitude normalization procedure was repeated for the iEMG and MF signals. Statistical analysis (Friedman test with Dunn's post hoc test) was performed on the time and amplitude normalized signals (MF, iEMG). Although the ANOVA results did not give statistically significant information about the onset of the muscle fatigue, linear regression (mean force vs. time) showed a decreasing slope (Pearson-r=0.9462, pfatigue starts after the 0s time interval as the muscles cannot attain their peak force levels. This implies that the most reliable interval for MVC calculation which is not affected by the muscle fatigue is from the onset of the EMG activity to the peak force time. Mean, SD, and range of this interval (excluding 2s gradual increase time) for 12 subjects were 2353, 1258ms and 536-4186ms, respectively. Exceeding this interval introduces estimation errors in the maximum amplitude calculations

Curved Microneedle Array-Based sEMG Electrode for Robust Long-Term Measurements and High Selectivity

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Minjae Kim

2015-07-01

Full Text Available Surface electromyography is widely used in many fields to infer human intention. However, conventional electrodes are not appropriate for long-term measurements and are easily influenced by the environment, so the range of applications of sEMG is limited. In this paper, we propose a flexible band-integrated, curved microneedle array electrode for robust long-term measurements, high selectivity, and easy applicability. Signal quality, in terms of long-term usability and sensitivity to perspiration, was investigated. Its motion-discriminating performance was also evaluated. The results show that the proposed electrode is robust to perspiration and can maintain a high-quality measuring ability for over 8 h. The proposed electrode also has high selectivity for motion compared with a commercial wet electrode and dry electrode.

Evaluating the Training Effects of Two Swallowing Rehabilitation Therapies Using Surface Electromyography--Chin Tuck Against Resistance (CTAR) Exercise and the Shaker Exercise.

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Sze, Wei Ping; Yoon, Wai Lam; Escoffier, Nicolas; Rickard Liow, Susan J

2016-04-01

In this study, the efficacy of two dysphagia interventions, the Chin Tuck against Resistance (CTAR) and Shaker exercises, were evaluated based on two principles in exercise science-muscle-specificity and training intensity. Both exercises were developed to strengthen the suprahyoid muscles, whose contractions facilitate the opening of the upper esophageal sphincter, thereby improving bolus transfer. Thirty-nine healthy adults performed two trials of both exercises in counter-balanced order. Surface electromyography (sEMG) recordings were simultaneously collected from suprahyoid muscle group and sternocleidomastoid muscle during the exercises. Converging results using sEMG amplitude analyses suggested that the CTAR was more specific in targeting the suprahyoid muscles than the Shaker exercise. Fatigue analyses on sEMG signals further indicated that the suprahyoid muscle group were equally or significantly fatigued (depending on metric), when participants carried out CTAR compared to the Shaker exercise. Importantly, unlike during Shaker exercise, the sternocleidomastoid muscles were significantly less activated and fatigued during CTAR. Lowering the chin against resistance is therefore sufficiently specific and intense to fatigue the suprahyoid muscles.

Comparison between sEMG and force as control interfaces to support planar arm movements in adults with Duchenne: a feasibility study.

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Lobo-Prat, Joan; Nizamis, Kostas; Janssen, Mariska M H P; Keemink, Arvid Q L; Veltink, Peter H; Koopman, Bart F J M; Stienen, Arno H A

2017-07-12

Adults with Duchenne muscular dystrophy (DMD) can benefit from devices that actively support their arm function. A critical component of such devices is the control interface as it is responsible for the human-machine interaction. Our previous work indicated that surface electromyography (sEMG) and force-based control with active gravity and joint-stiffness compensation were feasible solutions for the support of elbow movements (one degree of freedom). In this paper, we extend the evaluation of sEMG- and force-based control interfaces to simultaneous and proportional control of planar arm movements (two degrees of freedom). Three men with DMD (18-23 years-old) with different levels of arm function (i.e. Brooke scores of 4, 5 and 6) performed a series of line-tracing tasks over a tabletop surface using an experimental active arm support. The arm movements were controlled using three control methods: sEMG-based control, force-based control with stiffness compensation (FSC), and force-based control with no compensation (FNC). The movement performance was evaluated in terms of percentage of task completion, tracing error, smoothness and speed. For subject S1 (Brooke 4) FNC was the preferred method and performed better than FSC and sEMG. FNC was not usable for subject S2 (Brooke 5) and S3 (Brooke 6). Subject S2 presented significantly lower movement speed with sEMG than with FSC, yet he preferred sEMG since FSC was perceived to be too fatiguing. Subject S3 could not successfully use neither of the two force-based control methods, while with sEMG he could reach almost his entire workspace. Movement performance and subjective preference of the three control methods differed with the level of arm function of the participants. Our results indicate that all three control methods have to be considered in real applications, as they present complementary advantages and disadvantages. The fact that the two weaker subjects (S2 and S3) experienced the force-based control

Normalised Mutual Information of High-Density Surface Electromyography during Muscle Fatigue

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Adrian Bingham

2017-12-01

Full Text Available This study has developed a technique for identifying the presence of muscle fatigue based on the spatial changes of the normalised mutual information (NMI between multiple high density surface electromyography (HD-sEMG channels. Muscle fatigue in the tibialis anterior (TA during isometric contractions at 40% and 80% maximum voluntary contraction levels was investigated in ten healthy participants (Age range: 21 to 35 years; Mean age = 26 years; Male = 4, Female = 6. HD-sEMG was used to record 64 channels of sEMG using a 16 by 4 electrode array placed over the TA. The NMI of each electrode with every other electrode was calculated to form an NMI distribution for each electrode. The total NMI for each electrode (the summation of the electrode’s NMI distribution highlighted regions of high dependence in the electrode array and was observed to increase as the muscle fatigued. To summarise this increase, a function, M(k, was defined and was found to be significantly affected by fatigue and not by contraction force. The technique discussed in this study has overcome issues regarding electrode placement and was used to investigate how the dependences between sEMG signals within the same muscle change spatially during fatigue.

Discrete vs. Continuous Mapping of Facial Electromyography for Human-Machine-Interface Control: Performance and Training Effects

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Cler, Meredith J.; Stepp, Cara E.

2015-01-01

Individuals with high spinal cord injuries are unable to operate a keyboard and mouse with their hands. In this experiment, we compared two systems using surface electromyography (sEMG) recorded from facial muscles to control an onscreen keyboard to type five-letter words. Both systems used five sEMG sensors to capture muscle activity during five distinct facial gestures that were mapped to five cursor commands: move left, move right, move up, move down, and “click”. One system used a discrete movement and feedback algorithm in which the user produced one quick facial gesture, causing a corresponding discrete movement to an adjacent letter. The other system was continuously updated and allowed the user to control the cursor’s velocity by relative activation between different sEMG channels. Participants were trained on one system for four sessions on consecutive days, followed by one crossover session on the untrained system. Information transfer rates (ITRs) were high for both systems compared to other potential input modalities, both initially and with training (Session 1: 62.1 bits/min, Session 4: 105.1 bits/min). Users of the continuous system showed significantly higher ITRs than the discrete users. Future development will focus on improvements to both systems, which may offer differential advantages for users with various motor impairments. PMID:25616053

Effects of 12-wk eccentric calf muscle training on muscle-tendon glucose uptake and SEMG in patients with chronic Achilles tendon pain.

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Masood, Tahir; Kalliokoski, Kari; Magnusson, S Peter; Bojsen-Møller, Jens; Finni, Taija

2014-07-15

High-load eccentric exercises have been a key component in the conservative management of chronic Achilles tendinopathy. This study investigated the effects of a 12-wk progressive, home-based eccentric rehabilitation program on ankle plantar flexors' glucose uptake (GU) and myoelectric activity and Achilles tendon GU. A longitudinal study design with control (n = 10) and patient (n = 10) groups was used. Surface electromyography (SEMG) from four ankle plantar flexors and GU from the same muscles and the Achilles tendon were measured during submaximal intermittent isometric plantar flexion task. The results indicated that the symptomatic leg was weaker (P eccentric rehabilitation. Additionally, the rehabilitation resulted in greater GU in both soleus (P tendon GU than the controls (P effect on the tendon GU. Concerning SEMG, at baseline, soleus showed more relative activity in the symptomatic leg compared with both the asymptomatic and control legs (P Eccentric rehabilitation was effective in decreasing subjective severity of Achilles tendinopathy. It also resulted in redistribution of relative electrical activity, but not metabolic activity, within the triceps surae muscle. Copyright © 2014 the American Physiological Society.

Application of advanced biomechanical methods in studying low back pain – recent development in estimation of lower back loads and large-array surface electromyography and findings

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Bazrgari B

2017-07-01

Full Text Available Babak Bazrgari,1 Ting Xia2 1F. Joseph Halcomb III, M.D. Department of Biomedical Engineering, University of Kentucky, Lexington, KY, 2Palmer Center for Chiropractic Research, Palmer College of Chiropractic, Davenport, IA, USA Abstract: Low back pain (LBP is a major public health problem and the leading disabling musculoskeletal disorder globally. A number of biomechanical methods using kinematic, kinetic and/or neuromuscular approaches have been used to study LBP. In this narrative review, we report recent developments in two biomechanical methods: estimation of lower back loads and large-array surface electromyography (LA-SEMG and the findings associated with LBP. The ability to estimate lower back loads is very important for the prevention and the management of work-related low back injuries based on the mechanical loading model as one category of LBP classification. The methods used for estimation of lower back loads vary from simple rigid link-segment models to sophisticated, optimization-based finite element models. In general, reviewed reports of differences in mechanical loads experienced in lower back tissues between patients with LBP and asymptomatic individuals are not consistent. Such lack of consistency is primarily due to differences in activities under which lower back mechanical loads were investigated as well as heterogeneity of patient populations. The ability to examine trunk neuromuscular behavior is particularly relevant to the motor control model, another category of LBP classification. LA-SEMG not only is noninvasive but also provides spatial resolution within and across muscle groups. Studies using LA-SEMG showed that healthy individuals exhibit highly organized, symmetric back muscle activity patterns, suggesting an orderly recruitment of muscle fibers. In contrast, back muscle activity patterns in LBP patients are asymmetric or multifocal, suggesting lack of orderly muscle recruitment. LA-SEMG was also shown capable of

Comparison of algorithms to quantify muscle fatigue in upper limb muscles based on sEMG signals.

Science.gov (United States)

Kahl, Lorenz; Hofmann, Ulrich G

2016-11-01

This work compared the performance of six different fatigue detection algorithms quantifying muscle fatigue based on electromyographic signals. Surface electromyography (sEMG) was obtained by an experiment from upper arm contractions at three different load levels from twelve volunteers. Fatigue detection algorithms mean frequency (MNF), spectral moments ratio (SMR), the wavelet method WIRM1551, sample entropy (SampEn), fuzzy approximate entropy (fApEn) and recurrence quantification analysis (RQA%DET) were calculated. The resulting fatigue signals were compared considering the disturbances incorporated in fatiguing situations as well as according to the possibility to differentiate the load levels based on the fatigue signals. Furthermore we investigated the influence of the electrode locations on the fatigue detection quality and whether an optimized channel set is reasonable. The results of the MNF, SMR, WIRM1551 and fApEn algorithms fell close together. Due to the small amount of subjects in this study significant differences could not be found. In terms of disturbances the SMR algorithm showed a slight tendency to out-perform the others. Copyright © 2016 IPEM. Published by Elsevier Ltd. All rights reserved.

Reliability of surface electromyography timing parameters in gait in cervical spondylotic myelopathy.

LENUS (Irish Health Repository)

Malone, Ailish

2012-02-01

The aims of this study were to validate a computerised method to detect muscle activity from surface electromyography (SEMG) signals in gait in patients with cervical spondylotic myelopathy (CSM), and to evaluate the test-retest reliability of the activation times designated by this method. SEMG signals were recorded from rectus femoris (RF), biceps femoris (BF), tibialis anterior (TA), and medial gastrocnemius (MG), during gait in 12 participants with CSM on two separate test days. Four computerised activity detection methods, based on the Teager-Kaiser Energy Operator (TKEO), were applied to a subset of signals and compared to visual interpretation of muscle activation. The most accurate method was then applied to all signals for evaluation of test-retest reliability. A detection method based on a combined slope and amplitude threshold showed the highest agreement (87.5%) with visual interpretation. With respect to reliability, the standard error of measurement (SEM) of the timing of RF, TA and MG between test days was 5.5% stride duration or less, while the SEM of BF was 9.4%. The timing parameters of RF, TA and MG designated by this method were considered sufficiently reliable for use in clinical practice, however the reliability of BF was questionable.

Estimation of Handgrip Force from SEMG Based on Wavelet Scale Selection.

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Wang, Kai; Zhang, Xianmin; Ota, Jun; Huang, Yanjiang

2018-02-24

This paper proposes a nonlinear correlation-based wavelet scale selection technology to select the effective wavelet scales for the estimation of handgrip force from surface electromyograms (SEMG). The SEMG signal corresponding to gripping force was collected from extensor and flexor forearm muscles during the force-varying analysis task. We performed a computational sensitivity analysis on the initial nonlinear SEMG-handgrip force model. To explore the nonlinear correlation between ten wavelet scales and handgrip force, a large-scale iteration based on the Monte Carlo simulation was conducted. To choose a suitable combination of scales, we proposed a rule to combine wavelet scales based on the sensitivity of each scale and selected the appropriate combination of wavelet scales based on sequence combination analysis (SCA). The results of SCA indicated that the scale combination VI is suitable for estimating force from the extensors and the combination V is suitable for the flexors. The proposed method was compared to two former methods through prolonged static and force-varying contraction tasks. The experiment results showed that the root mean square errors derived by the proposed method for both static and force-varying contraction tasks were less than 20%. The accuracy and robustness of the handgrip force derived by the proposed method is better than that obtained by the former methods.

Entropic Analysis of Electromyography Time Series

Science.gov (United States)

Kaufman, Miron; Sung, Paul

2005-03-01

We are in the process of assessing the effectiveness of fractal and entropic measures for the diagnostic of low back pain from surface electromyography (EMG) time series. Surface electromyography (EMG) is used to assess patients with low back pain. In a typical EMG measurement, the voltage is measured every millisecond. We observed back muscle fatiguing during one minute, which results in a time series with 60,000 entries. We characterize the complexity of time series by computing the Shannon entropy time dependence. The analysis of the time series from different relevant muscles from healthy and low back pain (LBP) individuals provides evidence that the level of variability of back muscle activities is much larger for healthy individuals than for individuals with LBP. In general the time dependence of the entropy shows a crossover from a diffusive regime to a regime characterized by long time correlations (self organization) at about 0.01s.

A MATLAB-based graphical user interface for the identification of muscular activations from surface electromyography signals.

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Mengarelli, Alessandro; Cardarelli, Stefano; Verdini, Federica; Burattini, Laura; Fioretti, Sandro; Di Nardo, Francesco

2016-08-01

In this paper a graphical user interface (GUI) built in MATLAB® environment is presented. This interactive tool has been developed for the analysis of superficial electromyography (sEMG) signals and in particular for the assessment of the muscle activation time intervals. After the signal import, the tool performs a first analysis in a totally user independent way, providing a reliable computation of the muscular activation sequences. Furthermore, the user has the opportunity to modify each parameter of the on/off identification algorithm implemented in the presented tool. The presence of an user-friendly GUI allows the immediate evaluation of the effects that the modification of every single parameter has on the activation intervals recognition, through the real-time updating and visualization of the muscular activation/deactivation sequences. The possibility to accept the initial signal analysis or to modify the on/off identification with respect to each considered signal, with a real-time visual feedback, makes this GUI-based tool a valuable instrument in clinical, research applications and also in an educational perspective.

Comparison of regression models for estimation of isometric wrist joint torques using surface electromyography

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Menon Carlo

2011-09-01

Full Text Available Abstract Background Several regression models have been proposed for estimation of isometric joint torque using surface electromyography (SEMG signals. Common issues related to torque estimation models are degradation of model accuracy with passage of time, electrode displacement, and alteration of limb posture. This work compares the performance of the most commonly used regression models under these circumstances, in order to assist researchers with identifying the most appropriate model for a specific biomedical application. Methods Eleven healthy volunteers participated in this study. A custom-built rig, equipped with a torque sensor, was used to measure isometric torque as each volunteer flexed and extended his wrist. SEMG signals from eight forearm muscles, in addition to wrist joint torque data were gathered during the experiment. Additional data were gathered one hour and twenty-four hours following the completion of the first data gathering session, for the purpose of evaluating the effects of passage of time and electrode displacement on accuracy of models. Acquired SEMG signals were filtered, rectified, normalized and then fed to models for training. Results It was shown that mean adjusted coefficient of determination (Ra2 values decrease between 20%-35% for different models after one hour while altering arm posture decreased mean Ra2 values between 64% to 74% for different models. Conclusions Model estimation accuracy drops significantly with passage of time, electrode displacement, and alteration of limb posture. Therefore model retraining is crucial for preserving estimation accuracy. Data resampling can significantly reduce model training time without losing estimation accuracy. Among the models compared, ordinary least squares linear regression model (OLS was shown to have high isometric torque estimation accuracy combined with very short training times.

Age related neuromuscular changes in sEMG of m. Tibialis Anterior using higher order statistics (Gaussianity & linearity test).

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Siddiqi, Ariba; Arjunan, Sridhar P; Kumar, Dinesh K

2016-08-01

Age-associated changes in the surface electromyogram (sEMG) of Tibialis Anterior (TA) muscle can be attributable to neuromuscular alterations that precede strength loss. We have used our sEMG model of the Tibialis Anterior to interpret the age-related changes and compared with the experimental sEMG. Eighteen young (20-30 years) and 18 older (60-85 years) performed isometric dorsiflexion at 6 different percentage levels of maximum voluntary contractions (MVC), and their sEMG from the TA muscle was recorded. Six different age-related changes in the neuromuscular system were simulated using the sEMG model at the same MVCs as the experiment. The maximal power of the spectrum, Gaussianity and Linearity Test Statistics were computed from the simulated and experimental sEMG. A correlation analysis at α=0.05 was performed between the simulated and experimental age-related change in the sEMG features. The results show the loss in motor units was distinguished by the Gaussianity and Linearity test statistics; while the maximal power of the PSD distinguished between the muscular factors. The simulated condition of 40% loss of motor units with halved the number of fast fibers best correlated with the age-related change observed in the experimental sEMG higher order statistical features. The simulated aging condition found by this study corresponds with the moderate motor unit remodelling and negligible strength loss reported in literature for the cohorts aged 60-70 years.

Effects of Force Load, Muscle Fatigue, and Magnetic Stimulation on Surface Electromyography during Side Arm Lateral Raise Task: A Preliminary Study with Healthy Subjects.

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Cao, Liu; Wang, Ying; Hao, Dongmei; Rong, Yao; Yang, Lin; Zhang, Song; Zheng, Dingchang

2017-01-01

The aim of this study was to quantitatively investigate the effects of force load, muscle fatigue, and extremely low-frequency (ELF) magnetic stimulation on surface electromyography (SEMG) signal features during side arm lateral raise task. SEMG signals were recorded from 18 healthy subjects on the anterior deltoid using a BIOSEMI ActiveTwo system during side lateral raise task (with the right arm 90 degrees away from the body) with three different loads on the forearm (0 kg, 1 kg, and 3 kg; their order was randomized between subjects). The arm maintained the loads until the subject felt exhausted. The first 10 s recording for each load was regarded as nonfatigue status and the last 10 s before the subject was exhausted was regarded as fatigue status. The subject was then given a five-minute resting between different loads. Two days later, the same experiment was repeated on every subject, and this time the ELF magnetic stimulation was applied to the subject's deltoid muscle during the five-minute rest period. Three commonly used SEMG features, root mean square (RMS), median frequency (MDF), and sample entropy (SampEn), were analyzed and compared between different loads, nonfatigue/fatigue status, and ELF stimulation and no stimulation. Variance analysis results showed that the effect of force load on RMS was significant ( p 0.05). In comparison with nonfatigue status, for all the different force loads with and without ELF stimulation, RMS was significantly larger at fatigue (all p < 0.001) and MDF and SampEn were significantly smaller (all p < 0.001).

Mechanomyography versus Electromyography, in monitoring the muscular fatigue

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Tarata Mihai T

2003-02-01

Full Text Available Abstract Background The use of the mechanomyogram (MMG which detects muscular vibrations generated by fused individual fiber twitches has been refined. The study addresses a comparison of the MMG and surface electromyogram (SEMG in monitoring muscle fatigue. Methods The SEMG and MMG were recorded simultaneously from the same territory of motor units in two muscles (Biceps, Brachioradialis of the human (n = 18, during sustained contraction at 25 % MVC (maximal voluntary contraction. Results The RMS (root mean square of the SEMG and MMG increased with advancing fatigue; MF (median frequency of the PSD (power density spectra progressively decreased from the onset of the contraction. These findings (both muscles, all subjects, demonstrate both through the SEMG and MMG a central component of the fatigue. The MF regression slopes of MMG were closer to each other between men and women (Biceps 1.55%; Brachialis 13.2% than were the SEMG MF slopes (Biceps 25.32%; Brachialis 17.72%, which shows a smaller inter-sex variability for the MMG vs. SEMG. Conclusion The study presents another quantitative comparison (MF, RMS of MMG and SEMG, showing that MMG signal can be used for indication of the degree of muscle activation and for monitoring the muscle fatigue when the application of SEMG is not feasible (chronical implants, adverse environments contaminated by electrical noise.

Experiences in the creation of an electromyography database to help hand amputated persons.

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Atzori, Manfredo; Gijsberts, Arjan; Heynen, Simone; Hager, Anne-Gabrielle Mittaz; Castellimi, Claudio; Caputo, Barbara; Müller, Henning

2012-01-01

Currently, trans-radial amputees can only perform a few simple movements with prosthetic hands. This is mainly due to low control capabilities and the long training time that is required to learn controlling them with surface electromyography (sEMG). This is in contrast with recent advances in mechatronics, thanks to which mechanical hands have multiple degrees of freedom and in some cases force control. To help improve the situation, we are building the NinaPro (Non-Invasive Adaptive Prosthetics) database, a database of about 50 hand and wrist movements recorded from several healthy and currently very few amputated persons that will help the community to test and improve sEMG-based natural control systems for prosthetic hands. In this paper we describe the experimental experiences and practical aspects related to the data acquisition.

Grip Force and 3D Push-Pull Force Estimation Based on sEMG and GRNN

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Changcheng Wu

2017-06-01

Full Text Available The estimation of the grip force and the 3D push-pull force (push and pull force in the three dimension space from the electromyogram (EMG signal is of great importance in the dexterous control of the EMG prosthetic hand. In this paper, an action force estimation method which is based on the eight channels of the surface EMG (sEMG and the Generalized Regression Neural Network (GRNN is proposed to meet the requirements of the force control of the intelligent EMG prosthetic hand. Firstly, the experimental platform, the acquisition of the sEMG, the feature extraction of the sEMG and the construction of GRNN are described. Then, the multi-channels of the sEMG when the hand is moving are captured by the EMG sensors attached on eight different positions of the arm skin surface. Meanwhile, a grip force sensor and a three dimension force sensor are adopted to measure the output force of the human's hand. The characteristic matrix of the sEMG and the force signals are used to construct the GRNN. The mean absolute value and the root mean square of the estimation errors, the correlation coefficients between the actual force and the estimated force are employed to assess the accuracy of the estimation. Analysis of variance (ANOVA is also employed to test the difference of the force estimation. The experiments are implemented to verify the effectiveness of the proposed estimation method and the results show that the output force of the human's hand can be correctly estimated by using sEMG and GRNN method.

Detecting and Predicting Muscle Fatigue during Typing By SEMG Signal Processing and Artificial Neural Networks

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Elham Ghoochani

2011-03-01

Full Text Available Introduction: Repetitive strain injuries are one of the most prevalent problems in occupational diseases. Repetition, vibration and bad postures of the extremities are physical risk factors related to work that can cause chronic musculoskeletal disorders. Repetitive work on a computer with low level contraction requires the posture to be maintained for a long time, which can cause muscle fatigue. Muscle fatigue in shoulders and neck is one of the most prevalent problems reported with computer users especially during typing. Surface electromyography (SEMG signals are used for detecting muscle fatigue as a non-invasive method. Material and Methods: Nine healthy females volunteered for signal recoding during typing. EMG signals were recorded from the trapezius muscle, which is subjected to muscle fatigue during typing.  After signal analysis and feature extraction, detecting and predicting muscle fatigue was performed by using the MLP artificial neural network. Results: Recorded signals were analyzed in time and frequency domains for feature extraction. Results of classification showed that the MLP neural network can detect and predict muscle fatigue during typing with 80.79 % ± 1.04% accuracy. Conclusion: Intelligent classification and prediction of muscle fatigue can have many applications in human factors engineering (ergonomics, rehabilitation engineering and biofeedback equipment for mitigating the injuries of repetitive works.

Fractal based modelling and analysis of electromyography (EMG) to identify subtle actions.

Science.gov (United States)

Arjunan, Sridhar P; Kumar, Dinesh K

2007-01-01

The paper reports the use of fractal theory and fractal dimension to study the non-linear properties of surface electromyogram (sEMG) and to use these properties to classify subtle hand actions. The paper reports identifying a new feature of the fractal dimension, the bias that has been found to be useful in modelling the muscle activity and of sEMG. Experimental results demonstrate that the feature set consisting of bias values and fractal dimension of the recordings is suitable for classification of sEMG against the different hand gestures. The scatter plots demonstrate the presence of simple relationships of these features against the four hand gestures. The results indicate that there is small inter-experimental variation but large inter-subject variation. This may be due to differences in the size and shape of muscles for different subjects. The possible applications of this research include use in developing prosthetic hands, controlling machines and computers.

Repeatability of grasp recognition for robotic hand prosthesis control based on sEMG data.

Science.gov (United States)

Palermo, Francesca; Cognolato, Matteo; Gijsberts, Arjan; Muller, Henning; Caputo, Barbara; Atzori, Manfredo

2017-07-01

Control methods based on sEMG obtained promising results for hand prosthetics. Control system robustness is still often inadequate and does not allow the amputees to perform a large number of movements useful for everyday life. Only few studies analyzed the repeatability of sEMG classification of hand grasps. The main goals of this paper are to explore repeatability in sEMG data and to release a repeatability database with the recorded experiments. The data are recorded from 10 intact subjects repeating 7 grasps 12 times, twice a day for 5 days. The data are publicly available on the Ninapro web page. The analysis for the repeatability is based on the comparison of movement classification accuracy in several data acquisitions and for different subjects. The analysis is performed using mean absolute value and waveform length features and a Random Forest classifier. The accuracy obtained by training and testing on acquisitions at different times is on average 27.03% lower than training and testing on the same acquisition. The results obtained by training and testing on different acquisitions suggest that previous acquisitions can be used to train the classification algorithms. The inter-subject variability is remarkable, suggesting that specific characteristics of the subjects can affect repeatibility and sEMG classification accuracy. In conclusion, the results of this paper can contribute to develop more robust control systems for hand prostheses, while the presented data allows researchers to test repeatability in further analyses.

Effects of Force Load, Muscle Fatigue, and Magnetic Stimulation on Surface Electromyography during Side Arm Lateral Raise Task: A Preliminary Study with Healthy Subjects

Directory of Open Access Journals (Sweden)

Liu Cao

2017-01-01

Full Text Available The aim of this study was to quantitatively investigate the effects of force load, muscle fatigue, and extremely low-frequency (ELF magnetic stimulation on surface electromyography (SEMG signal features during side arm lateral raise task. SEMG signals were recorded from 18 healthy subjects on the anterior deltoid using a BIOSEMI ActiveTwo system during side lateral raise task (with the right arm 90 degrees away from the body with three different loads on the forearm (0 kg, 1 kg, and 3 kg; their order was randomized between subjects. The arm maintained the loads until the subject felt exhausted. The first 10 s recording for each load was regarded as nonfatigue status and the last 10 s before the subject was exhausted was regarded as fatigue status. The subject was then given a five-minute resting between different loads. Two days later, the same experiment was repeated on every subject, and this time the ELF magnetic stimulation was applied to the subject’s deltoid muscle during the five-minute rest period. Three commonly used SEMG features, root mean square (RMS, median frequency (MDF, and sample entropy (SampEn, were analyzed and compared between different loads, nonfatigue/fatigue status, and ELF stimulation and no stimulation. Variance analysis results showed that the effect of force load on RMS was significant (p0.05. In comparison with nonfatigue status, for all the different force loads with and without ELF stimulation, RMS was significantly larger at fatigue (all p<0.001 and MDF and SampEn were significantly smaller (all p<0.001.

Is there any change in pelvic floor electromyography during the first 6 months after radical retropubic prostatectomy?

Science.gov (United States)

Hacad, Claudia R; Glazer, Howard I; Zambon, João Paulo C; Burti, Juliana S; Almeida, Fernando G

2015-03-01

The aim of this study is to determine electromyographic pelvic floor muscles activity during the first 6 months post RRP and its relationship to urinary continence. Thirty-eight men (mean age of 63.1 ± 5.7 year) with prostate cancer scheduled for open radical retropubic prostatectomy were evaluated. pelvic radiotherapy, systemic or neurologic diseases, pre-operative International Prostate Symptoms Score (IPSS) >7 and OABq ≥8. Surface electromyography (sEMG) evaluation, IPSS, Urinary Distress Inventory, Incontinence Impact Questionnaire, and Overactive Bladder Questionnaire-short form were applied before and at 1, 3, and 6 months after RRP. Six months after surgery, 18 men (47.4 %) presented urinary leakage. The sEMG evaluations within the first 6 months presented changes in fast contraction amplitude (p = 0.006), rest amplitude after fast contraction (p = 0.04), 10 s sustained contraction mean amplitude (p = 0.024) and final rest amplitude (p = 0.011). We observed that continent and incontinent patients as a group presented electromyographic changes during the first 6 months after radical prostatectomy that could be justified by the denervation/reinnervation of the external urethral sphincter. This finding is consistent with the adaptation of the pelvic floor musculature to the new urethral sphincter condition following surgery.

A Novel Feature Optimization for Wearable Human-Computer Interfaces Using Surface Electromyography Sensors

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Han Sun

2018-03-01

Full Text Available The novel human-computer interface (HCI using bioelectrical signals as input is a valuable tool to improve the lives of people with disabilities. In this paper, surface electromyography (sEMG signals induced by four classes of wrist movements were acquired from four sites on the lower arm with our designed system. Forty-two features were extracted from the time, frequency and time-frequency domains. Optimal channels were determined from single-channel classification performance rank. The optimal-feature selection was according to a modified entropy criteria (EC and Fisher discrimination (FD criteria. The feature selection results were evaluated by four different classifiers, and compared with other conventional feature subsets. In online tests, the wearable system acquired real-time sEMG signals. The selected features and trained classifier model were used to control a telecar through four different paradigms in a designed environment with simple obstacles. Performance was evaluated based on travel time (TT and recognition rate (RR. The results of hardware evaluation verified the feasibility of our acquisition systems, and ensured signal quality. Single-channel analysis results indicated that the channel located on the extensor carpi ulnaris (ECU performed best with mean classification accuracy of 97.45% for all movement’s pairs. Channels placed on ECU and the extensor carpi radialis (ECR were selected according to the accuracy rank. Experimental results showed that the proposed FD method was better than other feature selection methods and single-type features. The combination of FD and random forest (RF performed best in offline analysis, with 96.77% multi-class RR. Online results illustrated that the state-machine paradigm with a 125 ms window had the highest maneuverability and was closest to real-life control. Subjects could accomplish online sessions by three sEMG-based paradigms, with average times of 46.02, 49.06 and 48.08 s

Electromyography physiology engineering and noninvasive applications

CERN Document Server

Parker, Philip; John Wiley & Sons

2004-01-01

"Featuring contributions from key innovators working in the field today, Electromyography reveals the broad applications of EMG data in areas as diverse as neurology, ergonomics, exercise physiology, rehabilitation, movement analysis, biofeedback, and myoelectric control of prostheses." "Electromyography offers physiologists, medical professionals, and students in biomedical engineering a new window into the possibilities of this technology."--Jacket.

SEMG activity of jaw-closing muscles during biting with different unilateral occlusal supports.

Science.gov (United States)

Wang, M-Q; He, J-J; Zhang, J-H; Wang, K; Svensson, P; Widmalm, S E

2010-09-01

The aim of this study was to test the hypothesis that experimental and reversible changes of occlusion affect the levels of surface electromyographic (SEMG) activity in the anterior temporalis and masseter areas during unilateral maximal voluntary biting (MVB) in centric and eccentric position. Changes were achieved by letting 21 healthy subjects bite with and without a cotton roll between the teeth. The placement alternated between sides and between premolar and molar areas. The SEMG activity level was lower when biting in eccentric position without than with a cotton roll between teeth (P 0.05). In the anterior temporalis area, the balancing side SEMG activity was lower in eccentric than in centric but only in molar-supported biting (P = 0.026). These results support that the masseter and anterior temporalis muscles have different roles in keeping the mandible in balance during unilateral supported MVB. Changes in occlusal stability achieved by biting with versus without a cotton roll were found to affect the SEMG activity levels.

A comparative analysis of three non-invasive Human-Machine Interfaces for the disabled

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Vikram eRavindra

2014-10-01

Full Text Available In the framework of rehabilitation robotics, a major role is played by theHuman-Machine Interface (HMI used to gather the patient's intent from biologicalsignals, and convert them into control signals for the robotic artifact. Surprisingly,decades of research haven't yet declared what the optimal HMI is in this context;in particular, the traditional approach based upon surface electromyography (sEMGstill yields unreliable results due to the inherent variability of the signal. Toovercome this problem, the scientific community has recently been advocating thediscovery, analysis and usage of novel HMIs to supersede or augment sEMG; a comparativeanalysis of such HMIs is therefore a very desirable investigation.In this paper we compare three such HMIs employed in the detection of finger forces,namely sEMG, ultrasound imaging and pressure sensing. The comparison is performed alongfour main lines: the accuracy in the prediction, the stability over time, the wearabilityand the cost. A psychophysical experiment involving ten intact subjects engaged ina simple finger-flexion task was set up. Our results show that, at least in thisexperiment, pressure sensing and sEMG yield comparably good prediction accuraciesas opposed to ultrasound imaging; and that pressure sensing enjoys a much better stabilitythan sEMG.Given that pressure sensors are as wearable as sEMG electrodes but way cheaper, we claimthat this HMI could represent a valid alternative /augmentation to sEMG to control amulti-fingered hand prosthesis.

Combining Electromyography and Tactile Myography to Improve Hand and Wrist Activity Detection in Prostheses

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Noémie Jaquier

2017-10-01

Full Text Available Despite recent advances in prosthetics and assistive robotics in general, robust simultaneous and proportional control of dexterous prosthetic devices remains an unsolved problem, mainly because of inadequate sensorization. In this paper, we study the application of regression to muscle activity, detected using a flexible tactile sensor recording muscle bulging in the forearm (tactile myography—TMG. The sensor is made of 320 highly sensitive cells organized in an array forming a bracelet. We propose the use of Gaussian process regression to improve the prediction of wrist, hand and single-finger activation, using TMG, surface electromyography (sEMG; the traditional approach in the field, and a combination of the two. We prove the effectiveness of the approach for different levels of activations in a real-time goal-reaching experiment using tactile data. Furthermore, we performed a batch comparison between the different forms of sensorization, using a Gaussian process with different kernel distances.

sEMG feature evaluation for identification of elbow angle resolution in graded arm movement.

Science.gov (United States)

Castro, Maria Claudia F; Colombini, Esther L; Aquino, Plinio T; Arjunan, Sridhar P; Kumar, Dinesh K

2014-11-25

Automatic and accurate identification of elbow angle from surface electromyogram (sEMG) is essential for myoelectric controlled upper limb exoskeleton systems. This requires appropriate selection of sEMG features, and identifying the limitations of such a system.This study has demonstrated that it is possible to identify three discrete positions of the elbow; full extension, right angle, and mid-way point, with window size of only 200 milliseconds. It was seen that while most features were suitable for this purpose, Power Spectral Density Averages (PSD-Av) performed best. The system correctly classified the sEMG against the elbow angle for 100% cases when only two discrete positions (full extension and elbow at right angle) were considered, while correct classification was 89% when there were three discrete positions. However, sEMG was unable to accurately determine the elbow position when five discrete angles were considered. It was also observed that there was no difference for extension or flexion phases.

Use of sEMG in identification of low level muscle activities: features based on ICA and fractal dimension.

Science.gov (United States)

Naik, Ganesh R; Kumar, Dinesh K; Arjunan, Sridhar

2009-01-01

This paper has experimentally verified and compared features of sEMG (Surface Electromyogram) such as ICA (Independent Component Analysis) and Fractal Dimension (FD) for identification of low level forearm muscle activities. The fractal dimension was used as a feature as reported in the literature. The normalized feature values were used as training and testing vectors for an Artificial neural network (ANN), in order to reduce inter-experimental variations. The identification accuracy using FD of four channels sEMG was 58%, and increased to 96% when the signals are separated to their independent components using ICA.

Muscle activity in sprinting: a review.

Science.gov (United States)

Howard, Róisín M; Conway, Richard; Harrison, Andrew J

2018-03-01

The use of electromyography (EMG) is widely recognised as a valuable tool for enhancing the understanding of performance drivers and potential injury risk in sprinting. The timings of muscle activations relative to running gait cycle phases and the technology used to obtain muscle activation data during sprinting are of particular interest to scientists and coaches. This review examined the main muscles being analysed by surface EMG (sEMG), their activations and timing, and the technologies used to gather sEMG during sprinting. Electronic databases were searched using 'Electromyography' OR 'EMG' AND 'running' OR 'sprinting'. Based on inclusion criteria, 18 articles were selected for review. While sEMG is widely used in biomechanics, relatively few studies have used sEMG in sprinting due to system constraints. The results demonstrated a focus on the leg muscles, with over 70% of the muscles analysed in the upper leg. This is consistent with the use of tethered and data logging EMG systems and many sprints being performed on treadmills. Through the recent advances in wireless EMG technology, an increase in the studies on high velocity movements such as sprinting is expected and this should allow practitioners to perform the analysis in an ecologically valid environment.

Relationship between lower limb position and pelvic floor muscle surface electromyography activity in menopausal women: a prospective observational study

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Halski T

2017-01-01

Full Text Available Tomasz Halski,1 Kuba Ptaszkowski,2 Lucyna Słupska,1 Robert Dymarek,3 Małgorzata Paprocka-Borowicz2 1Department of Physiotherapy, Opole Medical School, Opole, 2Department of Clinical Biomechanics and Physiotherapy in Motor System Disorders, 3Department of Nervous System Diseases, Faculty of Health Science, Wroclaw Medical University, Wroclaw, Poland Objectives: In physiotherapeutic practice, special attention is being given to the reciprocal anatomical, physiological, and biomechanical relationship of the pelvis and the structures connected to it. However, the scientific literature shows mainly the theoretical information about their mutual connections. The lack of information about these relations from a practical aspect coupled with the paucity of scientific papers on the impact of posture changes on the pelvic floor led the authors to conduct this study. The primary aim of this study was to compare the resting and functional bioelectrical activities of pelvic floor muscles (PFMs depending on three different positions of the lower limbs (positions A, B, and C in the supine position.Materials and methods: This was a prospective observational study evaluating resting and functional activities of the PFM depending on the position of the lower limbs. The study was carried out at the Department and Clinic of Urology, University Hospital in Wroclaw, Poland and the target group were women in the menopausal period. Bioelectrical activity of PFM was recorded using a surface electromyographic instrument in the supine position. Results of the values obtained in A, B, and C positions were compared using a one-way analysis of variance.Results: In position A, the average resting surface electromyography (sEMG activity of PFM was 6.9±2.6 µV; in position B, the result was 6.9±2.5 µV and in position C, the resting sEMG activity was 5.7±1.8 µV (P=0.0102. The results of the functional bioelectrical activity of PFM were as follows: position A – 20.3�

Muscle fiber velocity and electromyographic signs of fatigue in fibromyalgia

NARCIS (Netherlands)

Klaver-Krol, E.G.; Rasker, Johannes J.; Henriquez, N.R.; Verheijen, W.G.; Zwarts, M.J.

2012-01-01

Introduction: Fibromyalgia (FM) is a disorder of widespread muscular pain. We investigated possible differences in surface electromyography (sEMG) in clinically unaffected muscle between patients with FM and controls. Methods: sEMG was performed on the biceps brachii muscle of 13 women with FM and

A Novel Phonology- and Radical-Coded Chinese Sign Language Recognition Framework Using Accelerometer and Surface Electromyography Sensors.

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Cheng, Juan; Chen, Xun; Liu, Aiping; Peng, Hu

2015-09-15

Sign language recognition (SLR) is an important communication tool between the deaf and the external world. It is highly necessary to develop a worldwide continuous and large-vocabulary-scale SLR system for practical usage. In this paper, we propose a novel phonology- and radical-coded Chinese SLR framework to demonstrate the feasibility of continuous SLR using accelerometer (ACC) and surface electromyography (sEMG) sensors. The continuous Chinese characters, consisting of coded sign gestures, are first segmented into active segments using EMG signals by means of moving average algorithm. Then, features of each component are extracted from both ACC and sEMG signals of active segments (i.e., palm orientation represented by the mean and variance of ACC signals, hand movement represented by the fixed-point ACC sequence, and hand shape represented by both the mean absolute value (MAV) and autoregressive model coefficients (ARs)). Afterwards, palm orientation is first classified, distinguishing "Palm Downward" sign gestures from "Palm Inward" ones. Only the "Palm Inward" gestures are sent for further hand movement and hand shape recognition by dynamic time warping (DTW) algorithm and hidden Markov models (HMM) respectively. Finally, component recognition results are integrated to identify one certain coded gesture. Experimental results demonstrate that the proposed SLR framework with a vocabulary scale of 223 characters can achieve an averaged recognition accuracy of 96.01% ± 0.83% for coded gesture recognition tasks and 92.73% ± 1.47% for character recognition tasks. Besides, it demonstrats that sEMG signals are rather consistent for a given hand shape independent of hand movements. Hence, the number of training samples will not be significantly increased when the vocabulary scale increases, since not only the number of the completely new proposed coded gestures is constant and limited, but also the transition movement which connects successive signs needs no

Evaluation of higher order statistics parameters for multi channel sEMG using different force levels.

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Naik, Ganesh R; Kumar, Dinesh K

2011-01-01

The electromyograpy (EMG) signal provides information about the performance of muscles and nerves. The shape of the muscle signal and motor unit action potential (MUAP) varies due to the movement of the position of the electrode or due to changes in contraction level. This research deals with evaluating the non-Gaussianity in Surface Electromyogram signal (sEMG) using higher order statistics (HOS) parameters. To achieve this, experiments were conducted for four different finger and wrist actions at different levels of Maximum Voluntary Contractions (MVCs). Our experimental analysis shows that at constant force and for non-fatiguing contractions, probability density functions (PDF) of sEMG signals were non-Gaussian. For lesser MVCs (below 30% of MVC) PDF measures tends to be Gaussian process. The above measures were verified by computing the Kurtosis values for different MVCs.

Evaluation of muscle fatigue of wheelchair basketball players with spinal cord injury using recurrence quantification analysis of surface EMG.

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Uzun, S; Pourmoghaddam, A; Hieronymus, M; Thrasher, T A

2012-11-01

Wheelchair basketball is the most popular exercise activity among individuals with spinal cord injury (SCI). The purpose of this study was to investigate muscular endurance and fatigue in wheelchair basketball athletes with SCI using surface electromyography (SEMG) and maximal torque values. SEMG characteristics of 10 wheelchair basketball players (WBP) were compared to 13 able-bodied basketball players and 12 sedentary able-bodied subjects. Participants performed sustained isometric elbow flexion at 50% maximal voluntary contraction until exhaustion. Elbow flexion torque and SEMG signals were recorded from three elbow flexor muscles: biceps brachii longus, biceps brachii brevis and brachioradialis. SEMG signals were clustered into 0.5-s epochs with 50% overlap. Root mean square (RMS) and median frequency (MDF) of SEMG signals were calculated for each muscle and epoch as traditional fatigue monitoring. Recurrence quantification analysis was used to extract the percentage of determinism (%DET) of SEMG signals. The slope of the %DET for basketball players and WBP showed slower increase with time than the sedentary able-bodied control group for three different elbow flexor muscles, while no difference was observed for the slope of the %DET between basketball and WBP. This result indicated that the athletes are less fatigable during the task effort than the nonathletes. Normalized MDF slope decay exhibited similar results between the groups as %DET, while the slope of the normalized RMS failed to show any significant differences among the groups (p > 0.05). MDF and %DET could be useful for the evaluation of muscle fatigue in wheelchair basketball training. No conclusions about special training for WBP could be determined.

3D-printing soft sEMG sensing structures

NARCIS (Netherlands)

Wolterink, Gerjan; Sanders, Remco; Muijzer, Frodo; van Beijnum, Bert-Jan; Krijnen, Gijs

2017-01-01

This paper describes the development and characterization of soft and flexible 3D-printed sEMG electrodes. The electrodes are printed in one go on a low cost consumer multi-material FDM printer. The printed structures do not need any further production steps to give them conductive properties.

Robust functional statistics applied to Probability Density Function shape screening of sEMG data.

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Boudaoud, S; Rix, H; Al Harrach, M; Marin, F

2014-01-01

Recent studies pointed out possible shape modifications of the Probability Density Function (PDF) of surface electromyographical (sEMG) data according to several contexts like fatigue and muscle force increase. Following this idea, criteria have been proposed to monitor these shape modifications mainly using High Order Statistics (HOS) parameters like skewness and kurtosis. In experimental conditions, these parameters are confronted with small sample size in the estimation process. This small sample size induces errors in the estimated HOS parameters restraining real-time and precise sEMG PDF shape monitoring. Recently, a functional formalism, the Core Shape Model (CSM), has been used to analyse shape modifications of PDF curves. In this work, taking inspiration from CSM method, robust functional statistics are proposed to emulate both skewness and kurtosis behaviors. These functional statistics combine both kernel density estimation and PDF shape distances to evaluate shape modifications even in presence of small sample size. Then, the proposed statistics are tested, using Monte Carlo simulations, on both normal and Log-normal PDFs that mimic observed sEMG PDF shape behavior during muscle contraction. According to the obtained results, the functional statistics seem to be more robust than HOS parameters to small sample size effect and more accurate in sEMG PDF shape screening applications.

Optimal Elbow Angle for Extracting sEMG Signals During Fatiguing Dynamic Contraction

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Mohamed R. Al-Mulla

2015-09-01

Full Text Available Surface electromyographic (sEMG activity of the biceps muscle was recorded from 13 subjects. Data was recorded while subjects performed dynamic contraction until fatigue and the signals were segmented into two parts (Non-Fatigue and Fatigue. An evolutionary algorithm was used to determine the elbow angles that best separate (using Davies-Bouldin Index, DBI both Non-Fatigue and Fatigue segments of the sEMG signal. Establishing the optimal elbow angle for feature extraction used in the evolutionary process was based on 70% of the conducted sEMG trials. After completing 26 independent evolution runs, the best run containing the optimal elbow angles for separation (Non-Fatigue and Fatigue was selected and then tested on the remaining 30% of the data to measure the classification performance. Testing the performance of the optimal angle was undertaken on nine features extracted from each of the two classes (Non-Fatigue and Fatigue to quantify the performance. Results showed that the optimal elbow angles can be used for fatigue classification, showing 87.90% highest correct classification for one of the features and on average of all eight features (including worst performing features giving 78.45%.

Generating Human-Like Velocity-Adapted Jumping Gait from sEMG Signals for Bionic Leg’s Control

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Weiwei Yu

2017-01-01

Full Text Available In the case of dynamic motion such as jumping, an important fact in sEMG (surface Electromyogram signal based control on exoskeletons, myoelectric prostheses, and rehabilitation gait is that multichannel sEMG signals contain mass data and vary greatly with time, which makes it difficult to generate compliant gait. Inspired by the fact that muscle synergies leading to dimensionality reduction may simplify motor control and learning, this paper proposes a new approach to generate flexible gait based on muscle synergies extracted from sEMG signal. Two questions were discussed and solved, the first one concerning whether the same set of muscle synergies can explain the different phases of hopping movement with various velocities. The second one is about how to generate self-adapted gait with muscle synergies while alleviating model sensitivity to sEMG transient changes. From the experimental results, the proposed method shows good performance both in accuracy and in robustness for producing velocity-adapted vertical jumping gait. The method discussed in this paper provides a valuable reference for the sEMG-based control of bionic robot leg to generate human-like dynamic gait.

Gestures recognition based on wavelet and LLE

International Nuclear Information System (INIS)

Ai, Qingsong; Liu, Quan; Lu, Ying; Yuan, Tingting

2013-01-01

Wavelet analysis is a time–frequency, non-stationary method while the largest Lyapunov exponent (LLE) is used to judge the non-linear characteristic of systems. Because surface electromyography signal (SEMGS) is a complex signal that is characterized by non-stationary and non-linear properties. This paper combines wavelet coefficient and LLE together as the new feature of SEMGS. The proposed method not only reflects the non-stationary and non-linear characteristics of SEMGS, but also is suitable for its classification. Then, the BP (back propagation) neural network is employed to implement the identification of six gestures (fist clench, fist extension, wrist extension, wrist flexion, radial deviation, ulnar deviation). The experimental results indicate that based on the proposed method, the identification of these six gestures can reach an average rate of 97.71 %.

Surface electromyography physiology, engineering and applications

CERN Document Server

Farina, Dario

2016-01-01

The book presents a quantitative approach to the study and use of noninvasively detected electromyographic (EMG) signals, as well as their numerous applications in various aspects of the life sciences. Surface Electromyography: Physiology, Engineering, and Applications is an update of Electromyography: Physiology, Engineering, and Noninvasive Applications (Wiley-IEEE Press, 2004) and focuses on the developments that have taken place over the last decade. The first nine chapters deal with the generation, detection, understanding, interpretation, and modeling of EMG signals. Detection technology, with particular focus on EMG imaging techniques that are based on two-dimensional electrode arrays are also included in the first half of the book. The latter 11 chapters deal with applications, which range fro monitoring muscle fatigue, electrically elicited contractions, posture analysis, prevention of work-related and child-delivery-related neuromuscular disorders, ergonomics, movement analysis, physical therapy, ex...

Use of surface electromyography in phonation studies: an integrative review

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Balata, Patricia Maria Mendes; Silva, Hilton Justino da; Moraes, Kyvia Juliana Rocha de; Pernambuco, Leandro de Araújo; Moraes, Sílvia Regina Arruda de

2013-01-01

Summary Introduction: Surface electromyography has been used to assess the extrinsic laryngeal muscles during chewing and swallowing, but there have been few studies assessing these muscles during phonation. Objective: To investigate the current state of knowledge regarding the use of surface electromyography for evaluation of the electrical activity of the extrinsic muscles of the larynx during phonation by means of an integrative review. Method: We searched for articles and other papers in the PubMed, Medline/Bireme, and Scielo databases that were published between 1980 and 2012, by using the following descriptors: surface electromyography and voice, surface electromyography and phonation, and surface electromyography and dysphonia. The articles were selectedon the basis ofinclusion and exclusion criteria. Data Synthesis: This was carried out with a cross critical matrix. We selected 27 papers,i.e., 24 articles and 3 theses. The studies differed methodologically with regards to sample size and investigation techniques, making it difficult to compare them, but showed differences in electrical activity between the studied groups (dysphonicsubjects, non-dysphonicsubjects, singers, and others). Conclusion: Electromyography has clinical applicability when technical precautions with respect to application and analysis are obeyed. However, it is necessary to adopt a universal system of assessment tasks and related measurement techniques to allow comparisons between studies. PMID:25992030

Use of surface electromyography in phonation studies: an integrative review

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Balata, Patricia Maria Mendes

2014-01-01

Full Text Available Introduction: Surface electromyography has been used to assess the extrinsic laryngeal muscles during chewing and swallowing, but there have been few studies assessing these muscles during phonation. Objective: To investigate the current state of knowledge regarding the use of surface electromyography for evaluation of the electrical activity of the extrinsic muscles of the larynx during phonation by means of an integrative review. Method: We searched for articles and other papers in the PubMed, Medline/Bireme, and Scielo databases that were published between 1980 and 2012, by using the following descriptors: surface electromyography and voice, surface electromyography and phonation, and surface electromyography and dysphonia. The articles were selectedon the basis ofinclusion and exclusion criteria. Data Synthesis: This was carried out with a cross critical matrix. We selected 27 papers,i.e., 24 articles and 3 theses. The studies differed methodologically with regards to sample size and investigation techniques, making it difficult to compare them, but showed differences in electrical activity between the studied groups (dysphonicsubjects, non-dysphonicsubjects, singers, and others. Conclusion: Electromyography has clinical applicability when technical precautions with respect to application and analysis are obeyed. However, it is necessary to adopt a universal system of assessment tasks and related measurement techniques to allow comparisons between studies.

Computational Intelligence Based Data Fusion Algorithm for Dynamic sEMG and Skeletal Muscle Force Modelling

Energy Technology Data Exchange (ETDEWEB)

Chandrasekhar Potluri,; Madhavi Anugolu; Marco P. Schoen; D. Subbaram Naidu

2013-08-01

In this work, an array of three surface Electrography (sEMG) sensors are used to acquired muscle extension and contraction signals for 18 healthy test subjects. The skeletal muscle force is estimated using the acquired sEMG signals and a Non-linear Wiener Hammerstein model, relating the two signals in a dynamic fashion. The model is obtained from using System Identification (SI) algorithm. The obtained force models for each sensor are fused using a proposed fuzzy logic concept with the intent to improve the force estimation accuracy and resilience to sensor failure or misalignment. For the fuzzy logic inference system, the sEMG entropy, the relative error, and the correlation of the force signals are considered for defining the membership functions. The proposed fusion algorithm yields an average of 92.49% correlation between the actual force and the overall estimated force output. In addition, the proposed fusionbased approach is implemented on a test platform. Experiments indicate an improvement in finger/hand force estimation.

Muscle fiber velocity and electromyographic signs of fatigue in fibromyalgia.

Science.gov (United States)

Klaver-Król, Ewa G; Rasker, Johannes J; Henriquez, Nizare R; Verheijen, Wilma G; Zwarts, Machiel J

2012-11-01

Fibromyalgia (FM) is a disorder of widespread muscular pain. We investigated possible differences in surface electromyography (sEMG) in clinically unaffected muscle between patients with FM and controls. sEMG was performed on the biceps brachii muscle of 13 women with FM and 14 matched healthy controls during prolonged dynamic exercises, unloaded, and loaded up to 20% of maximum voluntary contraction. The sEMG parameters were: muscle fiber conduction velocity (CV); skewness of motor unit potential (peak) velocities; peak frequency (PF) (number of peaks per second); and average rectified voltage (ARV). There was significantly higher CV in the FM group. Although the FM group performed the tests equally well, their electromyographic fatigue was significantly less expressed compared with controls (in CV, PF, and ARV). In the patients with FM, we clearly showed functional abnormalities of the muscle membrane, which led to high conduction velocity and resistance to fatigue in electromyography. Copyright © 2012 Wiley Periodicals, Inc.

Using gastrocnemius sEMG and plasma α-synuclein for the prediction of freezing of gait in Parkinson's disease patients.

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Xiao-Ying Wang

Full Text Available Freezing of gait (FOG is a complicated gait disturbance in Parkinson's disease (PD and a relevant subclinical predictor algorithm is lacking. The main purpose of this study is to explore the potential value of surface electromyograph (sEMG and plasma α-synuclein levels as predictors of the FOG seen in PD. 21 PD patients and 15 normal controls were recruited. Motor function was evaluated using the Unified Parkinson's Disease Rating Scale (UPDRS and Freezing of gait questionnaire (FOG-Q. Simultaneously, gait analysis was also performed using VICON capture system in PD patients and sEMG data was recorded as well. Total plasma α-synuclein was quantitatively assessed by Luminex assay in all participants. Recruited PD patients were classified into two groups: PD patients with FOG (PD+FOG and without FOG (PD-FOG, based on clinical manifestation, the results of the FOG-Q and VICON capture system. PD+FOG patients displayed higher FOG-Q scores, decreased walking speed, smaller step length, smaller stride length and prolonged double support time compared to the PD-FOG in the gait trial. sEMG data indicated that gastrocnemius activity in PD+FOG patients was significantly reduced compared to PD-FOG patients. In addition, plasma α-synuclein levels were significantly decreased in the PD+FOG group compared to control group; however, no significant difference was found between the PD+FOG and PD-FOG groups. Our study revealed that gastrocnemius sEMG could be used to evaluate freezing gait in PD patients, while plasma α-synuclein might discriminate freezing of gait in PD patients from normal control, though no difference was found between the PD+FOG and PD-FOG groups.

Wavelet transform analysis of electromyography kung fu strikes data.

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Neto, Osmar Pinto; Marzullo, Ana Carolina de Miranda

2009-11-01

In martial arts and contact sports strikes are performed at near maximum speeds. For that reason, electromyography (EMG) analysis of such movements is non-trivial. This paper has three main goals: firstly, to investigate the differences in the EMG activity of muscles during strikes performed with and without impacts; secondly, to assess the advantages of using Sum of Significant Power (SSP) values instead of root mean square (rms) values when analyzing EMG data; and lastly to introduce a new method of calculating median frequency values using wavelet transforms (WMDF). EMG data of the deltoid anterior (DA), triceps brachii (TB) and brachioradialis (BR) muscles were collected from eight Kung Fu practitioners during strikes performed with and without impacts. SSP results indicated significant higher muscle activity (p = 0.023) for the strikes with impact. WMDF results, on the other hand, indicated significant lower values (p = 0. 007) for the strikes with impact. SSP results presented higher sensitivity than rms to quantify important signal differences and, at the same time, presented lower inter-subject coefficient of variations. The result of increase in SSP values and decrease in WMDF may suggest better synchronization of motor units for the strikes with impact performed by the experienced Kung Fu practitioners. Key PointsThe results show higher muscle activity and lower electromyography median frequencies for strikes with impact compared to strikes without.SSP results presented higher sensitivity and lower inter-subject coefficient of variations than rms results.Kung Fu palm strikes with impact may present better motor units' synchronization than strikes without.

A sEMG model with experimentally based simulation parameters.

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Wheeler, Katherine A; Shimada, Hiroshima; Kumar, Dinesh K; Arjunan, Sridhar P

2010-01-01

A differential, time-invariant, surface electromyogram (sEMG) model has been implemented. While it is based on existing EMG models, the novelty of this implementation is that it assigns more accurate distributions of variables to create realistic motor unit (MU) characteristics. Variables such as muscle fibre conduction velocity, jitter (the change in the interpulse interval between subsequent action potential firings) and motor unit size have been considered to follow normal distributions about an experimentally obtained mean. In addition, motor unit firing frequencies have been considered to have non-linear and type based distributions that are in accordance with experimental results. Motor unit recruitment thresholds have been considered to be related to the MU type. The model has been used to simulate single channel differential sEMG signals from voluntary, isometric contractions of the biceps brachii muscle. The model has been experimentally verified by conducting experiments on three subjects. Comparison between simulated signals and experimental recordings shows that the Root Mean Square (RMS) increases linearly with force in both cases. The simulated signals also show similar values and rates of change of RMS to the experimental signals.

Monitorando a deglutição através da eletromiografia de superfície Monitoring swallowing with surface electromyography

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Maria das Graças Wanderley de Sales Coriolano

2010-06-01

Full Text Available OBJETIVO: descrever o método de registro da eletromiografia de superfície através da utilização de um protocolo desenvolvido para o estudo da deglutição e demonstrar a deglutição de um paciente com doença de Parkinson e de um sujeito normal através do registro da eletromiografia de superfície (EMGs. MÉTODOS: para ilustrar os parâmetros eletrofisiológicos registrados após execução do protocolo foram utilizados dois voluntários do sexo feminino, sendo um sem doença e outro apresentando doença de Parkinson (DP no estágio III de acordo com a escala de Hoehn e Yahr. Os parâmetros analisados pelo foram: a duração da atividade elétrica durante a deglutição, a amplitude (rms e o limite de disfagia. RESULTADOS: os resultados mostram diferenças entre os eletromiogramas ilustrativos. CONCLUSÃO: a EMGs pode ser utilizada como método de avaliação e monitorização da deglutição de sujeitos sem doença e com DP.PURPOSE: to describe the registering method of the surface electromyography (sEMG through the use of a protocol developed for swallowing study and to demonstrate the swallowing pattern of a patient with Parkinson’s disease and of normal individuals through the sEMG registering. METHODS: to illustrate the registered electrophysiologic parameters execution of the protocol we used two volunteers of the feminine gender, being one without disease and the other one with Parkinson’s disease (PD in III period of training in accordance with the scale of Hoehn and Yahr. The analyzed parameters had been the duration of the electric activity during swallowing, the amplitude (rms and the dysphagia limit. RESULTS: the results show differences amongst the illustrative electromyograms. CONCLUSION: sEMG can be used as method for evaluating and monitoring the swallowing pattern of citizens with no disease and with PD.

Materials and optimized designs for human-machine interfaces via epidermal electronics.

Science.gov (United States)

Jeong, Jae-Woong; Yeo, Woon-Hong; Akhtar, Aadeel; Norton, James J S; Kwack, Young-Jin; Li, Shuo; Jung, Sung-Young; Su, Yewang; Lee, Woosik; Xia, Jing; Cheng, Huanyu; Huang, Yonggang; Choi, Woon-Seop; Bretl, Timothy; Rogers, John A

2013-12-17

Thin, soft, and elastic electronics with physical properties well matched to the epidermis can be conformally and robustly integrated with the skin. Materials and optimized designs for such devices are presented for surface electromyography (sEMG). The findings enable sEMG from wide ranging areas of the body. The measurements have quality sufficient for advanced forms of human-machine interface. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Virtual Control of Prosthetic Hand Based on Grasping Patterns and Estimated Force from Semg

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Zhu Gao-Ke

2016-01-01

Full Text Available Myoelectric prosthetic hands aim to serve upper limb amputees. The myoelectric control of the hand grasp action is a kind of real-time or online method. Thus it is of great necessity to carry on a study of online prosthetic hand electrical control. In this paper, the strategy of simultaneous EMG decoding of grasping patterns and grasping force was realized by controlling a virtual multi-degree-freedom prosthetic hand and a real one-degree-freedom prosthetic hand simultaneously. The former realized the grasping patterns from the recognition of the sEMG pattern. The other implemented the grasping force from sEMG force decoding. The results show that the control method is effective and feasible.

A computational model to investigate the effect of pennation angle on surface electromyogram of Tibialis Anterior.

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Diptasree Maitra Ghosh

Full Text Available This study has described and experimentally validated the differential electrodes surface electromyography (sEMG model for tibialis anterior muscles during isometric contraction. This model has investigated the effect of pennation angle on the simulated sEMG signal. The results show that there is no significant effect of pennation angle in the range 0° to 20° to the single fibre action potential shape recorded on the skin surface. However, the changes with respect to pennation angle are observed in sEMG amplitude, frequency and fractal dimension. It is also observed that at different levels of muscle contractions there is similarity in the relationships with Root Mean Square, Median Frequency, and Fractal Dimension of the recorded and simulated sEMG signals.

Differential contributions of ankle plantarflexors during submaximal isometric muscle action

DEFF Research Database (Denmark)

Masood, Tahir; Bojsen-Møller, Jens; Kalliokoski, Kari K

2014-01-01

The objective of this study was to investigate the relative contributions of superficial and deep ankle plantarflexors during repetitive submaximal isometric contractions using surface electromyography (SEMG) and positron emission tomography (PET). Myoelectric signals were obtained from twelve...

A Methodological Approach to Quantifying Plyometric Intensity.

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Jarvis, Mark M; Graham-Smith, Phil; Comfort, Paul

2016-09-01

Jarvis, MM, Graham-Smith, P, and Comfort, P. A Methodological approach to quantifying plyometric intensity. J Strength Cond Res 30(9): 2522-2532, 2016-In contrast to other methods of training, the quantification of plyometric exercise intensity is poorly defined. The purpose of this study was to evaluate the suitability of a range of neuromuscular and mechanical variables to describe the intensity of plyometric exercises. Seven male recreationally active subjects performed a series of 7 plyometric exercises. Neuromuscular activity was measured using surface electromyography (SEMG) at vastus lateralis (VL) and biceps femoris (BF). Surface electromyography data were divided into concentric (CON) and eccentric (ECC) phases of movement. Mechanical output was measured by ground reaction forces and processed to provide peak impact ground reaction force (PF), peak eccentric power (PEP), and impulse (IMP). Statistical analysis was conducted to assess the reliability intraclass correlation coefficient and sensitivity smallest detectable difference of all variables. Mean values of SEMG demonstrate high reliability (r ≥ 0.82), excluding ECC VL during a 40-cm drop jump (r = 0.74). PF, PEP, and IMP demonstrated high reliability (r ≥ 0.85). Statistical power for force variables was excellent (power = 1.0), and good for SEMG (power ≥0.86) excluding CON BF (power = 0.57). There was no significant difference (p > 0.05) in CON SEMG between exercises. Eccentric phase SEMG only distinguished between exercises involving a landing and those that did not (percentage of maximal voluntary isometric contraction [%MVIC] = no landing -65 ± 5, landing -140 ± 8). Peak eccentric power, PF, and IMP all distinguished between exercises. In conclusion, CON neuromuscular activity does not appear to vary when intent is maximal, whereas ECC activity is dependent on the presence of a landing. Force characteristics provide a reliable and sensitive measure enabling precise description of intensity

Age and Electromyographic Frequency Alterations during Walking in Children with Cerebral Palsy

OpenAIRE

Lauer, Richard T.; Pierce, Samuel R.; Tucker, Carole A.; Barbe, Mary F.; Prosser, Laura A.

2009-01-01

The use of surface electromyography (sEMG) recorded during ambulation has provided valuable insight into motor development and changes with age in the pediatric population. However, no studies have reported sEMG differences with age in the children with cerebral palsy (CP). In this study, data from 50 children were divided retrospectively into four groups, representing either an older (above the age of 7 years) or younger (below the age of 7 years) age group with either typical development (T...

[Recognition of walking stance phase and swing phase based on moving window].

Science.gov (United States)

Geng, Xiaobo; Yang, Peng; Wang, Xinran; Geng, Yanli; Han, Yu

2014-04-01

Wearing transfemoral prosthesis is the only way to complete daily physical activity for amputees. Motion pattern recognition is important for the control of prosthesis, especially in the recognizing swing phase and stance phase. In this paper, it is reported that surface electromyography (sEMG) signal is used in swing and stance phase recognition. sEMG signal of related muscles was sampled by Infiniti of a Canadian company. The sEMG signal was then filtered by weighted filtering window and analyzed by height permitted window. The starting time of stance phase and swing phase is determined through analyzing special muscles. The sEMG signal of rectus femoris was used in stance phase recognition and sEMG signal of tibialis anterior is used in swing phase recognition. In a certain tolerating range, the double windows theory, including weighted filtering window and height permitted window, can reach a high accuracy rate. Through experiments, the real walking consciousness of the people was reflected by sEMG signal of related muscles. Using related muscles to recognize swing and stance phase is reachable. The theory used in this paper is useful for analyzing sEMG signal and actual prosthesis control.

Wireless electronic-tattoo for long-term high fidelity facial muscle recordings

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Inzelberg, Lilah; David Pur, Moshe; Steinberg, Stanislav; Rand, David; Farah, Maroun; Hanein, Yael

2017-05-01

Facial surface electromyography (sEMG) is a powerful tool for objective evaluation of human facial expressions and was accordingly suggested in recent years for a wide range of psychological and neurological assessment applications. Owing to technical challenges, in particular the cumbersome gelled electrodes, the use of facial sEMG was so far limited. Using innovative facial temporary tattoos optimized specifically for facial applications, we demonstrate the use of sEMG as a platform for robust identification of facial muscle activation. In particular, differentiation between diverse facial muscles is demonstrated. We also demonstrate a wireless version of the system. The potential use of the presented technology for user-experience monitoring and objective psychological and neurological evaluations is discussed.

Reliability of surface EMG measurements from the suprahyoid muscle complex

DEFF Research Database (Denmark)

Kothari, Mohit; Stubbs, Peter William; Pedersen, Asger Roer

2017-01-01

of using the suprahyoid muscle complex (SMC) using surface electromyography (sEMG) to assess changes to neural pathways by determining the reliability of measurements in healthy participants over days. Methods: Seventeen healthy participants were recruited. Measurements were performed twice with one week...... on stimulus type/intensity) had significantly different MEP values between day 1 and day 2 for single pulse and paired pulse TMS. A large stimulus artefact resulted in MEP responses that could not be assessed in four participants. Conclusions: The assessment of the SMC using sEMG following TMS was poorly...... reliable for ≈50% of participants. Although using sEMG to assess swallowing musculature function is easier to perform clinically and more comfortable to patients than invasive measures, as the measurement of muscle activity using TMS is unreliable, the use of sEMG for this muscle group is not recommended...

Virtual Sensor of Surface Electromyography in a New Extensive Fault-Tolerant Classification System.

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de Moura, Karina de O A; Balbinot, Alexandre

2018-05-01

A few prosthetic control systems in the scientific literature obtain pattern recognition algorithms adapted to changes that occur in the myoelectric signal over time and, frequently, such systems are not natural and intuitive. These are some of the several challenges for myoelectric prostheses for everyday use. The concept of the virtual sensor, which has as its fundamental objective to estimate unavailable measures based on other available measures, is being used in other fields of research. The virtual sensor technique applied to surface electromyography can help to minimize these problems, typically related to the degradation of the myoelectric signal that usually leads to a decrease in the classification accuracy of the movements characterized by computational intelligent systems. This paper presents a virtual sensor in a new extensive fault-tolerant classification system to maintain the classification accuracy after the occurrence of the following contaminants: ECG interference, electrode displacement, movement artifacts, power line interference, and saturation. The Time-Varying Autoregressive Moving Average (TVARMA) and Time-Varying Kalman filter (TVK) models are compared to define the most robust model for the virtual sensor. Results of movement classification were presented comparing the usual classification techniques with the method of the degraded signal replacement and classifier retraining. The experimental results were evaluated for these five noise types in 16 surface electromyography (sEMG) channel degradation case studies. The proposed system without using classifier retraining techniques recovered of mean classification accuracy was of 4% to 38% for electrode displacement, movement artifacts, and saturation noise. The best mean classification considering all signal contaminants and channel combinations evaluated was the classification using the retraining method, replacing the degraded channel by the virtual sensor TVARMA model. This method

Surface EMG signals based motion intent recognition using multi-layer ELM

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Wang, Jianhui; Qi, Lin; Wang, Xiao

2017-11-01

The upper-limb rehabilitation robot is regard as a useful tool to help patients with hemiplegic to do repetitive exercise. The surface electromyography (sEMG) contains motion information as the electric signals are generated and related to nerve-muscle motion. These sEMG signals, representing human's intentions of active motions, are introduced into the rehabilitation robot system to recognize upper-limb movements. Traditionally, the feature extraction is an indispensable part of drawing significant information from original signals, which is a tedious task requiring rich and related experience. This paper employs a deep learning scheme to extract the internal features of the sEMG signals using an advanced Extreme Learning Machine based auto-encoder (ELMAE). The mathematical information contained in the multi-layer structure of the ELM-AE is used as the high-level representation of the internal features of the sEMG signals, and thus a simple ELM can post-process the extracted features, formulating the entire multi-layer ELM (ML-ELM) algorithm. The method is employed for the sEMG based neural intentions recognition afterwards. The case studies show the adopted deep learning algorithm (ELM-AE) is capable of yielding higher classification accuracy compared to the Principle Component Analysis (PCA) scheme in 5 different types of upper-limb motions. This indicates the effectiveness and the learning capability of the ML-ELM in such motion intent recognition applications.

Long-term surface EMG monitoring using K-means clustering and compressive sensing

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Balouchestani, Mohammadreza; Krishnan, Sridhar

2015-05-01

In this work, we present an advanced K-means clustering algorithm based on Compressed Sensing theory (CS) in combination with the K-Singular Value Decomposition (K-SVD) method for Clustering of long-term recording of surface Electromyography (sEMG) signals. The long-term monitoring of sEMG signals aims at recording of the electrical activity produced by muscles which are very useful procedure for treatment and diagnostic purposes as well as for detection of various pathologies. The proposed algorithm is examined for three scenarios of sEMG signals including healthy person (sEMG-Healthy), a patient with myopathy (sEMG-Myopathy), and a patient with neuropathy (sEMG-Neuropathr), respectively. The proposed algorithm can easily scan large sEMG datasets of long-term sEMG recording. We test the proposed algorithm with Principal Component Analysis (PCA) and Linear Correlation Coefficient (LCC) dimensionality reduction methods. Then, the output of the proposed algorithm is fed to K-Nearest Neighbours (K-NN) and Probabilistic Neural Network (PNN) classifiers in order to calclute the clustering performance. The proposed algorithm achieves a classification accuracy of 99.22%. This ability allows reducing 17% of Average Classification Error (ACE), 9% of Training Error (TE), and 18% of Root Mean Square Error (RMSE). The proposed algorithm also reduces 14% clustering energy consumption compared to the existing K-Means clustering algorithm.

Laryngeal electromyography in movement disorders: preliminary data

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Kimaid Paulo A.T.

2004-01-01

Full Text Available This study describes preliminary laryngeal electromyography (LEMG data and botulinum toxin treatment in patients with dysphonia due to movement disorders. Twenty-five patients who had been clinically selected for botulinum toxin administration were examined, 19 with suspected laryngeal dystonia or spasmodic dysphonia (SD, 5 with vocal tremor, and 1 with Gilles de la Tourette syndrome (GTS. LEMG evaluations were performed before botulinum toxin administration using monopolar electrodes. Electromyography was consistent with dystonia in 14 patients and normal in 5, and differences in frequency suggesting essential tremor in 3 and Parkinson tremors in 2. The different LEMG patterns and significant improvement in our patients from botulinum toxin therapy has led us to perform laryngeal electromyography as a routine in UNICAMP movement disorders ambulatory.

Continuous Estimation of Human Multi-Joint Angles From sEMG Using a State-Space Model.

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Ding, Qichuan; Han, Jianda; Zhao, Xingang

2017-09-01

Due to the couplings among joint-relative muscles, it is a challenge to accurately estimate continuous multi-joint movements from multi-channel sEMG signals. Traditional approaches always build a nonlinear regression model, such as artificial neural network, to predict the multi-joint movement variables using sEMG as inputs. However, the redundant sEMG-data are always not distinguished; the prediction errors cannot be evaluated and corrected online as well. In this work, a correlation-based redundancy-segmentation method is proposed to segment the sEMG-vector including redundancy into irredundant and redundant subvectors. Then, a general state-space framework is developed to build the motion model by regarding the irredundant subvector as input and the redundant one as measurement output. With the built state-space motion model, a closed-loop prediction-correction algorithm, i.e., the unscented Kalman filter (UKF), can be employed to estimate the multi-joint angles from sEMG, where the redundant sEMG-data are used to reject model uncertainties. After having fully employed the redundancy, the proposed method can provide accurate and smooth estimation results. Comprehensive experiments are conducted on the multi-joint movements of the upper limb. The maximum RMSE of the estimations obtained by the proposed method is 0.16±0.03, which is significantly less than 0.25±0.06 and 0.27±0.07 (p < 0.05) obtained by common neural networks.

Effect of clinical parameters on the control of myoelectric robotic prosthetic hands.

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Atzori, Manfredo; Gijsberts, Arjan; Castellini, Claudio; Caputo, Barbara; Hager, Anne-Gabrielle Mittaz; Elsig, Simone; Giatsidis, Giorgio; Bassetto, Franco; Müller, Henning

2016-01-01

Improving the functionality of prosthetic hands with noninvasive techniques is still a challenge. Surface electromyography (sEMG) currently gives limited control capabilities; however, the application of machine learning to the analysis of sEMG signals is promising and has recently been applied in practice, but many questions still remain. In this study, we recorded the sEMG activity of the forearm of 11 male subjects with transradial amputation who were mentally performing 40 hand and wrist movements. The classification performance and the number of independent movements (defined as the subset of movements that could be distinguished with >90% accuracy) were studied in relationship to clinical parameters related to the amputation. The analysis showed that classification accuracy and the number of independent movements increased significantly with phantom limb sensation intensity, remaining forearm percentage, and temporal distance to the amputation. The classification results suggest the possibility of naturally controlling up to 11 movements of a robotic prosthetic hand with almost no training. Knowledge of the relationship between classification accuracy and clinical parameters adds new information regarding the nature of phantom limb pain as well as other clinical parameters, and it can lay the foundations for future "functional amputation" procedures in surgery.

Dexterous hand gestures recognition based on low-density sEMG signals for upper-limb forearm amputees

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John Jairo Villarejo Mayor

2017-08-01

Full Text Available Abstract Introduction Intuitive prosthesis control is one of the most important challenges in order to reduce the user effort in learning how to use an artificial hand. This work presents the development of a novel method for pattern recognition of sEMG signals able to discriminate, in a very accurate way, dexterous hand and fingers movements using a reduced number of electrodes, which implies more confidence and usability for amputees. Methods The system was evaluated for ten forearm amputees and the results were compared with the performance of able-bodied subjects. Multiple sEMG features based on fractal analysis (detrended fluctuation analysis and Higuchi’s fractal dimension combined with traditional magnitude-based features were analyzed. Genetic algorithms and sequential forward selection were used to select the best set of features. Support vector machine (SVM, K-nearest neighbors (KNN and linear discriminant analysis (LDA were analyzed to classify individual finger flexion, hand gestures and different grasps using four electrodes, performing contractions in a natural way to accomplish these tasks. Statistical significance was computed for all the methods using different set of features, for both groups of subjects (able-bodied and amputees. Results The results showed average accuracy up to 99.2% for able-bodied subjects and 98.94% for amputees using SVM, followed very closely by KNN. However, KNN also produces a good performance, as it has a lower computational complexity, which implies an advantage for real-time applications. Conclusion The results show that the method proposed is promising for accurately controlling dexterous prosthetic hands, providing more functionality and better acceptance for amputees.

Suprahyoid Muscle Complex: A Reliable Neural Assessment Tool For Dysphagia?

DEFF Research Database (Denmark)

Kothari, Mohit; Stubbs, Peter William; Pedersen, Asger Roer

be a non-invasive reliable neural assessment tool for patients with dysphagia. Objective: To investigate the possibility of using the suprahyoid muscle complex (SMC) using surface electromyography (sEMG) to assess changes to neural pathways by determining the reliability of measurements in healthy...

A Novel Hybrid Model for Drawing Trace Reconstruction from Multichannel Surface Electromyographic Activity.

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Chen, Yumiao; Yang, Zhongliang

2017-01-01

Recently, several researchers have considered the problem of reconstruction of handwriting and other meaningful arm and hand movements from surface electromyography (sEMG). Although much progress has been made, several practical limitations may still affect the clinical applicability of sEMG-based techniques. In this paper, a novel three-step hybrid model of coordinate state transition, sEMG feature extraction and gene expression programming (GEP) prediction is proposed for reconstructing drawing traces of 12 basic one-stroke shapes from multichannel surface electromyography. Using a specially designed coordinate data acquisition system, we recorded the coordinate data of drawing traces collected in accordance with the time series while 7-channel EMG signals were recorded. As a widely-used time domain feature, Root Mean Square (RMS) was extracted with the analysis window. The preliminary reconstruction models can be established by GEP. Then, the original drawing traces can be approximated by a constructed prediction model. Applying the three-step hybrid model, we were able to convert seven channels of EMG activity recorded from the arm muscles into smooth reconstructions of drawing traces. The hybrid model can yield a mean accuracy of 74% in within-group design (one set of prediction models for all shapes) and 86% in between-group design (one separate set of prediction models for each shape), averaged for the reconstructed x and y coordinates. It can be concluded that it is feasible for the proposed three-step hybrid model to improve the reconstruction ability of drawing traces from sEMG.

Motor unit properties of biceps brachii in chronic stroke patients assessed with high-density surface EMG

NARCIS (Netherlands)

Kallenberg, L.A.C.; Hermens, Hermanus J.

2009-01-01

The aim of this study was to investigate motor unit (MU) characteristics of the biceps brachii in post-stroke patients, using high-density surface electromyography (sEMG). Eighteen chronic hemiparetic stroke patients took part. The Fugl-Meyer score for the upper extremity was assessed. Subjects

Central motor control failure in fibromyalgia: a surface electromyography study.

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Casale, Roberto; Sarzi-Puttini, Piercarlo; Atzeni, Fabiola; Gazzoni, Marco; Buskila, Dan; Rainoldi, Alberto

2009-07-01

Fibromyalgia (FM) is characterised by diffuse musculoskeletal pain and stiffness at multiple sites, tender points in characteristic locations, and the frequent presence of symptoms such as fatigue. The aim of this study was to assess whether the myoelectrical manifestations of fatigue in patients affected by FM are central or peripheral in origin. Eight female patients aged 55.6 +/- 13.6 years (FM group) and eight healthy female volunteers aged 50.3 +/- 9.3 years (MCG) were studied by means of non-invasive surface electromyography (s-EMG) involving a linear array of 16 electrodes placed on the skin overlying the biceps brachii muscle, with muscle fatigue being evoked by means of voluntary and involuntary (electrically elicited) contractions. Maximal voluntary contractions (MVCs), motor unit action potential conduction velocity distributions (mean +/- SD and skewness), and the mean power frequency of the spectrum (MNF) were estimated in order to assess whether there were any significant differences between the two groups and contraction types. The motor pattern of recruitment during voluntary contractions was altered in the FM patients, who also showed fewer myoelectrical manifestations of fatigue (normalised conduction velocity rate of changes: -0.074 +/- 0.052%/s in FM vs -0.196 +/- 0.133%/s in MCG; normalised MNF rate of changes: -0.29 +/- 0.16%/s in FM vs -0.66 +/- 0.34%/s in MCG). Mean conduction velocity distribution and skewnesses values were higher (p fatigue in FM is the electrophysiological expression of muscle remodelling in terms of the prevalence of slow conducting fatigue-resistant type I fibres. As the only between-group differences concerned voluntary contractions, they are probably more related to central motor control failure than muscle membrane alterations, which suggests pathological muscle fibre remodelling related to altered suprasegmental control.

Age-associated changes in muscle activity during isometric contraction.

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Arjunan, Sridhar P; Kumar, Dinesh K

2013-04-01

We investigated the effect of age on the complexity of muscle activity and the variance in the force of isometric contraction. Surface electromyography (sEMG) from biceps brachii muscle and force of contraction were recorded from 96 subjects (20-70 years of age) during isometric contractions. There was a reduction in the complexity of sEMG associated with aging. The relationship of age and complexity was approximated using a bilinear fit, with the average knee point at 45 years. There was an age-associated increase in the coefficient of variation (CoV) of the force of muscle contraction, and this increase was correlated with the decrease in complexity of sEMG (r(2) = 0.76). There was an age-associated increase in CoV and also a reduction in the complexity of sEMG. The correlation between these 2 factors can be explained based on the age-associated increase in motor unit density. Copyright © 2012 Wiley Periodicals, Inc.

Anal sphincter electromyography in patients with Anorectal Dysfunctions

International Nuclear Information System (INIS)

Trinchet Soler, Rafael; Hidalgo Marrero, Yanet; Espichicoque Megret, Arianne; Manzano Suarez, Jianeya; Perez Gonzales, Ruth Maite

2009-01-01

The purpose of this work is to evaluate the electromyography value of anal sphincter in patients with anorectal dysfunctions. Anorectal dysfunctions are frequent reason of pediatric consultation in children, especially with anal incontinence. A study of series of cases in patient with anorectal dysfunctions was carried out from January 2002 to January of 2006. 65 patients were studied. Anorectal malformations (ARM) represented the predominant affection with 38 patients (58.5%), prevailing the male sex in 25 patients (65.8%). Encopresis and intestinal agagliosis dicrease was observed. Sphincter was found before surgical treatment through electromyography in patients with anorectal malformations and colostomy; in those with definitive operation and open colostomy, it avoided the operation in a patient that did not have muscular activity of the external sphincter. In children already operated and with closed colostomy several electromyography changes were observed in correspondence with different incontinence grades. In encopresis cases the study was useful to rule out sphincter functional alterations. Electromyography was pathological in all the operated patients of intestinal aganglionosis. This procedure was very useful for anal incontinence study that helped to determine and establish the prognosis. (author)

Assessment of early onset of driver fatigue using multimodal fatigue measures in a static simulator.

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Jagannath, M; Balasubramanian, Venkatesh

2014-07-01

Driver fatigue is an important contributor to road accidents. This paper reports a study that evaluated driver fatigue using multimodal fatigue measures, i.e., surface electromyography (sEMG), electroencephalography (EEG), seat interface pressure, blood pressure, heart rate and oxygen saturation level. Twenty male participants volunteered in this study by performing 60 min of driving on a static simulator. Results from sEMG showed significant physical fatigue (ρ fatigue. This will help us understand the influence of physical and mental fatigue on driver during monotonous driving. Copyright © 2014 Elsevier Ltd and The Ergonomics Society. All rights reserved.

Proximal Neuromuscular Control Protects Against Hamstring Injuries in Male Soccer Players: A Prospective Study With Electromyography Time-Series Analysis During Maximal Sprinting.

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Schuermans, Joke; Danneels, Lieven; Van Tiggelen, Damien; Palmans, Tanneke; Witvrouw, Erik

2017-05-01

With their unremittingly high incidence rate and detrimental functional repercussions, hamstring injuries remain a substantial problem in male soccer. Proximal neuromuscular control ("core stability") is considered to be of key importance in primary and secondary hamstring injury prevention, although scientific evidence and insights on the exact nature of the core-hamstring association are nonexistent at present. The muscle activation pattern throughout the running cycle would not differ between participants based on injury occurrence during follow-up. Case-control study; Level of evidence, 3. Sixty amateur soccer players participated in a multimuscle surface electromyography (sEMG) assessment during maximal acceleration to full-speed sprinting. Subsequently, hamstring injury occurrence was registered during a 1.5-season follow-up period. Hamstring, gluteal, and trunk muscle activity time series during the airborne and stance phases of acceleration were evaluated and statistically explored for a possible causal association with injury occurrence and absence from sport during follow-up. Players who did not experience a hamstring injury during follow-up had significantly higher amounts of gluteal muscle activity during the front swing phase ( P = .027) and higher amounts of trunk muscle activity during the backswing phase of sprinting ( P = .042). In particular, the risk of sustaining a hamstring injury during follow-up lowered by 20% and 6%, with a 10% increment in normalized muscle activity of the gluteus maximus during the front swing and the trunk muscles during the backswing, respectively ( P hamstring injury occurrence in male soccer players. Higher amounts of gluteal and trunk muscle activity during the airborne phases of sprinting were associated with a lower risk of hamstring injuries during follow-up. Hence, the present results provide a basis for improved, evidence-based rehabilitation and prevention, particularly focusing on increasing neuromuscular

Laryngeal Electromyography for Prognosis of Vocal Fold Paralysis.

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Pardo-Maza, Adriana; García-Lopez, Isabel; Santiago-Pérez, Susana; Gavilán, Javier

2017-01-01

This study aimed to determine the value of laryngeal electromyography in the prognosis of vocal fold paralysis. This is a retrospective descriptive study. This study included 80 patients diagnosed with unilateral or bilateral vocal fold paralysis on flexible laryngoscopy between 2002 and 2014 in a tertiary medical center. Laryngeal electromyography using a standardized protocol was performed; the outcome measures were classified and analyzed into two groups according to the degree of injury. Group 1 included patients with mild to moderate injury, and group 2 included patients with severe to complete injury. Prognosis was correlated with vocal fold motion recovery status with a minimum of 6 months of follow-up since the symptoms onset using positive and negative predictive values. Sixty patients showed acute or chronic recurrent laryngeal neuropathy in laryngeal electromyography. Twelve of 41 patients included in group 1 recovered motion, and 30 of 35 patients included in group 2 did not recover, resulting in 88.2% of positive predictive value and 35.7% of negative predictive value. Our data confirm that laryngeal electromyography is a useful clinical tool in predicting poor recovery in patients with vocal fold paralysis. It allows identification of candidates for early intervention. Copyright © 2017 The Voice Foundation. Published by Elsevier Inc. All rights reserved.

Basic Hand Gestures Classification Based on Surface Electromyography

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Aleksander Palkowski

2016-01-01

Full Text Available This paper presents an innovative classification system for hand gestures using 2-channel surface electromyography analysis. The system developed uses the Support Vector Machine classifier, for which the kernel function and parameter optimisation are conducted additionally by the Cuckoo Search swarm algorithm. The system developed is compared with standard Support Vector Machine classifiers with various kernel functions. The average classification rate of 98.12% has been achieved for the proposed method.

WAVELET TRANSFORM ANALYSIS OF ELECTROMYOGRAPHY KUNG FU STRIKES DATA

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Ana Carolina de Miranda Marzullo

2009-11-01

Full Text Available In martial arts and contact sports strikes are performed at near maximum speeds. For that reason, electromyography (EMG analysis of such movements is non-trivial. This paper has three main goals: firstly, to investigate the differences in the EMG activity of muscles during strikes performed with and without impacts; secondly, to assess the advantages of using Sum of Significant Power (SSP values instead of root mean square (rms values when analyzing EMG data; and lastly to introduce a new method of calculating median frequency values using wavelet transforms (WMDF. EMG data of the deltoid anterior (DA, triceps brachii (TB and brachioradialis (BR muscles were collected from eight Kung Fu practitioners during strikes performed with and without impacts. SSP results indicated significant higher muscle activity (p = 0.023 for the strikes with impact. WMDF results, on the other hand, indicated significant lower values (p = 0. 007 for the strikes with impact. SSP results presented higher sensitivity than rms to quantify important signal differences and, at the same time, presented lower inter-subject coefficient of variations. The result of increase in SSP values and decrease in WMDF may suggest better synchronization of motor units for the strikes with impact performed by the experienced Kung Fu practitioners

A canonical correlation analysis based EMG classification algorithm for eliminating electrode shift effect.

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Zhe Fan; Zhong Wang; Guanglin Li; Ruomei Wang

2016-08-01

Motion classification system based on surface Electromyography (sEMG) pattern recognition has achieved good results in experimental condition. But it is still a challenge for clinical implement and practical application. Many factors contribute to the difficulty of clinical use of the EMG based dexterous control. The most obvious and important is the noise in the EMG signal caused by electrode shift, muscle fatigue, motion artifact, inherent instability of signal and biological signals such as Electrocardiogram. In this paper, a novel method based on Canonical Correlation Analysis (CCA) was developed to eliminate the reduction of classification accuracy caused by electrode shift. The average classification accuracy of our method were above 95% for the healthy subjects. In the process, we validated the influence of electrode shift on motion classification accuracy and discovered the strong correlation with correlation coefficient of >0.9 between shift position data and normal position data.

Relationships between Paraspinal Muscle Activity and Lumbar Inter-Vertebral Range of Motion

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Alister du Rose

2016-01-01

Full Text Available Control of the lumbar spine requires contributions from both the active and passive sub-systems. Identifying interactions between these systems may provide insight into the mechanisms of low back pain. However, as a first step it is important to investigate what is normal. The purpose of this study was to explore the relationships between the lumbar inter-vertebral range of motion and paraspinal muscle activity during weight-bearing flexion in healthy controls using quantitative fluoroscopy (QF and surface electromyography (sEMG. Contemporaneous lumbar sEMG and QF motion sequences were recorded during controlled active flexion of 60° using electrodes placed over Longissimus thoracis pars thoracis (TES, Longissimus thoracis pars lumborum (LES, and Multifidus (LMU. Normalised root mean square (RMS sEMG amplitude data were averaged over five epochs, and the change in amplitude between epochs was calculated. The sEMG ratios of LMU/LES LMU/TES and LES/TES were also determined. QF was used to measure the maximum inter-vertebral range of motion from L2-S1, and correlation coefficients were calculated between sEMG amplitude variables and these measurements. Intra- and inter-session sEMG amplitude repeatability was also assessed for all three paraspinal muscles. The sEMG amplitude measurements were highly repeatable, and sEMG amplitude changes correlated significantly with L4-5 and L5-S1 IV-RoMmax (r = −0.47 to 0.59. The sEMG amplitude ratio of LES/TES also correlated with L4-L5 IV-RoMmax (r = −0.53. The relationships found may be important when considering rehabilitation for low back pain.

Relationships between Paraspinal Muscle Activity and Lumbar Inter-Vertebral Range of Motion.

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du Rose, Alister; Breen, Alan

2016-01-05

Control of the lumbar spine requires contributions from both the active and passive sub-systems. Identifying interactions between these systems may provide insight into the mechanisms of low back pain. However, as a first step it is important to investigate what is normal. The purpose of this study was to explore the relationships between the lumbar inter-vertebral range of motion and paraspinal muscle activity during weight-bearing flexion in healthy controls using quantitative fluoroscopy (QF) and surface electromyography (sEMG). Contemporaneous lumbar sEMG and QF motion sequences were recorded during controlled active flexion of 60° using electrodes placed over Longissimus thoracis pars thoracis (TES), Longissimus thoracis pars lumborum (LES), and Multifidus (LMU). Normalised root mean square (RMS) sEMG amplitude data were averaged over five epochs, and the change in amplitude between epochs was calculated. The sEMG ratios of LMU/LES LMU/TES and LES/TES were also determined. QF was used to measure the maximum inter-vertebral range of motion from L2-S1, and correlation coefficients were calculated between sEMG amplitude variables and these measurements. Intra- and inter-session sEMG amplitude repeatability was also assessed for all three paraspinal muscles. The sEMG amplitude measurements were highly repeatable, and sEMG amplitude changes correlated significantly with L4-5 and L5-S1 IV-RoMmax (r = -0.47 to 0.59). The sEMG amplitude ratio of LES/TES also correlated with L4-L5 IV-RoMmax (r = -0.53). The relationships found may be important when considering rehabilitation for low back pain.

Duration of observation required in detecting fasciculation potentials in amyotrophic lateral sclerosis using high-density surface EMG

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Zhou Ping

2012-10-01

Full Text Available Abstract Background High-density surface electromyography (HD-SEMG has recently emerged as a potentially useful tool in the evaluation of amyotrophic lateral sclerosis (ALS. This study addresses a practical constraint that arises when applying HD-SEMG for supporting the diagnosis of ALS; specifically, how long the surface EMG should be recorded before one can be confident that fasciculation potentials (FPs are absent in a muscle being tested. Methods HD-SEMG recordings of 29 muscles from 11 ALS patients were analyzed. We used the distribution of intervals between FPs, and estimated the observation duration needed to record from one to five FPs with a probability approaching unity. Such an approach was previously tested by Mills with a concentric needle electrode. Results We found that the duration of recording was up to 70 s in order to record a single FP with a probability approaching unity. Increasing recording time to 2 minutes, the probability of recording five FPs approached approximately 0.95. Conclusions HD-SEMG appears to be a suitable method for capturing FPs comparable to intramuscular needle EMG.

The Comparison between Spectral and Entropic Measures Following Fatigue in Erector Spinae Muscles

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Saeed Talebian

2016-03-01

Full Text Available Background: Surface electromyography (sEMG of muscles is a non-invasive tool that can be helpful in the assessment of muscle function and some motor control evaluations. A loss of force, known as muscle fatigue is accompanied by changes in muscle electrical activity. One of the most commonly used surface EMG parameters which reflects paraspinal muscle fatigue during different tasks and positions is median frequency. Although it is widely known that the electromyography power spectrum shifts to lower frequencies during fatiguing contraction, an opinion exists that the validity of spectral shifts in assessment of fatigue is questionable. Some researchers have examined whether other quantities derived from sEMG signals are better indicators for muscle fatigue. Following cyclic flexion/extension and consequence fatigue, variation in sEMG signals may be complex for study. The aim of this study was to determine which of the median frequency (MF or entropic (ENTR is more sensitive for measuring muscular fatigue in erector spinae muscles during cyclic flexion/extension. Methods: Surface electromyography of erector spine muscles was recorded in 25 healthy subjects during cyclic dynamic contractions. The experimental session consisted of two parts: measurement of Maximal Voluntary Contraction (MVC, and performing the fatigue test. All subjects performed rhythmic flexion/extension with 50% MVC loading against B-200 Isostation, about 4-6 minutes. The MF and ENTR of the muscle activities were computed to assess muscular fatigue. Results: Paired sample t-tests showed that MF and ENTR changes after fatigue test were significant (P<0.001. Percentage changes of both MF and ENTR were reduced, this reduction for ENTR was more than 40% (P<0.001. Conclusion: It seems that the changes of ENTR in muscle activities have the ability to measure muscular fatigue and is more sensitive in comparison to MF.

Electromyographic Analysis of the Hip Extension Pattern in Visually Impaired Athletes

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Halski Tomasz

2015-12-01

Full Text Available The objective of the study was to determine the order of muscle recruitment during the active hip joint extension in particular positions in young visually impaired athletes. The average recruitment time (ART of the gluteus maximus (GM and the hamstring muscle group (HMG was assessed by the means of surface electromyography (sEMG. The sequence of muscle recruitment in the female and male group was also taken into consideration. This study followed a prospective, cross – sectional, randomised design, where 76 visually impaired athletes between the age of 18–25 years were enrolled into the research and selected on chosen inclusion and exclusion criteria. Finally, 64 young subjects (32 men and 32 women were included in the study (age: 21.1 ± 1.05 years; body mass: 68.4 ± 12.4 kg; body height: 1.74 ± 0.09 m; BMI: 22.20 ± 2.25 kg/m2. All subjects were analysed for the ART of the GM and HMG during the active hip extension performed in two different positions, as well as resting and functional sEMG activity of each muscle. Between gender differences were comprised and the correlations between the ART of the GM and HMG with their functional sEMG activity during hip extension in both positions were shown. No significant differences between the ART of the GM and HMG were found (p>0.05. Furthermore, there was no significant difference of ART among both tested positions, as well in male as female subjects (p>0.05.

Simulation of facial expressions using person-specific sEMG signals controlling a biomechanical face model.

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Eskes, Merijn; Balm, Alfons J M; van Alphen, Maarten J A; Smeele, Ludi E; Stavness, Ian; van der Heijden, Ferdinand

2018-01-01

Functional inoperability in advanced oral cancer is difficult to assess preoperatively. To assess functions of lips and tongue, biomechanical models are required. Apart from adjusting generic models to individual anatomy, muscle activation patterns (MAPs) driving patient-specific functional movements are necessary to predict remaining functional outcome. We aim to evaluate how volunteer-specific MAPs derived from surface electromyographic (sEMG) signals control a biomechanical face model. Muscle activity of seven facial muscles in six volunteers was measured bilaterally with sEMG. A triple camera set-up recorded 3D lip movement. The generic face model in ArtiSynth was adapted to our needs. We controlled the model using the volunteer-specific MAPs. Three activation strategies were tested: activating all muscles [Formula: see text], selecting the three muscles showing highest muscle activity bilaterally [Formula: see text]-this was calculated by taking the mean of left and right muscles and then selecting the three with highest variance-and activating the muscles considered most relevant per instruction [Formula: see text], bilaterally. The model's lip movement was compared to the actual lip movement performed by the volunteers, using 3D correlation coefficients [Formula: see text]. The correlation coefficient between simulations and measurements with [Formula: see text] resulted in a median [Formula: see text] of 0.77. [Formula: see text] had a median [Formula: see text] of 0.78, whereas with [Formula: see text] the median [Formula: see text] decreased to 0.45. We demonstrated that MAPs derived from noninvasive sEMG measurements can control movement of the lips in a generic finite element face model with a median [Formula: see text] of 0.78. Ultimately, this is important to show the patient-specific residual movement using the patient's own MAPs. When the required treatment tools and personalisation techniques for geometry and anatomy become available, this may

Automated Algorithm for Generalized Tonic–Clonic Epileptic Seizure Onset Detection Based on sEMG Zero-Crossing Rate

DEFF Research Database (Denmark)

Conradsen, Isa; Beniczky, Sándor; Hoppe, Karsten

2012-01-01

were analyzed from 11 consecutive patients. Our method is based on a high-pass filtering with a cutoff at 150 Hz, and monitoring a count of zero crossings with a hysteresis of $\\pm 50\\,\\mu \\hbox{V}$ . Based on data from one sEMG electrode (on the deltoid muscle), we achieved a sensitivity of 100...

Is the timed loaded standing test a valid measure of back muscle endurance in people with vertebral osteoporosis?

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Newman, M; Newman, R; Hughes, T; Vadher, K; Barker, K L

2018-04-01

Timed loaded standing (TLS) is a suggested measure of back muscle endurance for people with vertebral osteoporosis. Surface electromyography revealed back muscles work harder and fatigue during TLS. The test end-point and total time were associated with back fatigue. The findings help demonstrate the concurrent validity of the TLS test. The TLS test is suggested as a measure of back muscle endurance for patients with vertebral osteoporosis. However, to date, no study has demonstrated that TLS does measure back extensor or erector spinae (ES) muscle endurance. We used surface electromyography (sEMG) to investigate the performance of the thoracic ES muscles during TLS. Thirty-six people with vertebral osteoporosis with a mean age of 71.6 (range 45-86) years participated. sEMG recordings were made of the ES at T3 and T12 bilaterally during quiet standing (QS) and TLS. The relative (%) change in sEMG amplitude between conditions was compared. Fatigue was evaluated by analysing the change in median frequency (MF) of the sEMG signal during TLS, and the correlation between maximal TLS time and rate of MF decline was examined. Activity in the ES increased significantly during TLS at all electrode locations. During TLS, the MF declined at a mean rate of -24.2% per minute (95% C.I. -26.5 to -21.9%). The MF slope and test time were strongly correlated (r 2  = 0.71), and at test end, the final MF dropped to an average 89% (95% C.I. 85 to 93%) of initial MF. Twenty-eight participants (78%) reported fatigue was the main reason for stopping, and for eight (22%), it was pain. This study demonstrates that TLS challenges the ES muscles in the thoracic region and results in ES fatigue. Endurance time and the point at which the TLS test ends are strongly related to ES fatigue.

Robust Bio-Signal Based Control of an Intelligent Wheelchair

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Dongyi Chen

2013-09-01

Full Text Available In this paper, an adaptive human-machine interaction (HMI method that is based on surface electromyography (sEMG signals is proposed for the hands-free control of an intelligent wheelchair. sEMG signals generated by the facial movements are obtained by a convenient dry electrodes sensing device. After the signals features are extracted from the autoregressive model, control data samples are updated and trained by an incremental online learning algorithm in real-time. Experimental results show that the proposed method can significantly improve the classification accuracy and training speed. Moreover, this method can effectively reduce the influence of muscle fatigue during a long time operation of sEMG-based HMI.

Relationship Between Laryngeal Electromyography and Video Laryngostroboscopy in Vocal Fold Paralysis.

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Maamary, Joel A; Cole, Ian; Darveniza, Paul; Pemberton, Cecilia; Brake, Helen Mary; Tisch, Stephen

2017-09-01

The objective of this study was to better define the relationship of laryngeal electromyography and video laryngostroboscopy in the diagnosis of vocal fold paralysis. Retrospective diagnostic cohort study with cross-sectional data analysis METHODS: Data were obtained from 57 patients with unilateral vocal fold paralysis who attended a large tertiary voice referral center. Electromyographic findings were classified according to recurrent laryngeal nerve, superior laryngeal nerve, and high vagal/combined lesions. Video laryngostroboscopy recordings were classified according to the position of the immobile fold into median, paramedian, lateral, and a foreshortened/hooded vocal fold. The position of the paralyzed vocal fold was then analyzed according to the lesion as determined by electromyography. The recurrent laryngeal nerve was affected in the majority of cases with left-sided lesions more common than right. Vocal fold position differed between recurrent laryngeal and combined vagal lesions. Recurrent laryngeal nerve lesions were more commonly associated with a laterally displaced immobile fold. No fold position was suggestive of a combined vagal lesion. The inter-rater reliability for determining fold position was high. Laryngeal electromyography is useful in diagnosing neuromuscular dysfunction of the larynx and best practice recommends its continued implementation along with laryngostroboscopy. While recurrent laryngeal nerve lesions are more likely to present with a lateral vocal fold, this does not occur in all cases. Such findings indicate that further unknown mechanisms contribute to fold position in unilateral paralysis. Copyright © 2017 The Voice Foundation. Published by Elsevier Inc. All rights reserved.

Hamstring Activity in the Anterior Cruciate Ligament Injured Patient: Injury Implications and Comparison With Quadriceps Activity.

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Frank, Rachel M; Lundberg, Hannah; Wimmer, Markus A; Forsythe, Brian; Bach, Bernard R; Verma, Nikhil N; Cole, Brian J

2016-08-01

To investigate the potential causes of diminished knee extension after acute anterior cruciate ligament (ACL) injury using both surface electromyography (sEMG) analysis of the quadriceps and hamstrings, and gait analysis to assess muscle action and tone. Consecutive patients with an acute ACL tear underwent sEMG and gait analysis within 2 weeks of injury, before ACL reconstruction. Standard motion analysis techniques were used and sEMG data were collected simultaneously with gait data. T-tests were used to determine differences between the ACL-deficient and control subjects in knee flexion angles, peak external knee joint moments, and total time that a muscle was activated ("on") during gait. External knee moments were expressed as a percentage of body weight times height. Ten patients (mean age 24 ± 4 years) were included at a mean 10.2 days between injury and analysis; 10 uninjured, matched control subjects were included for comparison. There were significant increases in minimum flexion angle at heel strike (5.92 ± 3.39 v -3.49 ± 4.55, P hamstring activity "on" time during gait (P > .05). In patients with acute ACL injury, the ACL-deficient limb does not reach as much extension as controls. Although the rectus femoris is "on" for shorter periods during the gait cycle, there is no difference in hamstring time on during gait. This information may help clinicians better understand muscle function and gait patterns in the acute time period after ACL injury. Level III, case control study. Copyright © 2016 Arthroscopy Association of North America. Published by Elsevier Inc. All rights reserved.

A Pilot Study of Individual Muscle Force Prediction during Elbow Flexion and Extension in the Neurorehabilitation Field

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Jiateng Hou

2016-11-01

Full Text Available This paper proposes a neuromusculoskeletal (NMS model to predict individual muscle force during elbow flexion and extension. Four male subjects were asked to do voluntary elbow flexion and extension. An inertial sensor and surface electromyography (sEMG sensors were attached to subject's forearm. Joint angle calculated by fusion of acceleration and angular rate using an extended Kalman filter (EKF and muscle activations obtained from the sEMG signals were taken as the inputs of the proposed NMS model to determine individual muscle force. The result shows that our NMS model can predict individual muscle force accurately, with the ability to reflect subject-specific joint dynamics and neural control solutions. Our method incorporates sEMG and motion data, making it possible to get a deeper understanding of neurological, physiological, and anatomical characteristics of human dynamic movement. We demonstrate the potential of the proposed NMS model for evaluating the function of upper limb movements in the field of neurorehabilitation.

Muscle Fatigue Analysis of the Deltoid during Three Head-Related Static Isometric Contraction Tasks

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Wenxiang Cui

2017-05-01

Full Text Available This study aimed to investigate the fatiguing characteristics of muscle-tendon units (MTUs within skeletal muscles during static isometric contraction tasks. The deltoid was selected as the target muscle and three head-related static isometric contraction tasks were designed to activate three heads of the deltoid in different modes. Nine male subjects participated in this study. Surface electromyography (SEMG signals were collected synchronously from the three heads of the deltoid. The performances of five SEMG parameters, including root mean square (RMS, mean power frequency (MPF, the first coefficient of autoregressive model (ARC1, sample entropy (SE and Higuchi’s fractal dimension (HFD, in quantification of fatigue, were evaluated in terms of sensitivity to variability ratio (SVR and consistency firstly. Then, the HFD parameter was selected as the fatigue index for further muscle fatigue analysis. The experimental results demonstrated that the three deltoid heads presented different activation modes during three head-related fatiguing contractions. The fatiguing characteristics of the three heads were found to be task-dependent, and the heads kept in a relatively high activation level were more prone to fatigue. In addition, the differences in fatiguing rate between heads increased with the increase in load. The findings of this study can be helpful in better understanding the underlying neuromuscular control strategies of the central nervous system (CNS. Based on the results of this study, the CNS was thought to control the contraction of the deltoid by taking the three heads as functional units, but a certain synergy among heads might also exist to accomplish a contraction task.

Changes in motor unit behavior following isometric fatigue of the first dorsal interosseous muscle

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Rymer, William Z.; Lowery, Madeleine M.; Suresh, Nina L.

2015-01-01

The neuromuscular strategies employed to compensate for fatigue-induced muscle force deficits are not clearly understood. This study utilizes surface electromyography (sEMG) together with recordings of a population of individual motor unit action potentials (MUAPs) to investigate potential compensatory alterations in motor unit (MU) behavior immediately following a sustained fatiguing contraction and after a recovery period. EMG activity was recorded during abduction of the first dorsal interosseous in 12 subjects at 20% maximum voluntary contraction (MVC), before and directly after a 30% MVC fatiguing contraction to task failure, with additional 20% MVC contractions following a 10-min rest. The amplitude, duration and mean firing rate (MFR) of MUAPs extracted with a sEMG decomposition system were analyzed, together with sEMG root-mean-square (RMS) amplitude and median frequency (MPF). MUAP duration and amplitude increased immediately postfatigue and were correlated with changes to sEMG MPF and RMS, respectively. After 10 min, MUAP duration and sEMG MPF recovered to prefatigue values but MUAP amplitude and sEMG RMS remained elevated. MU MFR and recruitment thresholds decreased postfatigue and recovered following rest. The increase in MUAP and sEMG amplitude likely reflects recruitment of larger MUs, while recruitment compression is an additional compensatory strategy directly postfatigue. Recovery of MU MFR in parallel with MUAP duration suggests a possible role for metabolically sensitive afferents in MFR depression postfatigue. This study provides insight into fatigue-induced neuromuscular changes by examining the properties of a large population of concurrently recorded single MUs and outlines possible compensatory strategies involving alterations in MU recruitment and MFR. PMID:25761952

A novel approach for SEMG signal classification with adaptive local binary patterns.

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Ertuğrul, Ömer Faruk; Kaya, Yılmaz; Tekin, Ramazan

2016-07-01

Feature extraction plays a major role in the pattern recognition process, and this paper presents a novel feature extraction approach, adaptive local binary pattern (aLBP). aLBP is built on the local binary pattern (LBP), which is an image processing method, and one-dimensional local binary pattern (1D-LBP). In LBP, each pixel is compared with its neighbors. Similarly, in 1D-LBP, each data in the raw is judged against its neighbors. 1D-LBP extracts feature based on local changes in the signal. Therefore, it has high a potential to be employed in medical purposes. Since, each action or abnormality, which is recorded in SEMG signals, has its own pattern, and via the 1D-LBP these (hidden) patterns may be detected. But, the positions of the neighbors in 1D-LBP are constant depending on the position of the data in the raw. Also, both LBP and 1D-LBP are very sensitive to noise. Therefore, its capacity in detecting hidden patterns is limited. To overcome these drawbacks, aLBP was proposed. In aLBP, the positions of the neighbors and their values can be assigned adaptively via the down-sampling and the smoothing coefficients. Therefore, the potential to detect (hidden) patterns, which may express an illness or an action, is really increased. To validate the proposed feature extraction approach, two different datasets were employed. Achieved accuracies by the proposed approach were higher than obtained results by employed popular feature extraction approaches and the reported results in the literature. Obtained accuracy results were brought out that the proposed method can be employed to investigate SEMG signals. In summary, this work attempts to develop an adaptive feature extraction scheme that can be utilized for extracting features from local changes in different categories of time-varying signals.

Evaluating the Ergonomic Benefit of a Wrist Brace on Wrist Posture, Muscle Activity, Rotational Stiffness, and Peak Shovel-Ground Impact Force During a Simulated Tree-Planting Task.

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Sheahan, Peter J; Cashaback, Joshua G A; Fischer, Steven L

2017-09-01

Background Tree planters are at a high risk for wrist injury due to awkward postures and high wrist loads experienced during each planting cycle, specifically at shovel-ground impact. Wrist joint stiffness provides a measure that integrates postural and loading information. Objective The purpose of this study was to evaluate wrist joint stiffness requirements at the instant of shovel-ground impact during tree planting and determine if a wrist brace could alter muscular contributions to wrist joint stiffness. Method Planters simulated tree planting with and without wearing a brace on their planting arm. Surface electromyography (sEMG) from six forearm muscles and wrist kinematics were collected and used to calculate muscular contributions to joint rotational stiffness about the wrist. Results Wrist joint stiffness increased with brace use, an unanticipated and negative consequence of wearing a brace. As a potential benefit, planters achieved a more neutrally oriented wrist angle about the flexion/extension axis, although a less neutral wrist angle about the ulnar/radial axis was observed. Muscle activity did not change between conditions. Conclusion The joint stiffness analysis, combining kinematic and sEMG information in a biologically relevant manner, revealed clear limitations with the interface between the brace grip and shovel handle that jeopardized the prophylactic benefits of the current brace design. This limitation was not as evident when considering kinematics and sEMG data independently. Application A neuromechanical model (joint rotational stiffness) enhanced our ability to evaluate the brace design relative to kinematic and sEMG parameter-based metrics alone.

Muscle fatigue and contraction intensity modulates the complexity of surface electromyography.

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Cashaback, Joshua G A; Cluff, Tyler; Potvin, Jim R

2013-02-01

Nonlinear dynamical techniques offer a powerful approach for the investigation of physiological time series. Multiscale entropy analyses have shown that pathological and aging systems are less complex than healthy systems and this finding has been attributed to degraded physiological control processes. A similar phenomenon may arise during fatiguing muscle contractions where surface electromyography signals undergo temporal and spectral changes that arise from the impaired regulation of muscle force production. Here we examine the affect of fatigue and contraction intensity on the short and long-term complexity of biceps brachii surface electromyography. To investigate, we used an isometric muscle fatigue protocol (parsed into three windows) and three contraction intensities (% of maximal elbow joint moment: 40%, 70% and 100%). We found that fatigue reduced the short-term complexity of biceps brachii activity during the last third of the fatiguing contraction. We also found that the complexity of surface electromyography is dependent on contraction intensity. Our results show that multiscale entropy is sensitive to muscle fatigue and contraction intensity and we argue it is imperative that both factors be considered when evaluating the complexity of surface electromyography signals. Our data contribute to a converging body of evidence showing that multiscale entropy can quantify subtle information content in physiological time series. Copyright © 2012 Elsevier Ltd. All rights reserved.

Diagnosis of cauda equina abnormalities by using electromyography, discography, and epidurography in dogs

International Nuclear Information System (INIS)

Sisson, A.F.; LeCouteur, R.A.; Ingram, J.T.; Park, R.D.; Child, G.

1992-01-01

Electromyography (EMG), L7-S1 discography and epidurography were investigated in 15 dogs with clinical signs of cauda equina dysfunction and in 7 control dogs without such clinical signs. Electromyography of paraspinal and pelvic limb muscles was done in 13 of 15 affected dogs. An L7-S1 discogram followed by an epidurogram was performed in all 22 dogs using 20% iopamidol. Results of discograms, epidurograms, and gross necropsy examinations were normal in six of seven control dogs. The one dog in which these studies were abnormal had a mild L7-S1 disc protrusion that did not result in nerve root compression at necropsy. Electromyographic analysis was 100% accurate in predicting the presence or absence of cauda equina disease. None of the results of discograms were falsely negative. Twelve of 15 discograms in clinically affected dogs indicated dorsal disc protrusion, but 2 of these protrusions were found to be noncompressive at surgery (13% error). Abnormal epidurograms occurred in 9 of 15 clinically affected dogs. There was one false positive and two false negatives (20% error). Electromyography was a sensitive screening technique for the presence of cauda equina disease. Discography may be more sensitive for detection of L7-S1 disc protrusion than epidurography. An abnormal radiographic contrast study of the cauda equina may only be useful when combined with an abnormal EMG

[Analysis of the Muscle Fatigue Based on Band Spectrum Entropy of Multi-channel Surface Electromyography].

Science.gov (United States)

Liu, Jian; Zou, Renling; Zhang, Dongheng; Xu, Xiulin; Hu, Xiufang

2016-06-01

Exercise-induced muscle fatigue is a phenomenon that the maximum voluntary contraction force or power output of muscle is temporarily reduced due to muscular movement.If the fatigue is not treated properly,it will bring about a severe injury to the human body.With multi-channel collection of lower limb surface electromyography signals,this article analyzes the muscle fatigue by adoption of band spectrum entropy method which combined electromyographic signal spectral analysis and nonlinear dynamics.The experimental result indicated that with the increase of muscle fatigue,muscle signal spectrum began to move to low frequency,the energy concentrated,the system complexity came down,and the band spectrum entropy which reflected the complexity was also reduced.By monitoring the entropy,we can measure the degree of muscle fatigue,and provide an indicator to judge fatigue degree for the sports training and clinical rehabilitation training.

Analysis of Muscle Contraction on Pottery Manufacturing Process Using Electromyography (EMG)

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Soewardi, Hartomo; Azka Rahmayani, Amalia

2016-01-01

One of the most common problems in pottery manufacturing process is musculoskeletal disorders on workers. This disorder was caused by uncomfortable posture where the workers sit on the floor with one leg was folded and another was twisted for long duration. Back, waist, buttock, and right knee frequently experience the disorders. The objective of this research is to investigate the muscle contraction at such body part of workers in manufacturing process of pottery. Electromyography is used to investigate the muscle contraction based on the median frequency signal. Focus measurements is conducted on four muscles types. They are lower interscapular muscle on the right and left side, dorsal lumbar muscle, and lateral hamstring muscle. Statistical analysis is conducted to test differences of muscle contraction between female and male. The result of this research showed that the muscle which reached the highest contraction is dorsal lumbar muscle with the average of median frequency is 51,84 Hz. Then followed by lower interscapular muscle on the left side with the average of median frequency is 31,30 hz, lower interscapular muscle on the right side average of median frequency is 31,24 Hz, and lateral hamstring muscle average of median frequency is 21,77 Hz. Based on the statistic analysis result, there were no differences between male and female on left and right lower interscapular muscle and dorsal lumbar muscle but there were differences on lateral hamstring muscle with the significance level is 5%. Besides that, there were differences for all combination muscle types with the level of significance is 5%.

Determination of effective treatment duration of interferential current therapy using electromyography

OpenAIRE

Youn, Jong-In; Lee, Ho Sub; Lee, Sangkwan

2016-01-01

[Purpose] This study used electromyography to measure the effective treatment duration of interferential current therapy for muscle fatigue. [Subjects and Methods] Fifteen healthy adult men volunteered to participate in the study (age: 24.2 ? 1.3?years; weight: 67.6 ? 4.92?kg; height: 176.4 ? 4.92?cm). All subjects performed 5?min of isometric back extension exercise to produce muscle fatigue, and were then treated with interferential current therapy for 15?min, with electromyography monitori...

Flexion-relaxation ratio in computer workers with and without chronic neck pain.

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Pinheiro, Carina Ferreira; dos Santos, Marina Foresti; Chaves, Thais Cristina

2016-02-01

This study evaluated the flexion-relaxation phenomenon (FRP) and flexion-relaxation ratios (FR-ratios) using surface electromyography (sEMG) of the cervical extensor muscles of computer workers with and without chronic neck pain, as well as of healthy subjects who were not computer users. This study comprised 60 subjects 20-45years of age, of which 20 were computer workers with chronic neck pain (CPG), 20 were computer workers without neck pain (NPG), and 20 were control individuals who do not use computers for work and use them less than 4h/day for other purposes (CG). FRP and FR-ratios were analyzed using sEMG of the cervical extensors. Analysis of FR-ratios showed smaller values in the semispinalis capitis muscles of the two groups of workers compared to the control group. The reference FR-ratio (flexion relaxation ratio [FRR], defined as the maximum activity in 1s of the re-extension/full flexion sEMG activity) was significantly higher in the computer workers with neck pain compared to the CG (CPG: 3.10, 95% confidence interval [CI95%] 2.50-3.70; NPG: 2.33, CI95% 1.93-2.74; CG: 1.99, CI95% 1.81-2.17; pneck pain, and such results suggested that each FR-ratio could have a different application. Copyright © 2016 Elsevier Ltd. All rights reserved.

The risk of hematoma following extensive electromyography of the lumbar paraspinal muscles

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London, Zachary; Quint, Douglas J.; Haig, Andrew J.; Yamakawa, Karen S. J.

2012-01-01

Introduction The purpose of this study is to provide a controlled trial looking at the risk of paraspinal hematoma formation following extensive paraspinal muscle electromyography. Methods 54 subjects ages 55-80 underwent MRI of the lumbar spine before or shortly after electromyography using the paraspinal mapping technique. A neuroradiologist, blinded to the temporal relationship between the EMG and MRI, reviewed the MRIs to look for hematomas in or around the paraspinal muscles. Results Two MRIs demonstrated definite paraspinal hematomas, while 10 were found to have possible hematomas. All hematomas were hematoma and either the timing of the EMG or the use of aspirin or other non-steroidal anti-inflammatory drugs. Discussion Paraspinal electromyography can be considered safe in the general population and those taking non-steroidal anti-inflammatory drugs. PMID:22644875

Effectiveness of the Wavelet Transform on the Surface EMG to Understand the Muscle Fatigue During Walk

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Hussain, M. S.; Mamun, Md.

2012-01-01

Muscle fatigue is the decline in ability of a muscle to create force. Electromyography (EMG) is a medical technique for measuring muscle response to nervous stimulation. During a sustained muscle contraction, the power spectrum of the EMG shifts towards lower frequencies. These effects are due to muscle fatigue. Muscle fatigue is often a result of unhealthy work practice. In this research, the effectiveness of the wavelet transform applied to the surface EMG (SEMG) signal as a means of understanding muscle fatigue during walk is presented. Power spectrum and bispectrum analysis on the EMG signal getting from right rectus femoris muscle is executed utilizing various wavelet functions (WFs). It is possible to recognize muscle fatigue appreciably with the proper choice of the WF. The outcome proves that the most momentous changes in the EMG power spectrum are symbolized by WF Daubechies45. Moreover, this research has compared bispectrum properties to the other WFs. To determine muscle fatigue during gait, Daubechies45 is used in this research to analyze the SEMG signal.

Clinical and computerized evaluation in study of temporo-mandibular joint intracapsular disease.

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Ciavarella, D; Mastrovincenzo, M; Sabatucci, A; Parziale, V; Granatelli, F; Violante, F; Bossù, M; Lo Muzio, L; Chimenti, C

2010-03-01

In this work authors show a diagnostic criteria in study of TMID: neuro occlusal clinical evaluation (NOE), T-Scan 2 system and surface electromyography (sEMG). Nine patients 25-30 years old with TMID problem and 9 healthy group control have been selected and examined. On each patients it has been performed NOE, T-Scan and sEMG test. NOE has been calculated on each patient photos lateral mandibular excursion angle called: masticatory functional angle (AFM). T-Scan System is a computerized occlusal analyzer that provide in-depth understanding of the overall balance of the occlusion. At the same time of T-Scan record sEMG tests, in resting position and in maximum clench, have been performed. In healthy control there were no AFM difference. In no healthy group there were difference between the two AFM greater than 6 degrees. T-Scan COF showed how in healthy group control there was never a difference of COF greater than 5%. In no healthy group the difference were greater than 5% Pjoint sound than the balance side P<0.001. sEMG show how in TMID patients maximum masseter activation is always lower than maximum masseter activation of healthy subjects P<0.001. Neuro occlusal clinical evaluation (NOE) in TMID patients is supported by instrumental evaluation.

Evaluation of Bioelectrical Activity of Pelvic Floor Muscles and Synergistic Muscles Depending on Orientation of Pelvis in Menopausal Women with Symptoms of Stress Urinary Incontinence: A Preliminary Observational Study

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Tomasz Halski

2014-01-01

Full Text Available Objectives. Evaluation of resting and functional bioelectrical activity of the pelvic floor muscles (PFM and the synergistic muscles, depending on the orientation of the pelvis, in anterior (P1 and posterior (P2 pelvic tilt. Design. Preliminary, prospective observational study. Setting. Department and Clinic of Urology, University Hospital in Wroclaw, Poland. Participants. Thirty-two menopausal and postmenopausal women with stress urinary incontinence were recruited. Based on inclusion and exclusion criteria, sixteen women aged 55 to 70 years were enrolled in the study. Primary Outcome Measures. Evaluation of resting and functional bioelectrical activity of the pelvic floor muscles by electromyography (sEMG and vaginal probe. Secondary Outcome Measures. Evaluation of activity of the synergistic muscles by sEMG and surface electrodes. Results. No significant differences between orientations P1 and P2 were found in functional and resting sEMG activity of the PFM. During resting and functional PFM activity, higher electrical activity in P2 than in P1 has been recorded in some of the synergistic muscles. Conclusions. This preliminary study does not provide initial evidence that pelvic tilt influences PFM activation. Although different activity of synergistic muscles occurs in various orientations of the pelvic tilt, it does not have to affect the sEMG activity of the PFM.

Neural network committees for finger joint angle estimation from surface EMG signals

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Reddy Narender P

2009-01-01

Full Text Available Abstract Background In virtual reality (VR systems, the user's finger and hand positions are sensed and used to control the virtual environments. Direct biocontrol of VR environments using surface electromyography (SEMG signals may be more synergistic and unconstraining to the user. The purpose of the present investigation was to develop a technique to predict the finger joint angle from the surface EMG measurements of the extensor muscle using neural network models. Methodology SEMG together with the actual joint angle measurements were obtained while the subject was performing flexion-extension rotation of the index finger at three speeds. Several neural networks were trained to predict the joint angle from the parameters extracted from the SEMG signals. The best networks were selected to form six committees. The neural network committees were evaluated using data from new subjects. Results There was hysteresis in the measured SMEG signals during the flexion-extension cycle. However, neural network committees were able to predict the joint angle with reasonable accuracy. RMS errors ranged from 0.085 ± 0.036 for fast speed finger-extension to 0.147 ± 0.026 for slow speed finger extension, and from 0.098 ± 0.023 for the fast speed finger flexion to 0.163 ± 0.054 for slow speed finger flexion. Conclusion Although hysteresis was observed in the measured SEMG signals, the committees of neural networks were able to predict the finger joint angle from SEMG signals.

Tensor veli palatini electromyography for monitoring Eustachian tube rehabilitation in otitis media.

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Picciotti, P M; Della Marca, G; D'Alatri, L; Lucidi, D; Rigante, M; Scarano, E

2017-05-01

The pathogenesis of otitis media is related to Eustachian tube dysfunction. The tensor veli palatini muscle actively opens the Eustachian tube and promotes middle-ear ventilation. This study describes a technique for paratubal electromyography that uses a surface, non-invasive electrode able to record tensor veli palatini muscle activity during swallowing. Twenty otitis media patients and 10 healthy patients underwent tensor veli palatini electromyography. Activity of this muscle before and after Eustachian tube rehabilitation was also assessed. In 78.5 per cent of patients, the electromyography duration phase and/or amplitude were reduced in the affected side. The muscle action potential was impaired in all patients who underwent Eustachian tube rehabilitation. This study confirmed that Eustachian tube muscle dysfunction has a role in otitis media pathogenesis and showed that muscle activity increases after Eustachian tube rehabilitation therapy.

Assessment of Muscle Fatigue Associated with Prolonged Standing in the Workplace

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Omar, Abdul Rahman; Saman, Alias Mohd; Othman, Ibrahim

2012-01-01

Objectives The objectives of this study were to determine the psychological fatigue and analyze muscle activity of production workers who are performing processes jobs while standing for prolonged time periods. Methods The psychological fatigue experienced by the workers was obtained through questionnaire surveys. Meanwhile, muscle activity has been analyzed using surface electromyography (sEMG) measurement. Lower extremities muscles include: erector spinae, tibialis anterior, and gastrocnemius were concurrently measured for more than five hours of standing. Twenty male production workers in a metal stamping company participated as subjects in this study. The subjects were required to undergo questionnaire surveys and sEMG measurement. Results Results of the questionnaire surveys found that all subjects experienced psychological fatigue due to prolonged standing jobs. Similarly, muscle fatigue has been identified through sEMG measurement. Based on the non-parametric statistical test using the Spearman's rank order correlation, the left erector spinae obtained a moderate positive correlation and statistically significant (rs = 0.552, p fatigue and to muscle fatigue among the production workers. PMID:22953228

Mandibular kinematics and masticatory muscles EMG in patients with short lasting TMD of mild-moderate severity.

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De Felício, Cláudia Maria; Mapelli, Andrea; Sidequersky, Fernanda Vincia; Tartaglia, Gianluca M; Sforza, Chiarella

2013-06-01

Mandibular kinematic and standardized surface electromyography (sEMG) characteristics of masticatory muscles of subjects with short lasting TMD of mild-moderate severity were examined. Volunteers were submitted to clinical examination and questionnaire of severity. Ten subjects with TMD (age 27.3years, SD 7.8) and 10 control subjects without TMD, matched by age, were selected. Mandibular movements were recorded during free maximum mouth opening and closing (O-C) and unilateral, left and right, gum chewing. sEMG of the masseter and temporal muscles was performed during maximum teeth clenching either on cotton rolls or in intercuspal position, and during gum chewing. sEMG indices were obtained. Subjects with TMD, relative to control subjects, had lower relative mandibular rotation at the end of mouth opening, larger mean number of intersection between interincisal O-C paths during mastication and smaller asymmetry between working and balancing side, with participation beyond the expected of the contralateral muscles (Pkinematic parameters and the EMG indices of the static test, although some changes in the mastication were observed. Copyright © 2013 Elsevier Ltd. All rights reserved.

Simultaneous 31P NMR spectroscopy and EMG in exercising and recovering human skeletal muscle: technical aspects

DEFF Research Database (Denmark)

Vestergaard-Poulsen, P; Thomsen, C; Sinkjaer, T

1994-01-01

The bioenergetics of human skeletal muscle can be studied by 31P NMR spectroscopy (31P-MRS) and by surface electromyography (SEMG). Simultaneous 31P-MRS and SEMG permit accurate and noninvasive studies of the correlation between metabolic and electrical changes in exercising and recovering human....... A nonmagnetic ergometer was used for ankle dorsiflexions that activated only the anterior tibial muscle as verified by post exercise imaging. The coil design and the adiabatic sech/tanh pulse improved sensitivity by 45% and 56% respectively, compared with standard techniques. Simultaneous electromyographic...... recordings did not deteriorate the NMR spectra. The VARPRO time domain fitting routine was very suitable for estimating 31P muscle spectra. With these methods it was possible to accurately estimate parameters describing metabolic and electrical changes during rest, exercise and the entire recovery period...

Comparison of sEMG-Based Feature Extraction and Motion Classification Methods for Upper-Limb Movement

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Shuxiang Guo

2015-04-01

Full Text Available The surface electromyography (sEMG technique is proposed for muscle activation detection and intuitive control of prostheses or robot arms. Motion recognition is widely used to map sEMG signals to the target motions. One of the main factors preventing the implementation of this kind of method for real-time applications is the unsatisfactory motion recognition rate and time consumption. The purpose of this paper is to compare eight combinations of four feature extraction methods (Root Mean Square (RMS, Detrended Fluctuation Analysis (DFA, Weight Peaks (WP, and Muscular Model (MM and two classifiers (Neural Networks (NN and Support Vector Machine (SVM, for the task of mapping sEMG signals to eight upper-limb motions, to find out the relation between these methods and propose a proper combination to solve this issue. Seven subjects participated in the experiment and six muscles of the upper-limb were selected to record sEMG signals. The experimental results showed that NN classifier obtained the highest recognition accuracy rate (88.7% during the training process while SVM performed better in real-time experiments (85.9%. For time consumption, SVM took less time than NN during the training process but needed more time for real-time computation. Among the four feature extraction methods, WP had the highest recognition rate for the training process (97.7% while MM performed the best during real-time tests (94.3%. The combination of MM and NN is recommended for strict real-time applications while a combination of MM and SVM will be more suitable when time consumption is not a key requirement.

Electroencephalogram–Electromyography Coupling Analysis in Stroke Based on Symbolic Transfer Entropy

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Yunyuan Gao

2018-01-01

Full Text Available The coupling strength between electroencephalogram (EEG and electromyography (EMG signals during motion control reflects the interaction between the cerebral motor cortex and muscles. Therefore, neuromuscular coupling characterization is instructive in assessing motor function. In this study, to overcome the limitation of losing the characteristics of signals in conventional time series symbolization methods, a variable scale symbolic transfer entropy (VS-STE analysis approach was proposed for corticomuscular coupling evaluation. Post-stroke patients (n = 5 and healthy volunteers (n = 7 were recruited and participated in various tasks (left and right hand gripping, elbow bending. The proposed VS-STE was employed to evaluate the corticomuscular coupling strength between the EEG signal measured from the motor cortex and EMG signal measured from the upper limb in both the time-domain and frequency-domain. Results showed a greater strength of the bi-directional (EEG-to-EMG and EMG-to-EEG VS-STE in post-stroke patients compared to healthy controls. In addition, the strongest EEG–EMG coupling strength was observed in the beta frequency band (15–35 Hz during the upper limb movement. The predefined coupling strength of EMG-to-EEG in the affected side of the patient was larger than that of EEG-to-EMG. In conclusion, the results suggested that the corticomuscular coupling is bi-directional, and the proposed VS-STE can be used to quantitatively characterize the non-linear synchronization characteristics and information interaction between the primary motor cortex and muscles.

Improved prosthetic hand control with concurrent use of myoelectric and inertial measurements

OpenAIRE

Krasoulis, Agamemnon; Kyranou, Iris; Erden, Mustapha Suphi; Nazarpour, Kianoush; Vijayakumar, Sethu

2017-01-01

Background Myoelectric pattern recognition systems can decode movement intention to drive upper-limb prostheses. Despite recent advances in academic research, the commercial adoption of such systems remains low. This limitation is mainly due to the lack of classification robustness and a simultaneous requirement for a large number of electromyogram (EMG) electrodes. We propose to address these two issues by using a multi-modal approach which combines surface electromyography (sEMG) with inert...

Multiple Impulse Therapy in the Assessment of Paraspinal Muscle Tone in Patients with Low Back Pain.

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Haładaj, Robert; Topol, Mirosław

2016-11-30

Back pain is quite common in contemporary society, whose expectations of an effective analgesic therapy in conservative treatment lead to a necessity of searching for new diagnostic and therapeutic methods in physiotherapy. Out of the numerous physical therapy methods, Multiple Impulse Therapy (MIT) deserves special consideration. This paper aims to present and analyse the outcomes of MIT concerning paraspinal muscle tone and pain intensity in patients with low back pain. The study enrolled 117 patients (50 women and 67 men; average age of 45.3 yrs) with lumbar conditions confirmed by imaging studies. The participants received five MIT sessions within 14 days. Moreover, both before and after the therapy all the patients underwent bilateral assessment of the paraspinal muscle tone by surface electromyography (sEMG) with the NoraxonMyoTrace 400 system and an interactive head of the PulStarFRAS device. A VAS was used for evaluation of pain severity. The analysis of significance of differences between scores before and after treatment showed that all the parameters changed significantly (MIT: 11.11 Ibf before and 8.89 Ibf after the therapy; VAS: 6.04 before and 3.38 afterwards; sEMG: 9.29uV before and 7.51uV afterwards). 1. Multiple Impulse Therapy (MIT) is an effective and non-invasive method of back pain treatment. 2. MIT significantly reduces paraspinal muscle tone, as confirmed by sEMG results, and shows a strong analgesic effect.

Oral muscles are progressively affected in Duchenne muscular dystrophy: implications for dysphagia treatment.

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van den Engel-Hoek, Lenie; Erasmus, Corrie E; Hendriks, Jan C M; Geurts, Alexander C H; Klein, Willemijn M; Pillen, Sigrid; Sie, Lilian T; de Swart, Bert J M; de Groot, Imelda J M

2013-05-01

Dysphagia is reported in advanced stages of Duchenne muscular dystrophy (DMD). The population of DMD is changing due to an increasing survival. We aimed to describe the dysphagia in consecutive stages and to assess the underlying mechanisms of dysphagia in DMD, in order to develop mechanism based recommendations for safe swallowing. In this cross-sectional study, participants were divided into: early and late ambulatory stage (AS, n = 6), early non-ambulatory stage (ENAS, n = 7), and late non-ambulatory stage (LNAS, n = 11). Quantitative oral muscle ultrasound was performed to quantify echo intensity. Swallowing was assessed with a video fluoroscopic swallow study, surface electromyography (sEMG) of the submental muscle group and tongue pressure. Differences in outcome parameters among the three DMD stages were tested with analysis of variance. Oral muscles related to swallowing were progressively affected, starting in the AS with the geniohyoid muscle. Tongue (pseudo) hypertrophy was found in 70 % of patients in the ENAS and LNAS. Oral phase problems and post-swallow residue were observed, mostly in the LNAS with solid food. sEMG and tongue pressure data of swallowing solid food revealed the lowest sEMG amplitude, the longest duration and lowest tongue pressure in the LNAS. In case of swallowing problems in DMD, based on the disturbed mechanisms of swallowing, it is suggested to (1) adjust meals in terms of less solid food, and (2) drink water after meals to clear the oropharyngeal area.

Seizure Onset Detection based on a Uni- or Multi-modal Intelligent Seizure Acquisition (UISA/MISA) System

DEFF Research Database (Denmark)

Conradsen, Isa; Beniczky, Sándor; Wolf, Peter

2010-01-01

An automatic Uni- or Multi-modal Inteligent Seizure Acquisition (UISA/MISA) system is highly applicable for onset detection of epileptic seizures based on motion data. The modalities used are surface electromyography (sEMG), acceleration (ACC) and angular velocity (ANG). The new proposed automatic...... algorithm on motion data is extracting features as “log-sum” measures of discrete wavelet components. Classification into the two groups “seizure” versus “nonseizure” is made based on the support vector machine (SVM) algorithm. The algorithm performs with a sensitivity of 91-100%, a median latency of 1...... second and a specificity of 100% on multi-modal data from five healthy subjects simulating seizures. The uni-modal algorithm based on sEMG data from the subjects and patients performs satisfactorily in some cases. As expected, our results clearly show superiority of the multimodal approach, as compared...

The Ninapro database: A resource for sEMG naturally controlled robotic hand prosthetics.

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Atzori, Manfredo; Muller, Henning

2015-01-01

The dexterous natural control of robotic prosthetic hands with non-invasive techniques is still a challenge: surface electromyography gives some control capabilities but these are limited, often not natural and require long training times; the application of pattern recognition techniques recently started to be applied in practice. While results in the scientific literature are promising they have to be improved to reach the real needs. The Ninapro database aims to improve the field of naturally controlled robotic hand prosthetics by permitting to worldwide research groups to develop and test movement recognition and force control algorithms on a benchmark database. Currently, the Ninapro database includes data from 67 intact subjects and 11 amputated subject performing approximately 50 different movements. The data are aimed at permitting the study of the relationships between surface electromyography, kinematics and dynamics. The Ninapro acquisition protocol was created in order to be easy to be reproduced. Currently, the number of datasets included in the database is increasing thanks to the collaboration of several research groups.

Generation of synthetic surface electromyography signals under fatigue conditions for varying force inputs using feedback control algorithm.

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Venugopal, G; Deepak, P; Ghosh, Diptasree M; Ramakrishnan, S

2017-11-01

Surface electromyography is a non-invasive technique used for recording the electrical activity of neuromuscular systems. These signals are random, complex and multi-component. There are several techniques to extract information about the force exerted by muscles during any activity. This work attempts to generate surface electromyography signals for various magnitudes of force under isometric non-fatigue and fatigue conditions using a feedback model. The model is based on existing current distribution, volume conductor relations, the feedback control algorithm for rate coding and generation of firing pattern. The result shows that synthetic surface electromyography signals are highly complex in both non-fatigue and fatigue conditions. Furthermore, surface electromyography signals have higher amplitude and lower frequency under fatigue condition. This model can be used to study the influence of various signal parameters under fatigue and non-fatigue conditions.

Bioelectrical activity of the pelvic floor muscles after 6-week biofeedback training in nulliparous continent women.

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Chmielewska, Daria; Stania, Magdalena; Smykla, Agnieszka; Kwaśna, Krystyna; Błaszczak, Edward; Sobota, Grzegorz; Skrzypulec-Plinta, Violetta

2016-01-01

The aim of the study was to evaluate the effects of a 6-week sEMG-biofeedback-assisted pelvic floor muscle training program on pelvic floor muscle activity in young continent women. Pelvic floor muscle activity was recorded using a vaginal probe during five experimental trials. Biofeedback training was continued for 6 weeks, 3 times a week. Muscle strenghtening and endurance exercises were performed alternately. SEMG (surface electromyography) measurements were recorded on four different occasions: before training started, after the third week of training, after the sixth week of training, and one month after training ended. A 6-week sEMG-biofeedback-assisted pelvic floor muscle training program significantly decreased the resting activity of the pelvic floor muscles in supine lying and standing. The ability to relax the pelvic floor muscles after a sustained 60-second contraction improved significantly after the 6-week training in both positions. SEMG-biofeedback training program did not seem to affect the activity of the pelvic floor muscles or muscle fatigue during voluntary pelvic floor muscle contractions. SEMG-biofeedback-assisted pelvic floor muscle training might be recommended for physiotherapists to improve the effectiveness of their relaxation techniques.

Treatment of post-stroke dysphagia by vitalstim therapy coupled with conventional swallowing training.

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Xia, Wenguang; Zheng, Chanjuan; Lei, Qingtao; Tang, Zhouping; Hua, Qiang; Zhang, Yangpu; Zhu, Suiqiang

2011-02-01

To investigate the effects of VitalStim therapy coupled with conventional swallowing training on recovery of post-stroke dysphagia, a total of 120 patients with post-stroke dysphagia were randomly and evenly divided into three groups: conventional swallowing therapy group, VitalStim therapy group, and VitalStim therapy plus conventional swallowing therapy group. Prior to and after the treatment, signals of surface electromyography (sEMG) of swallowing muscles were detected, swallowing function was evaluated by using the Standardized Swallowing Assessment (SSA) and Videofluoroscopic Swallowing Study (VFSS) tests, and swallowing-related quality of life (SWAL-QOL) was evaluated using the SWAL-QOL questionnaire. There were significant differences in sEMG value, SSA, VFSS, and SWAL-QOL scores in each group between prior to and after treatment. After 4-week treatment, sEMG value, SSA, VFSS and SWAL-QOL scores were significantly greater in the VitalStim therapy plus conventional swallowing training group than in the conventional swallowing training group and VitalStim therapy group, but no significant difference existed between conventional swallowing therapy group and VitalStim therapy group. It was concluded that VitalStim therapy coupled with conventional swallowing training was conducive to recovery of post-stroke dysphagia.

All on Four® fixed implant support rehabilitation: a masticatory function study.

Science.gov (United States)

De Rossi, Moara; Santos, Carla Moreto; Migliorança, Reginaldo; Regalo, Simone Cecílio Hallak

2014-08-01

Fixed implant-supported prostheses according to All-on-Four® (Nobel Biocare, Goteborg, Sweden) principles have become an accepted treatment modality in totally edentulous patients, whereas the functional effect of this therapy is limited. The purpose of this study was to evaluate the muscular function of patients totally rehabilitated with All-on-Four. This study evaluated 63 patients. Twenty-one patients were successfully rehabilitated with maxillary and mandibular All-on-Four (no dropout implants, satisfactory aesthetic and function demands prosthesis), 21 patients were dentate, and 21 were rehabilitated with double complete dentures. Electromyography was carried out during clenching, nonhabitual and habitual chewing, and rest. All values were standardized as percentage of a maximum voluntary contraction. Data were analyzed by ANOVA to compare groups and paired t-test was used for comparison between sides within each group. All groups presented symmetric muscular activity. The All-on-Four and dentate groups had a similar muscles surface electromyography (sEMG) contraction pattern, that is, a higher sEMG activity of masseter than temporalis muscles, differing (p ≤ .05) from those of denture group. Not one statistical difference was found between All-on-Four and dentate groups. The muscular function similarity of All-on-Four and dentate patients shows that this treatment concept may be considered as a good option for oral rehabilitation in edentulous patients. © 2013 Wiley Periodicals, Inc.

Electromyographic evaluation in children orthodontically treated for skeletal Class II malocclusion: Comparison of two treatment techniques.

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Ortu, Eleonora; Pietropaoli, Davide; Adib, Fray; Masci, Chiara; Giannoni, Mario; Monaco, Annalisa

2017-11-16

Objective To compare the clinical efficacy of two techniques for fabricating a Bimler device by assessing the patient's surface electromyography (sEMG) activity at rest before treatment and six months after treatment. Methods Twenty-four patients undergoing orthodontic treatment were enrolled in the study; 12 formed the test group and wore a Bimler device fabricated with a Myoprint impression using neuromuscular orthodontic technique and 12 formed the control group and were treated by traditional orthodontic technique with a wax bite in protrusion. The "rest" sEMG of each patient was recorded prior to treatment and six months after treatment. Results The neuromuscular-designed Bimler device was more comfortable and provided better treatment results than the traditional Bimler device. Conclusion This study suggests that the patient group subjected to neuromuscular orthodontic treatment had a treatment outcome with more relaxed masticatory muscles and better function versus the traditional orthodontic treatment.

Postnatal changes in electromyographic signals during piglet growth, and in relation to muscle fibre types

DEFF Research Database (Denmark)

Andersen, Ninette Kieme; Ravn, L.S.; Guy, J.H.

2008-01-01

This study uses non-invasive evoked surface electromyography (SEMG) to investigate postnatal muscle development in pigs, and to assess any correlation between recorded signal parameters and muscle fibre types in two different skeletal muscles. Four litters (n=43) of Large White x Landrace pigs were...... used. Evoked SEMG mesurements were taken on days 2, 5, 14, 26, 60 and 151 post partum from m. Longissimus dorsi (LD) and on days 14, 26, 60 and 151 post partum from m. Biceps femoris (BF). A third of each litter was slaughtered at days 27, 61 and 153 post partum. Biopsy samples for LD and BF were taken...... to categorize day 5 post partum, whilst for BF significant increases occurred from days 14 to 26 post partum. Fibre type development in both muscles showed a significant decrease in type IIA fibre number (Ptype IIB fibre number (P

Evaluation of vibrant muscles over the shoulder region among workers of the hand screen printing industry.

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Subramaniam, Shankar; Raju, Naveenkumar; Jeganathan, Karthick; Periyasamy, Mohankumar

2018-06-01

This study focuses on evaluation of the muscle activities associated with shoulder pain among workers of the hand screen printing (HSP) industry. Activities of three major muscles which showed higher muscle activity for a HSP job were observed for fatigue using surface electromyography (SEMG). The anatomical sites were chosen on the basis of a statistical survey and a visual inspection conducted before the experiment. Activities of the deltoid, teres major and infraspinatus were recorded using SEMG and the nature of muscle activities was studied for about 50 m of cloth printing. Data collected were processed using LabVIEW 2014 and the activities were analyzed using statistical tests and regression analyses. The results showed an increased risk of shoulder disorders with an increase in working time. Some of the risks which might cause disorders were predicted from the results; inspection and possible mitigations were suggested.

Assessing altered motor unit recruitment patterns in paretic muscles of stroke survivors using surface electromyography

Science.gov (United States)

Hu, Xiaogang; Suresh, Aneesha K.; Rymer, William Z.; Suresh, Nina L.

2015-12-01

Objective. The advancement of surface electromyogram (sEMG) recording and signal processing techniques has allowed us to characterize the recruitment properties of a substantial population of motor units (MUs) non-invasively. Here we seek to determine whether MU recruitment properties are modified in paretic muscles of hemispheric stroke survivors. Approach. Using an advanced EMG sensor array, we recorded sEMG during isometric contractions of the first dorsal interosseous muscle over a range of contraction levels, from 20% to 60% of maximum, in both paretic and contralateral muscles of stroke survivors. Using MU decomposition techniques, MU action potential amplitudes and recruitment thresholds were derived for simultaneously activated MUs in each isometric contraction. Main results. Our results show a significant disruption of recruitment organization in paretic muscles, in that the size principle describing recruitment rank order was materially distorted. MUs were recruited over a very narrow force range with increasing force output, generating a strong clustering effect, when referenced to recruitment force magnitude. Such disturbances in MU properties also correlated well with the impairment of voluntary force generation. Significance. Our findings provide direct evidence regarding MU recruitment modifications in paretic muscles of stroke survivors, and suggest that these modifications may contribute to weakness for voluntary contractions.

Fuzzy approximate entropy analysis of chaotic and natural complex systems: detecting muscle fatigue using electromyography signals.

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Xie, Hong-Bo; Guo, Jing-Yi; Zheng, Yong-Ping

2010-04-01

In the present contribution, a complexity measure is proposed to assess surface electromyography (EMG) in the study of muscle fatigue during sustained, isometric muscle contractions. Approximate entropy (ApEn) is believed to provide quantitative information about the complexity of experimental data that is often corrupted with noise, short data length, and in many cases, has inherent dynamics that exhibit both deterministic and stochastic behaviors. We developed an improved ApEn measure, i.e., fuzzy approximate entropy (fApEn), which utilizes the fuzzy membership function to define the vectors' similarity. Tests were conducted on independent, identically distributed (i.i.d.) Gaussian and uniform noises, a chirp signal, MIX processes, Rossler equation, and Henon map. Compared with the standard ApEn, the fApEn showed better monotonicity, relative consistency, and more robustness to noise when characterizing signals with different complexities. Performance analysis on experimental EMG signals demonstrated that the fApEn significantly decreased during the development of muscle fatigue, which is a similar trend to that of the mean frequency (MNF) of the EMG signal, while the standard ApEn failed to detect this change. Moreover, fApEn of EMG demonstrated a better robustness to the length of the analysis window in comparison with the MNF of EMG. The results suggest that the fApEn of an EMG signal may potentially become a new reliable method for muscle fatigue assessment and be applicable to other short noisy physiological signal analysis.

EMG evaluation of hip adduction exercises for soccer players

DEFF Research Database (Denmark)

Serner, Andreas; Jakobsen, Markus Due; Andersen, Lars Louis

2014-01-01

INTRODUCTION: Exercise programmes are used in the prevention and treatment of adductor-related groin injuries in soccer; however, there is a lack of knowledge concerning the intensity of frequently used exercises. OBJECTIVE: Primarily to investigate muscle activity of adductor longus during six...... traditional and two new hip adduction exercises. Additionally, to analyse muscle activation of gluteals and abdominals. MATERIALS AND METHODS: 40 healthy male elite soccer players, training >5 h a week, participated in the study. Muscle activity using surface electromyography (sEMG) was measured bilaterally...

Quantitative estimation of muscle fatigue using surface electromyography during static muscle contraction.

Science.gov (United States)

Soo, Yewguan; Sugi, Masao; Nishino, Masataka; Yokoi, Hiroshi; Arai, Tamio; Kato, Ryu; Nakamura, Tatsuhiro; Ota, Jun

2009-01-01

Muscle fatigue is commonly associated with the musculoskeletal disorder problem. Previously, various techniques were proposed to index the muscle fatigue from electromyography signal. However, quantitative measurement is still difficult to achieve. This study aimed at proposing a method to estimate the degree of muscle fatigue quantitatively. A fatigue model was first constructed using handgrip dynamometer by conducting a series of static contraction tasks. Then the degree muscle fatigue can be estimated from electromyography signal with reasonable accuracy. The error of the estimated muscle fatigue was less than 10% MVC and no significant difference was found between the estimated value and the one measured using force sensor. Although the results were promising, there were still some limitations that need to be overcome in future study.

Efecto del incremento de la PEEP en la actividad muscular respiratoria evaluado con electromiografía de superficie en individuos sanos bajo ventilación espontánea

Directory of Open Access Journals (Sweden)

Hernández-Valdivieso, Alher Mauricio

2016-07-01

Full Text Available Introduction: In a mechanically ventilated patient with increased airway resistance, the expiratory time span is insufficient to exhale all the inspired volume. In order to maintain oxygenation and to reduce the workload of respiratory muscles, it is common to apply an extrinsic positive end-expiratory pressure (PEEP that reduces tissue collapsibility, counterbalancing the increased resistance. Several studies have shown the usefulness of surface electromyography (sEMG to quantify the work of breathing (WOB, particularly in patients with obstructive diseases. Objective: To assess the effect of incremental PEEP in the respiratory muscle activity through sEMG in healthy volunteers noninvasively ventilated. Methods: Study of muscle activity in 10 healthy male volunteers, noninvasively ventilated for 20 minutes. The extrinsic PEEP was applied from 0 to 5 cm H2O in steps of 1 cm H2O at 30 seconds intervals. Results: The bio-potentials of diaphragm and sternocleidomastoid muscles revealed different breathing patterns in response to incremental PEEP: 1 increase in the workload of both muscles during inspiration and expiration; 2 increase in the workload of only one muscle; 3 a remarkable increase in muscle activity only in expiration. Conclusion: In noninvasively ventilated volunteers, sEMG quantitatively relates the PEEP level with changes in sternocleidomastoid and diaphragm activity.

Self-Recalibrating Surface EMG Pattern Recognition for Neuroprosthesis Control Based on Convolutional Neural Network.

Science.gov (United States)

Zhai, Xiaolong; Jelfs, Beth; Chan, Rosa H M; Tin, Chung

2017-01-01

Hand movement classification based on surface electromyography (sEMG) pattern recognition is a promising approach for upper limb neuroprosthetic control. However, maintaining day-to-day performance is challenged by the non-stationary nature of sEMG in real-life operation. In this study, we propose a self-recalibrating classifier that can be automatically updated to maintain a stable performance over time without the need for user retraining. Our classifier is based on convolutional neural network (CNN) using short latency dimension-reduced sEMG spectrograms as inputs. The pretrained classifier is recalibrated routinely using a corrected version of the prediction results from recent testing sessions. Our proposed system was evaluated with the NinaPro database comprising of hand movement data of 40 intact and 11 amputee subjects. Our system was able to achieve ~10.18% (intact, 50 movement types) and ~2.99% (amputee, 10 movement types) increase in classification accuracy averaged over five testing sessions with respect to the unrecalibrated classifier. When compared with a support vector machine (SVM) classifier, our CNN-based system consistently showed higher absolute performance and larger improvement as well as more efficient training. These results suggest that the proposed system can be a useful tool to facilitate long-term adoption of prosthetics for amputees in real-life applications.

A soft robotic exomusculature glove with integrated sEMG sensing for hand rehabilitation.

Science.gov (United States)

Delph, Michael A; Fischer, Sarah A; Gauthier, Phillip W; Luna, Carlos H Martinez; Clancy, Edward A; Fischer, Gregory S

2013-06-01

Stroke affects 750,000 people annually, and 80% of stroke survivors are left with weakened limbs and hands. Repetitive hand movement is often used as a rehabilitation technique in order to regain hand movement and strength. In order to facilitate this rehabilitation, a robotic glove was designed to aid in the movement and coordination of gripping exercises. This glove utilizes a cable system to open and close a patients hand. The cables are actuated by servomotors, mounted in a backpack weighing 13.2 lbs including battery power sources. The glove can be controlled in terms of finger position and grip force through switch interface, software program, or surface myoelectric (sEMG) signal. The primary control modes of the system provide: active assistance, active resistance and a preprogrammed mode. This project developed a working prototype of the rehabilitative robotic glove which actuates the fingers over a full range of motion across one degree-of-freedom, and is capable of generating a maximum 15N grip force.

Study of the SEMG probability distribution of the paretic tibialis anterior muscle

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Cherniz, AnalIa S; Bonell, Claudia E; Tabernig, Carolina B [Laboratorio de Ingenieria de Rehabilitacion e Investigaciones Neuromusculares y Sensoriales, Facultad de Ingenieria, UNER, Oro Verde (Argentina)

2007-11-15

The surface electromyographic signal is a stochastic signal that has been modeled as a Gaussian process, with a zero mean. It has been experimentally proved that this probability distribution can be adjusted with less error to a Laplacian type distribution. The selection of estimators for the detection of changes in the amplitude of the muscular signal depends, among other things, on the type of distribution. In the case of subjects with lesions to the superior motor neuron, the lack of central control affects the muscular tone, the force and the patterns of muscular movement involved in activities such as the gait cycle. In this work, the distribution types of the SEMG signal amplitudes of the tibialis anterior muscle are evaluated during gait, both in two healthy subjects and in two hemiparetic ones in order to select the estimators that best characterize them. It was observed that the Laplacian distribution function would be the one that best adjusts to the experimental data in the studied subjects, although this largely depends on the subject and on the data segment analyzed.

Study of the SEMG probability distribution of the paretic tibialis anterior muscle

International Nuclear Information System (INIS)

Cherniz, AnalIa S; Bonell, Claudia E; Tabernig, Carolina B

2007-01-01

The surface electromyographic signal is a stochastic signal that has been modeled as a Gaussian process, with a zero mean. It has been experimentally proved that this probability distribution can be adjusted with less error to a Laplacian type distribution. The selection of estimators for the detection of changes in the amplitude of the muscular signal depends, among other things, on the type of distribution. In the case of subjects with lesions to the superior motor neuron, the lack of central control affects the muscular tone, the force and the patterns of muscular movement involved in activities such as the gait cycle. In this work, the distribution types of the SEMG signal amplitudes of the tibialis anterior muscle are evaluated during gait, both in two healthy subjects and in two hemiparetic ones in order to select the estimators that best characterize them. It was observed that the Laplacian distribution function would be the one that best adjusts to the experimental data in the studied subjects, although this largely depends on the subject and on the data segment analyzed

The management of lactose intolerance among primary care physicians and its correlation with management by gastroenterologists: the SEPD-SEMG national survey

Directory of Open Access Journals (Sweden)

Federico Argüelles-Arias

2015-09-01

Full Text Available Introduction and aims: The understanding of lactose intolerance (LI is limited in some professional settings. Sociedad Española de Patología Digestiva (SEPD and Sociedad Española de Medicina General (SEMG have developed a survey in order to: a Analyze primary care physicians (PCPs knowledge and clinical management; and b to compare results with those of a previous survey of Spanish gastroenterologists (GEs. Material and methods: An online questionnaire was sent to SEMG members with 27 items on various issues: Demographics, occupational characteristics, outlook on LI, diagnostic tests, treatment, and follow-up. Results were compared to those from a survey of GEs. Results: A total of 456 PCPs responded, versus 477 GEs. PCPs had an older mean age and longer professional experience. Level of understanding of LI was similar, albeit a higher proportion of PCPs lacked epidemiological awareness (p 0.001, and LI symptoms as overlapping those of irritable bowel syndrome (93.5 vs. 88.2%; p = 0.005, although symptoms perceived as suspicious of LI were similar in both groups. Dietary recommendations were recognized as the primary therapeutic approach. Conclusion: This study reveals the outlook of PCPs on LI, and allows comparison with that of GEs, as a basis for the development of strategies aimed at improving LI understanding, approach and management in our setting.

Towards NIRS-based hand movement recognition.

Science.gov (United States)

Paleari, Marco; Luciani, Riccardo; Ariano, Paolo

2017-07-01

This work reports on preliminary results about on hand movement recognition with Near InfraRed Spectroscopy (NIRS) and surface ElectroMyoGraphy (sEMG). Either basing on physical contact (touchscreens, data-gloves, etc.), vision techniques (Microsoft Kinect, Sony PlayStation Move, etc.), or other modalities, hand movement recognition is a pervasive function in today environment and it is at the base of many gaming, social, and medical applications. Albeit, in recent years, the use of muscle information extracted by sEMG has spread out from the medical applications to contaminate the consumer world, this technique still falls short when dealing with movements of the hand. We tested NIRS as a technique to get another point of view on the muscle phenomena and proved that, within a specific movements selection, NIRS can be used to recognize movements and return information regarding muscles at different depths. Furthermore, we propose here three different multimodal movement recognition approaches and compare their performances.

Analysis of the times involved in processing and communication in a lower limb simulation system controlled by SEMG

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Profumieri, A.; Bonell, C.; Catalfamo, P.; Cherniz, A.

2016-04-01

Virtual reality has been proposed for different applications, including the evaluation of new control strategies and training protocols for upper limb prostheses and for the study of new rehabilitation programs. In this study, a lower limb simulation environment commanded by surface electromyography signals is evaluated. The time delays generated by the acquisition and processing stages for the signals that would command the knee joint, were measured and different acquisition windows were analysed. The subjective perception of the quality of simulation was also evaluated when extra delays were added to the process. The results showed that the acquisition window is responsible for the longest delay. Also, the basic implemented processes allowed for the acquisition of three signal channels for commanding the simulation. Finally, the communication between different applications is arguably efficient, although it depends on the amount of data to be sent.

Investigating Facial Electromyography as an Indicator of Cognitive Workload

Science.gov (United States)

2017-02-22

operator’s ability to perform at the level required to prevent hazardous consequences (Young & Stanton, 2002). Cognitive overload and underload can both...the operator’s performance to lessen performance abatement induced by cognitive overload or underload (Wilson & Russell, 2007; Hoepf, Middendorf...Investigating Facial Electromyography as an Indicator of Cognitive Workload 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) 5d

Investigation of Physiological Properties of Nerves and Muscles Using Electromyography

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Roe, Seán M.; Johnson, Christopher D.; Tansey, Etain A.

2014-01-01

The measurement and representation of the electrical activity of muscles [electromyography (EMG)] have a long history from the Victorian Era until today. Currently, EMG has uses both as a research tool, in noninvasively recording muscle activation, and clinically in the diagnosis and assessment of nerve and muscle disease and injury as well as in…

Surface EMG and intra-socket force measurement to control a prosthetic device

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Sanford, Joe; Patterson, Rita; Popa, Dan

2015-06-01

Surface electromyography (SEMG) has been shown to be a robust and reliable interaction method allowing for basic control of powered prosthetic devices. Research has shown a marked decrease in EMG-classification efficiency throughout activities of daily life due to socket shift and movement and fatigue as well as changes in degree of fit of the socket throughout the subject's lifetime. Users with the most severe levels of amputation require the most complex devices with the greatest number of degrees of freedom. Controlling complex dexterous devices with limited available inputs requires the addition of sensing and interaction modalities. However, the larger the amputation severity, the fewer viable SEMG sites are available as control inputs. Previous work reported the use of intra-socket pressure, as measured during wrist flexion and extension, and has shown that it is possible to control a powered prosthetic device with pressure sensors. In this paper, we present data correlations of SEMG data with intra-socket pressure data. Surface EMG sensors and force sensors were housed within a simulated prosthetic cuff fit to a healthy-limbed subject. EMG and intra-socket force data was collected from inside the cuff as a subject performed pre-defined grip motions with their dominant hand. Data fusion algorithms were explored and allowed a subject to use both intra-socket pressure and SEMG data as control inputs for a powered prosthetic device. This additional input modality allows for an improvement in input classification as well as information regarding socket fit through out activities of daily life.

Effect of vibrotactile feedback on an EMG-based proportional cursor control system.

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Li, Shunchong; Chen, Xingyu; Zhang, Dingguo; Sheng, Xinjun; Zhu, Xiangyang

2013-01-01

Surface electromyography (sEMG) has been introduced into the bio-mechatronics systems, however, most of them are lack of the sensory feedback. In this paper, the effect of vibrotactile feedback for a myoelectric cursor control system is investigated quantitatively. Simultaneous and proportional control signals are extracted from EMG using a muscle synergy model. Different types of feedback including vibrotactile feedback and visual feedback are added, assessed and compared with each other. The results show that vibrotactile feedback is capable of improving the performance of EMG-based human machine interface.

[Design of an embedded stroke rehabilitation apparatus system based on Linux computer engineering].

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Zhuang, Pengfei; Tian, XueLong; Zhu, Lin

2014-04-01

A realizaton project of electrical stimulator aimed at motor dysfunction of stroke is proposed in this paper. Based on neurophysiological biofeedback, this system, using an ARM9 S3C2440 as the core processor, integrates collection and display of surface electromyography (sEMG) signal, as well as neuromuscular electrical stimulation (NMES) into one system. By embedding Linux system, the project is able to use Qt/Embedded as a graphical interface design tool to accomplish the design of stroke rehabilitation apparatus. Experiments showed that this system worked well.

Neural mechanisms of intermuscular coherence: Implications for the rectification of surface electromyography

NARCIS (Netherlands)

Boonstra, T.W.; Breakspear, M.

2012-01-01

Oscillatory activity plays a crucial role in corticospinal control of muscle synergies and is widely investigated using corticospinal and intermuscular synchronization. However, the neurophysiological mechanisms that translate these rhythmic patterns into surface electromyography (EMG) are not well

[Surface electromyography signal classification using gray system theory].

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Xie, Hongbo; Ma, Congbin; Wang, Zhizhong; Huang, Hai

2004-12-01

A new method based on gray correlation was introduced to improve the identification rate in artificial limb. The electromyography (EMG) signal was first transformed into time-frequency domain by wavelet transform. Singular value decomposition (SVD) was then used to extract feature vector from the wavelet coefficient for pattern recognition. The decision was made according to the maximum gray correlation coefficient. Compared with neural network recognition, this robust method has an almost equivalent recognition rate but much lower computation costs and less training samples.

Quantitative electromyography in ambulatory boys with Duchenne muscular dystrophy.

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Verma, Sumit; Lin, Jenny; Travers, Curtis; McCracken, Courtney; Shah, Durga

2017-12-01

This study's objective was to evaluate quantitative electromyography (QEMG) using multiple-motor-unit (multi-MUP) analysis in Duchenne muscular dystrophy (DMD). Ambulatory DMD boys, aged 5-15 years, were evaluated with QEMG at 6-month intervals over 14 months. EMG was performed in the right biceps brachii (BB) and tibialis anterior (TA) muscles. Normative QEMG data were obtained from age-matched healthy boys. Wilcoxon signed-rank tests were performed. Eighteen DMD subjects were enrolled, with a median age of 7 (interquartile range 7-10) years. Six-month evaluations were performed on 14 subjects. QEMG showed significantly abnormal mean MUP duration in BB and TA muscles, with no significant change over 6 months. QEMG is a sensitive electrophysiological marker of myopathy in DMD. Preliminary data do not reflect a significant change in MUP parameters over a 6-month interval; long-term follow-up QEMG studies are needed to understand its role as a biomarker for disease progression. Muscle Nerve 56: 1361-1364, 2017. © 2017 Wiley Periodicals, Inc.

A preliminary evaluation of myoelectrical energy distribution of the front neck muscles in pharyngeal phase during normal swallowing.

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Mingxing Zhu; Wanzhang Yang; Samuel, Oluwarotimi Williams; Yun Xiang; Jianping Huang; Haiqing Zou; Guanglin Li

2016-08-01

Pharyngeal phase is a central hub of swallowing in which food bolus pass through from the oral cavity to the esophageal. Proper understanding of the muscular activities in the pharyngeal phase is useful for assessing swallowing function and the occurrence of dysphagia in humans. In this study, high-density (HD) surface electromyography (sEMG) was used to study the muscular activities in the pharyngeal phase during swallowing tasks involving three healthy male subjects. The root mean square (RMS) of the HD sEMG data was computed by using a series of segmented windows as myoelectrical energy. And the RMS of each window covering all channels (16×5) formed a matrix. During the pharyngeal phase of swallowing, three of the matrixes were chosen and normalized to obtain the HD energy maps and the statistical parameter. The maps across different viscosity levels offered the energy distribution which showed the muscular activities of the left and right sides of the front neck muscles. In addition, the normalized average RMS (NARE) across different viscosity levels revealed a left-right significant correlation (r=0.868±0.629, pstronger correlation when swallowing water. This pilot study suggests that HD sEMG would be a potential tool to evaluate muscular activities in pharyngeal phase during normal swallowing. Also, it might provide useful information for dysphagia diagnosis.

[Evaluation of swallowing function with surface electromyography before and after tonsillectomy].

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Gürkan, Emre; Veyseller, Bayram; Açıkalın, Reşit Murat; Elbistanlı, Suphi; Yurtsever, Serveren; Acar, Hürtan

2011-01-01

In this study, we evaluated the swallowing function with surface electromyography before and after tonsillectomy. Twenty patients (12 males, 8 females; mean age 23.8 years; range 17 to 30 years) who had tonsillectomy indication as study group, and 10 healthy individuals (8 males, 2 females; mean age 26 years; range 18 to 35 years) as control group were included in this prospective study between October 2008 and February 2009. Due to their significant role on oral and faringeal phases of swallowing; the surface electromyography prosedure is performed on the masseter muscle, the submental-submandibular muscle group and the infrahyoid muscles to measure their electrical activity and duration of contraction. For this purpose, single swallow and continuous drinking of 100 cc water tests were applied to each patient preoperatively and; in the postoperative 1st week and the 1st month. The preoperative duration of drinking periods were significanly longer in the study group compared to the control group (p<0.05). At the end of the first postoperative week the duration of drinking 100 cc water test was significantly longer than the preoperative mean of the study group (p<0.05). After one month single- swallow durations of study group were significantly shorter then the preoperative mean (p<0.05). The electrical activity of the masseter and infrahyoid muscles were significantly higher in study group compared with control group (p<0.05). The close proximity of the surgical area to the muscles affects swallowing after tonsillectomy. The surface electromyography is a simple, non-invasive and reliable method for postoperative evaluation of the swallowing functions of the throat muscles and thereby allows monitoring of the recovery and functional improvement of these muscles.

Surface EMG characteristics of people with multiple sclerosis during static contractions of the knee extensors.

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Scott, Sasha M; Hughes, Adrienne R; Galloway, Stuart D R; Hunter, Angus M

2011-01-01

This study was designed to determine whether any alterations existed in surface electromyography (sEMG) in people with multiple sclerosis (MS) during isometric contractions of the knee extensors. Fifteen people with MS and 14 matched controls (mean ± SD age and body mass index 53·7 ± 10·5 versus 54·6 ± 9·6 years and 27·7 ± 6·1 versus 26·5 ± 4, respectively) completed 20%, 40%, 60% and 80% of their maximal voluntary contraction (MVC) of the knee extensors. sEMG was recorded from the vastus lateralis where muscle fibre conduction velocity (MFCV) and sEMG amplitude (RMS) were assessed. Body composition was determined using dual-energy X-ray absorptiometry and physical activity with the use of accelerometry. People with MS showed significantly (P<0·05) faster MFCV during MVC (6·6 ± 2·7 versus 4·7 ± 1·4 m s(-1) ) and all submaximal contractions, while RMS was significantly (P<0·05) less (0·11 ± 0·03 versus 0·24 ± 0·06 mV) in comparison with the controls. MVC along with specific thigh lean mass to torque, rate of force development and mean physical activity were significantly (P<0·01) less in PwMS. People with MS have elevated MFCV alongside reduced RMS during isometric contraction. This elevation in MFCV should be accounted for when interpreting sEMG from people with MS. © 2010 University of Stirling. Clinical physiology and Functional Imaging © 2010 Scandinavian Society of Clinical Physiology and Nuclear Medicine.

Deep learning with convolutional neural networks: a resource for the control of robotic prosthetic hands via electromyography

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Manfredo Atzori

2016-09-01

Full Text Available Motivation: Natural control methods based on surface electromyography and pattern recognition are promising for hand prosthetics. However, the control robustness offered by scientific research is still not sufficient for many real life applications and commercial prostheses are in the best case capable to offer natural control for only a few movements. Objective: In recent years deep learning revolutionized several fields of machine learning, including computer vision and speech recognition. Our objective is to test its capabilities for the natural control of robotic hands via surface electromyography by providing a baseline on a large number of intact and amputated subjects. Methods: We tested convolutional networks for the classification of an average of 50 hand movements in 67 intact subjects and 11 hand amputated subjects. The simple architecture of the neural network allowed to make several tests in order to evaluate the effect of pre-processing, layer architecture, data augmentation and optimization. The classification results are compared with a set of classical classification methods applied on the same datasets.Results: The classification accuracy obtained with convolutional neural networks using the proposed architecture is higher than the average results obtained with the classical classification methods but lower than the results obtained with the best reference methods in our tests. Significance: The results show that convolutional neural networks with a very simple architecture can produce accuracy comparable to the average classical classification methods. They show that several factors (including pre-processing, the architecture of the net and the optimization parameters can be fundamental for the analysis of surface electromyography data. Finally, the results suggest that deeper and more complex networks may increase dexterous control robustness, thus contributing to bridge the gap between the market and scientific research

Comparación entre la respuesta de la actividad muscular lumbar en plataforma vibratoria y en ejercicio clásico de squat isométrico en 30º y 60º. (A comparison of the lumbar muscle activity responsein 30º and 60º isometric squat between whole-body vibration and a classic exercise.

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Alejandro Santos-Lozano

2012-01-01

Full Text Available Whole-body vibration (WBV has improved as a variety of exercises, so it is necessary know muscles responses to the vibration stimulus.The aim of this work was to study and to compare the change in muscle activation in the lumbar area and lower body between the whole-body vibration exercise and classic strength exercises in isometric squat.23 subjects were exposed to six different loads in one of each exercise mode: vibration or classic strength. Both exercises were performed at 30º and 60º semi-squat position. Muscle activity of the lower body and lumbar area was measured using surface electromyography activity (EMG.The results showed that the response of lumbar area in WBV was lower than in the classic strength exercise at the same value of lower body sEMG. Lumbar sEMG was highest for the classic exercise. Moreover, during 30º squat sEMG was higher than during 60ºsquat.ResumenEl aumento del uso de la plataforma vibratoria como forma de realizar ejercicio conlleva la necesidad de conocer las respuestas musculares al estímulo de la misma.El objetivo de este trabajo ha sido estudiar y comparar la respuesta de la activación muscular de la zona lumbar y del tren inferior en el trabajo de plataforma vibratoria con el trabajo clásico de fuerza en un squat isométrico.23 sujetos fueron sometidos a 6 condiciones de vibración y a 6 de un trabajo clásico de pesas. Se analizó la sEMG del tren inferior y de la zona lumbar en un trabajo isométrico de un squat con flexión de 30º y 60º de rodilla.Los resultados muestran que para un mismo valor de sEMG del tren inferior, los valores de sEMG de la zona lumbar son menores en el ejercicio vibratorio. Existiendo en el trabajo de pesas una mayor exigencia en la zona lumbar. Además, con una flexión de 30º la activación muscular es mayor en todas las condiciones. (p

Evaluating abdominal core muscle fatigue: Assessment of the validity and reliability of the prone bridging test.

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De Blaiser, C; De Ridder, R; Willems, T; Danneels, L; Vanden Bossche, L; Palmans, T; Roosen, P

2018-02-01

The aims of this study were to research the amplitude and median frequency characteristics of selected abdominal, back, and hip muscles of healthy subjects during a prone bridging endurance test, based on surface electromyography (sEMG), (a) to determine if the prone bridging test is a valid field test to measure abdominal muscle fatigue, and (b) to evaluate if the current method of administrating the prone bridging test is reliable. Thirty healthy subjects participated in this experiment. The sEMG activity of seven abdominal, back, and hip muscles was bilaterally measured. Normalized median frequencies were computed from the EMG power spectra. The prone bridging tests were repeated on separate days to evaluate inter and intratester reliability. Significant differences in normalized median frequency slope (NMF slope ) values between several abdominal, back, and hip muscles could be demonstrated. Moderate-to-high correlation coefficients were shown between NMF slope values and endurance time. Multiple backward linear regression revealed that the test endurance time could only be significantly predicted by the NMF slope of the rectus abdominis. Statistical analysis showed excellent reliability (ICC=0.87-0.89). The findings of this study support the validity and reliability of the prone bridging test for evaluating abdominal muscle fatigue. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Immediate effects of neuromuscular joint facilitation intervention after anterior cruciate ligament reconstruction.

Science.gov (United States)

Wang, Lei

2016-07-01

[Purpose] The aim of this study was to examine the immediate effects of neuromuscular joint facilitation (NJF) on the functional activity level after rehabilitation of anterior cruciate ligament (ACL) reconstruction. [Subjects and Methods] Ten young subjects (8 males and 2 females) who underwent ACL reconstruction were included in the study. The subjects were divided into two groups, namely, knee joint extension muscle strength training (MST) group and knee joint extension outside rotation pattern of NJF group. Extension strength was measured in both groups before and after the experiment. Surface electromyography (sEMG) of the vastus medialis and vastus lateralis muscles and joint position error (JPE) test of the knee joint were also conducted. [Results] JPE test results and extension strength measurements in the NJF group were improved compared with those in the MST group. Moreover, the average discharge of the vastus medialis and vastus lateralis muscles on sEMG in the NJF group was significantly increased after MST and NJF treatments. [Conclusion] The obtained results suggest that NJF training in patients with ACL reconstruction can improve knee proprioception ability and muscle strength.

Electromyography in the assessment and therapy of lower urinary tract dysfunction in adults

DEFF Research Database (Denmark)

Krhut, Jan; Zachoval, Roman; Rosier, Peter F W M

2018-01-01

AIM: To present the teaching module "Electromyography in the assessment and therapy of lower urinary tract dysfunction in adults." This teaching module embodies a presentation, in combination with this manuscript. This manuscript serves as a scientific background review; the evidence base made...

Feasibility and safety of early lower limb robot-assisted training in sub-acute stroke patients: a pilot study.

Science.gov (United States)

Gandolfi, Marialuisa; Geroin, Christian; Tomelleri, Christopher; Maddalena, Isacco; Kirilova Dimitrova, Eleonora; Picelli, Alessandro; Smania, Nicola; Waldner, Andreas

2017-12-01

So far, the development of robotic devices for the early lower limb mobilization in the sub-acute phase after stroke has received limited attention. To explore the feasibility of a newly robotic-stationary gait training in sub-acute stroke patients. To report the training effects on lower limb function and muscle activation. A pilot study. Rehabilitation ward. Two sub-acute stroke inpatients and ten age-matched healthy controls were enrolled. Healthy controls served as normative data. Patients underwent 10 robot-assisted training sessions (20 minutes, 5 days/week) in alternating stepping movements (500 repetitions/session) on a hospital bed in addition to conventional rehabilitation. Feasibility outcome measures were compliance, physiotherapist time, and responses to self-report questionnaires. Efficacy outcomes were bilateral lower limb muscle activation pattern as measured by surface electromyography (sEMG), Motricity Index (MI), Medical Research Council (MRC) grade, and Ashworth Scale (AS) scores before and after training. No adverse events occurred. No significant differences in sEMG activity between patients and healthy controls were observed. Post-training improvement in MI and MRC scores, but no significant changes in AS scores, were recorded. Post-treatment sEMG analysis of muscle activation patterns showed a significant delay in rectus femoris offset (P=0.02) and prolonged duration of biceps femoris (P=0.04) compared to pretreatment. The robot-assisted training with our device was feasible and safe. It induced physiological muscle activations pattern in both stroke patients and healthy controls. Full-scale studies are needed to explore its potential role in post-stroke recovery. This robotic device may enrich early rehabilitation in subacute stroke patients by inducing physiological muscle activation patterns. Future studies are warranted to evaluate its effects on promoting restorative mechanisms involved in lower limb recovery after stroke.

Electromyographic analysis of the three subdivisions of gluteus medius during weight-bearing exercises

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O'Sullivan Kieran

2010-07-01

Full Text Available Abstract Background Gluteus medius (GM dysfunction is associated with many musculoskeletal disorders. Rehabilitation exercises aimed at strengthening GM appear to improve lower limb kinematics and reduce pain. However, there is a lack of evidence to identify which exercises best activate GM. In particular, as GM consists of three distinct subdivisions, it is unclear if GM activation is consistent across these subdivisions during exercise. The aim of this study was to determine the activation of the anterior, middle and posterior subdivisions of GM during weight-bearing exercises. Methods A single session, repeated-measures design. The activity of each GM subdivision was measured in 15 pain-free subjects using surface electromyography (sEMG during three weight-bearing exercises; wall squat (WS, pelvic drop (PD and wall press (WP. Muscle activity was expressed relative to maximum voluntary isometric contraction (MVIC. Differences in muscle activation were determined using one-way repeated measures ANOVA with post-hoc Bonferroni analysis. Results The activation of each GM subdivision during the exercises was significantly different (interaction effect; p Discussion Posterior GM displayed higher activation across all three exercises than both anterior and middle GM. The WP produced the highest %MVIC activation for all GM subdivisions, and this was most pronounced for posterior GM. Clinicians may use these results to effectively progress strengthening exercises for GM in the rehabilitation of lower extremity injuries.

Fractal feature of sEMG from Flexor digitorum superficialis muscle correlated with levels of contraction during low-level finger flexions.

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Arjunan, Sridhar P; Kumar, Dinesh K; Naik, Ganesh R

2010-01-01

This research paper reports an experimental study on identification of the changes in fractal properties of surface Electromyogram (sEMG) with the changes in the force levels during low-level finger flexions. In the previous study, the authors have identified a novel fractal feature, Maximum fractal length (MFL) as a measure of strength of low-level contractions and has used this feature to identify various wrist and finger movements. This study has tested the relationship between the MFL and force of contraction. The results suggest that changes in MFL is correlated with the changes in contraction levels (20%, 50% and 80% maximum voluntary contraction (MVC)) during low-level muscle activation such as finger flexions. From the statistical analysis and by visualisation using box-plot, it is observed that MFL (p ≈ 0.001) is a more correlated to force of contraction compared to RMS (p≈0.05), even when the muscle contraction is less than 50% MVC during low-level finger flexions. This work has established that this fractal feature will be useful in providing information about changes in levels of force during low-level finger movements for prosthetic control or human computer interface.

Classification of rhythmic locomotor patterns in electromyographic signals using fuzzy sets

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Thrasher Timothy A

2011-12-01

Full Text Available Abstract Background Locomotor control is accomplished by a complex integration of neural mechanisms including a central pattern generator, spinal reflexes and supraspinal control centres. Patterns of muscle activation during walking exhibit an underlying structure in which groups of muscles seem to activate in united bursts. Presented here is a statistical approach for analyzing Surface Electromyography (SEMG data with the goal of classifying rhythmic "burst" patterns that are consistent with a central pattern generator model of locomotor control. Methods A fuzzy model of rhythmic locomotor patterns was optimized and evaluated using SEMG data from a convenience sample of four able-bodied individuals. As well, two subjects with pathological gait participated: one with Parkinson's Disease, and one with incomplete spinal cord injury. Subjects walked overground and on a treadmill while SEMG was recorded from major muscles of the lower extremities. The model was fit to half of the recorded data using non-linear optimization and validated against the other half of the data. The coefficient of determination, R2, was used to interpret the model's goodness of fit. Results Using four fuzzy burst patterns, the model was able to explain approximately 70-83% of the variance in muscle activation during treadmill gait and 74% during overground gait. When five burst functions were used, one function was found to be redundant. The model explained 81-83% of the variance in the Parkinsonian gait, and only 46-59% of the variance in spinal cord injured gait. Conclusions The analytical approach proposed in this article is a novel way to interpret multichannel SEMG signals by reducing the data into basic rhythmic patterns. This can help us better understand the role of rhythmic patterns in locomotor control.

Influence of bench angle on upper extremity muscular activation during bench press exercise.

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Lauver, Jakob D; Cayot, Trent E; Scheuermann, Barry W

2016-01-01

This study compared the muscular activation of the pectoralis major, anterior deltoid and triceps brachii during a free-weight barbell bench press performed at 0°, 30°, 45° and -15° bench angles. Fourteen healthy resistance trained males (age 21.4 ± 0.4 years) participated in this study. One set of six repetitions for each bench press conditions at 65% one repetition maximum were performed. Surface electromyography (sEMG) was utilised to examine the muscular activation of the selected muscles during the eccentric and concentric phases. In addition, each phase was subdivided into 25% contraction durations, resulting in four separate time points for comparison between bench conditions. The sEMG of upper pectoralis displayed no difference during any of the bench conditions when examining the complete concentric contraction, however differences during 26-50% contraction duration were found for both the 30° [122.5 ± 10.1% maximal voluntary isometric contraction (MVIC)] and 45° (124 ± 9.1% MVIC) bench condition, resulting in greater sEMG compared to horizontal (98.2 ± 5.4% MVIC) and -15 (96.1 ± 5.5% MVIC). The sEMG of lower pectoralis was greater during -15° (100.4 ± 5.7% MVIC), 30° (86.6 ± 4.8% MVIC) and horizontal (100.1 ± 5.2% MVIC) bench conditions compared to the 45° (71.9 ± 4.5% MVIC) for the whole concentric contraction. The results of this study support the use of a horizontal bench to achieve muscular activation of both the upper and lower heads of the pectoralis. However, a bench incline angle of 30° or 45° resulted in greater muscular activation during certain time points, suggesting that it is important to consider how muscular activation is affected at various time points when selecting bench press exercises.

Detection of tonic epileptic seizures based on surface electromyography

DEFF Research Database (Denmark)

Larsen, Sigge N.; Conradsen, Isa; Beniczky, Sandor

2014-01-01

The purpose of this project was to design an algorithm for detection of tonic seizures based on surface electromyography signals from the deltoids. A successful algorithm has a future prospect of being implemented in a wearable device as part of an alarm system. This has already been done......, median frequency, zero crossing rate and approximate entropy. These features were used as input in the random forest classifier to decide if a data segment was from a seizure or not. The goal was to develop a generic algorithm for all tonic seizures, but better results were achieved when certain...

Recovery of facial expressions using functional electrical stimulation after full-face transplantation.

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Topçu, Çağdaş; Uysal, Hilmi; Özkan, Ömer; Özkan, Özlenen; Polat, Övünç; Bedeloğlu, Merve; Akgül, Arzu; Döğer, Ela Naz; Sever, Refik; Çolak, Ömer Halil

2018-03-06

We assessed the recovery of 2 face transplantation patients with measures of complexity during neuromuscular rehabilitation. Cognitive rehabilitation methods and functional electrical stimulation were used to improve facial emotional expressions of full-face transplantation patients for 5 months. Rehabilitation and analyses were conducted at approximately 3 years after full facial transplantation in the patient group. We report complexity analysis of surface electromyography signals of these two patients in comparison to the results of 10 healthy individuals. Facial surface electromyography data were collected during 6 basic emotional expressions and 4 primary facial movements from 2 full-face transplantation patients and 10 healthy individuals to determine a strategy of functional electrical stimulation and understand the mechanisms of rehabilitation. A new personalized rehabilitation technique was developed using the wavelet packet method. Rehabilitation sessions were applied twice a month for 5 months. Subsequently, motor and functional progress was assessed by comparing the fuzzy entropy of surface electromyography data against the results obtained from patients before rehabilitation and the mean results obtained from 10 healthy subjects. At the end of personalized rehabilitation, the patient group showed improvements in their facial symmetry and their ability to perform basic facial expressions and primary facial movements. Similarity in the pattern of fuzzy entropy for facial expressions between the patient group and healthy individuals increased. Synkinesis was detected during primary facial movements in the patient group, and one patient showed synkinesis during the happiness expression. Synkinesis in the lower face region of one of the patients was eliminated for the lid tightening movement. The recovery of emotional expressions after personalized rehabilitation was satisfactory to the patients. The assessment with complexity analysis of sEMG data can be

Perceived exertion during muscle fatigue as reflected in movement-related cortical potentials: an event-related potential study.

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Guo, Feng; Sun, Yong-Jun; Zhang, Ri-Hui

2017-02-08

The aim of this study was to explore the mechanism on perceived exertion during muscle fatigue. A total of 15 individuals in the fatigue group and 13 individuals in the nonfatigue group were recruited into this study, performing 200 intermittent handgrip contractions with 30% maximal voluntary contraction. The force, surface electromyography (sEMG), movement-related cortical potentials (MRCPs), and rating perception of effort (RPE) were combined to evaluate the perceived exertion during muscle fatigue. The maximal handgrip force significantly decreased (Pfatigue. The RPE scores reported by the individuals and the motor potential amplitude of MRCPs in the fatigue group significantly increased (Pfatigue but could also reflect the peripheral local muscle fatigue.

Effects of 12-wk eccentric calf muscle training on muscle-tendon glucose uptake and SEMG in patients with chronic Achilles tendon pain

DEFF Research Database (Denmark)

Masood, Tahir; Kalliokoski, Kari; Magnusson, S Peter

2014-01-01

High-load eccentric exercises have been a key component in the conservative management of chronic Achilles tendinopathy. This study investigated the effects of a 12-wk progressive, home-based eccentric rehabilitation program on ankle plantar flexors' glucose uptake (GU) and myoelectric activity......, while the asymptomatic leg displayed higher uptake for medial gastrocnemius and flexor hallucis longus (P tendon GU than the controls (P effect on the tendon GU. Concerning SEMG, at baseline, soleus showed more relative...... within- or between-group differences. Eccentric rehabilitation was effective in decreasing subjective severity of Achilles tendinopathy. It also resulted in redistribution of relative electrical activity, but not metabolic activity, within the triceps surae muscle....

Auto-Encoder based Deep Learning for Surface Electromyography Signal Processing

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Marwa Farouk Ibrahim Ibrahim

2018-01-01

Full Text Available Feature extraction is taking a very vital and essential part of bio-signal processing. We need to choose one of two paths to identify and select features in any system. The most popular track is engineering handcrafted, which mainly depends on the user experience and the field of application. While the other path is feature learning, which depends on training the system on recognising and picking the best features that match the application. The main concept of feature learning is to create a model that is expected to be able to learn the best features without any human intervention instead of recourse the traditional methods for feature extraction or reduction and avoid dealing with feature extraction that depends on researcher experience. In this paper, Auto-Encoder will be utilised as a feature learning algorithm to practice the recommended model to excerpt the useful features from the surface electromyography signal. Deep learning method will be suggested by using Auto-Encoder to learn features. Wavelet Packet, Spectrogram, and Wavelet will be employed to represent the surface electromyography signal in our recommended model. Then, the newly represented bio-signal will be fed to stacked autoencoder (2 stages to learn features and finally, the behaviour of the proposed algorithm will be estimated by hiring different classifiers such as Extreme Learning Machine, Support Vector Machine, and SoftMax Layer. The Rectified Linear Unit (ReLU will be created as an activation function for extreme learning machine classifier besides existing functions such as sigmoid and radial basis function. ReLU will show a better classification ability than sigmoid and Radial basis function (RBF for wavelet, Wavelet scale 5 and wavelet packet signal representations implemented techniques. ReLU will illustrate better classification ability, as an activation function, than sigmoid and poorer than RBF for spectrogram signal representation. Both confidence interval and

Associations between apparent diffusion coefficient and electromyography parameters in myositis-A preliminary study.

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Meyer, Hans-Jonas; Emmer, Alexander; Kornhuber, Malte; Surov, Alexey

2018-05-01

MRI is widely used in several muscle disorders. Diffusion-weighted imaging (DWI) is an emergent imaging modality sensitive to microstructural alterations in tissue. The apparent diffusion coefficient (ADC) is used to quantify the random motion of water molecules. Electromyography (EMG) is a clinically used diagnostic tool in myositis. The aim of this study was to elucidate possible associations between ADC values and EMG findings in myositis patients. Seven patients (eight investigated muscles) with myositis (mean age 51.43 ± 19 years) were included in this study. The diagnosis was confirmed by histopathology in every case. DWI was obtained with a 1.5-T scanner using two b-values 0 and 1000 s/mm². In all patients, a needle electromyography (EMG) was performed within 3 days to the MRI. The following EMG parameters were studied: motor unit action potential (MUAP) amplitudes and durations, as well as pathological spontaneous activity. Spearman's correlation coefficient was used to analyze associations between investigated parameters. The estimated mean ADC mean value was 1.51 ± 0.29 × 10 -3  mm²/s, mean ADC min was 1.28 ± 0.27 × 10 -3  mm²/s, and mean ADC max was 1.73 ± 0.28 × 10 -3  mm²/s. Correlation analysis identified significant associations between ADC mean and duration of the MUAP (p   = .78 P = .0279) and between ADC min and duration of the MUAP (p = .85, P = .01). There were no significant differences according to pathological spontaneous activity. ADC mean and ADC min showed strong positive correlations with the duration of the MUAP in myositis patients. Both modalities might similarly reflect muscle fiber loss in myositis patients.

Oral-motor and electromyographic characterization of patients submitted to open a nd closed reductions of mandibular condyle fracture.

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Silva, Amanda Pagliotto da; Sassi, Fernanda Chiarion; Andrade, Claudia Regina Furquim de

To characterize the oral-motor system of adults with mandibular condyle facture comparing the performance of individuals submitted to open reduction with internal fixation (ORIF) and closed reduction with mandibulomaxillary fixation (CRMMF). Study participants were 26 adults divided into three groups: G1 - eight individuals submitted to ORIF for correction of condyle fracture; G2 - nine individuals submitted to CRMMF for correction of condyle fracture; CG - nine healthy volunteers with no alterations of the orofacial myofunctional system. All participants underwent the same clinical protocol: assessment of the orofacial myofunctional system; evaluation of the mandibular range of motion; and surface electromyography (sEMG) of the masticatory muscles. Results indicated that patients with condyle fractures from both groups presented significant differences compared with those from the control group in terms of mobility of the oral-motor organs, mastication, and deglutition. Regarding the measures obtained for mandibular movements, participants with facial fractures from both groups showed significant differences compared with those from the control group, indicating greater restrictions in mandibular motion. As for the analysis of sEMG results, G1 patients presented more symmetrical masseter activation during the task of maximal voluntary teeth clenching. Patients with mandibular condyle fractures present significant deficits in posture, mobility, and function of the oral-motor system. The type of medical treatment does not influence the results of muscle function during the first six months after fracture reduction. Individuals submitted to ORIF of the condyle fracture present more symmetrical activation of the masseter muscle.

Eletromiografia laríngea e análise vocal em pacientes com Mal de Parkinson: estudo comparativo Laryngeal electromyography and acoustic voice analysis in Parkinson's disease: a comparative study

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Ana Paula Zarzur

2010-02-01

Full Text Available A doença ou Mal de Parkinson se deve à deficiência dopaminérgica nos núcleos da base que geram alterações motoras. Comprometimento da comunicação verbal ocorre em 70 a 90% dos doentes. Existem poucas referências da aplicação da eletromiografia no estudo dos músculos laríngeos em pacientes com a doença de Parkinson. OBJETIVOS: Definir o padrão contrátil da musculatura intrínseca da laringe e sua correlação com a análise acústica vocal nos parkinsonianos. CASUÍSTICA E MÉTODO: Estudo prospectivo onde 26 adultos com o diagnóstico de Mal de Parkinson foram submetidos à eletromiografia laríngea e análise acústica vocal. Foram coletados potenciais de ação, tanto em repouso vocal quanto em fonação. Para a análise acústica da voz foram utilizados os programas VOXMETRIA® e GRAM 5.1.6®. RESULTADOS: O padrão eletromiográfico predominante no grupo estudo foi o de hipercontratibilidade (ou recrutamento aumentado durante repouso vocal que ocorreu em 73% dos indivíduos, sem que houvesse registro eletromiográfico de tremor. Quanto às características vocais, detectou-se a presença de tremor vocal no traçado do espectrograma (VOXMETRIA E GRAM e na avaliação perceptivo-auditiva em 69,5 % e 61 % dos sujeitos, respectivamente. CONCLUSÃO: O tremor vocal foi a característica acústica predominante no grupo estudado, sem que houvesse correlação eletromiográfica.Parkinson's disease (PD involves a progressive depletion of dopamine in the basal ganglia leading to motor alterations. Oral communication impairment occurs in 75% to 90% of patients and has been poorly studied. AIM: to asses laryngeal electromyography (LEMG patterns and correlate them to vocal analysis in patients with Parkinson's disease. MATERIALS AND METHODS: This is a prospective study. Twenty six adults with PD underwent laryngeal electromyography. Rest and phonation potentials were analyzed. VOXMETRIA® and GRAM 5.1.6. ® were used in acoustic analysis

The influence of foot arch on ankle joint torques andon sEMG signal amplitude in selected lower leg muscles

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Żebrowska Kinga

2016-09-01

Full Text Available Introduction: This study sought to assess the influence of proper foot arch on electromyographic activity of selected lower limb muscles. The aim of this work was to evaluate the effects of foot arch on the activity of selected muscles and to determine whether electromyography might help to identify types of flat feet resulting from muscle- or ligament-related causes.

Electromyography (EMG) analysis on impact of classroom chair and table usage among primary school students in Perlis

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Jing, Ewe Hui; Shan, Lim Shaiu; Effendi, M. S. M.; Rosli, Muhamad Farizuan

2017-09-01

The existing design of primary school classroom chair and table had brought low back pain, neck pain and shoulder pain problems respectively among students in primary school. The purpose of this study is to relate the electromyography (EMG) analysis with the most critical area of the body during sitting and writing. Six male and six female primary school students from SK Seri Perlis with no back pain, neck pain and shoulder pain problems involved were invited as respondents in this study. EMG experiment was carried out by first determined the critical point at T9 and L3 from thoracic and lumbar segment respectively for ECG electrode placement and performed with a series of sitting trials for analysis. The sitting trials performed were slouch to lumbopelvic sitting and slouch to thoracic sitting follow by instruction. Next, the electrode placement was identified at C2-C3 on cervical spine for neck and at midpoint between C7 to the lateral edge of acromion spanning for shoulder respectively. These points were identified for a series of writing task performing for the EMG analysis. There were two type of writing task which included writing by looking at the whiteboard and paper placed on the table. The subjects were instructed to rest during the experiment when necessary. During lumbopelvic sitting posture, the average muscle activation on lumbar area was at the highest peak. The peak indicated that there was critical effect from the experimental finding. The performance of writing task from whiteboard gave rise a higher impact on neck muscle while writing task from paper had a greater impact on shoulder muscle. The critical affected muscle on these areas was proven on these written tasks. The EMG experiment showed that the existing design of primary school classroom chair and table had brought impact on lumbar, neck and shoulder towards the students who were using. A future recommendation suggests that to redesign primary school classroom chair and table which

Voluntary low-force contraction elicits prolonged low-frequency fatigue and changes in surface electromyography and mechanomyography

DEFF Research Database (Denmark)

Blangsted, Anne Katrine; Sjøgaard, Gisela; Madeleine, Pascal

2005-01-01

Controversies exist regarding objective documentation of fatigue development with low-force contractions. We hypothesized that non-exhaustive, low-force muscle contraction may induce prolonged low-frequency fatigue (LFF) that in the subsequent recovery period is detectable by electromyography (EMG...

Effective Low-Power Wearable Wireless Surface EMG Sensor Design Based on Analog-Compressed Sensing

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Mohammadreza Balouchestani

2014-12-01

Full Text Available Surface Electromyography (sEMG is a non-invasive measurement process that does not involve tools and instruments to break the skin or physically enter the body to investigate and evaluate the muscular activities produced by skeletal muscles. The main drawbacks of existing sEMG systems are: (1 they are not able to provide real-time monitoring; (2 they suffer from long processing time and low speed; (3 they are not effective for wireless healthcare systems because they consume huge power. In this work, we present an analog-based Compressed Sensing (CS architecture, which consists of three novel algorithms for design and implementation of wearable wireless sEMG bio-sensor. At the transmitter side, two new algorithms are presented in order to apply the analog-CS theory before Analog to Digital Converter (ADC. At the receiver side, a robust reconstruction algorithm based on a combination of ℓ1-ℓ1-optimization and Block Sparse Bayesian Learning (BSBL framework is presented to reconstruct the original bio-signals from the compressed bio-signals. The proposed architecture allows reducing the sampling rate to 25% of Nyquist Rate (NR. In addition, the proposed architecture reduces the power consumption to 40%, Percentage Residual Difference (PRD to 24%, Root Mean Squared Error (RMSE to 2%, and the computation time from 22 s to 9.01 s, which provide good background for establishing wearable wireless healthcare systems. The proposed architecture achieves robust performance in low Signal-to-Noise Ratio (SNR for the reconstruction process.

An Autonomous Wearable System for Predicting and Detecting Localised Muscle Fatigue

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Al-Mulla, Mohamed R.; Sepulveda, Francisco; Colley, Martin

2011-01-01

Muscle fatigue is an established area of research and various types of muscle fatigue have been clinically investigated in order to fully understand the condition. This paper demonstrates a non-invasive technique used to automate the fatigue detection and prediction process. The system utilises the clinical aspects such as kinematics and surface electromyography (sEMG) of an athlete during isometric contractions. Various signal analysis methods are used illustrating their applicability in real-time settings. This demonstrated system can be used in sports scenarios to promote muscle growth/performance or prevent injury. To date, research on localised muscle fatigue focuses on the clinical side and lacks the implementation for detecting/predicting localised muscle fatigue using an autonomous system. Results show that automating the process of localised muscle fatigue detection/prediction is promising. The autonomous fatigue system was tested on five individuals showing 90.37% accuracy on average of correct classification and an error of 4.35% in predicting the time to when fatigue will onset. PMID:22319367

An Autonomous Wearable System for Predicting and Detecting Localised Muscle Fatigue

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Martin Colley

2011-01-01

Full Text Available Muscle fatigue is an established area of research and various types of muscle fatigue have been clinically investigated in order to fully understand the condition. This paper demonstrates a non-invasive technique used to automate the fatigue detection and prediction process. The system utilises the clinical aspects such as kinematics and surface electromyography (sEMG of an athlete during isometric contractions. Various signal analysis methods are used illustrating their applicability in real-time settings. This demonstrated system can be used in sports scenarios to promote muscle growth/performance or prevent injury. To date, research on localised muscle fatigue focuses on the clinical side and lacks the implementation for detecting/predicting localised muscle fatigue using an autonomous system. Results show that automating the process of localised muscle fatigue detection/prediction is promising. The autonomous fatigue system was tested on five individuals showing 90.37% accuracy on average of correct classification and an error of 4.35% in predicting the time to when fatigue will onset.

The risk of iatrogenic pneumothorax after electromyography.

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Kassardjian, Charles D; O'gorman, Cullen M; Sorenson, Eric J

2016-04-01

Pneumothorax is a potentially serious complication of electromyography (EMG). Data on the frequency of pneumothorax after EMG are lacking. The purpose of this study was to determine the frequency, timing, and risk factors for iatrogenic pneumothorax after EMG. Cases of pneumothorax after EMG were reviewed for clinical, electrophysiological, and radiological data. Of 64,490 EMG studies, 7 patients had an association between the EMG and pneumothorax. All patients were symptomatic and presented within 24 hours of EMG. Sampling of serratus anterior and diaphragm was causative in 1 patient each. In 5 patients, multiple high-risk muscles were sampled. The highest frequency of pneumothorax was observed with examination of serratus anterior (0.445%) and diaphragm (0.149%). The frequency of symptomatic iatrogenic pneumothorax after EMG appears to be low, and examinations of serratus anterior and diaphragm carry the highest risk. Electromyographers should be aware of the risk of pneumothorax and should counsel patients accordingly. © 2015 Wiley Periodicals, Inc.

The Eligibility of Surface Electromyography in the Assessment of Paraspinal Muscles Fatigue Following Interventions in Patients with Chronic Low Back Pain: A Systematic Review

OpenAIRE

Nahid Rahmani; Mohammad Ali Mohseni-Bandpei; Iraj Abdollahi

2013-01-01

Objective: Evaluation of paraspinal muscles endurance in patients with chronic low back pain (LBP) seems to be of great importance. Many studies demonstrated that surface electromyography has merit to assess muscle fatigue using frequency spectrum. The purpose of this study was to systematically review the eligibility of the surface electromyography in the assessment of paraspinal muscles fatigue changes following different interventions in patients with chronic LBP. Materials & Methods: ...

Impact of Functional Appliances on Muscle Activity: A Surface Electromyography Study in Children

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Woźniak, Krzysztof; Piątkowska, Dagmara; Szyszka-Sommerfeld, Liliana; Buczkowska-Radlińska, Jadwiga

2015-01-01

Background Electromyography (EMG) is the most objective tool for assessing changes in the electrical activity of the masticatory muscles. The purpose of the study was to evaluate the tone of the masseter and anterior temporalis muscles in growing children before and after 6 months of treatment with functional removable orthodontic appliances. Material/Methods The sample conisted of 51 patients with a mean age 10.7 years with Class II malocclusion. EMG recordings were performed by using a DAB-Bluetooth instrument (Zebris Medical GmbH, Germany). Recordings were performed in mandibular rest position, during maximum voluntary contraction (MVC), and during maximum effort. Results The results of the study indicated that the electrical activity of the muscles in each of the clinical situations was the same in the group of girls and boys. The factor that determined the activity of the muscles was their type. In mandibular rest position and in MVC, the activity of the temporalis muscles was significantly higher that that of the masseter muscels. The maximum effort test indicated a higher fatigue in masseter than in temporalis muscles. Conclusions Surface electromyography is a useful tool for monitoring muscle activity. A 6-month period of functional therapy resulted in changes in the activity of the masticatory muscles. PMID:25600247

Muscle fatigue in women with primary biliary cirrhosis: Spectral analysis of surface electromyography

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Biagini, Maria Rosa; Tozzi, Alessandro; Grippo, Antonello; Galli, Andrea; Milani, Stefano; Amantini, Aldo

2006-01-01

AIM: To evaluate the myoelectric manifestations of peripheral fatigability in patients with primary biliary cirrhosis in comparison to healthy subjects. METHODS: Sixteen women with primary biliary cirrhosis without comorbidity and 13 healthy women matched for age and body mass index (BMI) completed the self-reported questionnaire fatigue impact scale. All subjects underwent surface electromyography assessment of peripheral fatigability. Anterior tibial muscle isometric voluntary contraction was executed for 20 s at 80% of maximal voluntary isometric contraction. During the exercise electromyographic signal series were recorded and root mean square (expression of central drive) as well as mean and median of electromyographic signal frequency spectrum (estimates of muscle fatigability) were computed. Each subject executed the trial two times. EMG parameters were normalized, then linear regression was applied and slopes were calculated. RESULTS: Seven patients were fatigued (median fatigue impact scale score: 38, range: 26-66) and 9 were not fatigued (median fatigue impact scale score: 7, range: 0-17). The maximal voluntary isometric contraction was similar in patients (82, 54-115 N) and controls (87, 74-101 N), and in patients with high (81, 54-115 N) and low fatigue impact scale scores (86, 65-106 N). Root mean square as well as mean and median of frequency spectrum slopes were compared with the Mann-Whitney U test, and no significant difference was found between fatigued and non-fatigued patients and controls. CONCLUSION: No instrumental evidence of peripheral fatigability can be found in women with primary biliary cirrhosis but no comorbidity, suggesting that fatigue in such patients may be of central origin. PMID:16937530

Muscle-fiber conduction velocity and electromyography as diagnostic tools in patients with suspected inflammatory myopathy: a prospective study.

NARCIS (Netherlands)

Blijham, P.J.; Hengstman, G.J.D.; Laak, H.J. ter; Engelen, B.G.M. van; Zwarts, M.J.

2004-01-01

Combinations of different techniques can increase the diagnostic yield from neurophysiological examination of muscle. In 25 patients with suspected inflammatory myopathy, we prospectively performed needle electromyography (EMG) and measured muscle-fiber conduction velocity (MFCV) in a single muscle,

The use of surface electromyography as a tool in differentiating temporomandibular disorders from neck disorders.

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Ferrario, Virgilio F; Tartaglia, Gianluca M; Luraghi, Francesca E; Sforza, Chiarella

2007-11-01

The aim of this study was to assess the electromyographic characteristics of the masticatory muscles (masseter and temporalis) of patients with either "temporomandibular joint disorder" or "neck pain". Surface electromyography of the right and left masseter and temporalis muscles was performed during maximum teeth clenching in 38 patients aged 21-67 years who had either (a) temporomandibular joint disorder (24 patients); (b) "neck pain" (13 patients). Ninety-five control, healthy subjects were also examined. During clenching, standardized total muscle activities (electromyographic potentials over time) were significantly different in the three groups: 75 microV/microVs% in the temporomandibular joint disorder patients, 124 microV/microVs% in the neck pain patients, and 95 microV/microVs% in the control subjects (analysis of variance, Ptemporomandibular joint disorder patients also had significantly (Pneck pain patients (87%) or control subjects (92%). A linear discriminant function analysis allowed a significant separation between the two patient groups, with a single patient error of 18.2%. Surface electromyographic analysis during clenching allowed to differentiate between patients with a temporomandibular joint disorder and patients with a neck pain problem.

Assessment of Diaphragm and External Intercostals Fatigue from Surface EMG using Cervical Magnetic Stimulation

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Ya-Ju Chang

2008-03-01

Full Text Available This study was designed: (1 to test the reliability of surface electromyography (sEMG recording of the diaphragm and external intercostals contractions response to cervical magnetic stimulation (CMS, (2 to examine the amount and the types of inspiratory muscle fatigue that developed after maximum voluntary ventilation (MVV maneuvers.Ten male college students without physical disability (22.1±2.0 years old participated in the study and each completed a control (quiet breathing trial and a fatigue (MVV maneuvers trial sequentially. In the quiet breathing trial, the subjects maintained quiet breathing for five minutes. The subjects performed five maximal static inspiratory efforts and received five CMS before and after the quiet breathing. In the MVV trial, subjects performed five maximal inspiratory efforts and received five CMS before, immediately after, and ten minutes after two sets of MVV maneuvers performed five minutes apart. Maximal inspiratory pressure (PImax, sEMG of diaphragm and external intercostals during maximal static inspiratory efforts and during CMS were recorded. In the quiet breathing trial, high intraclass correlation coefficients (ICC=0.95-0.99 were observed in all the variables. In the MVV trial, the PImax, the EMG amplitude and the median power frequency during maximal static inspiratory efforts significantly decreased in both the diaphragm and the external intercostals immediately after the MVV maneuvers Sensors 2008, 8 2175 (P 0.05. It is concluded that the sEMG recordings of the diaphragm during maximal static inspiratory efforts and in response to CMS allow reproducible sequential assessment of diaphragm contractility. MVV maneuvers resulted in inspiratory muscles fatigue, possibly central fatigue.

Wireless sEMG-Based Body-Machine Interface for Assistive Technology Devices.

Science.gov (United States)

Fall, Cheikh Latyr; Gagnon-Turcotte, Gabriel; Dube, Jean-Francois; Gagne, Jean Simon; Delisle, Yanick; Campeau-Lecours, Alexandre; Gosselin, Clement; Gosselin, Benoit

2017-07-01

Assistive technology (AT) tools and appliances are being more and more widely used and developed worldwide to improve the autonomy of people living with disabilities and ease the interaction with their environment. This paper describes an intuitive and wireless surface electromyography (sEMG) based body-machine interface for AT tools. Spinal cord injuries at C5-C8 levels affect patients' arms, forearms, hands, and fingers control. Thus, using classical AT control interfaces (keypads, joysticks, etc.) is often difficult or impossible. The proposed system reads the AT users' residual functional capacities through their sEMG activity, and converts them into appropriate commands using a threshold-based control algorithm. It has proven to be suitable as a control alternative for assistive devices and has been tested with the JACO arm, an articulated assistive device of which the vocation is to help people living with upper-body disabilities in their daily life activities. The wireless prototype, the architecture of which is based on a 3-channel sEMG measurement system and a 915-MHz wireless transceiver built around a low-power microcontroller, uses low-cost off-the-shelf commercial components. The embedded controller is compared with JACO's regular joystick-based interface, using combinations of forearm, pectoral, masseter, and trapeze muscles. The measured index of performance values is 0.88, 0.51, and 0.41 bits/s, respectively, for correlation coefficients with the Fitt's model of 0.75, 0.85, and 0.67. These results demonstrate that the proposed controller offers an attractive alternative to conventional interfaces, such as joystick devices, for upper-body disabled people using ATs such as JACO.

Assessing the Therapeutic Effect of 630 nm Light-Emitting Diodes Irradiation on the Recovery of Exercise-Induced Hand Muscle Fatigue with Surface Electromyogram

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Dandan Yang

2012-01-01

Full Text Available This paper aims to investigate the effect of light emitting diode therapy (LEDT on exercise-induced hand muscle fatigue by measuring the surface electromyography (sEMG of flexor digitorum superficialis. Ten healthy volunteers were randomly placed in the equal sized LEDT group and control group. All subjects performed a sustained fatiguing isometric contraction with the combination of four fingertips except thumb at 30% of maximal voluntary contraction (MVC until exhaustion. The active LEDT or an identical passive rest therapy was then applied to flexor digitorum superficialis. Each subject was required to perform a re-fatigue task immediately after therapy which was the same as the pre-fatigue task. Average rectified value (ARV and fractal dimension (FD of sEMG were calculated. ARV and FD were significantly different between active LEDT and passive rest groups at 20%–50%, 70%–80%, and 100% of normalized contraction time (P<0.05. Compared to passive rest, active LEDT induced significantly smaller increase in ARV values and decrease in FD values, which shows that LEDT is effective on the recovery of muscle fatigue. Our preliminary results also suggest that ARV and FD are potential replacements of biochemical markers to assess the effects of LEDT on muscle fatigue.

Cross-correlation of motor activity signals from dc-magnetoencephalography, near-infrared spectroscopy, and electromyography.

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Sander, Tilmann H; Leistner, Stefanie; Wabnitz, Heidrun; Mackert, Bruno-Marcel; Macdonald, Rainer; Trahms, Lutz

2010-01-01

Neuronal and vascular responses due to finger movements were synchronously measured using dc-magnetoencephalography (dcMEG) and time-resolved near-infrared spectroscopy (trNIRS). The finger movements were monitored with electromyography (EMG). Cortical responses related to the finger movement sequence were extracted by independent component analysis from both the dcMEG and the trNIRS data. The temporal relations between EMG rate, dcMEG, and trNIRS responses were assessed pairwise using the cross-correlation function (CCF), which does not require epoch averaging. A positive lag on a scale of seconds was found for the maximum of the CCF between dcMEG and trNIRS. A zero lag is observed for the CCF between dcMEG and EMG. Additionally this CCF exhibits oscillations at the frequency of individual finger movements. These findings show that the dcMEG with a bandwidth up to 8 Hz records both slow and faster neuronal responses, whereas the vascular response is confirmed to change on a scale of seconds.

Assessment of a wearable force- and electromyography device and comparison of the related signals for myocontrol

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Mathilde Connan

2016-11-01

Full Text Available In the frame of assistive robotics, multi-finger prosthetic hand/wrists have recently appeared,offering an increasing level of dexterity; however, in practice their control is limited to a few handgrips and still unreliable, with the effect that pattern recognition has not yet appeared in the clinicalenvironment. According to the scientific community, one of the keys to improve the situation ismulti-modal sensing, i.e., using diverse sensor modalities to interpret the subject’s intent andimprove the reliability and safety of the control system in daily life activities. In this work, wefirst describe and test a novel wireless, wearable force- and electromyography device; throughan experiment conducted on ten intact subjects, we then compare the obtained signals bothqualitatively and quantitatively, highlighting their advantages and disadvantages. Our resultsindicate that force-myography yields signals which are more stable across time during whenevera pattern is held, than those obtained by electromyography. We speculate that fusion of the twomodalities might be advantageous to improve the reliability of myocontrol in the near future.

Motor, affective and cognitive empathy in adolescence : Interrelations between facial electromyography and self-reported trait and state measures

NARCIS (Netherlands)

Van der Graaff, Jolien; Meeus, Wim; de Wied, Minet; van Boxtel, Anton; van Lier, Pol A C; Koot, Hans M.; Branje, Susan J. T.

2016-01-01

This study examined interrelations of trait and state empathy in an adolescent sample. Self-reported affective trait empathy and cognitive trait empathy were assessed during a home visit. During a test session at the university, motor empathy (facial electromyography), and self-reported affective

Effects of muscle fatigue on the usability of a myoelectric human-computer interface.

Science.gov (United States)

Barszap, Alexander G; Skavhaug, Ida-Maria; Joshi, Sanjay S

2016-10-01

Electromyography-based human-computer interface development is an active field of research. However, knowledge on the effects of muscle fatigue for specific devices is limited. We have developed a novel myoelectric human-computer interface in which subjects continuously navigate a cursor to targets by manipulating a single surface electromyography (sEMG) signal. Two-dimensional control is achieved through simultaneous adjustments of power in two frequency bands through a series of dynamic low-level muscle contractions. Here, we investigate the potential effects of muscle fatigue during the use of our interface. In the first session, eight subjects completed 300 cursor-to-target trials without breaks; four using a wrist muscle and four using a head muscle. The wrist subjects returned for a second session in which a static fatiguing exercise took place at regular intervals in-between cursor-to-target trials. In the first session we observed no declines in performance as a function of use, even after the long period of use. In the second session, we observed clear changes in cursor trajectories, paired with a target-specific decrease in hit rates. Copyright © 2016 Elsevier B.V. All rights reserved.

Coherence explored between emotion components: evidence from event-related potentials and facial electromyography.

Science.gov (United States)

Gentsch, Kornelia; Grandjean, Didier; Scherer, Klaus R

2014-04-01

Componential theories assume that emotion episodes consist of emergent and dynamic response changes to relevant events in different components, such as appraisal, physiology, motivation, expression, and subjective feeling. In particular, Scherer's Component Process Model hypothesizes that subjective feeling emerges when the synchronization (or coherence) of appraisal-driven changes between emotion components has reached a critical threshold. We examined the prerequisite of this synchronization hypothesis for appraisal-driven response changes in facial expression. The appraisal process was manipulated by using feedback stimuli, presented in a gambling task. Participants' responses to the feedback were investigated in concurrently recorded brain activity related to appraisal (event-related potentials, ERP) and facial muscle activity (electromyography, EMG). Using principal component analysis, the prediction of appraisal-driven response changes in facial EMG was examined. Results support this prediction: early cognitive processes (related to the feedback-related negativity) seem to primarily affect the upper face, whereas processes that modulate P300 amplitudes tend to predominantly drive cheek region responses. Copyright © 2013 Elsevier B.V. All rights reserved.

Use of multiple-site performance-contingent SEMG reward programming in pediatric rehabilitation: a retrospective review.

Science.gov (United States)

Bolek, Jeffrey E

2006-09-01

We completed a retrospective review of the effectiveness of multi-site, performance-contingent reward programming on functional change in motor performance of 16 treatment resistant children. Patients were previously treated in physical or occupational therapy for head control, standing balance training, sitting and upper extremity use (brachial plexus injury). They then participated in a program that utilized multiple surface electromyography sites the use of which was rewarded with videos for performing the correct constellation of recruitment pattern (e.g., contracting some muscles while relaxing others). Onset of reward was calibrated for each patient and transfer of skill to outside the clinic was encouraged by linking a verbal cue to the correct motor plan. Fourteen of the 16 patients improved. The implications of the use of this technique in the treatment of motor dysfunction is discussed.

Effects of Hydrotherapy on postural control and electromyography parameters in men with chronic non-specific low back pain

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Mahdi Mahjur

2016-05-01

Full Text Available The aim of this study was to evaluate effects of hydrotherapy on postural control and electromyography parameters in men with chronic non-specific low back pain. Thirty men with chronic non-specific LBP divided into two hydrotherapy and control groups, randomly and equally. Electromyographic activity of erector spinae muscles and balance measured for both of groups before and after intervention. Hydrotherapy program was consisted of 24 sessions. Subjects in control group didn’t have any special activity. Two-way variance was used to interpret the data and correlated and independent T-tests were used for analysis of data at the significance level of (P0.05. However, a significant difference observed between two groups in balance index (P<0.05.

Effect of a Short Time Concentric Versus Eccentric Training Program on Electromyography Activity and Peak Torque of Quadriceps

DEFF Research Database (Denmark)

Carvalho, Alberto; Caserotti, Paolo; Carvalho, C.

2014-01-01

The purpose of this study was to examine the effect of an 8-week concentric (CON) versus eccentric (ECC) isokinetic training program on the electromyography (EMG) signal amplitude of vastus medialis (VM), vastus lateralis (VL) and rectus femoris (RF). Also, the isometric (ISO) and dynamic maximum...

Electromyography-Guided Botulinum Toxin Injection Into the Cricothyroid Muscles in Bilateral Vocal Fold Abductor Paralysis

OpenAIRE

Sahin, Mustafa; Aydogdu, Ibrahim; Akyildiz, Serdar; Erdinc, Munevver; Ozturk, Kerem; Ogut, Fatih

2016-01-01

Objectives Bilateral vocal fold abductor paralysis (BVFAP) both deteriorates quality of life and may cause life-threatening respiratory problems. The aim of this study was to reduce respiratory symptoms in BVFAP patients using cricothyroid (CT) botulinum toxin (BTX) injection. Methods Before and 2 weeks and 4 months after bilateral BTX injection into the CT muscles under electromyography; alterations in respiratory, acoustic, aerodynamic and quality of life parameters were evaluated in BVFAP ...

Electromyography and the study of sports movements: a review.

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Clarys, J P; Cabri, J

1993-10-01

Within electromyography (EMG), a particular specialty has been developed wherein the aim is to use EMG for the study of muscular function and co-ordination. This area of research is usually called kinesiological EMG. The general aims of kinesiological EMG are to analyse the function and co-ordination of muscles in different movements and postures, in healthy subjects as well as in the disabled, in skilled actions as well as during training, in humans as well as in animals, under laboratory conditions as well as during daily or vocational activities. This is often done by a combination of electromyographical and kinesiological or biomechanical measurement techniques. Because there are over 400 skeletal muscles in the human body and both irregular and complex involvement of the muscles may occur in neuromuscular diseases and in voluntary occupational or sports movements, it is impossible to sample all of the muscles of the entire body during the performance of complex motor skills. In addition, the measurement of kinesiological EMG in sport and specific field circumstances, such as the track and/or soccer field, the alpine ski slope, the swimming pool and the ice rink, demands a specific technological and methodological approach, adaptable to both the field and the sport circumstances. Sport movement techniques and skills, training approaches and methods, ergonomic verification of the human-machine interaction have, amongst others, a highly specialized muscular activity in common. The knowledge of such muscular action in all its aspects, its evaluation and its feedback should allow for the optimization of movement, of sports materials, of training possibilities and, in the end, of sports performance. Drawing conclusions from a review of the EMG research of 32 sports, covering over 100 different complex skills, including methodological approaches, is an impossible task. We have attempted to set standards concerning the EMG methodology at the beginning of this review

Improved Prediction of Preterm Delivery Using Empirical Mode Decomposition Analysis of Uterine Electromyography Signals.

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Peng Ren

Full Text Available Preterm delivery increases the risk of infant mortality and morbidity, and therefore developing reliable methods for predicting its likelihood are of great importance. Previous work using uterine electromyography (EMG recordings has shown that they may provide a promising and objective way for predicting risk of preterm delivery. However, to date attempts at utilizing computational approaches to achieve sufficient predictive confidence, in terms of area under the curve (AUC values, have not achieved the high discrimination accuracy that a clinical application requires. In our study, we propose a new analytical approach for assessing the risk of preterm delivery using EMG recordings which firstly employs Empirical Mode Decomposition (EMD to obtain their Intrinsic Mode Functions (IMF. Next, the entropy values of both instantaneous amplitude and instantaneous frequency of the first ten IMF components are computed in order to derive ratios of these two distinct components as features. Discrimination accuracy of this approach compared to those proposed previously was then calculated using six differently representative classifiers. Finally, three different electrode positions were analyzed for their prediction accuracy of preterm delivery in order to establish which uterine EMG recording location was optimal signal data. Overall, our results show a clear improvement in prediction accuracy of preterm delivery risk compared with previous approaches, achieving an impressive maximum AUC value of 0.986 when using signals from an electrode positioned below the navel. In sum, this provides a promising new method for analyzing uterine EMG signals to permit accurate clinical assessment of preterm delivery risk.

Identification of first-stage labor arrest by electromyography in term nulliparous women after induction of labor.

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Vasak, Blanka; Graatsma, Elisabeth M; Hekman-Drost, Elske; Eijkemans, Marinus J; Schagen van Leeuwen, Jules H; Visser, Gerard H A; Jacod, Benoit C

2017-07-01

Worldwide induction and cesarean delivery rates have increased rapidly, with consequences for subsequent pregnancies. The majority of intrapartum cesarean deliveries are performed for failure to progress, typically in nulliparous women at term. Current uterine registration techniques fail to identify inefficient contractions leading to first-stage labor arrest. An alternative technique, uterine electromyography has been shown to identify inefficient contractions leading to first-stage arrest of labor in nulliparous women with spontaneous onset of labor at term. The objective of this study was to determine whether this finding can be reproduced in induction of labor. Uterine activity was measured in 141 nulliparous women with singleton term pregnancies and a fetus in cephalic position during induced labor. Electrical activity of the myometrium during contractions was characterized by its power density spectrum. No significant differences were found in contraction characteristics between women with induced labor delivering vaginally with or without oxytocin and women with arrested labor with subsequent cesarean delivery. Uterine electromyography shows no correlation with progression of labor in induced labor, which is in contrast to spontaneous labor. © 2017 Nordic Federation of Societies of Obstetrics and Gynecology.

Hamstring injury prevention in soccer: Before or after training?

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Lovell, R; Knox, M; Weston, M; Siegler, J C; Brennan, S; Marshall, P W M

2018-02-01

We examined the effects of a 12-week program of Nordic hamstring exercises (NHE), administered before or after football training, upon eccentric hamstring strength, muscle activity, and architectural adaptations. Amateur soccer players were randomized into three groups. The control group (CON; n=11) undertook core stability exercises, whereas a periodized NHE program was delivered either before (NHE BEF ; n=10) or after (NHE AFT ; n=14) biweekly training sessions. Outcome measures included peak torque and concomitant normalized peak surface electromyography signals (sEMG) of the biceps femoris (BF) and medial hamstring (MH) muscles during knee flexor maximal eccentric contractions, performed at 30°·s -1 . Ultrasonography was used to determine BF muscle thickness, muscle fiber pennation angle, and fascicle length. Performing the NHE derived likely moderate peak torque increases in both NHE BEF (+11.9%; 90% confidence interval: 3.6%-20.9%) and NHE AFT (+11.6%; 2.6%-21.5%) vs CON. Maximum sEMG increases were moderately greater in the BF of both NHE training groups vs CON. There were likely moderate increases in BF muscle thickness (+0.17 cm; 0.05-0.29 cm) and likely small pennation angle increases (+1.03°; -0.08° to 2.14°) in NHE AFT vs CON and NHE BEF . BF fascicle length increases were likely greater in NHE BEF (+1.58 cm; 0.48-2.68 cm; small effect) vs CON and NHE AFT . A 12-week eccentric hamstring strengthening program increased strength and sEMG to a similar magnitude irrespective of its scheduling relative to the football training session. However, architectural adaptations to support the strength gains differed according to the timing of the injury prevention program. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Pelvic floor muscle assessment outcomes in women with and without provoked vestibulodynia and the impact of a physical therapy program.

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Gentilcore-Saulnier, Evelyne; McLean, Linda; Goldfinger, Corrie; Pukall, Caroline F; Chamberlain, Susan

2010-02-01

Physical therapy (PT) may reduce the pain associated with provoked vestibulodynia (PVD) based on previous findings that pelvic floor muscle dysfunction (PFMD) is associated with PVD symptoms. The goals of this study were: (i) to determine whether women with and without PVD differ on measures of pelvic floor muscle (PFM) behavior; and (ii) to assess the impact of PT treatment for women with PVD on these measures. Eleven women with PVD and 11 control women completed an assessment evaluating PFM behavior using surface electromyography (SEMG) recordings and a digital intravaginal assessment. Women with PVD repeated the assessment after they had undergone eight PT treatment sessions of manual therapy, biofeedback, electrical stimulation, dilator insertions, and home exercises. Superficial and deep PFM SEMG tonic activity and phasic activity in response to a painful pressure stimulus, PFM digital assessment variables (tone, flexibility, relaxation capacity, and strength). At pretreatment, women with PVD had higher tonic SEMG activity in their superficial PFMs compared with the control group, whereas no differences were found in the deep PFMs. Both groups demonstrated contractile responses to the painful pressure stimulus that were significantly higher in the superficial as compared with the deep PFMs, with the responses in the PVD group being higher than those in control women. Women with PVD had higher PFM tone, decreased PFM flexibility and lower PFM relaxation capacity compared with control women. Posttreatment improvements included less PFM responsiveness to pain, less PFM tone, improved vaginal flexibility, and improved PFM relaxation capacity, such that women with PVD no longer differed from controls on these measures. Women with PVD demonstrated altered PFM behavior when compared with controls, providing empirical evidence of PFMD, especially at the superficial layer. A PT rehabilitation program specifically targeting PFMD normalized PFM behavior in women with PVD.

Upper Limb Static-Stretching Protocol Decreases Maximal Concentric Jump Performance

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Paulo H. Marchetti

2014-12-01

Full Text Available The purpose of the present study was to evaluate the acute effects of an upper limb static-stretching (SS protocol on the maximal concentric jump performance. We recruited 25 young healthy, male, resistance trained individuals (stretched group, n = 15 and control group, n = 10 in this study. The randomized between group experimental protocol consisted of a three trials of maximal concentric jump task, before and after a SS of the upper limb. Vertical ground reaction forces (vGRF and surface electromyography (sEMG of both gastrocnemius lateralis (GL and vastus lateralis (VL were acquired. An extensive SS was employed consisting of ten stretches of 30 seconds, with 15 seconds of rest, and 70-90% of the point of discomfort (POD. ANOVA (2x2 (group x condition was used for shoulder joint range of motion (ROM, vGRF and sEMG. A significant interaction for passive ROM of the shoulder joint revealed significant increases between pre- and post-SS protocol (p < 0.001. A significant interaction demonstrated decreased peak force and an increased peak propulsion duration between pre- and post-stretching only for stretch group (p = 0.021, and p = 0.024, respectively. There was a significant main effect between groups (stretch and control for peak force for control group (p = 0.045. Regarding sEMG variables, there were no significant differences between groups (control versus stretched or condition (pre-stretching versus post-stretching for the peak amplitude of RMS and IEMG for both muscles (VL and GL. In conclusion, an acute extensive SS can increase the shoulder ROM, and negatively affect both the propulsion duration and peak force of the maximal concentric jump, without providing significant changes in muscle activation.

Vocal fold motion outcome based on excellent prognosis with laryngeal electromyography.

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Smith, Libby J; Rosen, Clark A; Munin, Michael C

2016-10-01

As laryngeal electromyography (LEMG) becomes more refined, accurate predictions of vocal fold motion recovery are possible. Focus has been on outcomes for patients with poor prognosis for vocal fold motion recovery. Limited information is available regarding the expected rate of purposeful vocal fold motion recovery when there is good to normal motor recruitment, no signs of denervation, and no signs of synkinetic activity with LEMG, termed excellent prognosis. The objective of this study is to determine the rate of vocal fold motion recovery with excellent prognosis findings on LEMG after acute recurrent laryngeal nerve injury. Retrospective review. Patients undergoing a standardized LEMG protocol, consisting of qualitative (evaluation of motor recruitment, motor unit configuration, detection of fibrillations, presence of synkinesis) and quantitative (turns analysis) measurements were evaluated for purposeful vocal-fold motion recovery, calculated after at least 6 months since onset of injury. Twenty-three patients who underwent LEMG for acute vocal fold paralysis met the inclusion criteria of excellent prognosis. Eighteen patients (78.3%) recovered vocal fold motion, as determined by flexible laryngoscopy. Nearly 80% of patients determined to have excellent prognosis for vocal fold motion recovery experienced return of vocal fold motion. This information will help clinicians not only counsel their patients on expectations but will also help guide treatment. 4. Laryngoscope, 126:2310-2314, 2016. © 2016 The American Laryngological, Rhinological and Otological Society, Inc.

Single-fiber electromyography analysis of botulinum toxin diffusion in patients with fatigue and pseudobotulism.

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Ruet, Alexis; Durand, Marie Christine; Denys, Pierre; Lofaso, Frederic; Genet, François; Schnitzler, Alexis

2015-06-01

To characterize electromyographic abnormalities according to symptoms (asymptomatic, fatigue, pseudobotulism) reported 1 month after botulinum toxin injection. Retrospective, single-center study comparing single-fiber electromyography (SFEMG) in the extensor digitorum communis (EDC) or orbicularis oculi (OO) muscles. Hospital. Four groups of adults treated for spasticity or neurologic bladder hyperactivity (N=55): control group (asymptomatic patients: n=17), fatigue group (unusual fatigue with no weakness: n=15), pseudobotulism group (muscle weakness and/or visual disturbance: n=20), and botulism group (from intensive care unit of the same hospital: n=3). Not applicable. Mean jitter, percentage of pathologic fibers, and percentage of blocked fibers were compared between groups. SFEMG was abnormal for 17.6% of control patients and 75% of patients in the pseudobotulism group. There were no differences between the control and fatigue groups. Mean jitter, percentage of pathologic fibers, and percentage of blocked fibers of the EDC muscle were significantly higher in the pseudobotulism group than in the fatigue and control groups. There were no differences between groups for the OO muscle. The SFEMG results in the botulism group were qualitatively similar to those of the pseudobotulism group. SFEMG of the EDC muscle confirmed diffusion of the toxin into muscles distant from the injection site in the pseudobotulism group. SFEMG in the OO muscle is not useful for the diagnosis of diffusion. No major signs of diffusion of botulinum toxin type A were found away from the injection site in patients with fatigue but no motor weakness. Such fatigue may be related to other mechanisms. Copyright © 2015 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.

Estimating Neural Control from Concentric vs. Eccentric Surface Electromyographic Representations during Fatiguing, Cyclic Submaximal Back Extension Exercises

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Gerold R. Ebenbichler

2017-05-01

Full Text Available Purpose: To investigate the differences in neural control of back muscles activated during the eccentric vs. the concentric portions of a cyclic, submaximal, fatiguing trunk extension exercise via the analysis of amplitude and time-frequency parameters derived from surface electromyographic (SEMG data.Methods: Using back dynamometers, 87 healthy volunteers performed three maximum voluntary isometric trunk extensions (MVC's, an isometric trunk extension at 80% MVC, and 25 cyclic, dynamic trunk extensions at 50% MVC. Dynamic testing was performed with the trunk angular displacement ranging from 0° to 40° and the trunk angular velocity set at 20°/s. SEMG data was recorded bilaterally from the iliocostalis lumborum at L1, the longissimus dorsi at L2, and the multifidus muscles at L5. The initial value and slope of the root mean square (RMS-SEMG and the instantaneous median frequency (IMDF-SEMG estimates derived from the SEMG recorded during each exercise cycle were used to investigate the differences in MU control marking the eccentric vs. the concentric portions of the exercise.Results: During the concentric portions of the exercise, the initial RMS-SEMG values were almost twice those observed during the eccentric portions of the exercise. The RMS-SEMG values generally increased during the concentric portions of the exercise while they mostly remained unchanged during the eccentric portions of the exercise with significant differences between contraction types. Neither the initial IMDF-SEMG values nor the time-course of the IMDF-SEMG values significantly differed between the eccentric and the concentric portions of the exercise.Conclusions: The comparison of the investigated SEMG parameters revealed distinct neural control strategies during the eccentric vs. the concentric portions of the cyclic exercise. We explain these differences by relying upon the principles of orderly recruitment and common drive governing motor unit behavior.

Gender variability in electromyographic activity, in vivo behaviour of the human gastrocnemius and mechanical capacity during the take-off phase of a countermovement jump.

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Rubio-Arias, Jacobo Ángel; Ramos-Campo, Domingo Jesús; Peña Amaro, José; Esteban, Paula; Mendizábal, Susana; Jiménez, José Fernando

2017-11-01

The purpose of this study was to analyse gender differences in neuromuscular behaviour of the gastrocnemius and vastus lateralis during the take-off phase of a countermovement jump (CMJ), using direct measures (ground reaction forces, muscle activity and dynamic ultrasound). Sixty-four young adults (aged 18-25 years) participated voluntarily in this study, 35 men and 29 women. The firing of the trigger allowed obtainment of data collection vertical ground reaction forces (GRF), surface electromyography activity (sEMG) and dynamic ultrasound gastrocnemius of both legs. Statistically significant gender differences were observed in the jump performance, which appear to be based on differences in muscle architecture and the electrical activation of the gastrocnemius muscles and vastus lateralis. So while men developed greater peak power, velocity take-offs and jump heights, jump kinetics compared to women, women also required a higher electrical activity to develop lower power values. Additionally, the men had higher values pennation angles and muscle thickness than women. Men show higher performance of the jump test than women, due to significant statistical differences in the values of muscle architecture (pennation angle and thickness muscle), lower Neural Efficiency Index and a higher amount of sEMG activity per second during the take-off phase of a CMJ. © 2016 Scandinavian Society of Clinical Physiology and Nuclear Medicine. Published by John Wiley & Sons Ltd.

Sport-specific endurance plank test for evaluation of global core muscle function.

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Tong, Tom K; Wu, Shing; Nie, Jinlei

2014-02-01

To examine the validity and reliability of a sports-specific endurance plank test for the evaluation of global core muscle function. Repeated-measures study. Laboratory environment. Twenty-eight male and eight female young athletes. Surface electromyography (sEMG) of selected trunk flexors and extensors, and an intervention of pre-fatigue core workout were applied for test validation. Intraclass correlation coefficient (ICC), coefficient of variation (CV), and the measurement bias ratio */÷ ratio limits of agreement (LOA) were calculated to assess reliability and measurement error. Test validity was shown by the sEMG of selected core muscles, which indicated >50% increase in muscle activation during the test; and the definite discrimination of the ∼30% reduction in global core muscle endurance subsequent to a pre-fatigue core workout. For test-retest reliability, when the first attempt of three repeated trials was considered as familiarisation, the ICC was 0.99 (95% CI: 0.98-0.99), CV was 2.0 ± 1.56% and the measurement bias ratio */÷ ratio LOA was 0.99 */÷ 1.07. The findings suggest that the sport-specific endurance plank test is a valid, reliable and practical method for assessing global core muscle endurance in athletes given that at least one familiarisation trial takes place prior to measurement. Copyright © 2013 Elsevier Ltd. All rights reserved.

Reliability of surface electromyography in the assessment of paraspinal muscle fatigue: an updated systematic review.

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Mohseni Bandpei, Mohammad A; Rahmani, Nahid; Majdoleslam, Basir; Abdollahi, Iraj; Ali, Shabnam Shah; Ahmad, Ashfaq

2014-09-01

The purpose of this study was to review the literature to determine whether surface electromyography (EMG) is a reliable tool to assess paraspinal muscle fatigue in healthy subjects and in patients with low back pain (LBP). A literature search for the period of 2000 to 2012 was performed, using PubMed, ProQuest, Science Direct, EMBASE, OVID, CINAHL, and MEDLINE databases. Electromyography, reliability, median frequency, paraspinal muscle, endurance, low back pain, and muscle fatigue were used as keywords. The literature search yielded 178 studies using the above keywords. Twelve articles were selected according to the inclusion criteria of the study. In 7 of the 12 studies, the surface EMG was only applied in healthy subjects, and in 5 studies, the reliability of surface EMG was investigated in patients with LBP or a comparison with a control group. In all of these studies, median frequency was shown to be a reliable EMG parameter to assess paraspinal muscles fatigue. There was a wide variation among studies in terms of methodology, surface EMG parameters, electrode location, procedure, and homogeneity of the study population. The results suggest that there seems to be a convincing body of evidence to support the merit of surface EMG in the assessment of paraspinal muscle fatigue in healthy subject and in patients with LBP. Copyright © 2014 National University of Health Sciences. Published by Elsevier Inc. All rights reserved.

A cross-sectional electromyography assessment in linear scleroderma patients

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2014-01-01

Background Muscle atrophy and asymmetric extremity growth is a common feature of linear scleroderma (LS). Extra-cutaneous features are also common and primary neurologic involvement, with sympathetic dysfunction, may have a pathogenic role in subcutaneous and muscle atrophy. The aim was investigate nerve conduction and muscle involvement by electromyography in pediatric patients with LS. Methods We conducted a retrospective review of LS pediatric patients who had regular follow up at a single pediatric center from 1997–2013. We selected participants if they had consistently good follow up and enrolled consecutive patients in the study. We examined LS photos as well as clinical, serological and imaging findings. Electromyograms (EMG) were performed with bilateral symmetric technique, using surface and needle electrodes, comparing the affected side with the contralateral side. Abnormal muscle activity was categorized as a myopathic or neurogenic pattern. Results Nine LS subjects were selected for EMG, 2 with Parry-Romberg/Hemifacial Atrophy Syndrome, 7 linear scleroderma of an extremity and 2 with mixed forms (linear and morphea). Electromyogram analysis indicated that all but one had asymmetric myopathic pattern in muscles underlying the linear streaks. Motor and sensory nerve conduction was also evaluated in upper and lower limbs and one presented a neurogenic pattern. Masticatory muscle testing showed a myopathic pattern in the atrophic face of 2 cases with head and face involvement. Conclusion In our small series of LS patients, we found a surprising amount of muscle dysfunction by EMG. The muscle involvement may be possibly related to a secondary peripheral nerve involvement due to LS inflammation and fibrosis. Further collaborative studies to confirm these findings are needed. PMID:25053924

Recurrent intractable hiccups treated by cervical phrenic nerve block under electromyography: report of a case.

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Sa, Young Jo; Song, Dae Heon; Kim, Jae Jun; Kim, Young Du; Kim, Chi Kyung; Moon, Seok Whan

2015-11-01

Intractable or persistent hiccups require intensive or invasive treatments. The use of a phrenic nerve block or destructive treatment for intractable hiccups has been reported to be a useful and discrete method that might be valuable to patients with this distressing problem and for whom diverse management efforts have failed. We herein report a successful treatment using a removable and adjustable ligature for the phrenic nerve in a patient with recurrent and intractable hiccups, which was employed under the guidance of electromyography.

Interacting proteins on human spermatozoa: adaptive evolution of the binding of semenogelin I to EPPIN.

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Erick J R Silva

Full Text Available Semenogelin I (SEMG1 is found in human semen coagulum and on the surface of spermatozoa bound to EPPIN. The physiological significance of the SEMG1/EPPIN interaction on the surface of spermatozoa is its capacity to modulate sperm progressive motility. The present study investigates the hypothesis that the interacting surface of SEMG1 and EPPIN co-evolved within the Hominoidea time scale, as a result of adaptive pressures applied by their roles in sperm protection and reproductive fitness. Our results indicate that some amino acid residues of SEMG1 and EPPIN possess a remarkable deficiency of variation among hominoid primates. We observe a distinct residue change unique to humans within the EPPIN sequence containing a SEMG1 interacting surface, namely His92. In addition, Bayes Empirical Bayes analysis for positive selection indicates that the SEMG1 Cys239 residue underwent positive selection in humans, probably as a consequence of its role in increasing the binding affinity of these interacting proteins. We confirm the critical role of Cys239 residue for SEMG1 binding to EPPIN and inhibition of sperm motility by showing that recombinant SEMG1 mutants in which Cys239 residue was changed to glycine, aspartic acid, histidine, serine or arginine have reduced capacity to interact to EPPIN and to inhibit human sperm motility in vitro. In conclusion, our results indicate that EPPIN and SEMG1 rapidly co-evolved in primates due to their critical role in the modulation of sperm motility in the semen coagulum, providing unique insights into the molecular co-evolution of sperm surface interacting proteins.

Analysis of applied forces and electromyography of back and shoulders muscles when performing a simulated hand scaling task.

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Porter, William; Gallagher, Sean; Torma-Krajewski, Janet

2010-05-01

Hand scaling is a physically demanding task responsible for numerous overexertion injuries in underground mining. Scaling requires the miner to use a long pry bar to remove loose rock, reducing the likelihood of rock fall injuries. The experiments described in this article simulated "rib" scaling (scaling a mine wall) from an elevated bucket to examine force generation and electromyographic responses using two types of scaling bars (steel and fiberglass-reinforced aluminum) at five target heights ranging from floor level to 176 cm. Ten male and six female subjects were tested in separate experiments. Peak and average force applied at the scaling bar tip and normalized electromyography (EMG) of the left and right pairs of the deltoid and erectores spinae muscles were obtained. Work height significantly affected peak prying force during scaling activities with highest force capacity at the lower levels. Bar type did not affect force generation. However, use of the lighter fiberglass bar required significantly more muscle activity to achieve the same force. Results of these studies suggest that miners scale points on the rock face that are below their knees, and reposition the bucket as often as necessary to do so. Published by Elsevier Ltd.

Real-time and wearable functional electrical stimulation system for volitional hand motor function control using the electromyography bridge method

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Hai-peng Wang

2017-01-01

Full Text Available Voluntary participation of hemiplegic patients is crucial for functional electrical stimulation therapy. A wearable functional electrical stimulation system has been proposed for real-time volitional hand motor function control using the electromyography bridge method. Through a series of novel design concepts, including the integration of a detecting circuit and an analog-to-digital converter, a miniaturized functional electrical stimulation circuit technique, a low-power super-regeneration chip for wireless receiving, and two wearable armbands, a prototype system has been established with reduced size, power, and overall cost. Based on wrist joint torque reproduction and classification experiments performed on six healthy subjects, the optimized surface electromyography thresholds and trained logistic regression classifier parameters were statistically chosen to establish wrist and hand motion control with high accuracy. Test results showed that wrist flexion/extension, hand grasp, and finger extension could be reproduced with high accuracy and low latency. This system can build a bridge of information transmission between healthy limbs and paralyzed limbs, effectively improve voluntary participation of hemiplegic patients, and elevate efficiency of rehabilitation training.

Olfactory ensheathing glia transplantation combined with LASERPONCTURE in human spinal cord injury: Results measured by electromyography monitoring.

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Bohbot, Albert

2010-01-01

Preliminary results were measured by electromyography monitoring (electromyoscan) on three subjects suffering from spinal cord injury and who underwent a double therapy. The aim of this study was to evaluate regained voluntary activity below the injury in subjects who received a double therapy: 1) an olfactory ensheathing glia (OEG) transplantation using procedures developed by Dr. Hongyun Huang at the Xishan Hospital and Rehabilitation Centre, Beijing, China, and 2) LASERPONCTURE developed by Albert Bohbot, Laboratoire de Recherches sur le LASERPONCTURE, La Chapelle Montlinard, France. Materials uses were the LASERPONCTURE device developed by Albert Bohbot; the PROCOMP5 equipment with softwares BIOGRAPH INFINITI 5 and REHAB SUITE; the sensors MYOSCAN-PRO EMG (SA9401M-50) to record muscle activity, and FLEX/PRO-SA9309M to record skin conductance were fixed on the skin. An infrared laser, whose frequencies and power settings cannot be disclosed due to its proprietary nature, was applied after an OEG injection performed according to Dr. Hongyun Huang's procedures. Three cases, two males and one female, were selected for this study. Presentation and comments of the graphs recordings of voluntary muscle activity below the injury are provided. This preliminary study suggests that the double therapy restores some voluntary muscle activity as measured by electromyography monitoring.

Congenital multiple cranial neuropathies: Relevance of orofacial electromyography in infants.

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Renault, Francis; Flores-Guevara, Roberto; Baudon, Jean-Jacques; Vazquez, Marie-Paule

2015-11-01

The aim of this study was to assess diagnoses and outcomes of infants with 2 or more cranial neuropathies identified using orofacial electromyography (EMG). This retrospective study involved 90 patients. Diagnoses took into account clinical, radiological, and genetic data. EMG examined the orbicularis oculi, genioglossus, and levator veli palatini muscles, and blink responses. To evaluate outcome, neurological disability, respiratory complications, and feeding difficulties were recorded. The patients had malformation syndromes (59), encephalopathies (29), or no underlying disorders (2). Neurogenic EMG signs were detected in a mean of 4 muscles, reflecting a mean of 3 affected nerves. EMG identified a higher number of neuropathies than clinical examination alone (82 vs. 31, facial; 56 vs. 2, pharyngeal; 25 vs. 3, hypoglossal). Poor outcome and death were more frequent when EMG identified ≥4 affected nerves (P = 0.02). EMG highlights multiple cranial neuropathies that can be clinically silent in infants with malformation syndromes or encephalopathies. © 2015 Wiley Periodicals, Inc.

Changes in shoulder muscle activity pattern on surface electromyography after breast cancer surgery.

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Yang, Eun Joo; Kwon, YoungOk

2018-02-01

Alterations in muscle activation and restricted shoulder mobility, which are common in breast cancer patients, have been found to affect upper limb function. The purpose of this study was to determine muscle activity patterns, and to compare the prevalence of abnormal patterns among the type of breast surgery. In total, 274 breast cancer patients were recruited after surgery. Type of breast surgery was divided into mastectomy without reconstruction (Mastectomy), reconstruction with tissue expander/implant (TEI), latissimus dorsi (LD) flap, or transverse rectus abdominis flap (TRAM). Activities of shoulder muscles were measured using surface electromyography. Experimental analysis was conducted using a Gaussian filter smoothing method with regression. Patients demonstrated different patterns of muscle activation, such as normal, lower muscle electrical activity, and tightness. After adjusting for BMI and breast surgery, the odds of lower muscle electrical activity and tightness in the TRAM are 40.2% and 38.4% less than in the Mastectomy only group. The prevalence of abnormal patterns was significantly greater in the ALND than SLNB in all except TRAM. Alterations in muscle activity patterns differed by breast surgery and reconstruction type. For breast cancer patients with ALND, TRAM may be the best choice for maintaining upper limb function. © 2017 Wiley Periodicals, Inc.

Electromyography Exposes Heterogeneity in Muscle Co-Contraction following Stroke

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Caitlin L. Banks

2017-12-01

Full Text Available Walking after stroke is often described as requiring excessive muscle co-contraction, yet, evidence that co-contraction is a ubiquitous motor control strategy for this population remains inconclusive. Co-contraction, the simultaneous activation of agonist and antagonist muscles, can be assessed with electromyography (EMG but is often described qualitatively. Here, our goal is to determine if co-contraction is associated with gait impairments following stroke. Fifteen individuals with chronic stroke and nine healthy controls walked on an instrumented treadmill at self-selected speed. Surface EMGs were collected from the medial gastrocnemius (MG, soleus (SOL, and tibialis anterior (TA of each leg. EMG envelope amplitudes were assessed in three ways: (1 no normalization, (2 normalization to the maximum value across the gait cycle, or (3 normalization to maximal M-wave. Three co-contraction indices were calculated across each agonist/antagonist muscle pair (MG/TA and SOL/TA to assess the effect of using various metrics to quantify co-contraction. Two factor ANOVAs were used to compare effects of group and normalization for each metric. Co-contraction during the terminal stance (TSt phase of gait is not different between healthy controls and the paretic leg of individuals post-stroke, regardless of the metric used to quantify co-contraction. Interestingly, co-contraction was similar between M-max and non-normalized EMG; however, normalization does not impact the ability to resolve group differences. While a modest correlation is revealed between the amount of TSt co-contraction and walking speed, the relationship is not sufficiently strong to motivate further exploration of a causal link between co-contraction and walking function after stroke. Co-contraction does not appear to be a common strategy employed by individuals after stroke. We recommend exploration of alternative EMG analysis approaches in an effort to learn more about the causal

Electromyography analysis of natural mastication behavior using varying mouthful quantities of two types of gels.

Science.gov (United States)

Kohyama, Kaoru; Gao, Zhihong; Ishihara, Sayaka; Funami, Takahiro; Nishinari, Katsuyoshi

2016-07-01

The objectives of this study were to examine the effects of mouthful quantities and mechanical properties of gels on natural mastication behaviors using electromyography (EMG). Two types of hydrocolloid gels (A and K) with similar fracture loads but different moduli and fracture strains were served to eleven normal women in 3-, 6-, 12-, and 24-g masses in a randomized order. EMG activities from both masseter muscles were recorded during natural mastication. Because of the similar fracture loads, the numbers of chews, total muscle activities, and entire oral processing times were similar for similar masses of both gel types. Prior to the first swallow, the more elastic K gel with a higher fracture strain required higher muscle activities than the brittle A gel, which had higher modulus. Majority of subjects had preferred sides of chewing, but all subjects with or without preferred sides used both masseters during the consumption of gels. Similar effects of masses and types of gels were observed in EMG activities of both sides of masseters. Contributions of the dominant side of chewing were diminished with increasing masses of gels, and the mass dependency on ratio of the dominant side was more pronounced with K gel. More repetitions of smaller masses required greater muscle activities and longer periods for the consumption of 24-g gel portions. Reduction in the masses with an increased number of repetitions necessitated slower eating and more mastication to consume the gel portions. These observations suggest that chewing using both sides is more effective and unconsciously reduces mastication times during the consumption of gels. Copyright © 2016 Elsevier Inc. All rights reserved.

Deglutição de respiradores orais e nasais: avaliação clínica fonoaudiológica e eletromiográfica Swallowing of oral and nose breathers: speech-language and electromyography assessment

Directory of Open Access Journals (Sweden)

Tais Regina Hennig

2009-12-01

action and tongue projection, that were analyzed in a descriptive form. The statistical analysis of the electromyography results was done through the t test in order to compare the groups. The statistical considered significance was 5% (p<0.05. RESULTS: in the clinical evaluation it was verified that any of the nose breathers showed atypical swallowing characteristics while 7 (87.5% of the mouth breathers showed labial action, 6 (75% showed mentalis action and 6 (75% showed tongue projection. In the electromyography evaluation, a higher muscular activity was verified, in the mouth breathers, when comparing to the nose breathers, in both lips, with a statistical significance. CONCLUSIONS: in this study it was verified that mouth breathers showed significant alterations in the swallowing functions when compared to the nose breathers that were observed through a clinical examination and electromyography evaluation.

Development of Hand Grip Assistive Device Control System for Old People through Electromyography (EMG) Signal Acquisitions

OpenAIRE

Khamis Herman; Mohamaddan Shahrol; Komeda Takashi; Alias Aidil Azli; Tanjong Shirley Jonathan; Julai Norhuzaimin; Hashim Nurul ‘Izzati

2017-01-01

The hand grip assistive device is a glove to assist old people who suffer from hand weakness in their daily life activities. The device earlier control system only use simple on and off switch. This required old people to use both hand to activate the device. The new control system of the hand grip assistive device was developed to allow single hand operation for old people. New control system take advantages of electromyography (EMG) and flex sensor which was implemented to the device. It wa...

The study of surface electromyography used for the assessment of abductor hallucis muscle activity in patients with hallux valgus.

Science.gov (United States)

Mortka, Kamila; Lisiński, Przemysław; Wiertel-Krawczuk, Agnieszka

2018-01-26

Hallux valgus is a common foot disorder. In patients with hallux valgus, the anatomy and biomechanics of foot is subject to alterations. The aim of this clinical and neurophysiological study is to compare the activity of abductor hallucis (AbdH) muscle between the group of patients with hallux valgus and control group of healthy people, with the use of surface electromyography. The study involved 44 feet with diagnosed hallux valgus (research group) and 42 feet without deformation (control group). The X-ray images, measurements of range of motion in the first metatarsophalangeal joint and in hallux interphalangeal joint, and the surface electromyography study recorded from AbdH muscle were performed. Considering the amplitude of motor unit action potential, study participants with hallux valgus demonstrate significantly less activity of AbdH muscle than people without hallux valgus deformity. This activity is not dependent on the severity of valgus, age, or range of motion. It is speculated that the changes of the AbdH function may occur in the period before clinical appearance of hallux valgus deformity, or at the onset of distortion development. Further studies are needed for a comprehensive assessment of AbdH muscle in patients with hallux valgus.

Continuous Wavelet Transform Analysis of Surface Electromyography for Muscle Fatigue Assessment on the Elbow Joint Motion

Directory of Open Access Journals (Sweden)

Triwiyanto Triwiyanto

2017-01-01

Full Text Available Studying muscle fatigue plays an important role in preventing the risks associated with musculoskeletal disorders. The effect of elbow-joint angle on time-frequency parameters during a repetitive motion provides valuable information in finding the most accurate position of the angle causing muscle fatigue. Therefore, the purpose of this study is to analyze the effect of muscle fatigue on the spectral and time-frequency domain parameters derived from electromyography (EMG signals using the Continuous Wavelet Transform (CWT. Four male participants were recruited to perform a repetitive motion (flexion and extension movements from a non-fatigue to fatigue condition. EMG signals were recorded from the biceps muscle. The recorded EMG signals were then analyzed offline using the complex Morlet wavelet. The time-frequency domain data were analyzed using the time-averaged wavelet spectrum (TAWS and the Scale-Average Wavelet Power (SAWP parameters. The spectral domain data were analyzed using the Instantaneous Mean Frequency (IMNF and the Instantaneous Mean Power Spectrum (IMNP parameters. The index of muscle fatigue was observed by calculating the increase of the IMNP and the decrease of the IMNF parameters. After performing a repetitive motion from non-fatigue to fatigue condition, the average of the IMNF value decreased by 15.69% and the average of the IMNP values increased by 84%, respectively. This study suggests that the reliable frequency band to detect muscle fatigue is 31.10-36.19Hz with linear regression parameters of 0.979mV^2Hz^(-1 and 0.0095mV^2Hz^(-1 for R^2 and slope, respectively.

Occlusal splint versus modified nociceptive trigeminal inhibition splint in bruxism therapy: a randomized, controlled trial using surface electromyography.

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Dalewski, B; Chruściel-Nogalska, M; Frączak, B

2015-12-01

An occlusal splint and a modified nociceptive trigeminal inhibition splint (AMPS, anterior deprogrammer, Kois deprogrammer, Lucia jig, etc.) are commonly and quite frequently used in the treatment of masticatory muscle disorders, although their sustainable and long-lasting effect on these muscles' function is still not very well known. Results of scant surface electromyography studies in patients with temporomandibular disorders have been contradictory. The aim of this study was to evaluate both devices in bruxism therapy; EMG activity levels during postural activity and maximum voluntary contraction of the superficial temporal and masseter muscles were compared before and after 30 days of treatment. Surface electromyography of the examined muscles was performed in two groups of bruxers (15 patients each). Patients in the first group used occlusal splints, while those in the second used modified nociceptive trigeminal inhibition splints. The trial was randomized, controlled and semi-blind. Neither device affected the asymmetry index or postural activity/maximum voluntary contraction ratio after 1 month of treatment. Neither the occlusal nor the nociceptive trigeminal inhibition splint showed any significant influence on the examined muscles. Different scientific methods should be considered in clinical applications that require either direct influence on the muscles' bioelectrical activity or a quantitative measurement of the treatment quality. © 2015 Australian Dental Association.

Brain-muscle-computer interface: mobile-phone prototype development and testing.

Science.gov (United States)

Vernon, Scott; Joshi, Sanjay S

2011-07-01

We report prototype development and testing of a new mobile-phone-based brain-muscle-computer interface for severely paralyzed persons, based on previous results from our group showing that humans may actively create specified power levels in two separate frequency bands of a single surface electromyography (sEMG) signal. EMG activity on the surface of a single face muscle site (auricularis superior) is recorded with a standard electrode. This analog electrical signal is imported into an Android-based mobile phone and digitized via an internal A/D converter. The digital signal is split, and then simultaneously filtered with two band-pass filters to extract total power within two separate frequency bands. The user-modulated power in each frequency band serves as two separate control channels for machine control. After signal processing, the Android phone sends commands to external devices via a Bluetooth interface. Users are trained to use the device via visually based operant conditioning, with simple cursor-to-target activities on the phone screen. The mobile-phone prototype interface is formally evaluated on a single advanced Spinal Muscle Atrophy subject, who has successfully used the interface in his home in evaluation trials and for remote control of a television. Development of this new device will not only guide future interface design for community use, but will also serve as an information technology bridge for in situ data collection to quantify human sEMG manipulation abilities for a relevant population.

Photobiomodulation delays the onset of skeletal muscle fatigue in a dose-dependent manner.

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Larkin-Kaiser, Kelly A; Borsa, Paul A; Baweja, Harsimran S; Moore, Molly A; Tillman, Mark D; George, Steven Z; Christou, Evangelos A

2016-09-01

Photobiomodulation (PBM) therapy has been implicated as an effective ergogenic aid to delay the onset of muscle fatigue. The purpose of this study was to examine the dose-response ergogenic properties of PBM therapy and its ability to prolong time to task failure by enhancing muscle activity and delaying the onset of muscle fatigue using a static positioning task. Nine participants (24.3 ± 4.9 years) received three doses of near-infrared (NIR) light therapy randomly on three separate sessions (sham, 240, and 480 J). For the positioning task, participants held a 30 % one-repetition maximum (1-RM) load using the index finger until volitional fatigue. Surface electromyography (sEMG) of the first dorsal interosseous muscle was recorded for the length of the positioning task. Outcomes included time to task failure (TTF), muscle fatigue, movement accuracy, motor output variability, and muscle activity (sEMG). The 240-J dose significantly extended TTF by 26 % (p = 0.032) compared with the sham dose. TTF for the 240-J dose was strongly associated with a decrease in muscle fatigue (R (2) = 0.54, p = 0.024). Our findings show that a 240-J dose of NIR light therapy is efficacious in delaying the onset and extent of muscle fatigue during submaximal isometric positioning tasks. Our findings suggest that NIR light therapy may be used as an ergogenic aid during functional tasks or post-injury rehabilitation.

A comparative study of various electrodes in electromyography of the striated urethral and anal sphincter in children

DEFF Research Database (Denmark)

Nielsen, K K; Kristensen, E S; Qvist, N

1985-01-01

The series comprised 41 children aged 6 to 14 years consecutively referred with recurrent urinary tract infection and/or enuresis. Carbon dioxide cystometry was carried out in the supine and the erect position and combined with simultaneous electromyography (EMG). The external urethral sphincter ....... Correlation between them was good, as was reproducibility. Perianal surface ECG electrodes are recommended for the evaluation of functional disturbances of the external sphincter. They are painless, easy to use, and are well tolerated by the patient....

Electromyography data for non-invasive naturally-controlled robotic hand prostheses.

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Atzori, Manfredo; Gijsberts, Arjan; Castellini, Claudio; Caputo, Barbara; Hager, Anne-Gabrielle Mittaz; Elsig, Simone; Giatsidis, Giorgio; Bassetto, Franco; Müller, Henning

2014-01-01

Recent advances in rehabilitation robotics suggest that it may be possible for hand-amputated subjects to recover at least a significant part of the lost hand functionality. The control of robotic prosthetic hands using non-invasive techniques is still a challenge in real life: myoelectric prostheses give limited control capabilities, the control is often unnatural and must be learned through long training times. Meanwhile, scientific literature results are promising but they are still far from fulfilling real-life needs. This work aims to close this gap by allowing worldwide research groups to develop and test movement recognition and force control algorithms on a benchmark scientific database. The database is targeted at studying the relationship between surface electromyography, hand kinematics and hand forces, with the final goal of developing non-invasive, naturally controlled, robotic hand prostheses. The validation section verifies that the data are similar to data acquired in real-life conditions, and that recognition of different hand tasks by applying state-of-the-art signal features and machine-learning algorithms is possible.

Motor unit number index (MUNIX) derivation from the relationship between the area and power of surface electromyogram: a computer simulation and clinical study

Science.gov (United States)

Miralles, Francesc

2018-06-01

Objective. The motor unit number index (MUNIX) is a technique based on the surface electromyogram (sEMG) that is gaining acceptance as a method for monitoring motor neuron loss, because it is reliable and produces less discomfort than other electrodiagnostic techniques having the same intended purpose. MUNIX assumes that the relationship between the area of sEMG obtained at increasing levels of muscle activation and the values of a variable called ‘ideal case motor unit count’ (ICMUC), defined as the product of the ratio between area and power of the compound muscle action potential (CMAP) by that of the sEMG, is described by a decreasing power function. Nevertheless, the reason for this comportment is unknown. The objective of this work is to investigate if the definition of MUNIX could derive from more basic properties of the sEMG. Approach. The CMAP and sEMG epochs obtained at different levels of muscle activation from (1) the abductor pollicis brevis (APB) muscle of persons with and without a carpal tunnel syndrome (CTS) and (2) from a computer model of sEMG generation previously published were analysed. Main results. MUNIX reflects the power relationship existing between the area and power of a sEMG. The exponent of this function was smaller in patients with motor CTS than in the rest of the subjects. The analysis of the relationship between the area and power of a sEMG could aid in distinguishing a MUNIX reduction due to a motoneuron loss from that due to a loss of muscle fibre. Significance. MUNIX is derived from the relationship between the area and power of a sEMG. This relationship changes when there is a loss of motor units (MUs), which partially explains the diagnostic sensibility of MUNIX. Although the reasons for this change are unknown, it could reflect an increase in the proportion of MUs of great amplitude.

Age-Related Increase in Electromyography Burst Activity in Males and Females

Directory of Open Access Journals (Sweden)

Olga Theou

2013-01-01

Full Text Available The rapid advancement of electromyography (EMG technology facilitates measurement of muscle activity outside the laboratory during daily life. The purpose of this study was to determine whether bursts in EMG recorded over a typical 8-hour day differed between young and old males and females. Muscle activity was recorded from biceps brachii, triceps brachii, vastus lateralis, and biceps femoris of 16 young and 15 old adults using portable surface EMG. Old muscles were active 16–27% of the time compared to 5–9% in young muscles. The number of bursts was greater in old than young adults and in females compared to males. Burst percentage and mean amplitude were greater in the flexor muscles compared with the extensor muscles. The greater burst activity in old adults coupled with the unique activity patterns across muscles in males and females provides further understanding of how changes in neuromuscular activity effects age-related functional decline between the sexes.

Non-invasive transabdominal uterine electromyography correlates with the strength of intrauterine pressure and is predictive of labor and delivery.

Science.gov (United States)

Maul, H; Maner, W L; Olson, G; Saade, G R; Garfield, R E

2004-05-01

The study was conducted to investigate whether the strength of uterine contractions monitored invasively by intrauterine pressure catheter could be determined from transabdominal electromyography (EMG) and to estimate whether EMG is a better predictor of true labor compared to tocodynamometry (TOCO). Uterine EMG was recorded from the abdominal surface in laboring patients simultaneously monitored with an intrauterine pressure catheter (n = 13) or TOCO (n = 24). Three to five contractions per patient and corresponding electrical bursts were randomly selected and analyzed (integral of intrauterine pressure; integral, frequency, amplitude of contraction curve on TOCO; burst energy for EMG). The Mann-Whitney test, Spearman correlation and receiver operator characteristics (ROC) analysis were used as appropriate (significance was assumed at a value of p TOCO parameters were different. In addition, burst energy levels were highly predictive of delivery within 48 h (AUC = 0.9531; p TOCO, transabdominal uterine EMG can be used reliably to predict labor and delivery.

Utilization and yield of nerve conduction studies and electromyography in older adults

LENUS (Irish Health Repository)

Mello, S

2016-02-01

Older adults are at increased risk of both central and peripheral neurological disorders. Impaired nerve and muscle deficits contribute to morbidity and reduced quality of life. Our aim was to define the utilization and yield of nerve conduction studies (NCS) and electromyography (EMG) in older adults. We reviewed NCS and EMG records for all patients older than age 65 in the year 2012. Of 1,530 NCS and EMGs performed, 352 (23%) were in patients older than 65 (mean age 73.7, 52% male). Two hundred and eighty-eight (83.7%) of NCS were abnormal as were 102 (71.8%) of EMGs. The likelihood of having an abnormal test result increased with increasing age. The most common diagnosis was peripheral neuropathy 231 (65.4%). The incidence of peripheral neuropathy is particularly high in this age group, and detection is vital to prevent morbidity and improve quality of life.

Effects of electrocardiography contamination and comparison of ECG removal methods on upper trapezius electromyography recordings.

Science.gov (United States)

Marker, Ryan J; Maluf, Katrina S

2014-12-01

Electromyography (EMG) recordings from the trapezius are often contaminated by the electrocardiography (ECG) signal, making it difficult to distinguish low-level muscle activity from muscular rest. This study investigates the influence of ECG contamination on EMG amplitude and frequency estimations in the upper trapezius during muscular rest and low-level contractions. A new method of ECG contamination removal, filtered template subtraction (FTS), is described and compared to 30 Hz high-pass filter (HPF) and averaged template subtraction (ATS) methods. FTS creates a unique template of each ECG artifact using a low-pass filtered copy of the contaminated signal, which is subtracted from contaminated periods in the original signal. ECG contamination results in an over-estimation of EMG amplitude during rest in the upper trapezius, with negligible effects on amplitude and frequency estimations during low-intensity isometric contractions. FTS and HPF successfully removed ECG contamination from periods of muscular rest, yet introduced errors during muscle contraction. Conversely, ATS failed to fully remove ECG contamination during muscular rest, yet did not introduce errors during muscle contraction. The relative advantages and disadvantages of different ECG contamination removal methods should be considered in the context of the specific motor tasks that require analysis. Copyright © 2014 Elsevier Ltd. All rights reserved.

Positioning of pedicle screws in adolescent idiopathic scoliosis using electromyography

Directory of Open Access Journals (Sweden)

Bruno Moreira Gavassi

2015-06-01

Full Text Available OBJECTIVE: To analyze the occurrence of poor positioning of pedicle screws inserted with the aid of intraoperative electromyographic stimulation in the treatment of Adolescent Idiopathic Scoliosis (AIS.METHODS: This is a prospective observational study including all patients undergoing surgical treatment for AIS, between March and December 2013 at a single institution. All procedures were monitored by electromyography of the inserted pedicle screws. The position of the screws was evaluated by assessment of postoperative CT and classified according to the specific AIS classification system.RESULTS: Sixteen patients were included in the study, totalizing 281 instrumented pedicles (17.5 per patient. No patient had any neurological deficit or complaint after surgery. In the axial plane, 195 screws were found in ideal position (69.4% while in the sagittal plane, 226 screws were found in ideal position (80.4%. Considering both the axial and the sagittal planes, it was observed that 59.1% (166/281 of the screws did not violate any cortical wall.CONCLUSION: The use of pedicle screws proved to be a safe technique without causing neurological damage in AIS surgeries, even with the occurrence of poor positioning of some implants.

[Electromyography Analysis of Rapid Eye Movement Sleep Behavior Disorder].

Science.gov (United States)

Nakano, Natsuko; Kinoshita, Fumiya; Takada, Hiroki; Nakayama, Meiho

2018-01-01

Polysomnography (PSG), which records physiological phenomena including brain waves, breathing status, and muscle tonus, is useful for the diagnosis of sleep disorders as a gold standard. However, measurement and analysis are complex for several specific sleep disorders, such as rapid eye movement (REM) sleep behavior disorder (RBD). Usually, brain waves during REM sleep indicate an awakening pattern under relaxed conditions of skeletal and antigravity muscles. However, these muscles are activated during REM sleep when patients suffer from RBD. These activated muscle movements during REM, so-called REM without atonia (RWA) recorded by PSG, may be related to a neurodegenerative disease such as Parkinson's disease. Thus, careful analysis of RWA is significant not only physically, but also clinically. Commonly, manual viewing measurement analysis of RWA is time-consuming. Therefore, quantitative studies on RWA are rarely reported. A software program, developed from Microsoft Office Excel ® , was used to semiautomatically analyze the RWA ratio extracted from PSG to compare with manual viewing measurement analysis. In addition, a quantitative muscle tonus study was carried out to evaluate the effect of medication on RBD patients. Using this new software program, we were able to analyze RWA on the same cases in approximately 15 min as compared with 60 min in the manual viewing measurement analysis. This software program can not only quantify RWA easily but also identify RWA waves for either phasic or tonic bursts. We consider that this software program will support physicians and scientists in their future research on RBD. We are planning to offer this software program for free to physicians and scientists.

Ankle muscle activity modulation during single-leg stance differs between children, young adults and seniors.

Science.gov (United States)

Kurz, Eduard; Faude, Oliver; Roth, Ralf; Zahner, Lukas; Donath, Lars

2018-02-01

Incomplete maturation and aging-induced declines of the neuromuscular system affect postural control both in children and older adults and lead to high fall rates. Age-specific comparisons of the modulation of ankle muscle activation and behavioral center of pressure (COP) indices during upright stance have been rarely conducted. The objective of the present study was to quantify aging effects on a neuromuscular level. Thus, surface electromyography (SEMG) modulation and co-activity of ankle muscles during single-leg standing was compared in healthy children, young adults and seniors. Postural steadiness (velocity and mean sway frequency of COP), relative muscle activation (SEMG modulation) and co-activation of two ankle muscles (tibialis anterior, TA; soleus, SO) were examined during single-leg stance in 19 children [age, 9.7 (SD 0.5) years], 30 adults [23.3 (1.5) years] and 29 seniors [62.7 (6.1) years]. Velocity of COP in medio-lateral and anterior-posterior directions, mean sway frequency in anterior-posterior direction, relative muscle activation (TA and SO) and co-activation revealed large age effects (P  0.14). Post-hoc comparisons indicated higher COP velocities, anterior-posterior frequencies, relative SO activation and co-activation in children and seniors when compared with adults. Relative TA activation was higher in children and adults compared with seniors (P seniors seems to be counteracted with higher TA/SO co-activity and SO modulation. However, TA modulation is higher in children and adults, whereas seniors' TA modulation capacity is diminished. An aging-induced decline of TA motor units might account for deteriorations of TA modulation in seniors.

Analysis of muscle fatigue conditions using time-frequency images and GLCM features

Directory of Open Access Journals (Sweden)

Karthick P.A.

2016-09-01

Full Text Available In this work, an attempt has been made to differentiate muscle non-fatigue and fatigue conditions using sEMG signals and texture representation of the time-frequency images. The sEMG signals are recorded from the biceps brachii muscle of 25 healthy adult volunteers during dynamic fatiguing contraction. The first and last curls of these signals are considered as the non-fatigue and fatigue zones, respectively. These signals are preprocessed and the time-frequency spectrum is computed using short time fourier transform (STFT. Gray-Level Co-occurrence Matrix (GLCM is extracted from low (15–45 Hz, medium (46–95 Hz and high (96–150 Hz frequency bands of the time-frequency images. Further, the features such as contrast, correlation, energy and homogeneity are calculated from the resultant matrices. The results show that the high frequency band based features are able to differentiate non-fatigue and fatigue conditions. The features such as correlation, contrast and homogeneity extracted at angles 0°, 45°, 90°, and 135° are found to be distinct with high statistical significance (p < 0.0001. Hence, this framework can be used for analysis of neuromuscular disorders.

Beauty in the eye of the beholder: Using facial electromyography to examine the association between eating disorder symptoms and perceptions of emaciation among undergraduate women.

Science.gov (United States)

Dodd, Dorian R; Velkoff, Elizabeth A; Forrest, Lauren N; Fussner, Lauren M; Smith, April

2017-06-01

Thin-ideal internalization, drive for thinness, and over-evaluation of the importance of thinness are associated with eating disorders (EDs). However, little research has examined to what extent perceptions of emaciation are also associated with ED symptoms. In the present study, 80 undergraduate women self-reported on ED symptomatology and perceptions of emaciated, thin, and overweight female bodies. While participants viewed images of these different body types, facial electromyography was used to measure activation of facial muscles associated with disgust reactions. Emaciated and overweight bodies were rated negatively and elicited facial responses consistent with disgust. Further, ED symptomatology was associated with pronounced aversion to overweight bodies (assessed via self-report pleasantness ratings), and attenuated negative affect to emaciated bodies (assessed via facial electromyography). The latter association was significant even when controlling for self-reported perceptions of emaciation, suggesting that psychophysiological methods in ED research may provide valuable information unavailable via self-report. Copyright © 2017 Elsevier Ltd. All rights reserved.

Multiscale musculoskeletal modelling, data–model fusion and electromyography-informed modelling

Science.gov (United States)

Zhang, J.; Heidlauf, T.; Sartori, M.; Besier, T.; Röhrle, O.; Lloyd, D.

2016-01-01

This paper proposes methods and technologies that advance the state of the art for modelling the musculoskeletal system across the spatial and temporal scales; and storing these using efficient ontologies and tools. We present population-based modelling as an efficient method to rapidly generate individual morphology from only a few measurements and to learn from the ever-increasing supply of imaging data available. We present multiscale methods for continuum muscle and bone models; and efficient mechanostatistical methods, both continuum and particle-based, to bridge the scales. Finally, we examine both the importance that muscles play in bone remodelling stimuli and the latest muscle force prediction methods that use electromyography-assisted modelling techniques to compute musculoskeletal forces that best reflect the underlying neuromuscular activity. Our proposal is that, in order to have a clinically relevant virtual physiological human, (i) bone and muscle mechanics must be considered together; (ii) models should be trained on population data to permit rapid generation and use underlying principal modes that describe both muscle patterns and morphology; and (iii) these tools need to be available in an open-source repository so that the scientific community may use, personalize and contribute to the database of models. PMID:27051510

Independence Between Two Channels of Surface Electromyogram Signal to Measure the Loss of Motor Units

Directory of Open Access Journals (Sweden)

Arjunan Sridhar P.

2015-06-01

Full Text Available This study has investigated the relationship in the connectivity of motor units in surface electromyogram (sEMG of biceps brachii muscle. It is hypothesized that with ageing, there is reduction/loss in number of motor units, leading to reduction in the independence between the channels of the recorded muscle activity. Two channels of sEMG were recorded during three levels of isometric muscle contraction: 50 %, 75 % and 100 % maximal voluntary contraction (MVC. 73 subjects (age range 20-70 participated in the experiments. The independence in channel index (ICI between the two sEMG recording locations was computed using the independent components and Frobenius norm. ANOVA Statistical analysis was performed to test the effect of age (loss of motor units and level of contraction on ICI. The results show that the ICI among the older cohort was significantly lower compared with the younger adults. This research study has shown that the reduction in number of motor units is reflected by the reduction in the ICI of the sEMG signal.

Estimation of muscle fatigue by ratio of mean frequency to average rectified value from surface electromyography.

Science.gov (United States)

Fernando, Jeffry Bonar; Yoshioka, Mototaka; Ozawa, Jun

2016-08-01

A new method to estimate muscle fatigue quantitatively from surface electromyography (EMG) is proposed. The ratio of mean frequency (MNF) to average rectified value (ARV) is used as the index of muscle fatigue, and muscle fatigue is detected when MNF/ARV falls below a pre-determined or pre-calculated baseline. MNF/ARV gives larger distinction between fatigued muscle and non-fatigued muscle. Experiment results show the effectiveness of our method in estimating muscle fatigue more correctly compared to conventional methods. An early evaluation based on the initial value of MNF/ARV and the subjective time when the subjects start feeling the fatigue also indicates the possibility of calculating baseline from the initial value of MNF/ARV.

FEATURE EXTRACTION FOR EMG BASED PROSTHESES CONTROL

Directory of Open Access Journals (Sweden)

R. Aishwarya

2013-01-01

Full Text Available The control of prosthetic limb would be more effective if it is based on Surface Electromyogram (SEMG signals from remnant muscles. The analysis of SEMG signals depend on a number of factors, such as amplitude as well as time- and frequency-domain properties. Time series analysis using Auto Regressive (AR model and Mean frequency which is tolerant to white Gaussian noise are used as feature extraction techniques. EMG Histogram is used as another feature vector that was seen to give more distinct classification. The work was done with SEMG dataset obtained from the NINAPRO DATABASE, a resource for bio robotics community. Eight classes of hand movements hand open, hand close, Wrist extension, Wrist flexion, Pointing index, Ulnar deviation, Thumbs up, Thumb opposite to little finger are taken into consideration and feature vectors are extracted. The feature vectors can be given to an artificial neural network for further classification in controlling the prosthetic arm which is not dealt in this paper.

Listening to music during electromyography does not influence the examinee's anxiety and pain levels.

Science.gov (United States)

Abraham, Alon; Drory, Vivian E

2014-09-01

Listening to music is a low-cost intervention that has demonstrated ability to reduce pain and anxiety levels in various medical procedures. Subjects undergoing electrophysiological examinations were randomized into a music-listening group and a control group. Visual analog scales were used to measure anxiety and pain levels during the procedure. Thirty subjects were randomized to each group. No statistically significant difference was found in anxiety or pain levels during the procedure between groups. However, most subjects in the music-listening group reported anxiety and pain reduction and would prefer to hear music in a future examination. Although listening to music during electrophysiological examinations did not reduce anxiety or pain significantly, most subjects felt a positive effect and would prefer to hear music; therefore, we suggest that music may be offered optionally in the electromyography laboratory setting. © 2014 Wiley Periodicals, Inc.

Decoding subtle forearm flexions using fractal features of surface electromyogram from single and multiple sensors.

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Arjunan, Sridhar Poosapadi; Kumar, Dinesh Kant

2010-10-21

Identifying finger and wrist flexion based actions using a single channel surface electromyogram (sEMG) can lead to a number of applications such as sEMG based controllers for near elbow amputees, human computer interface (HCI) devices for elderly and for defence personnel. These are currently infeasible because classification of sEMG is unreliable when the level of muscle contraction is low and there are multiple active muscles. The presence of noise and cross-talk from closely located and simultaneously active muscles is exaggerated when muscles are weakly active such as during sustained wrist and finger flexion. This paper reports the use of fractal properties of sEMG to reliably identify individual wrist and finger flexion, overcoming the earlier shortcomings. SEMG signal was recorded when the participant maintained pre-specified wrist and finger flexion movements for a period of time. Various established sEMG signal parameters such as root mean square (RMS), Mean absolute value (MAV), Variance (VAR) and Waveform length (WL) and the proposed fractal features: fractal dimension (FD) and maximum fractal length (MFL) were computed. Multi-variant analysis of variance (MANOVA) was conducted to determine the p value, indicative of the significance of the relationships between each of these parameters with the wrist and finger flexions. Classification accuracy was also computed using the trained artificial neural network (ANN) classifier to decode the desired subtle movements. The results indicate that the p value for the proposed feature set consisting of FD and MFL of single channel sEMG was 0.0001 while that of various combinations of the five established features ranged between 0.009 - 0.0172. From the accuracy of classification by the ANN, the average accuracy in identifying the wrist and finger flexions using the proposed feature set of single channel sEMG was 90%, while the average accuracy when using a combination of other features ranged between 58% and 73

Decoding subtle forearm flexions using fractal features of surface electromyogram from single and multiple sensors

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Kumar Dinesh

2010-10-01

Full Text Available Abstract Background Identifying finger and wrist flexion based actions using a single channel surface electromyogram (sEMG can lead to a number of applications such as sEMG based controllers for near elbow amputees, human computer interface (HCI devices for elderly and for defence personnel. These are currently infeasible because classification of sEMG is unreliable when the level of muscle contraction is low and there are multiple active muscles. The presence of noise and cross-talk from closely located and simultaneously active muscles is exaggerated when muscles are weakly active such as during sustained wrist and finger flexion. This paper reports the use of fractal properties of sEMG to reliably identify individual wrist and finger flexion, overcoming the earlier shortcomings. Methods SEMG signal was recorded when the participant maintained pre-specified wrist and finger flexion movements for a period of time. Various established sEMG signal parameters such as root mean square (RMS, Mean absolute value (MAV, Variance (VAR and Waveform length (WL and the proposed fractal features: fractal dimension (FD and maximum fractal length (MFL were computed. Multi-variant analysis of variance (MANOVA was conducted to determine the p value, indicative of the significance of the relationships between each of these parameters with the wrist and finger flexions. Classification accuracy was also computed using the trained artificial neural network (ANN classifier to decode the desired subtle movements. Results The results indicate that the p value for the proposed feature set consisting of FD and MFL of single channel sEMG was 0.0001 while that of various combinations of the five established features ranged between 0.009 - 0.0172. From the accuracy of classification by the ANN, the average accuracy in identifying the wrist and finger flexions using the proposed feature set of single channel sEMG was 90%, while the average accuracy when using a combination

Electromyography of the buccal musculature of octopus (Octopus bimaculoides): a test of the function of the muscle articulation in support and movement.

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Uyeno, Theodore A; Kier, William M

2007-01-01

The buccal mass musculature of the octopus (Octopus bimaculoides) was studied with electromyography to test the predictions of a previous morphological study in which we suggested that the muscles of the buccal mass serve as both the effectors of movement and as the joint itself, forming a new category of flexible joint termed a ;muscle articulation'. The predictions of muscle function were tested by correlating muscle electrical activity in isolated buccal masses with spontaneous beak movements. Bipolar electromyography electrodes were implanted in the various beak muscles and beak position was recorded simultaneously with an electronic movement monitor (N=14). The results are consistent with the hypothesis that the lateral mandibular muscles produce opening movements of the beaks and provide the first definitive explanation of the opening mechanism. The results are also consistent with the hypothesis that the superior mandibular muscle functions primarily in closing. Co-contraction of the lateral mandibular muscles and the superior mandibular muscles was also observed, suggesting that these muscles may also stabilize the beaks during movement or provide a means of controlling the location of the pivot between the beaks. This study provides an important first test of the predictions of the role of the complex musculature found in muscle articulations such as the cephalopod buccal mass.

Electromyography-controlled exoskeletal upper-limb-powered orthosis for exercise training after stroke.

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Stein, Joel; Narendran, Kailas; McBean, John; Krebs, Kathryn; Hughes, Richard

2007-04-01

Robot-assisted exercise shows promise as a means of providing exercise therapy for weakness that results from stroke or other neurological conditions. Exoskeletal or "wearable" robots can, in principle, provide therapeutic exercise and/or function as powered orthoses to help compensate for chronic weakness. We describe a novel electromyography (EMG)-controlled exoskeletal robotic brace for the elbow (the active joint brace) and the results of a pilot study conducted using this brace for exercise training in individuals with chronic hemiparesis after stroke. Eight stroke survivors with severe chronic hemiparesis were enrolled in this pilot study. One subject withdrew from the study because of scheduling conflicts. A second subject was unable to participate in the training protocol because of insufficient surface EMG activity to control the active joint brace. The six remaining subjects each underwent 18 hrs of exercise training using the device for a period of 6 wks. Outcome measures included the upper-extremity component of the Fugl-Meyer scale and the modified Ashworth scale of muscle hypertonicity. Analysis revealed that the mean upper-extremity component of the Fugl-Meyer scale increased from 15.5 (SD 3.88) to 19 (SD 3.95) (P = 0.04) at the conclusion of training for the six subjects who completed training. Combined (summated) modified Ashworth scale for the elbow flexors and extensors improved from 4.67 (+/-1.2 SD) to 2.33 (+/-0.653 SD) (P = 0.009) and improved for the entire upper limb as well. All subjects tolerated the device, and no complications occurred. EMG-controlled powered elbow orthoses can be successfully controlled by severely impaired hemiparetic stroke survivors. This technique shows promise as a new modality for assisted exercise training after stroke.

Efeitos da eletroestimulação do músculo vasto medial oblíquo em portadores de síndrome da dor patelofemoral: uma análise eletromiográfica Effects of electrical stimulation of vastus medialis obliquus muscle in patients with patellofemoral pain syndrome: an electromyographic analysis

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Fabiana R. Garcia

2010-12-01

Full Text Available CONTEXTUALIZAÇÃO: O uso da eletromiografia de superfície (EMG-S tem sido considerado como instrumento de avaliação quantitativa na síndrome da dor patelofemoral (SDPF. Tratamentos conservadores objetivam melhorar o alinhamento patelar, e a estimulação elétrica do músculo vasto medial oblíquo (VMO tem sido considerada por ser seletiva e não causar irritação articular. OBJETIVO: Verificar o efeito de um programa de fortalecimento muscular com estimulação elétrica do VMO na SDPF por meio da capacidade de avaliação da EMG-S. MÉTODOS: Participaram deste estudo 10 mulheres jovens (idade: 23,1±4,9 anos; massa corporal: 66,8±14,0 kg; estatura: 1,63±6,9 cm; IMC: 25,1±5,6 kg/m² com SDPF unilateral, as quais realizaram o teste funcional de subir degrau para captação da atividade eletromiográfica dos músculos VMO e vasto lateral (VL, antes e após um programa de estimulação elétrica do VMO. A eletroestimulação foi realizada três vezes por semana, durante seis semanas. Foram consideradas, para análise entre VMO e VL, as variáveis razão do tempo do início até o pico de ativação, razão da integral do sinal (teste t para amostras dependentes e diferença de início de ativação (teste de Wilcoxon, com n��vel de significância de pBACKGROUND: The use of surface electromyography (SEMG has been considered a tool for quantitative assessment of patellofemoral pain syndrome (PFPS. Conservative treatments aim to improve patellar alignment, and electrical stimulation of the vastus medialis obliquus (VMO muscle has been considered effective because it is selective and does not cause joint irritation. OBJECTIVE: This study aims to investigate the efficiency of a muscle strengthening program with electrical stimulation of the VMO muscle in PFPS by SEMG. METHODS: A group of ten young women (age: 23.1±4.9 years; body mass: 66.8±14.0 kg; height: 1.63±6.9 cm; BMI: 25.1±5.6 kg/m² with unilateral PFPS participated in the

Altered movement patterns and muscular activity during single and double leg squats in individuals with anterior cruciate ligament injury.

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Trulsson, Anna; Miller, Michael; Hansson, Gert-Åke; Gummesson, Christina; Garwicz, Martin

2015-02-13

Individuals with Anterior Cruciate Ligament (ACL) injury often show altered movement patterns, suggested to be partly due to impaired sensorimotor control. Here, we therefore aimed to assess muscular activity during movements often used in ACL-rehabilitation and to characterize associations between deviations in muscular activity and specific altered movement patterns, using and further exploring the previously developed Test for substitution Patterns (TSP). Sixteen participants (10 women) with unilateral ACL rupture performed Single and Double Leg Squats (SLS; DLS). Altered movement patterns were scored according to TSP, and Surface Electromyography (SEMG) was recorded bilaterally in six hip, thigh and shank muscles. To quantify deviations in muscular activity, SEMG ratios were calculated between homonymous muscles on injured and non-injured sides, and between antagonistic muscles on the same side. Correlations between deviations of injured/non-injured side SEMG ratios and specific altered movement patterns were calculated. Injured/non-injured ratios were low at transition from knee flexion to extension in quadriceps in SLS, and in quadriceps and hamstrings in DLS. On injured side, the quadriceps/hamstrings ratio prior to the beginning of DLS and end of DLS and SLS, and tibialis/gastrocnemius ratio at end of DLS were lower than on non-injured side. Correlations were found between specific altered movement patterns and deviating muscular activity at transition from knee flexion to extension in SLS, indicating that the more deviating the muscular activity on injured side, the more pronounced the altered movement pattern. "Knee medial to supporting foot" correlated to lower injured/non-injured ratios in gluteus medius (rs = -0.73, p = 0.001), "lateral displacement of hip-pelvis-region" to lower injured/non-injured ratios in quadriceps (rs = -0.54, p = 0.03) and "displacement of trunk" to higher injured/non-injured ratios in gluteus medius (rs = 0.62, p = 0

The Effects of Vibration and Muscle Fatigue on Trunk Sensorimotor Control in Low Back Pain Patients

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Abboud, Jacques; Nougarou, François; Normand, Martin C.

2015-01-01

Introduction Changes in sensorimotor function and increased trunk muscle fatigability have been identified in patients with chronic low back pain (cLBP). This study assessed the control of trunk force production in conditions with and without local erector spinae muscle vibration and evaluated the influence of muscle fatigue on trunk sensorimotor control. Methods Twenty non-specific cLBP patients and 20 healthy participants were asked to perform submaximal isometric trunk extension torque with and without local vibration stimulation, before and after a trunk extensor muscle fatigue protocol. Constant error (CE), variable error (VE) as well as absolute error (AE) in peak torque were computed and compared across conditions. Trunk extensor muscle activation during isometric contractions and during the fatigue protocol was measured using surface electromyography (sEMG). Results Force reproduction accuracy of the trunk was significantly lower in the patient group (CE = 9.81 ± 2.23 Nm; AE = 18.16 ± 3.97 Nm) than in healthy participants (CE = 4.44 ± 1.68 Nm; AE = 12.23 ± 2.44 Nm). Local erector spinae vibration induced a significant reduction in CE (4.33 ± 2.14 Nm) and AE (13.71 ± 3.45 Nm) mean scores in the patient group. Healthy participants conversely showed a significant increase in CE (8.17 ± 2.10 Nm) and AE (16.29 ± 2.82 Nm) mean scores under vibration conditions. The fatigue protocol induced erector spinae muscle fatigue as illustrated by a significant decrease in sEMG median time-frequency slopes. Following the fatigue protocol, patients with cLBP showed significant decrease in sEMG root mean square activity at L4-5 level and responded in similar manner with and without vibration stimulation in regard to CE mean scores. Conclusions Patients with cLBP have a less accurate force reproduction sense than healthy participants. Local muscle vibration led to significant trunk neuromuscular control improvements in the cLBP patients before and after a muscle

Value of Laryngeal Electromyography in Spasmodic Dysphonia Diagnosis and Therapy.

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Yang, Qingwen; Xu, Wen; Li, Yun; Cheng, Liyu

2015-07-01

To investigate the role of laryngeal electromyography (LEMG) in the diagnosis and treatment of spasmodic dysphonia (SD). The clinical manifestations, characteristics of motor unit potentials (MUPs), recruitment potentials, and laryngeal nerve evoked potentials (EPs) in LEMG, as well as the changes after botulinum toxin (BTX) treatment, were analyzed in 39 patients with adductor SD. The main clinical manifestations were a strained voice and phonation interruptions; in addition, the patients displayed hyper-adducted vocal folds during phonation. LEMG revealed significantly increased amplitudes of the thyroarytenoid muscle MUPs. The recruitment potentials were in a dense bunch, discharging full interference patterns with significantly increased amplitudes; the mean and maximum amplitude of recruitment potentials were 3090 μV and 5000 μV, respectively. The amplitude of EPs of thyroarytenoid muscle increased significantly; the mean and maximum amplitudes were 10.3 mV and 26.3 mV, respectively. After BTX was injected, the LEMG revealed denervation changes, and the EPs weakened or disappeared in the injected muscle. SD could be diagnosed, and the therapeutic efficacy of SD treatments could be evaluated based on clinical characteristics combined with LEMG characteristics. The increased amplitudes of the recruitment potentials and EPs of the thyroarytenoid muscle were the characteristic indexes. After BTX was injected, denervated potential characteristics appeared in the muscles. © The Author(s) 2015.

A new concept for evaluating muscle function in the lower extremities in cases of low back pain syndrome in anamnesis

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Przemysław Lisiński

2014-06-01

Full Text Available introduction. There are difficulties in objective evaluation of activity of the muscles in the lower extremities of patients after successful treatment of sciatica and pseudosciatica, when no clear clinical symptoms are detected. However, the existence of some muscle dysfunction can be hypothesised and its detection was the aim of the study. objective. Recordings from chosen lower extremity muscles during standing were performed as supplementary differential diagnosis in evaluation of these patients. EMG in standing positions constitutes a new methodological approach not described in detail. methods. Twenty patients (11 after sciatica and 9 after sciatica-like episodes were enrolled into the study. On the day of examination, clinical and electroneurographical (ENG; M and F waves tests studies showed no pathology. The percentage of maximal voluntary contraction (MVC defined muscle activity during standing. Mean amplitude and number of changes in muscle activity (fluctuations were measured in surface electromyography recordings (sEMG during normal standing and tandem positions. results and conclusions. Activity of proximal lower extremity muscles expressed as percentage of MVC was bilaterally increased in patients after sciatica in normal standing position, compared with results from the group of healthy volunteers (N=9. Patients after sciatica were also characterized with a significant increase of mean sEMG amplitude, recorded especially in distal muscles on the affected side during tandem position. This pathological change was related to decrease in ‘fluctuations’ frequency in patients after sciatica (P<0.001 more than after pseudosciatica (P<0.01 groups in both standing positions, compared to parameters of healthy volunteers. Sciatica and pseudosciatica in anamnesis cause different abnormal patterns of lower extremity muscle activity during standing positions when recorded with surface EMG.

The vastus lateralis neuromuscular activity during all-out cycling exercise.

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Bercier, Stephane; Halin, Renaud; Ravier, Philippe; Kahn, Jean-Francois; Jouanin, Jean-Claude; Lecoq, Anne-Marie; Buttelli, Olivier

2009-10-01

The objective of this work was to study modifications in motor control through surface electromyographic (sEMG) activity during a very short all-out cycling exercise. Twelve male cyclists (age 23+/-4 years) participated in this study. After a warm-up period, each subject performed three all-out cycling exercises of 6s separated by 2 min of complete rest. This protocol was repeated three times with a minimum of 2 days between each session. The braking torque imposed on cycling motion was 19 Nm. The sEMG of the vastus lateralis was recorded during the first seven contractions of the sprint. Time-frequency analysis of sEMG was performed using continuous wavelet transform. The mean power frequency (MPF, qualitative modifications in the recruitment of motor units) and signal energy (a quantitative indicator of modifications in the motor units recruitment) were computed for the frequency range 10-500 Hz. sEMG energy increased (P0.05) between contraction number 1 and 2, decreased (P recruitment of motor units (MUs) at the beginning of the sprint followed by a preferential recruitment of faster MUs at the end of the sprint, respectively.

Comparative study of a muscle stiffness sensor and electromyography and mechanomyography under fatigue conditions.

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Han, Hyonyoung; Jo, Sungho; Kim, Jung

2015-07-01

This paper proposes the feasibility of a stiffness measurement for muscle contraction force estimation under muscle fatigue conditions. Bioelectric signals have been widely studied for the estimation of the contraction force for physical human-robot interactions, but the correlation between the biosignal and actual motion is decreased under fatigue conditions. Muscle stiffness could be a useful contraction force estimator under fatigue conditions because it measures the same physical quantity as the muscle contraction that generates the force. Electromyography (EMG), mechanomyography (MMG), and a piezoelectric resonance-based active muscle stiffness sensor were used to analyze the biceps brachii under isometric muscle fatigue conditions with reference force sensors at the end of the joint. Compared to EMG and MMG, the change in the stiffness signal was smaller (p fatigue condition changed fatigue conditions. This result indicates that the muscle stiffness signal is less sensitive to muscle fatigue than other biosignals. This investigation provides insights into methods of monitoring and compensating for muscle fatigue.

Wrist Rehabilitation Assisted by an Electromyography-Driven Neuromuscular Electrical Stimulation Robot After Stroke.

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Hu, Xiao-Ling; Tong, Raymond Kai-yu; Ho, Newmen S K; Xue, Jing-jing; Rong, Wei; Li, Leonard S W

2015-09-01

Augmented physical training with assistance from robot and neuromuscular electrical stimulation (NMES) may introduce intensive motor improvement in chronic stroke. To compare the rehabilitation effectiveness achieved by NMES robot-assisted wrist training and that by robot-assisted training. This study was a single-blinded randomized controlled trial with a 3-month follow-up. Twenty-six hemiplegic subjects with chronic stroke were randomly assigned to receive 20-session wrist training with an electromyography (EMG)-driven NMES robot (NMES robot group, n = 11) and with an EMG-driven robot (robot group, n = 15), completed within 7 consecutive weeks. Clinical scores, Fugl-Meyer Assessment (FMA), Modified Ashworth Score (MAS), and Action Research Arm Test (ARAT) were used to evaluate the training effects before and after the training, as well as 3 months later. An EMG parameter, muscle co-contraction index, was also applied to investigate the session-by-session variation in muscular coordination patterns during the training. The improvement in FMA (shoulder/elbow, wrist/hand) obtained in the NMES robot group was more significant than the robot group (P rehabilitation progress. © The Author(s) 2014.

Electromyographic signal and force comparisons during maximal voluntary isometric contraction in water and on dry land.

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Pinto, Stephanie Santana; Liedtke, Giane Veiga; Alberton, Cristine Lima; da Silva, Eduardo Marczwski; Cadore, Eduardo Lusa; Kruel, Luiz Fernando Martins

2010-11-01

This study was designed to compare surface electromyographic (sEMG) signal and force production during maximal voluntary isometric contractions (MVCs) in water and on dry land. The reproducibility of sEMG and isometric force measurements between water and dry land environments was also assessed. Nine women performed MVC for elbow flexion and extension, hip flexion, and extension against identical fixed resistance in both environments. The sEMG signal from biceps brachii, triceps brachii, rectus femoris, and biceps femoris was recorded with waterproof adhesives placed over each electrode. The sEMG and force production showed no significant difference between water and dry land, except for HEX (p = 0.035). In addition, intraclass correlation coefficient values were significant and ranged from moderate to high (0.66-0.96) for sEMG and force production between environments. These results showed that the environment did not influence the sEMG and force in MVC.

The Psychophysiology of Posttraumatic Stress Disorder: A Meta-Analysis

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Pole, Nnamdi

2007-01-01

This meta-analysis of 58 resting baseline studies, 25 startle studies, 17 standardized trauma cue studies, and 22 idiographic trauma cue studies compared adults with and without posttraumatic stress disorder (PTSD) on psychophysiological variables: facial electromyography (EMG), heart rate (HR), skin conductance (SC), and blood pressure.…

Voluntary low-force contraction elicits prolonged low-frequency fatigue and changes in surface electromyography and mechanomyography

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Blangsted, Anne Katrine; Sjøgaard, Gisela; Madeleine, Pascal

2005-01-01

Controversies exist regarding objective documentation of fatigue development with low-force contractions. We hypothesized that non-exhaustive, low-force muscle contraction may induce prolonged low-frequency fatigue (LFF) that in the subsequent recovery period is detectable by electromyography (EMG......) and in particular mechanomyography (MMG) during low-force rather than high-force test contractions. Seven subjects performed static wrist extension at 10% maximal voluntary contraction (MVC) for 10 min (10%MVC10 min). Wrist force response to electrical stimulation of extensor carpi radialis muscle (ECR) quantified...... LFF. EMG and MMG were recorded from ECR during static test contractions at 5% and 80% MVC. Electrical stimulation, MVC, and test contractions were performed before 10%MVC10 min and at 10, 30, 90 and 150 min recovery. In spite of no changes in MVC, LFF persisted up to 150 min recovery but did...

Patterns of motor recruitment can be determined using surface EMG.

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Wakeling, James M

2009-04-01

Previous studies have reported how different populations of motor units (MUs) can be recruited during dynamic and locomotor tasks. It was hypothesised that the higher-threshold units would contribute higher-frequency components to the sEMG spectra due to their faster conduction velocities, and thus recruitment patterns that increase the proportion of high-threshold units active would lead to higher-frequency elements in the sEMG spectra. This idea was tested by using a model of varying recruitment coupled to a three-layer volume conductor model to generate a series of sEMG signals. The recruitment varied from (A) orderly recruitment where the lowest-threshold MUs were initially activated and higher-threshold MUs were sequentially recruited as the contraction progressed, (B) a recurrent inhibition model that started with orderly recruitment, but as the higher-threshold units were activated they inhibited the lower-threshold MUs (C) nine models with intermediate properties that were graded between these two extremes. The sEMG was processed using wavelet analysis and the spectral properties quantified by their mean frequency, and an angle theta that was determined from the principal components of the spectra. Recruitment strategies that resulted in a greater proportion of faster MUs being active had a significantly lower theta and higher mean frequency.

Detecting Nasal Vowels in Speech Interfaces Based on Surface Electromyography.

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João Freitas

Full Text Available Nasality is a very important characteristic of several languages, European Portuguese being one of them. This paper addresses the challenge of nasality detection in surface electromyography (EMG based speech interfaces. We explore the existence of useful information about the velum movement and also assess if muscles deeper down in the face and neck region can be measured using surface electrodes, and the best electrode location to do so. The procedure we adopted uses Real-Time Magnetic Resonance Imaging (RT-MRI, collected from a set of speakers, providing a method to interpret EMG data. By ensuring compatible data recording conditions, and proper time alignment between the EMG and the RT-MRI data, we are able to accurately estimate the time when the velum moves and the type of movement when a nasal vowel occurs. The combination of these two sources revealed interesting and distinct characteristics in the EMG signal when a nasal vowel is uttered, which motivated a classification experiment. Overall results of this experiment provide evidence that it is possible to detect velum movement using sensors positioned below the ear, between mastoid process and the mandible, in the upper neck region. In a frame-based classification scenario, error rates as low as 32.5% for all speakers and 23.4% for the best speaker have been achieved, for nasal vowel detection. This outcome stands as an encouraging result, fostering the grounds for deeper exploration of the proposed approach as a promising route to the development of an EMG-based speech interface for languages with strong nasal characteristics.

The LET Procedure for Prosthetic Myocontrol: Towards Multi-DOF Control Using Single-DOF Activations.

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Markus Nowak

Full Text Available Simultaneous and proportional myocontrol of dexterous hand prostheses is to a large extent still an open problem. With the advent of commercially and clinically available multi-fingered hand prostheses there are now more independent degrees of freedom (DOFs in prostheses than can be effectively controlled using surface electromyography (sEMG, the current standard human-machine interface for hand amputees. In particular, it is uncertain, whether several DOFs can be controlled simultaneously and proportionally by exclusively calibrating the intended activation of single DOFs. The problem is currently solved by training on all required combinations. However, as the number of available DOFs grows, this approach becomes overly long and poses a high cognitive burden on the subject. In this paper we present a novel approach to overcome this problem. Multi-DOF activations are artificially modelled from single-DOF ones using a simple linear combination of sEMG signals, which are then added to the training set. This procedure, which we named LET (Linearly Enhanced Training, provides an augmented data set to any machine-learning-based intent detection system. In two experiments involving intact subjects, one offline and one online, we trained a standard machine learning approach using the full data set containing single- and multi-DOF activations as well as using the LET-augmented data set in order to evaluate the performance of the LET procedure. The results indicate that the machine trained on the latter data set obtains worse results in the offline experiment compared to the full data set. However, the online implementation enables the user to perform multi-DOF tasks with almost the same precision as single-DOF tasks without the need of explicitly training multi-DOF activations. Moreover, the parameters involved in the system are statistically uniform across subjects.

Orthostatic Tremor and Orthostatic Myoclonus: Weight-bearing Hyperkinetic Disorders: A Systematic Review, New Insights, and Unresolved Questions

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Anhar Hassan

2016-11-01

Full Text Available Background: Orthostatic tremor (OT and orthostatic myoclonus (OM are weight-bearing hyperkinetic movement disorders most commonly affecting older people that induce “shaky legs” upon standing. OT is divided into “classical” and “slow” forms based on tremor frequency. In this paper, the first joint review of OT and OM, we review the literature and compare and contrast their demographic, clinical, electrophysiological, neuroimaging, pathophysiological, and treatment characteristics. Methods: A PubMed search up to July 2016 using the phrases “orthostatic tremor,” “orthostatic myoclonus,” “shaky legs,” and “shaky legs syndrome” was performed. Results: OT and OM should be suspected in older patients reporting unsteadiness with prolonged standing and/or who exhibit cautious, wide-based gaits. Surface electromyography (SEMG is necessary to verify the diagnoses. Functional neuroimaging and electrophysiology suggest the generator of classical OT lies within the cerebellothalamocortical network. For OM, and possibly slow OT, the frontal, subcortical cerebrum is the most likely origin. Clonazepam is the most useful medication for classical OT, and levetiracetam for OM, although results are often disappointing. Deep brain stimulation appears promising for classical OT. Rolling walkers reliably improve gait affected by these disorders, as both OT and OM attenuate when weight is transferred from the legs to the arms. Discussion: Orthostatic hyperkinesias are likely underdiagnosed, as SEMG is often unavailable in clinical practice, and thus may be more frequent than currently recognized. The shared weight-bearing induction of OT and OM may indicate a common pathophysiology. Further research, including use of animal models, is necessary to better define the prevalence and pathophysiology of OT and OM, in order to improve their treatment, and provide additional insights into basic balance and gait mechanisms.

Importance of electromyography and the electrophysiological severity scale in forensic reports.

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Bilgin, Nursel Gamsiz; Ozge, Aynur; Mert, Ertan; Yalçinkaya, Deniz E; Kar, Hakan

2007-05-01

Forensic reports on traumatic peripheral nerve injuries include dysfunction degrees of extremities, which are arranged according to the Turkish Penalty Code. The aim of this study is to discuss the role and importance of electromyography while preparing forensic reports in the cases of traumatic peripheral nerve injuries and the usefulness of scoring systems. A modified global scale, recommended by Mondelli et al., was used to assess the electrophysiological impairment of each peripheral nerve. Forensic reports of 106 patients, reported between 2002 and 2004, were evaluated. Thirty-four percent of the cases were reported as "total loss of function," 41.5% were reported as "functional disability," and there were no dysfunctions in the other cases in forensic reports that were prepared based on Council of Social Insurance Regulations of Health Processes and Guide prepared by the Council of Forensic Medicine and profession associations of forensic medicine. When we rearranged these forensic reports based on the electrophysiological severity scale (ESS), it was clearly found that all of the score 2 cases and 86.7% of the score 3 cases corresponded to "functional disability" and 91.4% of the score 4 cases correspond to "total loss of function." We found a significant correlation between the ESS and functional evaluation in peripheral nerve injury cases. Evaluation of functional disabilities in peripheral nerve injuries with the ESS represents a standardized and objective method used for forensic reports.

Estimation of tissue stiffness, reflex activity, optimal muscle length and slack length in stroke patients using an electromyography driven antagonistic wrist model.

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de Gooijer-van de Groep, Karin L; de Vlugt, Erwin; van der Krogt, Hanneke J; Helgadóttir, Áróra; Arendzen, J Hans; Meskers, Carel G M; de Groot, Jurriaan H

2016-06-01

About half of all chronic stroke patients experience loss of arm function coinciding with increased stiffness, reduced range of motion and a flexed wrist due to a change in neural and/or structural tissue properties. Quantitative assessment of these changes is of clinical importance, yet not trivial. The goal of this study was to quantify the neural and structural properties contributing to wrist joint stiffness and to compare these properties between healthy subjects and stroke patients. Stroke patients (n=32) and healthy volunteers (n=14) were measured using ramp-and-hold rotations applied to the wrist joint by a haptic manipulator. Neural (reflexive torque) and structural (connective tissue stiffness and slack lengths and (contractile) optimal muscle lengths) parameters were estimated using an electromyography driven antagonistic wrist model. Kruskal-Wallis analysis with multiple comparisons was used to compare results between healthy subjects, stroke patients with modified Ashworth score of zero and stroke patients with modified Ashworth score of one or more. Stroke patients with modified Ashworth score of one or more differed from healthy controls (Pslack length of connective tissue of the flexor muscles. Non-invasive quantitative analysis, including estimation of optimal muscle lengths, enables to identify neural and non-neural changes in chronic stroke patients. Monitoring these changes in time is important to understand the recovery process and to optimize treatment. Copyright © 2016 Elsevier Ltd. All rights reserved.

The Effect of Local Anesthetic Volume Within the Adductor Canal on Quadriceps Femoris Function Evaluated by Electromyography

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Grevstad, Ulrik; Jæger, Pia; Kløvgaard, Johan

2016-01-01

BACKGROUND: Single-injection adductor canal block (ACB) provides analgesia after knee surgery. Which nerves that are blocked by an ACB and what influence-if any-local anesthetic volume has on the effects remain undetermined. We hypothesized that effects on the nerve to the vastus medialis muscle......, they received a femoral nerve block and a placebo ACB. The effect on the vastus medialis (primary endpoint) and the vastus lateralis was evaluated using noninvasive electromyography (EMG). Quadriceps femoris muscle strength was evaluated using a dynamometer. RESULTS: There was a statistically significant......L was used (P = 0.0001). No statistically significant differences were found between volume and effect on the vastus lateralis (P = 0.81) or in muscle strength (P = 0.15). CONCLUSIONS: For ACB, there is a positive correlation between local anesthetic volume and effect on the vastus medialis muscle. Despite...

Evaluation of Myoelectric Activity of Paraspinal Muscles in Adolescents with Idiopathic Scoliosis during Habitual Standing and Sitting

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Garcia Kwok

2015-01-01

Full Text Available There is a number of research work in the literature that have applied sEMG biofeedback as an instrument for muscle rehabilitation. Therefore, sEMG is a good tool for this research work and is used to record the myoelectric activity in the paraspinal muscles of those with AIS during habitual standing and sitting. After the sEMG evaluation, the root-mean-square (RMS sEMG values of the paraspinal muscles in the habitual postures reflect the spinal curvature situation of the PUMC Type Ia and IIc subjects. Both groups have a stronger average RMS sEMG value on the convex side of the affected muscle regions. Correction to posture as instructed by the physiotherapist has helped the subjects to achieve a more balanced RMS sEMG ratio in the trapezius and latissimus dorsi regions; the erector spinae in the thoracic region and/or erector spinae in the lumbar region. It is, therefore, considered that with regular practice of the suggested positions, those with AIS can use motor learning to achieve a more balanced posture. Consequently, the findings can be used in less intrusive early orthotic intervention and provision of care to those with AIS.

Evaluation of Myoelectric Activity of Paraspinal Muscles in Adolescents with Idiopathic Scoliosis during Habitual Standing and Sitting.

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Kwok, Garcia; Yip, Joanne; Cheung, Mei-Chun; Yick, Kit-Lun

2015-01-01

There is a number of research work in the literature that have applied sEMG biofeedback as an instrument for muscle rehabilitation. Therefore, sEMG is a good tool for this research work and is used to record the myoelectric activity in the paraspinal muscles of those with AIS during habitual standing and sitting. After the sEMG evaluation, the root-mean-square (RMS) sEMG values of the paraspinal muscles in the habitual postures reflect the spinal curvature situation of the PUMC Type Ia and IIc subjects. Both groups have a stronger average RMS sEMG value on the convex side of the affected muscle regions. Correction to posture as instructed by the physiotherapist has helped the subjects to achieve a more balanced RMS sEMG ratio in the trapezius and latissimus dorsi regions; the erector spinae in the thoracic region and/or erector spinae in the lumbar region. It is, therefore, considered that with regular practice of the suggested positions, those with AIS can use motor learning to achieve a more balanced posture. Consequently, the findings can be used in less intrusive early orthotic intervention and provision of care to those with AIS.

Laryngeal electromyography-guided hyaluronic acid vocal fold injection for unilateral vocal fold paralysis: a prospective long-term follow-up outcome report.

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Wang, Chen-Chi; Chang, Ming-Hong; Jiang, Rong-San; Lai, Hsiu-Chin; De Virgilio, Armando; Wang, Ching-Ping; Wu, Shang-Heng; Liu, Shi-An; Liang, Kai-Li

2015-03-01

Unilateral vocal fold paralysis (UVFP) is a common voice disorder that may cause glottal closure insufficiency with hoarseness of voice. Laryngeal electromyography (LEMG)-guided hyaluronic acid vocal fold (VF) injection has been proposed as a treatment option to improve glottal closure with a satisfactory short-term effect. To our knowledge, this study reports the first long-term follow-up result of this treatment modality. To present the long-term treatment results of LEMG-guided hyaluronic acid VF injection for UVFP. Prospective study of the treatment results of 74 patients who received LEMG-guided hyaluronic acid VF injection for UVFP at a tertiary referral medical center from March 2010 to February 2013. In the office-based procedure, 1.0 mL of hyaluronic acid was injected via a 26-gauge monopolar injectable needle electrode into paralyzed thyroarytenoid muscles by LEMG guidance. Various glottal closure evaluations such as normalized glottal gap area, maximal phonation time, phonation quotient, mean airflow rate, perceptual GRBAS (grade, roughness, breathiness, asthenia, strain) scale, and Voice Handicap Index were compared before and after injection using the nonparametric Wilcoxon signed rank test within 1 month, at 6 months, and at the last follow-up examination. Sixty patients had been followed up for at least 6 months. Forty-four patients received only 1 injection, and 16 patients received repeated injections (2 injections for 13 patients and 3 for 3 patients). All the glottal closure parameters improved significantly (P injection and 16 (22%) who received repeated injections did not require another treatment after long-term follow-up. Laryngeal electromyography-guided hyaluronic acid VF injection is an option for treating UVFP with satisfactory results.

The effect of prior lumbar surgeries on the flexion relaxation phenomenon and its responsiveness to rehabilitative treatment.

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Neblett, Randy; Mayer, Tom G; Brede, Emily; Gatchel, Robert J

2014-06-01

Abnormal pretreatment flexion-relaxation in chronic disabling occupational lumbar spinal disorder patients has been shown to improve with functional restoration rehabilitation. Little is known about the effects of prior lumbar surgeries on flexion-relaxation and its responsiveness to treatment. To quantify the effect of prior lumbar surgeries on the flexion-relaxation phenomenon and its responsiveness to rehabilitative treatment. A prospective cohort study of chronic disabling occupational lumbar spinal disorder patients, including those with and without prior lumbar spinal surgeries. A sample of 126 chronic disabling occupational lumbar spinal disorder patients with prior work-related injuries entered an interdisciplinary functional restoration program and agreed to enroll in this study. Fifty-seven patients had undergone surgical decompression or discectomy (n=32) or lumbar fusion (n=25), and the rest had no history of prior injury-related spine surgery (n=69). At post-treatment, 116 patients were reevaluated, including those with prior decompressions or discectomies (n=30), lumbar fusions (n=21), and no surgery (n=65). A comparison group of 30 pain-free control subjects was tested with an identical assessment protocol, and compared with post-rehabilitation outcomes. Mean surface electromyography (SEMG) at maximum voluntary flexion; subject achievement of flexion-relaxation (SEMG≤3.5 μV); gross lumbar, true lumbar, and pelvic flexion ROM; and a pain visual analog scale self-report during forward bending task. Identical measures were obtained at pretreatment and post-treatment. Patients entered an interdisciplinary functional restoration program, including a quantitatively directed, medically supervised exercise process and a multimodal psychosocial disability management component. The functional restoration program was accompanied by a SEMG-assisted stretching training program, designed to teach relaxation of the lumbar musculature during end-range flexion

The Gluteus Medius Vs. Thigh Muscles Strength Ratio and Their Relation to Electromyography Amplitude During a Farmer’s Walk Exercise

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Stastny Petr

2015-03-01

Full Text Available The strength ratio between hamstrings and quadriceps (H/Q is associated with knee injuries as well as hip abductor muscle (HAB weakness. Sixteen resistance trained men (age, 32.5 ± 4.2 years performed 5 s maximal isometric contractions at 75° of knee flexion/extension and 15° of hip abduction on a dynamometer. After this isometric test they performed a Farmer´s walk exercise to find out if the muscle strength ratio predicted the electromyography amplitude expressed as a percentage of maximum voluntary isometric contraction (%MVIC. The carried load represented a moderate intensity of 75% of the exercise six repetitions maximum (6RM. Electromyography data from the vastus medialis (VM, vastus lateralis (VL, biceps femoris (BF and gluteus medius (Gmed on each leg were collected during the procedure. The groups selected were participants with H/Q ≥ 0.5, HQ < 0.5, HAB/H ≥ 1, HAB/H < 1, HAB/Q ≥ 0.5 and HAB/Q < 0.5. One way ANOVA showed that Gmed activity was significantly greater in the group with HAB/H < 1 (42 ± 14 %MVIC as compared to HAB/H ≥ 1 (26 ± 10 %MVIC and HAB/Q < 0.5 (47 ± 19 %MVIC compared to HAB/Q ≥ 0.5 (26 ± 12 %MVIC. The individuals with HAB/H < 1 were found to have greater activation of their Gmed during the Farmer’s walk exercise. Individuals with HAB/Q < 0.5 had greater activation of the Gmed. Gmed strength ratios predict the muscle involvement when a moderate amount of the external load is used. The Farmer’s walk is recommended as an exercise which can strengthen the gluteus medius, especially for individuals with a HAB/H ratio < 1 and HAB/Q < 0.5.

Clinical gait analysis : A review of research at the Interdepartmental Research group of Kinesiology in Leiden

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Daanen, H. A M

1990-01-01

In this article the methodology used in the Interdepartmental Research Group of Kinesiology to quantify (clinical) human gait is elaborated upon. Four methods are described: analysis of temporal parameters, goniometry, accelerometry and electromyography. A correct representation of electromyographic

Surface electromyography activity of the rectus abdominis, internal oblique, and external oblique muscles during forced expiration in healthy adults.

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Ito, Kenichi; Nonaka, Koji; Ogaya, Shinya; Ogi, Atsushi; Matsunaka, Chiaki; Horie, Jun

2016-06-01

We aimed to characterize rectus abdominis, internal oblique, and external oblique muscle activity in healthy adults under expiratory resistance using surface electromyography. We randomly assigned 42 healthy adult subjects to 3 groups: 30%, 20%, and 10% maximal expiratory intraoral pressure (PEmax). After measuring 100% PEmax and muscle activity during 100% PEmax, the activity and maximum voluntary contraction of each muscle during the assigned experimental condition were measured. At 100% PEmax, the external oblique (pinternal oblique (pexternal oblique (pinternal oblique (pexternal oblique: pinternal oblique: p<0.01). The abdominal oblique muscles are the most active during forced expiration. Moreover, 30% PEmax is the minimum intensity required to achieve significant, albeit very slight, muscle activity during expiratory resistance. Copyright © 2016 Elsevier Ltd. All rights reserved.

Surface electromyographic patterns of masticatory, neck, and trunk muscles in temporomandibular joint dysfunction patients undergoing anterior repositioning splint therapy.

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Tecco, Simona; Tetè, Stefano; D'Attilio, Michele; Perillo, Letizia; Festa, Felice

2008-12-01

The aim of this study was to investigate the surface electromyographic (sEMG) activity of neck, trunk, and masticatory muscles in subjects with temporomandibular joint (TMJ) internal derangement treated with anterior mandibular repositioning splints. sEMG activities of the muscles in 34 adult subjects (22 females and 12 males; mean age 30.4 years) with TMJ internal derangement were compared with a control group of 34 untreated adults (20 females and 14 males; mean age 31.8 years). sEMG activities of seven muscles (anterior and posterior temporalis, masseter, posterior cervicals, sternocleidomastoid, and upper and lower trapezius) were studied bilaterally, with the mandible in the rest position and during maximal voluntary clenching (MVC), at the beginning of therapy (T0) and after 10 weeks of treatment (T1). Paired and Student's t-tests were undertaken to determine differences between the T0 and T1 data and in sEMG activity between the study and control groups. At T0, paired masseter, sternocleidomastoid, and cervical muscles, in addition to the left anterior temporal and right lower trapezius, showed significantly greater sEMG activity (P = 0.0001; P = 0.0001; for left cervical, P = 0.03; for right cervical, P = 0.0001; P = 0.006 and P = 0.007 muscles, respectively) compared with the control group. This decreased over the remaining study period, such that after treatment, sEMG activity revealed no statistically significant difference when compared with the control group. During MVC at T0, paired masseter and anterior and posterior temporalis muscles showed significantly lower sEMG activity (P = 0.03; P = 0.005 and P = 0.04, respectively) compared with the control group. In contrast, at T1 sEMG activity significantly increased (P = 0.02; P = 0.004 and P = 0.04, respectively), but no difference was observed in relation to the control group. Splint therapy in subjects with internal disk derangement seems to affect sEMG activity of the masticatory, neck, and trunk

Test-retest reliability of trunk motor variability measured by large-array surface electromyography.

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Abboud, Jacques; Nougarou, François; Loranger, Michel; Descarreaux, Martin

2015-01-01

The objective of this study was to evaluate the test-retest reliability of the trunk muscle activity distribution in asymptomatic participants during muscle fatigue using large-array surface electromyography (EMG). Trunk muscle activity distribution was evaluated twice, with 3 to 4 days between them, in 27 asymptomatic volunteers using large-array surface EMG. Motor variability, assessed with 2 different variables (the centroid coordinates of the root mean square map and the dispersion variable), was evaluated during a low back muscle fatigue task. Test-retest reliability of muscle activity distribution was obtained using Pearson correlation coefficients. A shift in the distribution of EMG amplitude toward the lateral-caudal region of the lumbar erector spinae induced by muscle fatigue was observed. Moderate to very strong correlations were found between both sessions in the last 3 phases of the fatigue task for both motor variability variables, whereas weak to moderate correlations were found in the first phases of the fatigue task only for the dispersion variable. These findings show that, in asymptomatic participants, patterns of EMG activity are less reliable in initial stages of muscle fatigue, whereas later stages are characterized by highly reliable patterns of EMG activity. Copyright © 2015 National University of Health Sciences. Published by Elsevier Inc. All rights reserved.

The Advantages of Normalizing Electromyography to Ballistic Rather than Isometric or Isokinetic Tasks.

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Suydam, Stephen M; Manal, Kurt; Buchanan, Thomas S

2017-07-01

Isometric tasks have been a standard for electromyography (EMG) normalization stemming from anatomic and physiologic stability observed during contraction. Ballistic dynamic tasks have the benefit of eliciting maximum EMG signals for normalization, despite having the potential for greater signal variability. It is the purpose of this study to compare maximum voluntary isometric contraction (MVIC) to nonisometric tasks with increasing degrees of extrinsic variability, ie, joint range of motion, velocity, rate of contraction, etc., to determine if the ballistic tasks, which elicit larger peak EMG signals, are more reliable than the constrained MVIC. Fifteen subjects performed MVIC, isokinetic, maximum countermovement jump, and sprint tasks while EMG was collected from 9 muscles in the quadriceps, hamstrings, and lower leg. The results revealed the unconstrained ballistic tasks were more reliable compared to the constrained MVIC and isokinetic tasks for all triceps surae muscles. The EMG from sprinting was more reliable than the constrained cases for both the hamstrings and vasti. The most reliable EMG signals occurred when the body was permitted its natural, unconstrained motion. These results suggest that EMG is best normalized using ballistic tasks to provide the greatest within-subject reliability, which beneficially yield maximum EMG values.

Multi-channel electronics for secondary emission grid profile monitor of TTF linac

International Nuclear Information System (INIS)

Reingardt-Nikoulin, P.; Gaidash, V.; Mirzojan, A.; Kocharyan, V.; Noelle, D.

2004-01-01

According to the TTF beam experimental program, a measurement f the time dependence of the energy spread within the bunch train should be done by means of a standard device for profile measurements, that is Secondary Emission Grid (SEMG). SEMG on the high-energy TTF beam is placed in the focal plane of the magnet spectrometer. It should measure the total energy spread in the range from 0.1% up to a few percents for any single or any group of electron bunches in the bunch train of TTF Linac. SEMG profile measurements with new high sensitive electronics are described. Beam results of SEMG Monitor test are given for two modifications of an electronic preamplifier

Effects of electromyography-driven robot-aided hand training with neuromuscular electrical stimulation on hand control performance after chronic stroke.

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Rong, Wei; Tong, Kai Yu; Hu, Xiao Ling; Ho, Sze Kit

2015-03-01

An electromyography-driven robot system integrated with neuromuscular electrical stimulation (NMES) was developed to investigate its effectiveness on post-stroke rehabilitation. The performance of this system in assisting finger flexion/extension with different assistance combinations was evaluated in five stroke subjects. Then, a pilot study with 20-sessions training was conducted to evaluate the training's effectiveness. The results showed that combined assistance from the NMES-robot could improve finger movement accuracy, encourage muscle activation of the finger muscles and suppress excessive muscular activities in the elbow joint. When assistances from both NMES and the robot were 50% of their maximum assistances, finger-tracking performance had the best results, with the lowest root mean square error, greater range of motion, higher voluntary muscle activations of the finger joints and lower muscle co-contraction in the finger and elbow joints. Upper limb function improved after the 20-session training, indicated by the increased clinical scores of Fugl-Meyer Assessment, Action Research Arm Test and Wolf Motor Function Test. Muscle co-contraction was reduced in the finger and elbow joints reflected by the Modified Ashworth Scale. The findings demonstrated that an electromyography-driven NMES-robot used for chronic stroke improved hand function and tracking performance. Further research is warranted to validate the method on a larger scale. Implications for Rehabilitation The hand robotics and neuromuscular electrical stimulation (NMES) techniques are still separate systems in current post-stroke hand rehabilitation. This is the first study to investigate the combined effects of the NMES and robot on hand rehabilitation. The finger tracking performance was improved with the combined assistance from the EMG-driven NMES-robot hand system. The assistance from the robot could improve the finger movement accuracy and the assistance from the NMES could reduce the

The Comparing the Leg Muscles Electromyography during Single Leg Drop Landing in Pesplanus and Normal Men

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mostafa bazvand

2016-03-01

Full Text Available Objective: pesplanus is one of the changes that brings about changes in muscle activation patterns. Being aware of muscles activity changes in various standing positions among pesplanus patients provides insights into preventing lower extremity injuries in this population. The aim of this study was to compare leg muscles electromyography during various standing positions in pesplanus and normal subjects. Methods: 60 healthy male university students, 30 subjects with pesplanus deformity (with average age 23/54±3/57 year, average height 175/34±7/62 cm, average weight 74/87±10/72 kg and 30 normal subjects (with average age 22/97±2/38 year, average height 176/6±5/59 cm, average weight 73/58±8/36 kg participated in this comparative study. Deformity of pesplanus was assessed with navicular drop test. Each subject performed single-leg landing dropping from 30cm height onto a force platform where muscles activity was recorded with EMG device. For data analysis, Matlab and Spss softwares were used and independent sample t-test was used to compare the dependent variables at a significance level of P &le 0/05. Results: Significant differences were observed between the two groups for the activities of the longus peroneus and anterior tibialis muscles ( p&le0/05 while no significant differences were observed in other muscles. Conclusion: The changes in the normal structure of the foot might affect muscle activities during standing, which can cause changes in the injury patterns. Therefore, it is proposed that focusing on corrective exercises and therapy plan can reduce these risks.

Effect of age on changes in motor units functional connectivity.

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Arjunan, Sridhar P; Kumar, Dinesh

2015-08-01

With age, there is a change in functional connectivity of motor units in muscle. This leads to reduced muscle strength. This study has investigated the effect of age on the changes in the motor unit recruitment by measuring the mutual information between multiple channels of surface electromyogram (sEMG) of biceps brachii muscle. It is hypothesised that with ageing, there is a reduction in number of motor units, which can lead to an increase in the dependency of remaining motor units. This increase can be observed in the mutual information between the multiple channels of the muscle activity. Two channels of sEMG were recorded during the maximum level of isometric contraction. 28 healthy subjects (Young: age range 20-35years and Old: age range - 60-70years) participated in the experiments. The normalized mutual information (NMI), a measure of dependency factor, was computed for the sEMG recordings. Statistical analysis was performed to test the effect of age on NMI. The results show that the NMI among the older cohort was significantly higher when compared with the young adults.

Computation and Evaluation of Features of Surface Electromyogram to Identify the Force of Muscle Contraction and Muscle Fatigue

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Sridhar P. Arjunan

2014-01-01

Full Text Available The relationship between force of muscle contraction and muscle fatigue with six different features of surface electromyogram (sEMG was determined by conducting experiments on thirty-five volunteers. The participants performed isometric contractions at 50%, 75%, and 100% of their maximum voluntary contraction (MVC. Six features were considered in this study: normalised spectral index (NSM5, median frequency, root mean square, waveform length, normalised root mean square (NRMS, and increase in synchronization (IIS index. Analysis of variance (ANOVA and linear regression analysis were performed to determine the significance of the feature with respect to the three factors: muscle force, muscle fatigue, and subject. The results show that IIS index of sEMG had the highest correlation with muscle fatigue and the relationship was statistically significant (P0.05.

Computation and evaluation of features of surface electromyogram to identify the force of muscle contraction and muscle fatigue.

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Arjunan, Sridhar P; Kumar, Dinesh K; Naik, Ganesh

2014-01-01

The relationship between force of muscle contraction and muscle fatigue with six different features of surface electromyogram (sEMG) was determined by conducting experiments on thirty-five volunteers. The participants performed isometric contractions at 50%, 75%, and 100% of their maximum voluntary contraction (MVC). Six features were considered in this study: normalised spectral index (NSM5), median frequency, root mean square, waveform length, normalised root mean square (NRMS), and increase in synchronization (IIS) index. Analysis of variance (ANOVA) and linear regression analysis were performed to determine the significance of the feature with respect to the three factors: muscle force, muscle fatigue, and subject. The results show that IIS index of sEMG had the highest correlation with muscle fatigue and the relationship was statistically significant (P 0.05).

Electromyography-Guided Botulinum Toxin Injection Into the Cricothyroid Muscles in Bilateral Vocal Fold Abductor Paralysis.

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Sahin, Mustafa; Aydogdu, Ibrahim; Akyildiz, Serdar; Erdinc, Munevver; Ozturk, Kerem; Ogut, Fatih

2017-06-01

Bilateral vocal fold abductor paralysis (BVFAP) both deteriorates quality of life and may cause life-threatening respiratory problems. The aim of this study was to reduce respiratory symptoms in BVFAP patients using cricothyroid (CT) botulinum toxin (BTX) injection. Before and 2 weeks and 4 months after bilateral BTX injection into the CT muscles under electromyography; alterations in respiratory, acoustic, aerodynamic and quality of life parameters were evaluated in BVFAP patients with respiratory distress. For the respiratory evaluation modified Borg scale and spirometry, for the voice and aerodynamic evaluations Voice Handicap Index-30 (VHI-30), GRBAS, acoustic analysis (sound pressure level, F0, jitter%, shimmer%, noise-to-harmonic ratio) and maximum phonation time and for the quality of life assessment Short Form-36 (SF-36) form were used. All patients were female with a mean age of 47±8.1 years. There was a mean time of 11.8±5.5 (minimum 2, maximum 23) months between BVFAP development and BTX injection. In all cases, other than one case with unknown aetiology, the cause of vocal fold paralysis was prior thyroid surgery. In total 18.6±3.1 units of BTX were applied to the CTs. In the preinjection period, and the 2nd week and 4th month after injection, the Borg dyspnea scale was 7.3/5.3/5.0, FIV1 (forced inspiratory volume in one second) was 1.7/1.7/1.8 L, peak expiratory flow (PEF) was 1.4/1.7/2.1 L/sec, maximum phonation time was 7.0/6.4/6.2 seconds and VHI-30 was 63.2/52.2/61.7 respectively. There was no significant alteration in acoustic analysis parameters. Many of the patients reported transient dysphagia within the first week. There were insignificant increases in SF-36 sub-scale values. After BTX injection, improvements in the mean Borg score, PEF and FIV1 values and SF-36 sub-scale scores showed the restricted success of this approach. This modality may be kept in mind as a transient treatment option for patients refused persistent tracheotomy or

Development of Hand Grip Assistive Device Control System for Old People through Electromyography (EMG Signal Acquisitions

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Khamis Herman

2017-01-01

Full Text Available The hand grip assistive device is a glove to assist old people who suffer from hand weakness in their daily life activities. The device earlier control system only use simple on and off switch. This required old people to use both hand to activate the device. The new control system of the hand grip assistive device was developed to allow single hand operation for old people. New control system take advantages of electromyography (EMG and flex sensor which was implemented to the device. It was programmed into active and semi-active mode operation. EMG sensors were placed on the forearm to capture EMG signal of Flexor Digitorum Profundus muscle to activate the device. Flex sensor was used to indicate the finger position and placed on top of the finger. The signal from both sensors then used to control the device. The new control system allowed single hand operation and designed to prevent user from over depended on the device by activating it through moving their fingers.

Neck Kinematics and Electromyography While Wearing Head Supported Mass During Running.

Science.gov (United States)

Hanks, Matthew M; Sefton, JoEllen M; Oliver, Gretchen D

2018-01-01

Advanced combat helmets (ACH) coupled with night-vision goggles (NVG) are required for tactical athletes during training and service. Head and neck injuries due to head supported mass (HSM) are a common occurrence in military personnel. The current study aimed to investigate the effects of HSM on neck muscle fatigue that may lead to chronic stress and injury of the head and neck. Subjects wore an ACH and were affixed with electromagnetic sensors to obtain kinematic data, as well as EMG electrodes to obtain muscle activations of bilateral sternocleidomastoid, upper trapezius, and paraspinal muscles while running on a treadmill. Subjects performed a 2-min warmup at a walking pace, a 5-min warmup jog, running at a pace equal to 90% maximum heart rate until absolute fatigue, and lastly a 2-min cooldown at a walking pace. Kinematic and EMG data were collected over each 2-min interval. Days later, the same subjects wore the same ACH in addition to the NVG and performed the same protocol as the first session. This study showed significant differences in muscle activation of the right upper trapezius [F(1,31) = 10.100] and both sternocleidomastoid [F(1,31) = 12.280] muscles from pre-fatigue to absolute fatigue. There were no significant differences noted in the kinematic variables. This study suggests that HSM can fatigue bilateral neck flexors and rotators, as well as fatigue the neck extensors and rotators on the contralateral side of the mounted NVG.Hanks MM, Sefton JM, Oliver GD. Neck kinematics and electromyography while wearing head supported mass during running. Aerosp Med Hum Perform. 2018; 89(1):9-13.

Onset Detection in Surface Electromyographic Signals: A Systematic Comparison of Methods

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Claus Flachenecker

2001-06-01

Full Text Available Various methods to determine the onset of the electromyographic activity which occurs in response to a stimulus have been discussed in the literature over the last decade. Due to the stochastic characteristic of the surface electromyogram (SEMG, onset detection is a challenging task, especially in weak SEMG responses. The performance of the onset detection methods were tested, mostly by comparing their automated onset estimations to the manually determined onsets found by well-trained SEMG examiners. But a systematic comparison between methods, which reveals the benefits and the drawbacks of each method compared to the other ones and shows the specific dependence of the detection accuracy on signal parameters, is still lacking. In this paper, several classical threshold-based approaches as well as some statistically optimized algorithms were tested on large samples of simulated SEMG data with well-known signal parameters. Rating between methods is performed by comparing their performance to that of a statistically optimal maximum likelihood estimator which serves as reference method. In addition, performance was evaluated on real SEMG data obtained in a reaction time experiment. Results indicate that detection behavior strongly depends on SEMG parameters, such as onset rise time, signal-to-noise ratio or background activity level. It is shown that some of the threshold-based signal-power-estimation procedures are very sensitive to signal parameters, whereas statistically optimized algorithms are generally more robust.

Use of electromyography to optimize Lokomat® settings for subject-specific gait rehabilitation in post-stroke hemiparetic patients: A proof-of-concept study.

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Cherni, Yosra; Begon, Mickael; Chababe, Hicham; Moissenet, Florent

2017-09-01

While generic protocols exist for gait rehabilitation using robotic orthotics such as the Lokomat ® , several settings - guidance, body-weight support (BWS) and velocity - may be adjusted to individualize patient training. However, no systematic approach has yet emerged. Our objective was to assess the feasibility and effects of a systematic approach based on electromyography to determine subject-specific settings with application to the strengthening of the gluteus maximus muscle in post-stroke hemiparetic patients. Two male patients (61 and 65 years) with post-stroke hemiparesis performed up to 9 Lokomat ® trials by changing guidance and BWS while electromyography of the gluteus maximus was measured. For each subject, the settings that maximized gluteus maximus activity were used in 20 sessions of Lokomat ® training. Modified Functional Ambulation Classification (mFAC), 6-minutes walking test (6-MWT), and extensor strength were measured before and after training. The greatest gluteus maximus activity was observed at (Guidance: 70% -BWS: 20%) for Patient 1 and (Guidance: 80% - BWS: 30%) for Patient 2. In both patients, mFAC score increased from 4 to 7. The additional distance in 6-MWT increased beyond minimal clinically important difference (MCID=34.4m) reported for post-stroke patients. The isometric strength of hip extensors increased by 43 and 114%. Defining subject-specific settings for a Lokomat ® training was feasible and simple to implement. These two case reports suggest a benefit of this approach for muscle strengthening. It remains to demonstrate the superiority of such an approach for a wider population, compared to the use of a generic protocol. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

Random Forest-Based Recognition of Isolated Sign Language Subwords Using Data from Accelerometers and Surface Electromyographic Sensors.

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Su, Ruiliang; Chen, Xiang; Cao, Shuai; Zhang, Xu

2016-01-14

Sign language recognition (SLR) has been widely used for communication amongst the hearing-impaired and non-verbal community. This paper proposes an accurate and robust SLR framework using an improved decision tree as the base classifier of random forests. This framework was used to recognize Chinese sign language subwords using recordings from a pair of portable devices worn on both arms consisting of accelerometers (ACC) and surface electromyography (sEMG) sensors. The experimental results demonstrated the validity of the proposed random forest-based method for recognition of Chinese sign language (CSL) subwords. With the proposed method, 98.25% average accuracy was obtained for the classification of a list of 121 frequently used CSL subwords. Moreover, the random forests method demonstrated a superior performance in resisting the impact of bad training samples. When the proportion of bad samples in the training set reached 50%, the recognition error rate of the random forest-based method was only 10.67%, while that of a single decision tree adopted in our previous work was almost 27.5%. Our study offers a practical way of realizing a robust and wearable EMG-ACC-based SLR systems.

Force Myography to Control Robotic Upper Extremity Prostheses: A Feasibility Study

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Erina eCho

2016-03-01

Full Text Available Advancement in assistive technology has led to the commercial availability of multi-dexterous robotic prostheses for the upper extremity. The relatively low performance of the currently used techniques to detect the intention of the user to control such advanced robotic prostheses, however, limits their use. This article explores the use of force myography (FMG as a potential alternative to the well-established surface electro-myography (sEMG. Specifically, the use of FMG to control different grips of a commercially available robotic hand, Bebionic3, are investigated. Four male transradially amputated subjects participated in the study and a protocol was developed to assess the prediction accuracy of eleven grips. Different combinations of grips were examined ranging from six up to eleven grips. The results indicate that it is possible to classify six primary grips important in activities of daily living using FMG with an accuracy of above 70% in the residual limb. Additional strategies to increase classification accuracy, such as using the available modes on the Bebionic3, allowed results to improve up to 88.83% and 89.00% for opposed thumb and non-opposed thumb modes respectively.

Eletromiografia de superfície no diagnóstico da dominância lateral em crianças: aspectos psicomotores Surface electromyography in diagnosis of lateral dominance in children: psychomotor aspects

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Ceme Ferreira Jordy

1995-09-01

Full Text Available A dominância lateral foi verificada pelo eletromiograma de superfície em 100 crianças neurologicamente normais. Foram usados estímulos verbais durante os registros eletromiográficos. Em comparação com o diagnóstico clínico, a eletromiografia se revelou mais precisa, excluindo influências subjetivas nos resultados. Destrismo foi diagnosticado em 90 pacientes, canhotismo em 3 e dominância indefinida em 7. Mecanismos de ordem psicomotora são sugeridos para justificar as respostas motoras provocadas por estímulos verbais com conteúdo afetivo.Surface electromyography was used to verify the lateral dominance in 100 six to fourteen years old normal children. Electromyographic records were obtained during verbal stimulation. Dexterity was found in 90, sinistrality in 3 and indefinite dominance in 7 patients. Comparing with results from clinical examination, the electromyography seems more accurate and easy to perform. The responses obtained after verbal stimulations were attributed to a psychomotor phenomenon. Mechanisms involved in the production of muscle contractions after verbal stimulation, were not proved. Pharmacologic action of cathecolamines on the central motor neural subsystems is advanced.

Quantitative analysis of surface electromyography during epileptic and nonepileptic convulsive seizures

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Beniczky, S.; Conradsen, I.; Moldovan, M.

2014-01-01

, median frequency (MF), coherence, and duration of the seizures, of the clonic EMG discharges, and of the silent periods between the cloni. Based on wavelet analysis, we distinguished between a low-frequency component (LF 2-8 Hz) and a high-frequency component (HF 64-256 Hz). Results: Duration...... without rhythmic clonic movements....

Design of a Soft Robotic Elbow Sleeve with Passive and Intent-Controlled Actuation

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Tze Hui Koh

2017-10-01

Full Text Available The provision of continuous passive, and intent-based assisted movements for neuromuscular training can be incorporated into a robotic elbow sleeve. The objective of this study is to propose the design and test the functionality of a soft robotic elbow sleeve in assisting flexion and extension of the elbow, both passively and using intent-based motion reinforcement. First, the elbow sleeve was developed, using elastomeric and fabric-based pneumatic actuators, which are soft and lightweight, in order to address issues of non-portability and poor alignment with joints that conventional robotic rehabilitation devices are faced with. Second, the control system was developed to allow for: (i continuous passive actuation, in which the actuators will be activated in cycles, alternating between flexion and extension; and (ii an intent-based actuation, in which user intent is detected by surface electromyography (sEMG sensors attached to the biceps and triceps, and passed through a logic sequence to allow for flexion or extension of the elbow. Using this setup, the elbow sleeve was tested on six healthy subjects to assess the functionality of the device, in terms of the range of motion afforded by the device while in the continuous passive actuation. The results showed that the elbow sleeve is capable of achieving approximately 50% of the full range of motion of the elbow joint among all subjects. Next, further experiments were conducted to test the efficacy of the intent-based actuation on these healthy subjects. The results showed that all subjects were capable of achieving electromyography (EMG control of the elbow sleeve. These preliminary results show that the elbow sleeve is capable of carrying out continuous passive and intent-based assisted movements. Further investigation of the clinical implementation of the elbow sleeve for the neuromuscular training of neurologically-impaired persons, such as stroke survivors, is needed.

Preventing lower cranial nerve injuries during fourth ventricle tumor resection by utilizing intraoperative neurophysiological monitoring.

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Jahangiri, Faisal R; Minhas, Mazhar; Jane, John

2012-12-01

We present two cases illustrating the benefit of utilizing intraoperative neurophysiological monitoring (IONM) for prevention of injuries to the lower cranial nerves during fourth ventricle tumor resection surgeries. Multiple cranial nerve nuclei are located on the floor of the fourth ventricle with a high risk of permanent damage. Two male patients (ages 8 and 10 years) presented to the emergency department and had brain magnetic resonance imaging (MRI) scans showing brainstem/fourth ventricle tumors. During surgery, bilateral posterior tibial and median nerve somatosensory evoked potentials (SSEPs); four-limb and cranial nerves transcranial electrical motor evoked potentials (TCeMEPs); brainstem auditory evoked responses (BAERs); and spontaneous electromyography (s-EMG) were recorded. Electromyography (EMG) was monitored bilaterally from cranial nerves V VII, IX, X, XI, and XII. Total intravenous anesthesia was used. Neuromuscular blockade was used only for initial intubation. Pre-incision baselines were obtained with good morphology of waveforms. After exposure the floor of the fourth ventricle was mapped by triggered-EMG (t-EMG) using 0.4 to 1.0 mA. In both patients the tumor was entangled with cranial nerves VII to XII on the floor of the fourth ventricle. The surgeon made the decision not to resect the tumor in one case and limited the resection to 70% of the tumor in the second case on the basis of neurophysiological monitoring. This decision was made to minimize any post-operative neurological deficits due to surgical manipulation of the tumor involving the lower cranial nerves. Intraoperative spontaneous and triggered EMG was effectively utilized in preventing injuries to cranial nerves during surgical procedures. All signals remained stable during the surgical procedure. Postoperatively both patients were well with no additional cranial nerve weakness. At three months follow-up, the patients continued to have no deficits.

Inverse relationship between the complexity of midfoot kinematics and muscle activation in patients with medial tibial stress syndrome

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Rathleff, M S; Samani, Afshin; Olesen, C G

2011-01-01

Medial tibial stress syndrome is a common overuse injury characterized by pain located on the medial side of the lower leg during weight bearing activities such as gait. The purpose of this study was to apply linear and nonlinear methods to compare the structure of variability of midfoot kinematics...... and surface electromyographic (SEMG) signals between patients with medial tibial stress syndrome and healthy controls during gait. Fourteen patients diagnosed with medial tibial stress syndrome and 11 healthy controls were included from an orthopaedic clinic. SEMG from tibialis anterior and the soleus muscles...... as well as midfoot kinematics were recorded during 20 consecutive gait cycles. Permuted sample entropy and permutation entropy were used as a measure of complexity from SEMG signals and kinematics. SEMG signals in patients with medial tibial stress syndrome were characterized by higher structural...

Sit to stand in elderly fallers vs non-fallers: new insights from force platform and electromyography data.

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Chorin, Frédéric; Cornu, Christophe; Beaune, Bruno; Frère, Julien; Rahmani, Abderrahmane

2016-10-01

The sit-to-stand movement requires balance control and coordination between the trunk and lower limbs. For these reasons, it is commonly used in clinics for evaluating lower limb muscle function in the elderly. The aim of the present study was to point out re levant biomechanical and neurophysiological sit-to-stand parameters allowing comparison between elderly fallers and non-fallers. Ten elderly fallers and thirty non-fallers performed sit-to-stand movements. Sit-to-stand mechanical (maximal and mean force, impulse) and temporal parameters were measured in the vertical and anteroposterior axes using force platforms. Activity of rectus femoris, vastus lateralis, and gastrocnemius lateralis muscles was bilaterally recorded by surface electromyography. Time to realize sit-to-stand movements was significantly longer in elderly fallers compared to non-fallers (p movement are the most relevant parameters to differentiate fallers and non-fallers. Moreover, these factors highlight different strategies to rise from a chair between faller and non-faller group, suggesting that fallers would constantly adjust their control balance during the sit-to-stand movement.

Office-based Electromyography-guided Botulinum Toxin Injection to the Cricopharyngeus Muscle: Optimal Patient Selection and Technique.

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Kim, Min-Su; Kim, Go-Woon; Rho, Young-Soo; Kwon, Kee-Hwan; Chung, Eun-Jae

2017-05-01

This retrospective study was carried out to investigate the effectiveness and safety of office-based electromyography-guided injection of botulinum toxin in the cricopharyngeus muscle of patients who did not show upper esophageal sphincter passage in a swallowing study in spite of maximal swallowing rehabilitation. Thirty-six patients who showed no or limited ability to oral feed after maximum swallowing rehabilitation were enrolled. Video fluoroscopic swallowing study, flexible endoscopic evaluation of swallowing, disability rating scale, penetration aspiration score, and National Institutes of Health swallowing safety scale were used in the evaluation of dysphagia. Success was defined as nondependence on gastrostomy for patients who previously were dependent on gastrostomy and improvement in disability rating scale score after botulinum toxin injections. The total success rate was 63.9%. The complication rate was very low, with only 1 patient showing temporary unilateral vocal fold paralysis. Botulinum toxin injection was more effective in patients with cranial nerve IX or X palsy than in those without it ( P = .006). This procedure can be a simple, safe, and effective tool in patients with cricopharyngeal dysfunction after swallowing rehabilitation, especially for cranial nerve IX or X palsy.

Comparison of Efficiencies of Michigan Neuropathy Screening Instrument, Neurothesiometer, and Electromyography for Diagnosis of Diabetic Neuropathy

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Turkan Mete

2013-01-01

Full Text Available Aim. This study compares the effectiveness of Michigan Neuropathy Screening Instrument (MNSI, neurothesiometer, and electromyography (EMG in detecting diabetic peripheral neuropathy in patients with diabetes type 2. Materials and Methods. 106 patients with diabetes type 2 treated at the outpatient clinic of Ankara Numune Education and Research Hospital Department of Endocrinology between September 2008 and May 2009 were included in this study. Patients were evaluated by glycemic regulation tests, MNSI (questionnaire and physical examination, EMG (for detecting sensorial and motor defects in right median, ulnar, posterior tibial, and bilateral sural nerves, and neurothesiometer (for detecting alterations in cold and warm sensations as well as vibratory sensations. Results. According to the MNSI score, there was diabetic peripheral neuropathy in 34 (32.1% patients (score ≥2.5. However, when the patients were evaluated by EMG and neurothesiometer, neurological impairments were detected in 49 (46.2% and 79 (74.5% patients, respectively. Conclusion. According to our findings, questionnaires and physical examination often present lower diabetic peripheral neuropathy prevalence. Hence, we recommend that in the evaluation of diabetic patients neurological tests should be used for more accurate results and thus early treatment options to prevent neuropathic complications.

An electromyographic analysis of two handwriting grasp patterns.

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de Almeida, Pedro Henrique Tavares Queiroz; da Cruz, Daniel Marinho Cezar; Magna, Luis Alberto; Ferrigno, Iracema Serrat Vergotti

2013-08-01

Handwriting is a fundamental skill needed for the development of daily-life activities during lifetime and can be performed using different forms to hold the writing object. In this study, we monitored the sEMG activity of trapezius, biceps brachii, extensor carpi radialis brevis and flexor digitorum superficialis during a handwriting task with two groups of subjects using different grasp patterns. Twenty-four university students (thirteen males and eleven females; mean age of 22.04±2.8years) were included in this study. We randomly invited 12 subjects that used the Dynamic Tripod grasp and 12 subjects that used the Static Tripod grasp. The static tripod group showed statistically significant changes in the sEMG activity of trapezium and biceps brachii muscles during handwriting when compared to dynamic tripod group's subjects. No significant differences were found in extensor carpi radialis brevis and flexor digitorum superficialis activities among the two groups. The findings in this study suggest an increased activity of proximal muscles among subjects using a transitional grasp, indicating potential higher energy expenditure and muscular harm with the maintenance of this motor pattern in handwriting tasks, especially during the progression in academic life. Copyright © 2013 Elsevier Ltd. All rights reserved.

Pneumatic Muscles Actuated Lower-Limb Orthosis Model Verification with Actual Human Muscle Activation Patterns

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Dzahir M.A.M

2017-01-01

Full Text Available A review study was conducted on existing lower-limb orthosis systems for rehabilitation which implemented pneumatic muscle type of actuators with the aim to clarify the current and on-going research in this field. The implementation of pneumatic artificial muscle will play an important role for the development of the advanced robotic system. In this research a derivation model for the antagonistic mono- and bi-articular muscles using pneumatic artificial muscles of a lower limb orthosis will be verified with actual human’s muscle activities models. A healthy and young male 29 years old subject with height 174cm and weight 68kg was used as a test subject. Two mono-articular muscles Vastus Medialis (VM and Vastus Lateralis (VL were selected to verify the mono-articular muscle models and muscle synergy between anterior muscles. Two biarticular muscles Rectus Femoris (RF and Bicep Femoris (BF were selected to verify the bi-articular muscle models and muscle co-contraction between anterior-posterior muscles. The test was carried out on a treadmill with a speed of 4.0 km/h, which approximately around 1.25 m/s for completing one cycle of walking motion. The data was collected for about one minute on a treadmill and 20 complete cycles of walking motion were successfully recorded. For the evaluations, the mathematical model obtained from the derivation and the actual human muscle activation patterns obtained using the surface electromyography (sEMG system were compared and analysed. The results shown that, high correlation values ranging from 0.83 up to 0.93 were obtained in between the derivation model and the actual human muscle’s model for both mono- and biarticular muscles. As a conclusion, based on the verification with the sEMG muscle activities data and its correlation values, the proposed derivation models of the antagonistic mono- and bi-articular muscles were suitable to simulate and controls the pneumatic muscles actuated lower limb

The value of adding transcutaneous neuromuscular electrical stimulation (VitalStim) to traditional therapy for post-stroke dysphagia: a randomized controlled trial.

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Li, L; Li, Y; Huang, R; Yin, J; Shen, Y; Shi, J

2015-02-01

Dysphagia is not uncommon after stroke. Dysphagia may delay the functional recovery and substantially affects the quality of life after stroke, mainly if lest untreated. To detect and treat dysphagia as early as possible is critical for patients' recovery after stroke. Electrical stimulation has been reported as a treatment for pharyngeal dysphagia in recent studies, but the therapeutic effects of neuromuscular electrical stimulation (VitalStim®) therapy lacks convincing supporting evidence, needs further clinical investigation. To investigate the effects of neuromuscular electrical stimulation (VitalStim®) and traditional swallowing therapy on recovery of swallowing difficulties after stroke. Randomized controlled trial. University hospital. 135 stroke patients who had a diagnosis of dysphagia at the age between 50-80. 135 subjects were randomly divided into three groups: traditional swallowing therapy (N. = 45), VitalStim® therapy (N. = 45), and VitalStim® therapy plus traditional swallowing therapy (N. = 45). The traditional swallowing therapy included basic training and direct food intake training. Electrical stimulation was applied by an occupational therapist, using a modified hand-held battery-powered electrical stimulator (VitalStim® Dual Channel Unit and electrodes, Chattanooga Group, Hixson, TN, USA). Surface electromyography (sEMG), the Standardized Swallowing Assessment (SSA), Videofluoroscopic Swallowing Study (VFSS) and visual analog scale (VAS) were used to assess swallowing function before and 4 weeks after the treatment. The study included 118 subjects with dysphagia, 40 in the traditional swallowing therapy group and VitalStim® therapy group, 38 in the VitalStim and traditional swallowing therapy group. There were significant differences in sEMG value, SSA and VFSS scores in each group after the treatment (P VitalStim® and traditional swallowing therapy group than the other two groups (P VitalStim® therapy coupled with traditional

Effects of jump and balance training on knee kinematics and electromyography of female basketball athletes during a single limb drop landing: pre-post intervention study

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Nagano Yasuharu

2011-07-01

Full Text Available Abstract Background Some research studies have investigated the effects of anterior cruciate ligament (ACL injury prevention programs on knee kinematics during landing tasks; however the results were different among the studies. Even though tibial rotation is usually observed at the time of ACL injury, the effects of training programs for knee kinematics in the horizontal plane have not yet been analyzed. The purpose of this study was to determine the effects of a jump and balance training program on knee kinematics including tibial rotation as well as on electromyography of the quadriceps and hamstrings in female athletes. Methods Eight female basketball athletes participated in the experiment. All subjects performed a single limb landing at three different times: the initial test, five weeks later, and one week after completing training. The jump and balance training program lasted for five weeks. Knee kinematics and simultaneous electromyography of the rectus femoris and Hamstrings before training were compared with those measured after completing the training program. Results After training, regarding the position of the knee at foot contact, the knee flexion angle for the Post-training trial (mean (SE: 24.4 (2.1 deg was significantly larger than that for the Pre-training trial (19.3 (2.5 deg (p Conclusions The jump and balance training program successfully increased knee flexion and hamstring activity of female athletes during landing, and has the possibility of producing partial effects to avoid the characteristic knee position observed in ACL injury, thereby preventing injury. However, the expected changes in frontal and transverse kinematics of the knee were not observed.

Limitations of Spectral Electromyogramic Analysis to Determine the Onset of Neuromuscular Fatigue Threshold during Incremental Ergometer Cycling

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Iban Latasa, Alfredo Cordova, Armando Malanda, Javier Navallas, Ana Lavilla-Oiz, Javier Rodriguez-Falces

2016-03-01

Full Text Available Recently, a new method has been proposed to detect the onset of neuromuscular fatigue during an incremental cycling test by assessing the changes in spectral electromyographic (sEMG frequencies within individual exercise periods of the test. The method consists on determining the highest power output that can be sustained without a significant decrease in spectral frequencies. This study evaluated the validity of the new approach by assessing the changes in spectral indicators both throughout the whole test and within individual exercise periods of the test. Fourteen cyclists performed incremental cycle ergometer rides to exhaustion with bipolar surface EMG signals recorded from the vastus lateralis. The mean and median frequencies (Fmean and Fmedian, respectively of the sEMG power spectrum were calculated. The main findings were: (1 Examination of spectral indicators within individual exercise periods of the test showed that neither Fmean nor Fmedian decreased significantly during the last (most fatiguing exercise periods. (2 Examination of the whole incremental test showed that the behaviour of Fmean and Fmedian with increasing power output was highly inconsistent and varied greatly among subjects. (3 Over the whole incremental test, half of the participants exhibited a positive relation between spectral indicators and workload, whereas the other half demonstrated the opposite behavior. Collectively, these findings indicate that spectral sEMG indexes do not provide a reliable measure of the fatigue state of the muscle during an incremental cycling test. Moreover, it is concluded that it is not possible to determine the onset of neuromuscular fatigue during an incremental cycling test by examining spectral indicators within individual exercise periods of the test.

The Stroop matching task presents conflict at both the response and nonresponse levels: an event-related potential and electromyography study.

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Caldas, A L; Machado-Pinheiro, W; Souza, L B; Motta-Ribeiro, G C; David, I A

2012-09-01

In the Stroop matching task, a Stroop word is compared to a colored bar. The origin of the conflict presented by this task is a topic of current debate. In an effort to disentangle nonresponse and response conflicts, we recorded electromyography (EMG) and event-related potentials (ERPs) while participants performed the task. The N450 component was sensitive to the relationship of color surfaces, regardless of the response, suggesting the participation of nonresponse conflict. Incompatible arrays (e.g., incongruent Stroop stimuli during "same" responses) presented a substantial amount of double EMG activation and slower EMG latencies, suggesting the participation of response conflict. We propose that both response and nonresponse conflicts are sources of these effects. The combined use of the EMG and ERP techniques played an important role in elucidating the conflicts immersed in the Stroop matching task. Copyright © 2012 Society for Psychophysiological Research.

History of electromyography and nerve conduction studies: A tribute to the founding fathers.

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Kazamel, Mohamed; Warren, Paula Province

2017-09-01

The early development of nerve conduction studies (NCS) and electromyography (EMG) was linked to the discovery of electricity. This relationship had been concluded by observing the effect of applying electricity to the body of an animal and discovering that nerves and muscles themselves could produce electricity. We attempt to review the historical evolution of NCS and EMG over the last three centuries by reviewing the landmark publications of Galvani, Adrian, Denny-Brown, Larrabee, and Lambert. In 1771, Galvani showed that electrical stimulation of animal muscle tissue produced contraction and, thereby, the concept of animal electricity was born. In 1929, Adrian devised a method to record a single motor unit potential by connecting concentric needle electrodes to an amplifier and a loud speaker. In 1938, Denny-Brown described the fasciculation potentials and separated them from fibrillations. Toward the end of World War II, Larrabee began measuring the compound muscle action potential in healthy and injured nerves of war victims. In 1957, Lambert and Eaton described the electrophysiologic features of a new myasthenic syndrome associated with lung carcinoma. Overall, research on this topic was previously undertaken by neurophysiologists and then later by neurologists, with Adrian most likely being the first neurologist to be involved. The field greatly benefited from the invention of equipment that was capable of amplifying small bioelectrical currents by the beginning of the 20th century. Significant scientific and technical advances were later made during and after World War II which provided a large patient population with nerve injuries to study. Copyright © 2017 Elsevier Ltd. All rights reserved.

Developing control algorithms of a voluntary cough for an artificial bioengineered larynx using surface electromyography of chest muscles: A prospective cohort study.

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Banus, M S; Birchall, M A; Graveston, J A

2018-04-01

This prospective cohort study investigates the prediction of a voluntary cough using surface electromyography (EMG) of intercostal and diaphragm muscles, to develop control algorithms for an EMG-controlled artificial larynx. The Ear Institute, London. Electromyography onset compared to voluntary cough exhalation onset and to 100 ms (to give the artificial larynx the time to close the bioengineered vocal cords) before voluntary cough exhalation onset, in twelve healthy participants. In the 189 EMG of intercostal muscle-detected voluntary coughs, 172 coughs (91% CI 70-112) were detected before onset of cough exhalation and 128 coughs (67.6% CI 33.7-101.7) 100 ms before onset of cough exhalation. In the 158 EMG of diaphragm muscle-detected voluntary coughs, 149 coughs (94.3% CI 76.3-112.3) were detected before onset of cough exhalation and 102 coughs (64.6% CI 26.6-102.6) 100 ms before onset of cough exhalation. More coughs were detected before onset of cough exhalation when combining EMG activity of intercostal and diaphragm muscles and comparing this to intercostal muscle activity alone (183 coughs [96.8% CI 83.8-109.8] vs 172 coughs, P = .0294). When comparing the mentioned combination to diaphragm muscle activity alone, the higher percentage of detected coughs before cough exhalation onset was not found to be significant (183 coughs vs 149 coughs, P = .295). In addition, more coughs were detected 100 ms before onset of cough exhalation with the mentioned combination of EMG activity and comparing this to intercostal muscles alone (149 coughs [78.8% CI 48.8-108.8] vs 128 coughs, P = .0198) and to diaphragm muscles alone (149 coughs vs 102 coughs, P = .0038). Most voluntary coughs can be predicted based on combined EMG signals of intercostal and diaphragm muscles, and therefore, these two muscle groups will be useful in controlling the bioengineered vocal cords within the artificial larynx during a voluntary cough. © 2017 John Wiley & Sons Ltd.

Gait Analysis Using Wearable Sensors

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Hutian Feng

2012-02-01

Full Text Available Gait analysis using wearable sensors is an inexpensive, convenient, and efficient manner of providing useful information for multiple health-related applications. As a clinical tool applied in the rehabilitation and diagnosis of medical conditions and sport activities, gait analysis using wearable sensors shows great prospects. The current paper reviews available wearable sensors and ambulatory gait analysis methods based on the various wearable sensors. After an introduction of the gait phases, the principles and features of wearable sensors used in gait analysis are provided. The gait analysis methods based on wearable sensors is divided into gait kinematics, gait kinetics, and electromyography. Studies on the current methods are reviewed, and applications in sports, rehabilitation, and clinical diagnosis are summarized separately. With the development of sensor technology and the analysis method, gait analysis using wearable sensors is expected to play an increasingly important role in clinical applications.

Gait Analysis Using Wearable Sensors

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Tao, Weijun; Liu, Tao; Zheng, Rencheng; Feng, Hutian

2012-01-01

Gait analysis using wearable sensors is an inexpensive, convenient, and efficient manner of providing useful information for multiple health-related applications. As a clinical tool applied in the rehabilitation and diagnosis of medical conditions and sport activities, gait analysis using wearable sensors shows great prospects. The current paper reviews available wearable sensors and ambulatory gait analysis methods based on the various wearable sensors. After an introduction of the gait phases, the principles and features of wearable sensors used in gait analysis are provided. The gait analysis methods based on wearable sensors is divided into gait kinematics, gait kinetics, and electromyography. Studies on the current methods are reviewed, and applications in sports, rehabilitation, and clinical diagnosis are summarized separately. With the development of sensor technology and the analysis method, gait analysis using wearable sensors is expected to play an increasingly important role in clinical applications. PMID:22438763

Shoulder muscle fatigue during repetitive tasks as measured by electromyography and near-infrared spectroscopy.

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Ferguson, Sue A; Allread, W Gary; Le, Peter; Rose, Joseph; Marras, William S

2013-12-01

The objective of this study was to quantify shoulder muscle fatigue during repetitive exertions similar to motions found in automobile assembly tasks. Shoulder musculoskeletal disorders (MSDs) are a common and costly problem in automotive manufacturing. Ten subjects participated in the study. There were three independent variables: shoulder angle, frequency, and force. There were two types of dependent measures: percentage change in near-infrared spectroscopy (NIRS) measures and change in electromyography (EMG) median frequency. The anterior deltoid and trapezius muscles were measured for both NIRS and EMG. Also, EMG was collected on the middle deltoid and biceps muscles. The results showed that oxygenated hemoglobin decreased significantly due to the main effects (shoulder angle, frequency, and force). The percentage change in oxygenated hemoglobin had a significant interaction attributable to force and repetition for the anterior deltoid muscle, indicating that as repetition increased, the magnitude of the differences between the forces increased. The interaction of repetition and shoulder angle was also significant for the percentage change in oxygenated hemoglobin. The median frequency decreased significantly for the main effects; however, no interactions were statistically significant. There was significant shoulder muscle fatigue as a function of shoulder angle, task frequency, and force level. Furthermore, percentage change in oxygenated hemoglobin had two statistically significant interactions, enhancing our understanding of these risk factors. Ergonomists should examine interactions of force and repetition as well as shoulder angle and repetition when evaluating the risk of shoulder MSDs.

Fatigue effects upon sticking region and electromyography in a six-repetition maximum bench press.

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van den Tillaar, Roland; Saeterbakken, Atle Hole

2013-01-01

The aim of the study was to examine the sticking region and concomitant neuromuscular activation of the prime movers during six-repetition maximum (RM) bench pressing. We hypothesised that both peak velocities would decrease and that the electromyography (EMG) of the prime movers (deltoid, major pectoralis and triceps) would increase during the pre-sticking and sticking region during the six repetitions due to fatigue. Thirteen resistance-trained males (age 22.8 ± 2.2 years, stature 1.82 ± 0.06 m, body mass 83.4 ± 7.6 kg) performed 6-RM bench presses. Barbell kinematics and EMG activity of pectoralis major, deltoid anterior, and triceps brachii during the pre-, sticking and post-sticking region of each repetition in a 6-RM bench press were analysed. For both the sticking as the post-sticking region, the time increased significantly from the first to the sixth repetition. Vertical barbell height at the start of sticking region was lower, while the height at the end of the sticking region and post-sticking region did not change during the six repetitions. It was concluded that in 6-RM bench pressing performance, the sticking region is a poor mechanical force region due to the unchanged barbell height at the end of the sticking region. Furthermore, when fatigue occurs, the pectoralis and the deltoid muscles are responsible for surpassing the sticking region as indicated by their increased activity during the pre- and sticking region during the six-repetitions bench press.

Use of functional near-infrared spectroscopy to monitor cortical plasticity induced by transcranial direct current stimulation

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Khan, Bilal; Hervey, Nathan; Stowe, Ann; Hodics, Timea; Alexandrakis, George

2013-03-01

Electrical stimulation of the human cortex in conjunction with physical rehabilitation has been a valuable approach in facilitating the plasticity of the injured brain. One such method is transcranial direct current stimulation (tDCS) which is a non-invasive method to elicit neural stimulation by delivering current through electrodes placed on the scalp. In order to better understand the effects tDCS has on cortical plasticity, neuroimaging techniques have been used pre and post tDCS stimulation. Recently, neuroimaging methods have discovered changes in resting state cortical hemodynamics after the application of tDCS on human subjects. However, analysis of the cortical hemodynamic activity for a physical task during and post tDCS stimulation has not been studied to our knowledge. A viable and sensitive neuroimaging method to map changes in cortical hemodynamics during activation is functional near-infrared spectroscopy (fNIRS). In this study, the cortical activity during an event-related, left wrist curl task was mapped with fNIRS before, during, and after tDCS stimulation on eight healthy adults. Along with the fNIRS optodes, two electrodes were placed over the sensorimotor hand areas of both brain hemispheres to apply tDCS. Changes were found in both resting state cortical connectivity and cortical activation patterns that occurred during and after tDCS. Additionally, changes to surface electromyography (sEMG) measurements of the wrist flexor and extensor of both arms during the wrist curl movement, acquired concurrently with fNIRS, were analyzed and related to the transient cortical plastic changes induced by tDCS.

Electromyography (EMG) signal recognition using combined discrete wavelet transform based adaptive neuro-fuzzy inference systems (ANFIS)

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Arozi, Moh; Putri, Farika T.; Ariyanto, Mochammad; Khusnul Ari, M.; Munadi, Setiawan, Joga D.

2017-01-01

People with disabilities are increasing from year to year either due to congenital factors, sickness, accident factors and war. One form of disability is the case of interruptions of hand function. The condition requires and encourages the search for solutions in the form of creating an artificial hand with the ability as a human hand. The development of science in the field of neuroscience currently allows the use of electromyography (EMG) to control the motion of artificial prosthetic hand into the necessary use of EMG as an input signal to control artificial prosthetic hand. This study is the beginning of a significant research planned in the development of artificial prosthetic hand with EMG signal input. This initial research focused on the study of EMG signal recognition. Preliminary results show that the EMG signal recognition using combined discrete wavelet transform and Adaptive Neuro-Fuzzy Inference System (ANFIS) produces accuracy 98.3 % for training and 98.51% for testing. Thus the results can be used as an input signal for Simulink block diagram of a prosthetic hand that will be developed on next study. The research will proceed with the construction of artificial prosthetic hand along with Simulink program controlling and integrating everything into one system.

Evaluation of muscular activity duration in shoulders with rotator cuff tears using inertial sensors and electromyography

International Nuclear Information System (INIS)

Duc, Cyntia; Aminian, Kamiar; Pichonnaz, Claude; Farron, Alain; Jolles, Brigitte M; Bassin, Jean-Philippe

2014-01-01

Shoulder disorders, including rotator cuff tears, affect the shoulder function and result in adapted muscle activation. Although these adaptations have been studied in controlled conditions, free-living activities have not been investigated. Based on the kinematics measured with inertial sensors and portable electromyography, the objectives of this study were to quantify the duration of the muscular activation in the upper trapezius (UT), medial deltoid (MD) and biceps brachii (BB) during motion and to investigate the effect of rotator cuff tear in laboratory settings and daily conditions. The duration of movements and muscular activations were analysed separately and together using the relative time of activation (T EMG/mov ). Laboratory measurements showed the parameter’s reliability through movement repetitions (ICC > 0.74) and differences in painful shoulders compared with healthy ones (p < 0.05): longer activation for UT; longer activation for MD during abduction and tendency to shorter activation in other movements; shorter activation for BB. In daily conditions, T EMG/mov for UT was longer, whereas it was shorter for MD and BB (p < 0.05). Moreover, significant correlations were observed between these parameters and clinical scores. This study thus provides new insights into the rotator cuff tear effect on duration of muscular activation in daily activity. (paper)

Effects of jump and balance training on knee kinematics and electromyography of female basketball athletes during a single limb drop landing: pre-post intervention study.

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Nagano, Yasuharu; Ida, Hirofumi; Akai, Masami; Fukubayashi, Toru

2011-07-14

Some research studies have investigated the effects of anterior cruciate ligament (ACL) injury prevention programs on knee kinematics during landing tasks; however the results were different among the studies. Even though tibial rotation is usually observed at the time of ACL injury, the effects of training programs for knee kinematics in the horizontal plane have not yet been analyzed. The purpose of this study was to determine the effects of a jump and balance training program on knee kinematics including tibial rotation as well as on electromyography of the quadriceps and hamstrings in female athletes. Eight female basketball athletes participated in the experiment. All subjects performed a single limb landing at three different times: the initial test, five weeks later, and one week after completing training. The jump and balance training program lasted for five weeks. Knee kinematics and simultaneous electromyography of the rectus femoris and Hamstrings before training were compared with those measured after completing the training program. After training, regarding the position of the knee at foot contact, the knee flexion angle for the Post-training trial (mean (SE): 24.4 (2.1) deg) was significantly larger than that for the Pre-training trial (19.3 (2.5) deg) (p training trial (40.2 (1.9) deg) was significantly larger than that for the Pre-training trial (34.3 (2.5) deg) (p training. A significant increase was also found in the activity of the hamstrings 50 ms before foot contact (p jump and balance training program successfully increased knee flexion and hamstring activity of female athletes during landing, and has the possibility of producing partial effects to avoid the characteristic knee position observed in ACL injury, thereby preventing injury. However, the expected changes in frontal and transverse kinematics of the knee were not observed.

Ultrasonography for the diagnosis of tendinitis and electromyography for the diagnosis of peripheral neuropathy and upper limb radiculopathy: rheumatologists' perspectives.

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Helfenstein, Milton; Ferreira, Mario Soares; Maia, Anna Beatriz Assad; Siena, César Augusto Fávaro; Techy, Antonio

2013-01-01

To ascertain the value ascribed by Brazilian rheumatologists to ultrasonography (US) for diagnosing tendinitis and to electromyography (EMG) for diagnosing peripheral neuropathy and upper limb radiculopathy. In total, 165 rheumatologists answered an anonymous survey (sent via the internet) concerning the two exams, with respect to the following characteristics: reliability, diagnostic accuracy, the importance and necessity of these tests for diagnostic The study revealed that most of the rheumatologists recognised that these exams are operator-dependent, that clinicians do not rely entirely on the results, that these exams are not mandatory for the diagnoses listed, and that professionals who perform these exams should be better trained to provide reliable results. The Brazilian rheumatologists believe the following: the results of these exams should be interpreted with caution and are not definitive for diagnosis; musculoskeletal US and EMG should be performed by trained professionals; and there must be better preparation of the professionals who perform these exams.

Electromyography findings of the cricopharyngeus in association with ipsilateral pharyngeal and laryngeal muscles.

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Halum, Stacey L; Shemirani, Nima L; Merati, Albert L; Jaradeh, Safwan; Toohill, Robert J

2006-04-01

We reviewed a large series of cricopharyngeal (CP) muscle electromyography (EMG) results and compared them with the EMG results from the inferior constrictor (IC), thyroarytenoid, (TA), cricothyroid (CT), and posterior cricoarytenoid (PCA) muscles. We performed a retrospective review of all CP muscle EMG reports from studies performed between January 1996 and June 2003. All of the tested elements from the CP muscle EMG reports were recorded. The EMG results were recorded for the ipsilateral IC, TA, CT, and PCA muscles if they were simultaneously tested. Each muscle result was classified as normal, neurogenic inactive axonal injury (IAI), or neurogenic active axonal injury (AAI), and the muscle findings were compared. A patient chart review was performed to determine a clinical correlation. Fifty-nine patients underwent CP muscle EMG. Eighteen patients had bilateral EMG studies, making a total of 77 CP muscle studies. Nineteen sets of CP muscle results were normal, 43 demonstrated neurogenic IAI, and 15 demonstrated neurogenic AAI. The ipsilateral IC and CP muscles had the same innervation status in 27 of 28 studies (p muscle was studied simultaneously with the CP muscle, 31 of 50 studies had the same innervation status (p = .005). The ipsilateral CT and CP muscles demonstrated the same innervation status in 40 of 50 studies (p muscle findings and between the CP and CT muscle findings were both stronger than the correlation between the CP and TA muscle findings (p muscle findings have the strongest correlation with IC muscle findings, followed by the CT and TA muscles. This outcome does not support theories indicating that the recurrent laryngeal nerve innervates the CP muscle in all cases.

A Soft-Inflatable Exosuit for Knee Rehabilitation: Assisting Swing Phase During Walking

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Saivimal Sridar

2018-05-01

Full Text Available In this paper, we present a soft-inflatable exosuit to assist knee extension during gait training for stroke rehabilitation. The soft exosuit is designed to provide 25% of the knee moment required during the swing phase of the gait cycle and is integrated with inertial measurement units (IMUs and smart shoe insole sensors to improve gait phase detection and controller design. The stiffness of the knee joint during level walking is computed using inverse dynamics. The soft-inflatable actuators, with an I cross-section, are mechanically characterized at varying angles to enable generation of the required stiffness outputs. A linear relation between the inflatable actuator stiffness and internal pressure as a function of the knee angle is obtained, and a two-layer stiffness controller is implemented to assist the knee joint by providing appropriate stiffness during the swing phase. Finally, to evaluate the ability of the exosuit to assist in swing motion, surface-electromyography (sEMG sensors are placed on the three muscle groups of the quadriceps and two groups of the hamstrings, on three healthy participants. A reduction in muscle activity of the rectus femoris, vastus lateralis, and vastus medialis is observed, which demonstrates feasibility of operation and potential future usage of the soft inflatable exosuit by impaired users.

Embedded sensing: integrating sensors in 3-D printed structures

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A. Dijkshoorn

2018-03-01

Full Text Available Current additive manufacturing allows for the implementation of electrically interrogated 3-D printed sensors. In this contribution various technologies, sensing principles and applications are discussed. We will give both an overview of some of the sensors presented in literature as well as some of our own recent work on 3-D printed sensors. The 3-D printing methods discussed include fused deposition modelling (FDM, using multi-material printing and poly-jetting. Materials discussed are mainly thermoplastics and include thermoplastic polyurethane (TPU, both un-doped as well as doped with carbon black, polylactic acid (PLA and conductive inks. The sensors discussed are based on biopotential sensing, capacitive sensing and resistive sensing with applications in surface electromyography (sEMG and mechanical and tactile sensing. As these sensors are based on plastics they are in general flexible and therefore open new possibilities for sensing in soft structures, e.g. as used in soft robotics. At the same time they show many of the characteristics of plastics like hysteresis, drift and non-linearity. We will argue that 3-D printing of embedded sensors opens up exciting new possibilities but also that these sensors require us to rethink how to exploit non-ideal sensors.

Power-assistive finger exoskeleton with a palmar opening at the fingerpad.

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Heo, Pilwon; Kim, Jung

2014-11-01

This paper presents a powered finger exoskeleton with an open fingerpad, named the Open Fingerpad eXoskeleton (OFX). The palmar opening at the fingerpad allows for direct contact between the user's fingerpad and objects in order to make use of the wearer's own tactile sensation for dexterous manipulation. Lateral side walls at the end of the OFX's index finger module are equipped with custom load cells for estimating the wearer's pinch grip force. A pneumatic cylinder generates assistance force, which is determined according to the estimated pinch grip force. The OFX transmits the assistance force directly to the objects without exerting pressure on the wearer's finger. The advantage of the OFX over an exoskeleton with a closed fingerpad was validated experimentally. During static and dynamic manipulation of a test object, the OFX exhibited a lower safety margin than the closed exoskeleton, indicating a higher ability to adjust the grip force within an appropriate range. Furthermore, the benefit of force assistance in reducing the muscular burden was observed in terms of muscle fatigue during a static pinch grip. The median frequency (MDF) of the surface electromyography (sEMG) signal from the first dorsal interosseous (FDI) muscle displayed a lower reduction rate for the assisted condition, indicating a lower accumulation rate of muscle fatigue.

Motion tracking and electromyography-assisted identification of mirror hand contributions to functional near-infrared spectroscopy images acquired during a finger-tapping task performed by children with cerebral palsy

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Hervey, Nathan; Khan, Bilal; Shagman, Laura; Tian, Fenghua; Delgado, Mauricio R.; Tulchin-Francis, Kirsten; Shierk, Angela; Roberts, Heather; Smith, Linsley; Reid, Dahlia; Clegg, Nancy J.; Liu, Hanli; MacFarlane, Duncan; Alexandrakis, George

2014-01-01

Abstract. Recent studies have demonstrated functional near-infrared spectroscopy (fNIRS) to be a viable and sensitive method for imaging sensorimotor cortex activity in children with cerebral palsy (CP). However, during unilateral finger tapping, children with CP often exhibit unintended motions in the nontapping hand, known as mirror motions, which confuse the interpretation of resulting fNIRS images. This work presents a method for separating some of the mirror motion contributions to fNIRS images and demonstrates its application to fNIRS data from four children with CP performing a finger-tapping task with mirror motions. Finger motion and arm muscle activity were measured simultaneously with fNIRS signals using motion tracking and electromyography (EMG), respectively. Subsequently, subject-specific regressors were created from the motion capture or EMG data and independent component analysis was combined with a general linear model to create an fNIRS image representing activation due to the tapping hand and one image representing activation due to the mirror hand. The proposed method can provide information on how mirror motions contribute to fNIRS images, and in some cases, it helps remove mirror motion contamination from the tapping hand activation images. PMID:26157980

Isometric shoulder muscle activation patterns for 3-D planar forces: a methodology for musculo-skeletal model validation

NARCIS (Netherlands)

Groot, J.H.; Rozendaal, L.A.; Meskers, C.G.M.; Arwert, H.J.

2004-01-01

Objective. To present an isometric method for validation of a shoulder model simulation by means of experimentally obtained electromyography and addressing all muscles active around the shoulder joints. Background. Analysis of muscle force distribution in the shoulder by means of electromyography

Surface electromyography assessment of muscle activation patterns while sitting down in young healthy women and patients with ankylosing spondylitis [Povrchové elektromyografické hodnocení svalové aktivity ve zkoušce posazení u zdravých mladých žen a u pacientů s ankylozující spondylitidou

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Petr Uhlíř

2011-03-01

Full Text Available BACKGROUND: Muscle activation patterns depend on many factors. Surface electromyography (SEMG can reveal these patterns in subjects of different ages and health states. We studied patterns of muscle activation in two groups of subjects - healthy young women (as a control group and patients with ankylosing spondylitis. OBJECTIVE: The aim of this study was to register and compare muscle activation patterns while sitting down in these two groups in four situations with different positions of the lower and upper limbs. METHODS: Muscle activity was registered with the use of 8 channel surface polyelectromyography (Noraxon-Myosystem 1400A. We tested the following muscles bilaterally while the subjects were sitting down (tibialis anterior muscle, medial head of the gastrocnemius muscle, gluteus maximus muscle, erectores spinae muscles. The onset of each individual muscle's activity was determined by calculating the sum of the mean value of the SEMG baseline plus 10% of the maximum value of amplitude (peak. RESULTS: It was registered that the medial head of the gastrocnemius muscle and/or erectores spinae muscles were activated as the first ones in both groups of the subjects under study in most of the studied postural situations. We registered differences in timing (sequence of muscle activation among various studied body and limb positions (P–, P+, PD–, and PN–. A great degree of variability in the sequence of muscle activation was revealed, depending on the positions of the upper and lower limbs. CONCLUSIONS: We did not find any unique patterns of muscle activation in either of the two groups under study.[VÝCHODISKA: Časové zapojování (aktivace svalů je závislé na mnoha faktorech. Povrchová polyelektromyografie zachycuje vzorce zapojování svalů u probandů rozdílného věku a zdravotního stavu v různých podmínkách. CÍLE: Cílem studie byla registrace a hodnocení pořadí zapojování svalů v průběhu sedání u t

Treatment Efficacy of Electromyography versus Fiberscopy-Guided Botulinum Toxin Injection in Adductor Spasmodic Dysphonia Patients: A Prospective Comparative Study

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Kim, Jae Wook; Park, Jae Hong; Park, Ki Nam; Lee, Seung Won

2014-01-01

Introduction. This study prospectively evaluates and compares the treatment efficacy of botulinum toxin injection under electromyography guidance (EMG group) and percutaneous botulinum toxin injection under flexible fiberscopic guidance (fiberscopy group). Methods. Thirty patients with adductor spasmodic dysphonia (ADSD), who had never received treatment, were randomly allocated into EMG- or fiberscopy-guided botulinum toxin injections between March 2008 and February 2010. We assessed acoustic and aerodynamic voice parameters, and the voice handicap index (VHI) before injection and at 1, 3, and 6 months after injection. Results. The mean total dosage of botulinum toxin was similar for both groups: 1.7 ± 0.5 U for the EMG group and 1.8 ± 0.4 U for the fiberscopy group (P > 0.05). There were no significant differences in outcomes between the two groups in either the duration of effectiveness or complications such as breathy voice and aspiration. Conclusion. Botulinum toxin injection under fiberscopic guidance is a viable alternative to EMG-guided botulinum toxin injection for the treatment of adductor spasmodic dysphonia when EMG equipment is unavailable. PMID:25383369

Treatment Efficacy of Electromyography versus Fiberscopy-Guided Botulinum Toxin Injection in Adductor Spasmodic Dysphonia Patients: A Prospective Comparative Study

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Jae Wook Kim

2014-01-01

Full Text Available Introduction. This study prospectively evaluates and compares the treatment efficacy of botulinum toxin injection under electromyography guidance (EMG group and percutaneous botulinum toxin injection under flexible fiberscopic guidance (fiberscopy group. Methods. Thirty patients with adductor spasmodic dysphonia (ADSD, who had never received treatment, were randomly allocated into EMG- or fiberscopy-guided botulinum toxin injections between March 2008 and February 2010. We assessed acoustic and aerodynamic voice parameters, and the voice handicap index (VHI before injection and at 1, 3, and 6 months after injection. Results. The mean total dosage of botulinum toxin was similar for both groups: 1.7 ± 0.5 U for the EMG group and 1.8 ± 0.4 U for the fiberscopy group (P>0.05. There were no significant differences in outcomes between the two groups in either the duration of effectiveness or complications such as breathy voice and aspiration. Conclusion. Botulinum toxin injection under fiberscopic guidance is a viable alternative to EMG-guided botulinum toxin injection for the treatment of adductor spasmodic dysphonia when EMG equipment is unavailable.

Treatment efficacy of electromyography versus fiberscopy-guided botulinum toxin injection in adductor spasmodic dysphonia patients: a prospective comparative study.

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Kim, Jae Wook; Park, Jae Hong; Park, Ki Nam; Lee, Seung Won

2014-01-01

This study prospectively evaluates and compares the treatment efficacy of botulinum toxin injection under electromyography guidance (EMG group) and percutaneous botulinum toxin injection under flexible fiberscopic guidance (fiberscopy group). Thirty patients with adductor spasmodic dysphonia (ADSD), who had never received treatment, were randomly allocated into EMG- or fiberscopy-guided botulinum toxin injections between March 2008 and February 2010. We assessed acoustic and aerodynamic voice parameters, and the voice handicap index (VHI) before injection and at 1, 3, and 6 months after injection. The mean total dosage of botulinum toxin was similar for both groups: 1.7 ± 0.5 U for the EMG group and 1.8 ± 0.4 U for the fiberscopy group (P > 0.05). There were no significant differences in outcomes between the two groups in either the duration of effectiveness or complications such as breathy voice and aspiration. Botulinum toxin injection under fiberscopic guidance is a viable alternative to EMG-guided botulinum toxin injection for the treatment of adductor spasmodic dysphonia when EMG equipment is unavailable.

Motion tracking and electromyography assist the removal of mirror hand contributions to fNIRS images acquired during a finger tapping task performed by children with cerebral palsy

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Hervey, Nathan; Khan, Bilal; Shagman, Laura; Tian, Fenghua; Delgado, Mauricio R.; Tulchin-Francis, Kirsten; Shierk, Angela; Smith, Linsley; Reid, Dahlia; Clegg, Nancy J.; Liu, Hanli; MacFarlane, Duncan; Alexandrakis, George

2013-03-01

Functional neurological imaging has been shown to be valuable in evaluating brain plasticity in children with cerebral palsy (CP). In recent studies it has been demonstrated that functional near-infrared spectroscopy (fNIRS) is a viable and sensitive method for imaging motor cortex activities in children with CP. However, during unilateral finger tapping tasks children with CP often exhibit mirror motions (unintended motions in the non-tapping hand), and current fNIRS image formation techniques do not account for this. Therefore, the resulting fNIRS images contain activation from intended and unintended motions. In this study, cortical activity was mapped with fNIRS on four children with CP and five controls during a finger tapping task. Finger motion and arm muscle activation were concurrently measured using motion tracking cameras and electromyography (EMG). Subject-specific regressors were created from motion capture and EMG data and used in a general linear model (GLM) analysis in an attempt to create fNIRS images representative of different motions. The analysis provided an fNIRS image representing activation due to motion and muscle activity for each hand. This method could prove to be valuable in monitoring brain plasticity in children with CP by providing more consistent images between measurements. Additionally, muscle effort versus cortical effort was compared between control and CP subjects. More cortical effort was required to produce similar muscle effort in children with CP. It is possible this metric could be a valuable diagnostic tool in determining response to treatment.

Age-Associated Changes in the Spectral and Statistical Parameters of Surface Electromyogram of Tibialis Anterior.

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Siddiqi, Ariba; Arjunan, Sridhar Poosapadi; Kumar, Dinesh Kant

2016-01-01

Age-related neuromuscular change of Tibialis Anterior (TA) is a leading cause of muscle strength decline among the elderly. This study has established the baseline for age-associated changes in sEMG of TA at different levels of voluntary contraction. We have investigated the use of Gaussianity and maximal power of the power spectral density (PSD) as suitable features to identify age-associated changes in the surface electromyogram (sEMG). Eighteen younger (20-30 years) and 18 older (60-85 years) cohorts completed two trials of isometric dorsiflexion at four different force levels between 10% and 50% of the maximal voluntary contraction. Gaussianity and maximal power of the PSD of sEMG were determined. Results show a significant increase in sEMG's maximal power of the PSD and Gaussianity with increase in force for both cohorts. It was also observed that older cohorts had higher maximal power of the PSD and lower Gaussianity. These age-related differences observed in the PSD and Gaussianity could be due to motor unit remodelling. This can be useful for noninvasive tracking of age-associated neuromuscular changes.

Evoked electromyography to rocuronium in orbicularis oris and gastrocnemius in facial nerve injury in rabbits.

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Xing, Yian; Chen, Lianhua; Li, Shitong

2013-11-01

Muscles innervated by the facial nerve show different sensitivities to muscle relaxants than muscles innervated by somatic nerves, especially in the presence of facial nerve injury. We compared the evoked electromyography (EEMG) response of orbicularis oris and gastrocnemius in with and without a non-depolarizing muscle relaxant in a rabbit model of graded facial nerve injury. Differences in EEMG response and inhibition by rocuronium were measured in the orbicularis oris and gastrocnemius muscles 7 to 42 d after different levels of facial nerve crush injuries in adult rabbits. Baseline EEMG of orbicularis oris was significantly smaller than those of the gastrocnemius. Gastrocnemius was more sensitive to rocuronium than the facial muscles (P rocuronium was negatively correlated with the magnitude of facial nerve injury but the sensitivity to rocuronium was not. No significant difference was found in the onset time and the recovery time of rocuronium among gastrocnemius and normal or damaged facial muscles. Muscles innervated by somatic nerves are more sensitive to rocuronium than those innervated by the facial nerve, but while facial nerve injury reduced EEMG responses, the sensitivity to rocuronium is not altered. Partial neuromuscular blockade may be a suitable technique for conducting anesthesia and surgery safely when EEMG monitoring is needed to preserve and protect the facial nerve. Additional caution should be used if there is a risk of preexisting facial nerve injury. Copyright © 2013 Elsevier Inc. All rights reserved.

Electromyography and vaginal pressure of the pelvic floor muscles in women with recurrent vulvovaginal candidiasis and vulvodynia.

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Polpeta, Nádia Cristina; Giraldo, Paulo César; Juliato, Cássia Raquel Teatin; Yoshida, Laura Pagotto; do Amaral, Rose Luce Gomes; Eleutério, José

2012-01-01

To evaluate the electrical potentials and pressure exerted by the pelvic floor muscles in women with recurrent vulvovaginal candidiasis (RVVC) or vulvodynia as compared to control women. A cross-sectional study performed in the Female Outpatient Clinic of Genital Infections in the Department of Obstetrics and Gynecology of the Universidade Estadual de Campinas analyzed and compared electromyography (EMG) and vaginal pressure of the pelvic floor muscles in 61 women. Of these 61 women, 19 had vulvodynia, 12 had RVVC and 30 women had no disorder (control group). For data collection, the instrument used was the Miotool Uro device and its software Biotrainer (Miotec Ltd., Porto Alegre, Rio Grande do Sul, Brazil). The EMG evaluation of the pelvic floor muscles showed significantly lower values in the vulvodynia group (tonic contractions) and RVVC group (phasic and tonic contractions) when compared to the control group. No significant differences in basal tone EMG and vaginal pressure values at rest or during pelvic floor muscle contractions were found among groups. The maximum time of sustained contraction in patients with RVVC or vulvodynia was significantly lower (p < 0.0001) than in controls. Women with vulvodynia and RVVC have more frequent pelvic floor muscle dysfunction than controls when observed by EMG evaluation.

Development of a 3D workspace shoulder assessment tool incorporating electromyography and an inertial measurement unit-a preliminary study.

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Aslani, Navid; Noroozi, Siamak; Davenport, Philip; Hartley, Richard; Dupac, Mihai; Sewell, Philip

2018-06-01

Traditional shoulder range of movement (ROM) measurement tools suffer from inaccuracy or from long experimental setup times. Recently, it has been demonstrated that relatively low-cost wearable inertial measurement unit (IMU) sensors can overcome many of the limitations of traditional motion tracking systems. The aim of this study is to develop and evaluate a single IMU combined with an electromyography (EMG) sensor to monitor the 3D reachable workspace with simultaneous measurement of deltoid muscle activity across the shoulder ROM. Six volunteer subjects with healthy shoulders and one participant with a 'frozen' shoulder were recruited to the study. Arm movement in 3D space was plotted in spherical coordinates while the relative EMG intensity of any arm position is presented graphically. The results showed that there was an average ROM surface area of 27291 ± 538 deg 2 among all six healthy individuals and a ROM surface area of 13571 ± 308 deg 2 for the subject with frozen shoulder. All three sections of the deltoid show greater EMG activity at higher elevation angles. Using such tools enables individuals, surgeons and physiotherapists to measure the maximum envelope of motion in conjunction with muscle activity in order to provide an objective assessment of shoulder performance in the voluntary 3D workspace. Graphical abstract The aim of this study is to develop and evaluate a single IMU combined with an electromyography (EMG) sensor to monitor the 3D reachable workspace with simultaneous measurement of deltoid muscle activity across the shoulder ROM. The assessment tool consists of an IMU sensor, an EMG sensor, a microcontroller and a Bluetooth module. The assessment tool was attached to subjects arm. Individuals were instructed to move their arms with the elbow fully extended. They were then asked to provide the maximal voluntary elevation envelope of the arm in 3D space in multiple attempts starting from a small movement envelope going to the biggest

A systematic review of surface electromyography analyses of the bench press movement task

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Gołaś, Artur; Blazek, Dusan; Maszczyk, Adam; Wilk, Michał; Pietraszewski, Przemysław; Petr, Miroslav; Uhlir, Petr; Zając, Adam

2017-01-01

Background The bench press exercise (BP) plays an important role in recreational and professional training, in which muscle activity is an important multifactorial phenomenon. The objective of this paper is to systematically review electromyography (EMG) studies performed on the barbell BP exercise to answer the following research questions: Which muscles show the greatest activity during the flat BP? Which changes in muscle activity are related to specific conditions under which the BP movement is performed? Strategy PubMed, Scopus, Web of Science and Cochrane Central Register of Controlled Trials (CENTRAL) in the Cochrane Library were searched through June 10, 2016. A combination of the following search terms was used: bench press, chest press, board press, test, measure, assessment, dynamometer, kinematics and biomechanics. Only original, full-text articles were considered. Results The search process resulted in 14 relevant studies that were included in the discussion. The triceps brachii (TB) and pectoralis major (PM) muscles were found to have similar activity during the BP, which was significantly higher than the activity of the anterior deltoid. During the BP movement, muscle activity changes with exercise intensity, velocity of movement, fatigue, mental focus, movement phase and stability conditions, such as bar vibration or unstable surfaces. Under these circumstances, TB is the most common object of activity change. Conclusions PM and TB EMG activity is more dominant and shows greater EMG amplitude than anterior deltoid during the BP. There are six factors that can influence muscle activity during the BP; however, the most important factor is exercise intensity, which interacts with all other factors. The research on muscle activity in the BP has several unresolved areas, such as clearly and strongly defined guidelines to perform EMG measurements (e.g., how to elaborate with surface EMG limits) or guidelines for the use of exact muscle models. PMID

Evaluation of surgeon's muscle fatigue during thoracoscopic pulmonary lobectomy using interoperative surface electromyography.

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Yoon, Seung-Hyun; Jung, Myung-Chul; Park, Seong Yong

2016-06-01

The aim of this study was to document the physical stress experienced by a surgeon during thoracoscopic pulmonary lobectomy and mediastinal lymph node dissection for lung cancer by measuring the intraoperative electromyography (EMG). Surface EMG was recorded during 12 cases of thoracoscopic lobectomy. During the operation, 16 channels of a wireless EMG were used to measure muscle activity and fatigue from the bilateral muscles of the splenius capitis (SC), upper trapezius (UT), middle deltoid (MD), flexor carpi radialis (FCR), extensor carpi radialis (ECR), lumbar erector spinae (LES), rectus femoralis (RF), and tibialis anterior (TA). The EMG signals were processed to collect the values of the root mean square for muscle activity and median frequency (MF) for muscle fatigue. All operations were completed without adverse events. The mean operating time was 99.16±35.15 minutes. During the operation, the mean muscle activity of all muscles was 21.91±12.85 mV. High muscle activity was observed in the bilateral FCR and ECR, whereas low muscle activity was observed in the bilateral SC and LES. The final MFs in the bilateral SC and LES were found to be decreased from the initial status, which implied increased muscle fatigue. The muscles of the right and left LES were significantly fatigued by up to 29% and 37% compared to their initial status (P=0.021 and P=0.007, respectively). The MFs of the bilateral LES decreased with time (an average decreases of 0.008/5 minutes, P=0.002 in right LES and 0.004/5 minutes, P=0.018 in left LES). During thoracoscopic lobectomy, muscle fatigue was observed in muscles related to a static posture, such as the bilateral SC, UT, and ES. Further studies are required to investigate the ergonomic adjustments needed to reduce muscle fatigue in these static muscles.

A systematic review of surface electromyography analyses of the bench press movement task.

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Petr Stastny

Full Text Available The bench press exercise (BP plays an important role in recreational and professional training, in which muscle activity is an important multifactorial phenomenon. The objective of this paper is to systematically review electromyography (EMG studies performed on the barbell BP exercise to answer the following research questions: Which muscles show the greatest activity during the flat BP? Which changes in muscle activity are related to specific conditions under which the BP movement is performed?PubMed, Scopus, Web of Science and Cochrane Central Register of Controlled Trials (CENTRAL in the Cochrane Library were searched through June 10, 2016. A combination of the following search terms was used: bench press, chest press, board press, test, measure, assessment, dynamometer, kinematics and biomechanics. Only original, full-text articles were considered.The search process resulted in 14 relevant studies that were included in the discussion. The triceps brachii (TB and pectoralis major (PM muscles were found to have similar activity during the BP, which was significantly higher than the activity of the anterior deltoid. During the BP movement, muscle activity changes with exercise intensity, velocity of movement, fatigue, mental focus, movement phase and stability conditions, such as bar vibration or unstable surfaces. Under these circumstances, TB is the most common object of activity change.PM and TB EMG activity is more dominant and shows greater EMG amplitude than anterior deltoid during the BP. There are six factors that can influence muscle activity during the BP; however, the most important factor is exercise intensity, which interacts with all other factors. The research on muscle activity in the BP has several unresolved areas, such as clearly and strongly defined guidelines to perform EMG measurements (e.g., how to elaborate with surface EMG limits or guidelines for the use of exact muscle models.

A systematic review of surface electromyography analyses of the bench press movement task.

Science.gov (United States)

Stastny, Petr; Gołaś, Artur; Blazek, Dusan; Maszczyk, Adam; Wilk, Michał; Pietraszewski, Przemysław; Petr, Miroslav; Uhlir, Petr; Zając, Adam

2017-01-01

The bench press exercise (BP) plays an important role in recreational and professional training, in which muscle activity is an important multifactorial phenomenon. The objective of this paper is to systematically review electromyography (EMG) studies performed on the barbell BP exercise to answer the following research questions: Which muscles show the greatest activity during the flat BP? Which changes in muscle activity are related to specific conditions under which the BP movement is performed? PubMed, Scopus, Web of Science and Cochrane Central Register of Controlled Trials (CENTRAL) in the Cochrane Library were searched through June 10, 2016. A combination of the following search terms was used: bench press, chest press, board press, test, measure, assessment, dynamometer, kinematics and biomechanics. Only original, full-text articles were considered. The search process resulted in 14 relevant studies that were included in the discussion. The triceps brachii (TB) and pectoralis major (PM) muscles were found to have similar activity during the BP, which was significantly higher than the activity of the anterior deltoid. During the BP movement, muscle activity changes with exercise intensity, velocity of movement, fatigue, mental focus, movement phase and stability conditions, such as bar vibration or unstable surfaces. Under these circumstances, TB is the most common object of activity change. PM and TB EMG activity is more dominant and shows greater EMG amplitude than anterior deltoid during the BP. There are six factors that can influence muscle activity during the BP; however, the most important factor is exercise intensity, which interacts with all other factors. The research on muscle activity in the BP has several unresolved areas, such as clearly and strongly defined guidelines to perform EMG measurements (e.g., how to elaborate with surface EMG limits) or guidelines for the use of exact muscle models.

Stable tooth contacts in intercuspal occlusion makes for utilities of the jaw elevators during maximal voluntary clenching.

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Wang, X-R; Zhang, Y; Xing, N; Xu, Y-F; Wang, M-Q

2013-05-01

Data are inconsistent concerning whether the level of the surface electromyographic (SEMG) activity of jaw-closing muscles increases when biting forces elevated during maximal voluntary clenching (MVC). In this study, T-Scan III system and BioEMG III system were used to record bite force, occlusal contacts and SEMG activity of the anterior temporalis (TA) and of the masseter muscles (MM) simultaneously. Recordings were obtained from 16 healthy young adult males during different conditions: (i) a fast MVC from resting position to intercuspal position (ICP); (ii) mandibular movements from ICP to protrusive or lateral edge-to-edge positions with teeth in contact with biting; (iii) a fast MVC in protrusive and lateral edge-to-edge positions. A higher level of SEMG activity was associated with a higher bite force during occluding movements (P < 0.05). However, during fast MVC from rest to ICP, the largest number of occlusal contacts was achieved and distributed more symmetrically, the highest level of biting force was obtained, but the SEMG activity of the jaw elevator muscles was reduced compared with its maximum level (P < 0.05). This phenomenon was not observed during the fast MVC in protrusive or lateral edge-to-edge positions. The present results that a lower SEMG activity was associated with the largest number of occlusal contacts and the highest level of bite force during centric MVC demonstrated a complex integration of jaw-closing muscles when a stable occlusion is present. © 2013 Blackwell Publishing Ltd.

Patterns of variation across primates in jaw-muscle electromyography during mastication.

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Vinyard, Christopher J; Wall, Christine E; Williams, Susan H; Hylander, William L

2008-08-01

Biologists that study mammals continue to discuss the evolution of and functional variation in jaw-muscle activity during chewing. A major barrier to addressing these issues is collecting sufficient in vivo data to adequately capture neuromuscular variation in a clade. We combine data on jaw-muscle electromyography (EMG) collected during mastication from 14 species of primates and one of treeshrews to assess patterns of neuromuscular variation in primates. All data were collected and analyzed using the same methods. We examine the variance components for EMG parameters using a nested ANOVA design across successive hierarchical factors from chewing cycle through species for eight locations in the masseter and temporalis muscles. Variation in jaw-muscle EMGs was not distributed equally across hierarchical levels. The timing of peak EMG activity showed the largest variance components among chewing cycles. Relative levels of recruitment of jaw muscles showed the largest variance components among chewing sequences and cycles. We attribute variation among chewing cycles to (1) changes in food properties throughout the chewing sequence, (2) variation in bite location, and (3) the multiple ways jaw muscles can produce submaximal bite forces. We hypothesize that variation among chewing sequences is primarily related to variation in properties of food. The significant proportion of variation in EMGs potentially linked to food properties suggests that experimental biologists must pay close attention to foods given to research subjects in laboratory-based studies of feeding. The jaw muscles exhibit markedly different variance components among species suggesting that primate jaw muscles have evolved as distinct functional units. The balancing-side deep masseter (BDM) exhibits the most variation among species. This observation supports previous hypotheses linking variation in the timing and activation of the BDM to symphyseal fusion in anthropoid primates and in strepsirrhines

Comportamento temporal da velocidade de condução de potenciais de ação de unidades motoras sob condições de fadiga muscular Comportamiento temporal de la velocidad de conducción de potencias de acción de las unidades motoras sobre condiciones de fatiga muscular Temporal behavior of motor units action potential velocity under muscle fatigue conditions

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Marco Antonio Cavalcanti Garcia

2004-08-01

tipo de evaluación, a pesar de que comunmente es detectada a través de técnicas invasivas, mediante electrodos de borne o aguja. Asi mismo, el objetivo de este trabajo fue estimar la VCPAUM a través de la SEMG, evaluando su comportamiento temporal, en contracciones isométricas realizadas hasta la extenuación. Dieciocho voluntarios (nueve hombres y nueve mujeres; de edades entre 25,6 ± 6,8 años, alumnos de la EEFD/UFRJ, aceptaron de participar en el estudio. Las señales de EMG se tomaron a partir del músculo bíceps braquial derecho en tres diferentes niveles (25%, 50 e 75% de la carga máxima (CM, siendo, entonces, divididos en 3 trechos, correspondientes al tiempo total de gasto de la tarea, denominados: início (T1, medio (T2 y fin (T3. La VCPAUM presentó redución temporal durante el pasaje por los trechos (p Muscle fatigue, which is defined as the failure to maintain a required or expected force, has been investigated in both clinical and sports applications. On the investigation of muscle fatigue effects related to muscular control, surface electromyography (SEMG has been the most common electrodiagnostic method, because some different parameters can be extracted from the EMG signal. Among the parameters, motor units action potential conduction velocity (MUAPCV has been one of the most important, in spite of being usually detected through indwelling electrodes. Thus, the aim of this work was to estimate MUAPCV through SEMG, detecting its temporal behavior during isometric contractions until exhaustion. Eighteen students from EEFD/UFRJ (9 men and 9 women mean age 25.6 ± 6.8 years, right handed, consented to participate on this study. The EMG signals were collected from the right biceps braquii muscle through surface electrodes on 3 different levels of isometric contractions (25%, 50 e 75% of maximum load (ML, which were divided into 3 periods that would define the beginning (P1, the middle (P2, and the end (P3 of the contraction. MUAPCV presented a

Quantifying the lumbar flexion-relaxation phenomenon: theory, normative data, and clinical applications.

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Neblett, Randy; Mayer, Tom G; Gatchel, Robert J; Keeley, Janice; Proctor, Tim; Anagnostis, Christopher

2003-07-01

A two-part investigation was conducted: 1) a prospective study of asymptomatic subjects quantitatively comparing trunk mobility to surface electromyographic (sEMG) signals from the erector spinae during trunk flexion; and 2) a prospective repeated-measures cohort study of patients with chronic disabled work-related spinal disorder tested for the flexion-relaxation (FR) phenomenon while measured simultaneously for lumbar spine inclinometric range of motion (ROM). To describe a theoretical model for the potential use of FR unloaded in assessing patients with chronic low back pain patients before and after rehabilitation, and to establish a normative database (Part 1) for subsequent use in comparison to patients with chronic low back pain (Part 2). The second part of the study assessed the clinical utility of combined sEMG and ROM measurements for assessing the FR phenomenon as a test to assist potentially in planning rehabilitation programs, guiding patients' individual rehabilitation progress, and identifying early posttreatment outcome failures. The FR phenomenon has been recognized since 1951, and it can be reproducibly assessed in normal subjects with FR unloaded. It can be found intermittently in patients with chronic low back pain. Recent studies have moved toward deriving formulas to identify FR, but only a few have examined a potential relation between inclinometric lumbar motion measures and the sEMG signal. No previous studies have developed normative data potentially useful for objectively assessing nonoperative treatment progress, effort, or the validity of permanent impairment rating measures. In Part 1, 12 asymptomatic subjects were evaluated in an intra- and interrater repeated-measures protocol to examine reliability of sEMG signal readings in FR, as well as ROM measures at FR and maximum voluntary flexion. The mean sEMG signal averaging right-left electrode recordings, as well as the gross, true, and sacral lumbar ROM measurements, were recorded as

Initial Clinical Evaluation of the Modular Prosthetic Limb

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Briana N. Perry

2018-03-01

Full Text Available The Modular Prosthetic Limb (MPL was examined for its feasibility and usability as an advanced, dexterous upper extremity prosthesis with surface electromyography (sEMG control in with two individuals with below-elbow amputations. Compared to currently marketed prostheses, the MPL has a greater number of sequential and simultaneous degrees of motion, as well as wrist modularity, haptic feedback, and individual digit control. The MPL was successfully fit to a 33-year-old with a trans-radial amputation (TR01 and a 30-year-old with a wrist disarticulation amputation (TR02. To preserve anatomical limb length, we adjusted the powered degrees of freedom of wrist motion between users. Motor training began with practicing sEMG and pattern recognition control within the virtual integration environment (VIE. Prosthetic training sessions then allowed participants to complete a variety of activities of daily living with the MPL. Training and Motion Control Accuracy scores quantified their ability to consistently train and execute unique muscle-to-motion contraction patterns. Each user also completed one prosthetic functional metric—the Southampton Hand Assessment Procedure (SHAP for TR01 and the Jebsen-Taylor Hand Function Test (JHFT for TR02. Haptic feedback capabilities were integrated for TR01. TR01 achieved 95% accuracy at 84% of his VIE sessions. He demonstrated improved scores over a year of prosthetic training sessions, ultimately achieving simultaneous control of 13 of the 17 (76% attempted motions. His performance on the SHAP improved from baseline to final assessment with an increase in number of tasks achieved. TR01 also used vibrotactile sensors to successfully discriminate between hard and soft objects being grasped by the MPL hand. TR02 demonstrated 95% accuracy at 79% of his VIE sessions. He demonstrated improved scores over months of prosthetic training sessions, however there was a significant drop in scores initially following a mid

The Effects of Vibration and Muscle Fatigue on Trunk Sensorimotor Control in Low Back Pain Patients.

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Jean-Alexandre Boucher

Full Text Available Changes in sensorimotor function and increased trunk muscle fatigability have been identified in patients with chronic low back pain (cLBP. This study assessed the control of trunk force production in conditions with and without local erector spinae muscle vibration and evaluated the influence of muscle fatigue on trunk sensorimotor control.Twenty non-specific cLBP patients and 20 healthy participants were asked to perform submaximal isometric trunk extension torque with and without local vibration stimulation, before and after a trunk extensor muscle fatigue protocol. Constant error (CE, variable error (VE as well as absolute error (AE in peak torque were computed and compared across conditions. Trunk extensor muscle activation during isometric contractions and during the fatigue protocol was measured using surface electromyography (sEMG.Force reproduction accuracy of the trunk was significantly lower in the patient group (CE = 9.81 ± 2.23 Nm; AE = 18.16 ± 3.97 Nm than in healthy participants (CE = 4.44 ± 1.68 Nm; AE = 12.23 ± 2.44 Nm. Local erector spinae vibration induced a significant reduction in CE (4.33 ± 2.14 Nm and AE (13.71 ± 3.45 Nm mean scores in the patient group. Healthy participants conversely showed a significant increase in CE (8.17 ± 2.10 Nm and AE (16.29 ± 2.82 Nm mean scores under vibration conditions. The fatigue protocol induced erector spinae muscle fatigue as illustrated by a significant decrease in sEMG median time-frequency slopes. Following the fatigue protocol, patients with cLBP showed significant decrease in sEMG root mean square activity at L4-5 level and responded in similar manner with and without vibration stimulation in regard to CE mean scores.Patients with cLBP have a less accurate force reproduction sense than healthy participants. Local muscle vibration led to significant trunk neuromuscular control improvements in the cLBP patients before and after a muscle fatigue protocol. Muscle vibration

The Influence of Robotic Assistance on Reducing Neuromuscular Effort and Fatigue during Extravehicular Activity Glove Use

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Madden, Kaci E.; Deshpande, Ashish D.; Peters, Benjamin J.; Rogers, Jonathan M.; Laske, Evan A.; McBryan, Emily R.

2017-01-01

The three-layered, pressurized space suit glove worn by Extravehicular Activity (EVA) crew members during missions commonly causes hand and forearm fatigue. The Spacesuit RoboGlove (SSRG), a Phase VI EVA space suit glove modified with robotic grasp-assist capabilities, has been developed to augment grip strength in order to improve endurance and reduce the risk of injury in astronauts. The overall goals of this study were to i) quantify the neuromuscular modulations that occur in response to wearing a conventional Phase VI space suit glove (SSG) during a fatiguing task, and ii) determine the efficacy of Spacesuit RoboGlove (SSRG) in reversing the adverse neuromuscular modulations and restoring altered muscular activity to barehanded levels. Six subjects performed a fatigue sequence consisting of repetitive dynamic-gripping interspersed with isometric grip-holds under three conditions: barehanded, wearing pressurized SSG, and wearing pressurized SSRG. Surface electromyography (sEMG) from six forearm muscles (flexor digitorum superficialis (FDS), flexor carpi radialis (FCR), flexor carpi ulnaris (FCU), extensor digitorum (ED), extensor carpi radialis longus (ECRL), and extensor carpi ulnaris (ECU)) and subjective fatigue ratings were collected during each condition. Trends in amplitude and spectral distributions of the sEMG signals were used to derive metrics quantifying neuromuscular effort and fatigue that were compared across the glove conditions. Results showed that by augmenting finger flexion, the SSRG successfully reduced the neuromuscular effort needed to close the fingers of the space suit glove in more than half of subjects during two types of tasks. However, the SSRG required more neuromuscular effort to extend the fingers compared to a conventional SSG in many subjects. Psychologically, the SSRG aided subjects in feeling less fatigued during short periods of intense work compared to the SSG. The results of this study reveal the promise of the SSRG as a

Fractal based complexity measure and variation in force during sustained isometric muscle contraction: effect of aging.

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Arjunan, Sridhar P; Kumar, Dinesh K; Bastos, Teodiano

2012-01-01

This study has investigated the effect of age on the fractal based complexity measure of muscle activity and variance in the force of isometric muscle contraction. Surface electromyogram (sEMG) and force of muscle contraction were recorded from 40 healthy subjects categorized into: Group 1: Young - age range 20-30; 10 Males and 10 Females, Group 2: Old - age range 55-70; 10 Males and 10 Females during isometric exercise at Maximum Voluntary contraction (MVC). The results show that there is a reduction in the complexity of surface electromyogram (sEMG) associated with aging. The results demonstrate that there is an increase in the coefficient of variance (CoV) of the force of muscle contraction and a decrease in complexity of sEMG for the Old age group when compared with the Young age group.

Real-time intelligent pattern recognition algorithm for surface EMG signals

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Jahed Mehran

2007-12-01

Full Text Available Abstract Background Electromyography (EMG is the study of muscle function through the inquiry of electrical signals that the muscles emanate. EMG signals collected from the surface of the skin (Surface Electromyogram: sEMG can be used in different applications such as recognizing musculoskeletal neural based patterns intercepted for hand prosthesis movements. Current systems designed for controlling the prosthetic hands either have limited functions or can only be used to perform simple movements or use excessive amount of electrodes in order to achieve acceptable results. In an attempt to overcome these problems we have proposed an intelligent system to recognize hand movements and have provided a user assessment routine to evaluate the correctness of executed movements. Methods We propose to use an intelligent approach based on adaptive neuro-fuzzy inference system (ANFIS integrated with a real-time learning scheme to identify hand motion commands. For this purpose and to consider the effect of user evaluation on recognizing hand movements, vision feedback is applied to increase the capability of our system. By using this scheme the user may assess the correctness of the performed hand movement. In this work a hybrid method for training fuzzy system, consisting of back-propagation (BP and least mean square (LMS is utilized. Also in order to optimize the number of fuzzy rules, a subtractive clustering algorithm has been developed. To design an effective system, we consider a conventional scheme of EMG pattern recognition system. To design this system we propose to use two different sets of EMG features, namely time domain (TD and time-frequency representation (TFR. Also in order to decrease the undesirable effects of the dimension of these feature sets, principle component analysis (PCA is utilized. Results In this study, the myoelectric signals considered for classification consists of six unique hand movements. Features chosen for EMG signal

Emg Signal Analysis of Healthy and Neuropathic Individuals

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Gupta, Ashutosh; Sayed, Tabassum; Garg, Ridhi; Shreyam, Richa

2017-08-01

Electromyography is a method to evaluate levels of muscle activity. When a muscle contracts, an action potential is generated and this circulates along the muscular fibers. In electromyography, electrodes are connected to the skin and the electrical activity of muscles is measured and graph is plotted. The surface EMG signals picked up during the muscular activity are interfaced with a system. The EMG signals from individual suffering from Neuropathy and healthy individual, so obtained, are processed and analyzed using signal processing techniques. This project includes the investigation and interpretation of EMG signals of healthy and Neuropathic individuals using MATLAB. The prospective use of this study is in developing the prosthetic device for the people with Neuropathic disability.

Eletromiograma de superfície durante stress experimental como subsídio no diagnóstico da cefaléia tensional: resultados em 100 casos Surface scalp and neck electromyography with stress as diagnostic criterion in chronic tension headache: results in 100 cases

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Ceme Ferreira Jordy

1995-09-01

Full Text Available Eletromiograma de superfície foi realizado no crânio e pescoço, durante stress provocado por frio, em 100 pacientes sofrendo cefaléia crônica isolada. Os resultados de diagnóstico obtidos com a eletromiografia revelaram erro de 24% a 32% na avaliação clínica da cefaléia tensional segundo os critérios anamnésicos referendados pelo Comitê de Classificação das Cefaléias, da Sociedade Internacional de Cefaléia (1988. A eletromiografia durante stress é proposta como novo critério de diagnóstico da Cefaléia tensional.We report the use of surface scalp and neck electromyography during experimental stress state in a series of 100 out-patients suffering from chronic tension headache. Results revealed a 24% to 32% of diagnostic errors in the diagnostic obtained by routine anamnestic procedures and following the criteria recommended by the Headache Classification Commitee of the International Headache Society (1988. The electromyography with stress is proposed as a new diagnostic criterion for tension headache.

Natural control capabilities of robotic hands by hand amputated subjects.

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Atzori, Manfredo; Gijsberts, Arjan; Caputo, Barbara; Muller, Henning

2014-01-01

People with transradial hand amputations who own a myoelectric prosthesis currently have some control capabilities via sEMG. However, the control systems are still limited and not natural. The Ninapro project is aiming at helping the scientific community to overcome these limits through the creation of publicly available electromyography data sources to develop and test machine learning algorithms. In this paper we describe the movement classification results gained from three subjects with an homogeneous level of amputation, and we compare them with the results of 40 intact subjects. The number of considered subjects can seem small at first sight, but it is not considering the literature of the field (which has to face the difficulty of recruiting trans-radial hand amputated subjects). The classification is performed with four different classifiers and the obtained balanced classification rates are up to 58.6% on 50 movements, which is an excellent result compared to the current literature. Successively, for each subject we find a subset of up to 9 highly independent movements, (defined as movements that can be distinguished with more than 90% accuracy), which is a deeply innovative step in literature. The natural control of a robotic hand in so many movements could lead to an immediate progress in robotic hand prosthetics and it could deeply change the quality of life of amputated subjects.

The Evaluation of Bioelectrical Activity of Pelvic Floor Muscles Depending on Probe Location: A Pilot Study

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Tomasz Halski

2013-01-01

Full Text Available Objectives. The main objective was to determine how the depth of probe placement affects functional and resting bioelectrical activity of the PFM and whether the recorded signal might be dependent on the direction in which the probe is rotated. Participants. The study comprised of healthy, nulliparous women between the ages of 21 and 25. Outcome Measures. Bioelectric activity of the PFM was recorded from four locations of the vagina by surface EMG and vaginal probe. Results. There were no statistically significant differences between the results during functional sEMG activity. During resting sEMG activity, the highest bioelectrical activity of the PFM was observed in the L1 and the lowest in the L4 and a statistically significant difference between the highest and the lowest results of resting sEMG activity was observed (P=0.0043. Conclusion. Different electrodes placement during functional contraction of PFM does not affect the obtained results in sEMG evaluation. In order to diagnose the highest resting activity of PFM the recording plates should be placed toward the anterior vaginal wall and distally from the introitus. However, all of the PFM have similar bioelectrical activity and it seems that these muscles could be treated as a single muscle.

Estimation of the neural drive to the muscle from surface electromyograms

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Hofmann, David

Muscle force is highly correlated with the standard deviation of the surface electromyogram (sEMG) produced by the active muscle. Correctly estimating this quantity of non-stationary sEMG and understanding its relation to neural drive and muscle force is of paramount importance. The single constituents of the sEMG are called motor unit action potentials whose biphasic amplitude can interfere (named amplitude cancellation), potentially affecting the standard deviation (Keenan etal. 2005). However, when certain conditions are met the Campbell-Hardy theorem suggests that amplitude cancellation does not affect the standard deviation. By simulation of the sEMG, we verify the applicability of this theorem to myoelectric signals and investigate deviations from its conditions to obtain a more realistic setting. We find no difference in estimated standard deviation with and without interference, standing in stark contrast to previous results (Keenan etal. 2008, Farina etal. 2010). Furthermore, since the theorem provides us with the functional relationship between standard deviation and neural drive we conclude that complex methods based on high density electrode arrays and blind source separation might not bear substantial advantages for neural drive estimation (Farina and Holobar 2016). Funded by NIH Grant Number 1 R01 EB022872 and NSF Grant Number 1208126.

Effect of age and gender on the surface electromyogram during various levels of isometric contraction.

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Arjunan, Sridhar; Kumar, Dinesh; Kalra, Chandan; Burne, John; Bastos, Teodiano

2011-01-01

This study reports the effects of age and gender on the surface electromyogram while performing isometric contraction. Experiments were conducted with two age groups--Young (Age: 20-29) and Old (Age: 60-69) where they performed sustained isometric contractions at various force levels (50%, 75%, 100% of maximum voluntary contraction). Traditional features such as root mean square (RMS) and median frequency (MDF) were computed from the recorded sEMG. The result indicates that the MDF of sEMG was not significantly affected by age, but was impacted by gender in both age groups. Also there was a significant change in the RMS of sEMG with age and gender at all levels of contraction. The results also indicate a large inter-subject variation. This study will provide an understanding of the underlying physiological effects of muscle contraction and muscle fatigue in different cohorts.

New Swallowing Evaluation Using Piezoelectricity in Normal Individuals.

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Sogawa, Yuichiro; Kimura, Shinji; Harigai, Toru; Sakurai, Naoki; Toyosato, Akira; Nishikawa, Taro; Inoue, Makoto; Murasawa, Akira; Endo, Naoto

2015-12-01

This study aimed to elucidate the relationship between the piezoelectric waveform latency, hyoid bone movement, surface electromyogram (sEMG), and the pharyngeal transit time (PTT) during swallowing. Forty-one healthy subjects were divided into three age groups: younger (20-39 years, n = 8), middle-aged (40-59 years, n = 9), and older (60-79 years, n = 24). Motion analysis of the hyoid bone using videofluorography (VF), waveform analysis of the front neck using piezoelectric films, and sEMG of the suprahyoid muscle group were performed simultaneously. Latencies of the three movement phases were defined as upward (VFS1), forward (VFS2), and returning to starting position (VFS3). The three phases of the piezoelectric waveform-from wave initiation of the negative wave to the start of the second deep negative wave; from the start of the second deep negative wave to the start of the last positive wave (SLPW); and from the SLPW to the end of the last positive wave-were defined as PS1, PS2, and PS3, respectively. VFS1-3 and PS1-3 were significantly correlated. VFS1 and PS1 latencies were significantly longer with thick liquid than with thin liquid. VFS2, PS1, and PS2 latencies were longer in the older group than in the other two groups. The start of PS1 was nearly equal to those of sEMG and VFS1. Bolus arrival time in the valleculae was statistically equal to the end of the PS1 with both thin and thick liquids. To establish the swallowing screening using Piezoelectric film, further investigation is necessary in the dysphagia patients.

An investigation into the bilateral functional differences of the lower limb muscles in standing and walking

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Shengyun Liang

2016-08-01

Full Text Available To date, most studies use surface electromyographic (sEMG signals as the control source on active rehabilitation robots, and unilateral data are collected based on the gait symmetry hypothesis, which has caused much controversy. The purpose of this study is to quantitatively evaluate the sEMG activity asymmetry of bilateral muscles in lower extremities during functional tasks. Nine participants were instructed to perform static and dynamic steady state tests. sEMG signals from the tibialis anterior, soleus, medial gastrocnemius and lateral gastrocnemius muscles of bilateral lower extremities were recorded in the experiments. Muscle activities are quantified in terms of sEMG amplitude. We investigated whether characteristics of left limb and the one of the right limb have the same statistical characteristics during functional tasks using The Wilcoxon rank-sum test, and studied dynamic signal irregularity degree for sEMG activities via sample entropy. The total of muscle activities showed significant differences between left limb and right limb during the static steady state (p = 0.000. For dynamic steady states, there were significant differences for most muscle activities between left limb and right limb at different speeds (p = 0.000. Nevertheless, there was no difference between the lateral gastrocnemius for bilateral limb at 2.0 kilometers per hour (p = 0.060. For medial gastrocnemius, differences were not found between left limb and right limb at 1.0 and 3.0 kilometers per hours (p = 0.390 and p = 0.085, respectively. Similarly, there was no difference for soleus at 3.0 kilometers per hour (p = 0.115. The importance of the differences in muscle activities between left limb and right limb were found. These results can potentially be used for evaluating lower limb extremity function of special populations (elderly people or stroke patients in an objective and simple method.

Nonlinear smooth orthogonal decomposition of kinematic features of sawing reconstructs muscle fatigue evolution as indicated by electromyography.

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Segala, David B; Gates, Deanna H; Dingwell, Jonathan B; Chelidze, David

2011-03-01

Tracking or predicting physiological fatigue is important for developing more robust training protocols and better energy supplements and/or reducing muscle injuries. Current methodologies are usually impractical and/or invasive and may not be realizable outside of laboratory settings. It was recently demonstrated that smooth orthogonal decomposition (SOD) of phase space warping (PSW) features of motion kinematics can identify fatigue in individual muscle groups. We hypothesize that a nonlinear extension of SOD will identify more optimal fatigue coordinates and provide a lower-dimensional reconstruction of local fatigue dynamics than the linear SOD. Both linear and nonlinear SODs were applied to PSW features estimated from measured kinematics to reconstruct muscle fatigue dynamics in subjects performing a sawing motion. Ten healthy young right-handed subjects pushed a weighted handle back and forth until voluntary exhaustion. Three sets of joint kinematic angles were measured from the right upper extremity in addition to surface electromyography (EMG) recordings. The SOD coordinates of kinematic PSW features were compared against independently measured fatigue markers (i.e., mean and median EMG spectrum frequencies of individual muscle groups). This comparison was based on a least-squares linear fit of a fixed number of the dominant SOD coordinates to the appropriate local fatigue markers. Between subject variability showed that at most four to five nonlinear SOD coordinates were needed to reconstruct fatigue in local muscle groups, while on average 15 coordinates were needed for the linear SOD. Thus, the nonlinear coordinates provided a one-order-of-magnitude improvement over the linear ones.

Single-fiber Electromyography in the Extensor Digitorum Communis for the Predictive Prognosis of Ocular Myasthenia Gravis: A Retrospective Study of 102 Cases

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Yu-Zhou Guan

2015-01-01

Full Text Available Background: Single-fiber electromyography (SFEMG abnormality in the extensor digitorum communis (EDC was reported in ocular myasthenia gravis (OMG, which indicated subclinical involvement beyond extraocular muscles in OMG patients. The relationship between the abnormal findings of SFEMG in EDC and the probability for OMG to develop generalized myasthenia gravis (GMG is unknown. This retrospective study aimed to determine the predictive value of abnormality of SFEMG in EDC of OMG patients. Methods: One-hundred and two OMG patients underwent standard clinical diagnosis process and SFEMG test in EDC muscle when diagnosed and were clinically followed up for 5 years. The SFEMG data were compared between different clinical groups according to thymus status, onset age, and different outcome of OMG developing. Chances of progressing to GMG were compared between two different groups according to SFEMG and repetitive nerve stimulation (RNS results, acetylcholine receptor antibody (AchRAb titer, thymus status, and onset age. Results: Abnormal SFEMG results were observed in 84 (82.4% patients. The mean jitter, percentage of jitter >55 μs (%, and blocking were higher in OMG patients than in healthy volunteers. There were no statistical differences in jitter analysis between thymoma group and non-thymoma group (P = 0.65, or between the later OMG group and the later GMG group (P = 0.31, including mean jitter, percentage of jitter >55 μs (%, and blocking. Elderly group (≥45 years old had a higher mean jitter than younger group (t = 2.235, P = 0.028. Total 55 OMG developed GMG, including 47 in abnormal SFEMG group while 8 in normal SFEMG group. There was no statistical difference in the conversion rates between the two groups (χ2 = 0.790, P = 0.140. RNS abnormality, AchRab titer, or onset age had no correlation with OMG prognosis (P = 0.150, 0.070, 0.120, respectively while thymoma did (χ2 = 0.510, P = 0.020. Conclusion: SFEMG test in the EDC showed high

Electromyography

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... problem affecting the median nerve in the arm) Duchenne muscular dystrophy (inherited disease that involves muscle weakness) Facioscapulohumeral muscular dystrophy (Landouzy-Dejerine; disease of ...

A statistical model for predicting muscle performance

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Byerly, Diane Leslie De Caix

The objective of these studies was to develop a capability for predicting muscle performance and fatigue to be utilized for both space- and ground-based applications. To develop this predictive model, healthy test subjects performed a defined, repetitive dynamic exercise to failure using a Lordex spinal machine. Throughout the exercise, surface electromyography (SEMG) data were collected from the erector spinae using a Mega Electronics ME3000 muscle tester and surface electrodes placed on both sides of the back muscle. These data were analyzed using a 5th order Autoregressive (AR) model and statistical regression analysis. It was determined that an AR derived parameter, the mean average magnitude of AR poles, significantly correlated with the maximum number of repetitions (designated Rmax) that a test subject was able to perform. Using the mean average magnitude of AR poles, a test subject's performance to failure could be predicted as early as the sixth repetition of the exercise. This predictive model has the potential to provide a basis for improving post-space flight recovery, monitoring muscle atrophy in astronauts and assessing the effectiveness of countermeasures, monitoring astronaut performance and fatigue during Extravehicular Activity (EVA) operations, providing pre-flight assessment of the ability of an EVA crewmember to perform a given task, improving the design of training protocols and simulations for strenuous International Space Station assembly EVA, and enabling EVA work task sequences to be planned enhancing astronaut performance and safety. Potential ground-based, medical applications of the predictive model include monitoring muscle deterioration and performance resulting from illness, establishing safety guidelines in the industry for repetitive tasks, monitoring the stages of rehabilitation for muscle-related injuries sustained in sports and accidents, and enhancing athletic performance through improved training protocols while reducing

SURFACE ELECTROMYOGRAPHY OF MASSETER AND TEMPORAL MUSCLES WITH USE PERCENTAGE WHILE CHEWING ON CANDIDATES FOR GASTROPLASTY.

Science.gov (United States)

Santos, Andréa Cavalcante Dos; Silva, Carlos Antonio Bruno da

Surface electromyography identifies changes in the electrical potential of the muscles during each contraction. The percentage of use is a way to treat values enabling comparison between groups. To analyze the electrical activity and the percentage of use of masseter and temporal muscles during chewing in candidates for gastric bypass. It was used Surface Electromyography Miotool 200,400 (Miotec (r), Porto Alegre/RS, Brazil) integrated with Miograph 2.0 software, involving patients between 20-40 years old. Were included data on electrical activity simultaneously and in pairs of temporal muscle groups and masseter at rest, maximum intercuspation and during the chewing of food previously classified. Were enrolled 39 patients (59 women), mean age 27.1+/-5.7. The percentage of use focused on temporal muscle, in a range of 11-20, female literacy (n=11; 47.82) on the left side and 15 (65.21) on the right-hand side. In the male, nine (56.25) at left and 12 (75.00) on the right-hand side. In masseter, also in the range of 11 to 20, female literacy (n=10; 43.48) on the left side and 11 (47.83) on the right-hand side. In the male, nine (56.25) at left and eight (50.00) on the right-hand side. 40-50% of the sample showed electrical activity in muscles (masseter and temporal) with variable values, and after processing into percentage value, facilitating the comparison of load of used electrical activity between the group, as well as usage percentage was obtained of muscle fibers 11-20% values involving, representing a range that is considered as a reference to the group studied. The gender was not a variable. A eletromiografia de superfície identifica variações dos potenciais elétricos dos músculos durante cada contração realizada. O percentual de uso é uma forma de tratar valores possibilitando comparação entre grupos. Analisar a atividade elétrica e o percentual de uso dos músculos masséteres e temporais durante a mastigação em candidatos à gastroplastia

Design of a portable, intrinsically safe multichannel acquisition system for high-resolution, real-time processing HD-sEMG.

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Barone, Umberto; Merletti, Roberto

2013-08-01

A compact and portable system for real-time, multichannel, HD-sEMG acquisition is presented. The device is based on a modular, multiboard approach for scalability and to optimize power consumption for battery operating mode. The proposed modular approach allows us to configure the number of sEMG channels from 64 to 424. A plastic-optical-fiber-based 10/100 Ethernet link is implemented on a field-programmable gate array (FPGA)-based board for real-time, safety data transmission toward a personal computer or laptop for data storage and offline analysis. The high-performance A/D conversion stage, based on 24-bit ADC, allows us to automatically serialize the samples and transmits them on a single SPI bus connecting a sequence of up to 14 ADC chips in chain mode. The prototype is configured to work with 64 channels and a sample frequency of 2.441 ksps (derived from 25-MHz clock source), corresponding to a real data throughput of 3 Mbps. The prototype was assembled to demonstrate the available features (e.g., scalability) and evaluate the expected performances. The analog front end board could be dynamically configured to acquire sEMG signals in monopolar or single differential mode by means of FPGA I/O interface. The system can acquire continuously 64 channels for up to 5 h with a lightweight battery pack of 7.5 Vdc/2200 mAh. A PC-based application was also developed, by means of the open source Qt Development Kit from Nokia, for prototype characterization, sEMG measurements, and real-time visualization of 2-D maps.

Static stretching vs. dynamic warm-ups: a comparison of their effects on torque and electromyography output of the quadriceps and hamstring muscles.

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Williams, N; Coburn, J; Gillum, T

2015-11-01

The aim of this paper was to determine if two different warm-up protocols differently affect torque of the quadriceps and hamstrings, and electromyography (EMG) output of the rectus femoris (RF) and vastus lateralis (VL) when completing 30 maximal leg extensions and curls. Twenty-one healthy male (N.=8) and female (N.=13) subjects volunteered to participate in a familiarization session and three testing sessions. The three testing sessions control, dynamic, and static were completed in a counterbalanced order on non-consecutive days. First, subjects warmed-up on a treadmill for five minutes before completing six dynamic movements, six static-stretches, or no stretches. They then rested for five minutes before completing 30 maximal leg extensions and curls at a speed of 60 s-1. A significant decrease in quadriceps torque output over time was determined for the dynamic protocol when compared to the control (Phamstring torque or EMG output of the RF and VL. Short duration static-stretching has the ability to increase peak and average torque of the leg extensors, while some types of anaerobic exercise involving maximal contractions to fatigue may be hindered by performing dynamic movements as part of the warm-up.

Quantitative motor unit action potential analysis of supraspinatus, infraspinatus, deltoideus and biceps femoris muscles in adult Royal Dutch sport horses.

Science.gov (United States)

Jose-Cunilleras, E; Wijnberg, I D

2016-03-01

Reference values for quantitative electromyography (QEMG) in shoulder and hindlimb muscles of horses are limited. To determine normative data on QEMG analysis of supraspinatus (SS), infraspinatus (IS), deltoideus (DT) and biceps femoris (BF) muscles. Experimental observational study and retrospective case series. Seven adult healthy Royal Dutch sport horses underwent quantitative motor unit action potential analysis of each muscle using commercial electromyography equipment. Measurements were made according to published methods. One-way ANOVA was used to compare quantitative motor unit action potential variables between muscles, with post hoc testing according to Bonferroni, with significance set at Paction potential were 8.7-10.4 ms, 651-867 μV, 3.2-3.7, 3.7-4.7, 1054-1457 μV·ms and 1.1-1.5 for SS, 9.6-11.0 ms, 779-1082 μV, 3.3-3.7, 3.8-4.7, 1349-2204 μV·ms and 1.4-1.9 for IS, 6.0-9.1 ms, 370-691 μV, 2.9-3.7, 2.8-4.5, 380-1374 μV·ms and 0.3-1.3 for DT and 5.7-7.8 ms, 265-385 μV, 2.7-3.2, 2.6-3.1, 296-484 μV·ms and 0.2-0.5 for BF, respectively. Mean duration, amplitude, number of phases and turns, area and size index were significantly (P15% polyphasic motor unit action potentials in SS and IS muscles. Differences between muscles should be taken into account when performing QEMG in order to be able to distinguish normal horses from horses with suspected neurogenic or myogenic disorders. These normal data provide the basis for objective QEMG assessment of shoulder and hindlimb muscles. Quantitative electromyography appears to be helpful in diagnosing neuropathies and discriminating these from myopathies. © 2015 EVJ Ltd.

sEMG-Based Gesture Recognition with Convolution Neural Networks

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Zhen Ding

2018-06-01

Full Text Available The traditional classification methods for limb motion recognition based on sEMG have been deeply researched and shown promising results. However, information loss during feature extraction reduces the recognition accuracy. To obtain higher accuracy, the deep learning method was introduced. In this paper, we propose a parallel multiple-scale convolution architecture. Compared with the state-of-art methods, the proposed architecture fully considers the characteristics of the sEMG signal. Larger sizes of kernel filter than commonly used in other CNN-based hand recognition methods are adopted. Meanwhile, the characteristics of the sEMG signal, that is, muscle independence, is considered when designing the architecture. All the classification methods were evaluated on the NinaPro database. The results show that the proposed architecture has the highest recognition accuracy. Furthermore, the results indicate that parallel multiple-scale convolution architecture with larger size of kernel filter and considering muscle independence can significantly increase the classification accuracy.

Postprocessing algorithm for automated analysis of pelvic intraoperative neuromonitoring signals

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Wegner Celine

2016-09-01

Full Text Available Two dimensional pelvic intraoperative neuromonitoring (pIONM® is based on electric stimulation of autonomic nerves under observation of electromyography of internal anal sphincter (IAS and manometry of urinary bladder. The method provides nerve identification and verification of its’ functional integrity. Currently pIONM® is gaining increased attention in times where preservation of function is becoming more and more important. Ongoing technical and methodological developments in experimental and clinical settings require further analysis of the obtained signals. This work describes a postprocessing algorithm for pIONM® signals, developed for automated analysis of huge amount of recorded data. The analysis routine includes a graphical representation of the recorded signals in the time and frequency domain, as well as a quantitative evaluation by means of features calculated from the time and frequency domain. The produced plots are summarized automatically in a PowerPoint presentation. The calculated features are filled into a standardized Excel-sheet, ready for statistical analysis.

Evaluation of an Automated Swallow-Detection Algorithm Using Visual Biofeedback in Healthy Adults and Head and Neck Cancer Survivors.

Science.gov (United States)

Constantinescu, Gabriela; Kuffel, Kristina; Aalto, Daniel; Hodgetts, William; Rieger, Jana

2017-11-02

Mobile health (mHealth) technologies may offer an opportunity to address longstanding clinical challenges, such as access and adherence to swallowing therapy. Mobili-T ® is an mHealth device that uses surface electromyography (sEMG) to provide biofeedback on submental muscles activity during exercise. An automated swallow-detection algorithm was developed for Mobili-T ® . This study evaluated the performance of the swallow-detection algorithm. Ten healthy participants and 10 head and neck cancer (HNC) patients were fitted with the device. Signal was acquired during regular, effortful, and Mendelsohn maneuver saliva swallows, as well as lip presses, tongue, and head movements. Signals of interest were tagged during data acquisition and used to evaluate algorithm performance. Sensitivity and positive predictive values (PPV) were calculated for each participant. Saliva swallows were compared between HNC and controls in the four sEMG-based parameters used in the algorithm: duration, peak amplitude ratio, median frequency, and 15th percentile of the power spectrum density. In healthy participants, sensitivity and PPV were 92.3 and 83.9%, respectively. In HNC patients, sensitivity was 92.7% and PPV was 72.2%. In saliva swallows, HNC patients had longer event durations (U = 1925.5, p performed well with healthy participants and retained a high sensitivity, but had lowered PPV with HNC patients. With respect to Mobili-T ® , the algorithm will next be evaluated using the mHealth system.

Measurement of quadriceps endurance by fNIRS

Science.gov (United States)

Erdem, Devrim; Şayli, Ömer; Karahan, Mustafa; Akin, A.

2006-02-01

In this paper, the changes in muscle deoxygenation trends during a sustained isometric quadriceps (chair squat/half squat) endurance exercise were evaluated among twelve male subjects and the relationship between muscle oxygenation and endurance times was investigated by means of functional near-infrared spectroscopy (fNIRS). Neuromuscular activation and predictions of muscle performance decrements during extended fatiguing task was investigated by means of surface electromyography (sEMG). The results of the study showed that in the subjects who maintained exercise longer than five minutes (group 1), mean Hb recovery time (33 [sec.]) was 37.4% less than the others (group 2, 52.7 [sec.]). Also mean HbO II decline amplitude (2.53 [a.u.] in group 1 and 2.07 [a.u.] in group 2) and oxy decline amplitude (8.4 [a.u.] in group 1 and 3.04 [a.u.] in group 2) in the beginning of squat exercise are found to be 22.6% and 176.9% bigger in these group. For the EMG parameters, mean slope of MNF and MDF decline are found to be 57.5% and 42.2% bigger in magnitude in group 2 which indicates higher degree of decrement in mean and median frequencies although their mean squat duration time is less. This indicates higher index of fatigue for this group. It is concluded that training leads to altered oxygenation and oxygen extraction capability in the exercising muscle and investigated fNIRS parameters could be used for endurance evaluation.

Electrically and hybrid-induced muscle activations: effects of muscle size and fiber type

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Kelly Stratton

2016-07-01

Full Text Available The effect of three electrical stimulation (ES frequencies (10, 35, and 50 Hz on two muscle groups with different proportions of fast and slow twitch fibers (abductor pollicis brevis (APB and vastus lateralis (VL was explored. We evaluated the acute muscles’ responses individually and during hybrid activations (ES superimposed by voluntary activations. Surface electromyography (sEMG and force measurements were evaluated as outcomes. Ten healthy adults (mean age: 24.4 ± 2.5 years participated after signing an informed consent form approved by the university Institutional Review Board. Protocols were developed to: 1 compare EMG activities during each frequency for each muscle when generating 25% Maximum Voluntary Contraction (MVC force, and 2 compare EMG activities during each frequency when additional voluntary activation was superimposed over ES-induced 25% MVC to reach 50% and 75% MVC. Empirical mode decomposition (EMD was utilized to separate ES artifacts from voluntary muscle activation. For both muscles, higher stimulation frequency (35 and 50Hz induced higher electrical output detected at 25% of MVC, suggesting more recruitment with higher frequencies. Hybrid activation generated proportionally less electrical activity than ES alone. ES and voluntary activations appear to generate two different modes of muscle recruitment. ES may provoke muscle strength by activating more fatiguing fast acting fibers, but voluntary activation elicits more muscle coordination. Therefore, during the hybrid activation, less electrical activity may be detected due to recruitment of more fatigue-resistant deeper muscle fibers, not reachable by surface EMG.

The effect of early physiotherapy on the recovery of mandibular function after orthognathic surgery for class III correction. Part II: electromyographic activity of masticatory muscles.

Science.gov (United States)

Ko, Ellen Wen-Ching; Teng, Terry Te-Yi; Huang, Chiung Shing; Chen, Yu-Ray

2015-01-01

The study was conducted to evaluate the effect of early physical rehabilitation by comparing the differences of surface electromyographic (sEMG) activity in the masseter and anterior temporalis muscles after surgical correction of skeletal class III malocclusion. The prospective study included 63 patients; the experimental groups contained 31 patients who received early systematic physical rehabilitation; the control group (32 patients) did not receive physiotherapy. The amplitude of sEMG in the masticatory muscles reached 72.6-121.3% and 37.5-64.6% of pre-surgical values in the experimental and control groups respectively at 6 weeks after orthognathic surgery (OGS). At 6 months after OGS, the sEMG reached 135.1-233.4% and 89.6-122.5% of pre-surgical values in the experimental and control groups respectively. Most variables in the sEMG examination indicated that recovery of the masticatory muscles in the experimental group was better than the control group as estimated in the early phase (T1 to T2) and the total phase (T1 to T3); there were no significant differences between the mean recovery percentages in the later phase (T2 to T3). Early physical rehabilitative therapy is helpful for early recovery of muscle activity in masticatory muscles after OGS. After termination of physical therapy, no significant difference in recovery was indicated in patients with or without early physiotherapy. Copyright © 2014 European Association for Cranio-Maxillo-Facial Surgery. Published by Elsevier Ltd. All rights reserved.

Do changes in neuromuscular activation contribute to the knee extensor angle-torque relationship?

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Lanza, Marcel B; Balshaw, Thomas G; Folland, Jonathan P

2017-08-01

What is the central question of the study? Do changes in neuromuscular activation contribute to the knee extensor angle-torque relationship? What is the main finding and its importance? Both agonist (quadriceps) and antagonist coactivation (hamstrings) differed with knee joint angle during maximal isometric knee extensions and thus both are likely to contribute to the angle-torque relationship. Specifically, two independent measurement techniques showed quadriceps activation to be lower at more extended positions. These effects might influence the capacity for neural changes in response to training and rehabilitation at different knee joint angles. The influence of joint angle on knee extensor neuromuscular activation is unclear, owing in part to the diversity of surface electromyography (sEMG) and/or interpolated twitch technique (ITT) methods used. The aim of the study was to compare neuromuscular activation, using rigorous contemporary sEMG and ITT procedures, during isometric maximal voluntary contractions (iMVCs) of the quadriceps femoris at different knee joint angles and examine whether activation contributes to the angle-torque relationship. Sixteen healthy active men completed two familiarization sessions and two experimental sessions of isometric knee extension and knee flexion contractions. The experimental sessions included the following at each of four joint angles (25, 50, 80 and 106 deg): iMVCs (with and without superimposed evoked doublets); submaximal contractions with superimposed doublets; and evoked twitch and doublet contractions whilst voluntarily passive, and knee flexion iMVC at the same knee joint positions. The absolute quadriceps femoris EMG was normalized to the peak-to-peak amplitude of an evoked maximal M-wave, and the doublet-voluntary torque relationship was used to calculate activation with the ITT. Agonist activation, assessed with both normalized EMG and the ITT, was reduced at the more extended compared with the more flexed

RNA/DNA co-analysis from human saliva and semen stains--results of a third collaborative EDNAP exercise

DEFF Research Database (Denmark)

Haas, Claus; Hanson, E; Anjos, M J

2013-01-01

samples of human or non-human origin were analyzed by 20 participating laboratories using an RNA extraction or RNA/DNA co-extraction method. Two novel mRNA multiplexes were used: a saliva triplex (HTN3, STATH and MUC7) and a semen pentaplex (PRM1, PRM2, PSA, SEMG1 and TGM4). The laboratories used......A third collaborative exercise on RNA/DNA co-analysis for body fluid identification and STR profiling was organized by the European DNA Profiling Group (EDNAP). Twenty saliva and semen stains, four dilution series (10-0.01 µl saliva, 5-0.01 µl semen) and, optionally, bona fide or mock casework...... different chemistries and instrumentation and a majority (16/20) were able to successfully isolate and detect mRNA in dried stains. The simultaneous extraction of RNA and DNA from individual stains not only permitted a confirmation of the presence of saliva/semen (i.e. tissue/fluid source of origin...

Patellofemoral pain syndrome: electromyography in a frequency domain analysis

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Catelli, D. S.; Kuriki, H. U.; Polito, L. F.; Azevedo, F. M.; Negrão Filho, R. F.; Alves, N.

2011-09-01

The Patellofemoral Pain Syndrome (PFPS), has a multifactorial etiology and affects approximately 7 to 15% of the population, mostly women, youth, adults and active persons. PFPS causes anterior or retropatelar pain that is exacerbated during functional motor gestures, such as up and down stairs or spending long periods of time sitting, squatting or kneeling. As the diagnostic evaluation of this syndrome is still indirect, different mechanisms and methodologies try to make a classification that distinguishes patients with PFPS in relation to asymptomatic. Thereby, the purpose of this investigation was to determine the characteristics of the electromyographic (EMG) signal in the frequency domain of the vastus medialis oblique (VMO) and vastus lateralis (VL) in patients with PFPS, during the ascent of stairs. 33 young women (22 control group and 11 PFPS group), were evaluated by EMG during ascent of stairs. The VMO mean power frequency (MPF) and the VL frequency 95% (F95) were lower in symptomatic individuals. This may be related to the difference in muscle recruitment strategy exerted by each muscle in the PFPS group compared to the control group.

Eletromiografia de superfície para avaliação dos músculos do assoalho pélvico feminino: revisão de literatura Evaluation of female pelvic floor muscles using surface electromyography: literature review

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Ana Paula Magalhães Resende

2011-09-01

Full Text Available A eletromiografia de superfície tem grande importância clínica e de pesquisa para o fisioterapeuta. Apesar de captar a atividade elétrica promovida pelo recrutamento das unidades motoras, há boa correlação entre o número de unidades ativadas e a força muscular. É um dos métodos de maior especificidade na avaliação do assoalho pélvico, embora não haja consenso em relação à sua aplicação. Essa revisão de literatura foi desenvolvida com o objetivo de agrupar as informações sobre o uso da eletromiografia de superfície na avaliação do assoalho pélvico. Foram pesquisados artigos nas bases de dados Medline, PubMed, Lilacs, SciELO e Biblioteca Cochrane, e selecionados os que avaliassem o assoalho pélvico feminino por meio de eletromiografia de superfície. Apesar de sua metodologia ainda carecer de padronização, é um instrumento que deve ser considerado nas pesquisas científicas em nosso meio, pois parece apresentar boa reprodutibilidade e confiabilidade. Pacientes com disfunções do assoalho pélvico possuem alterações no tempo de ativação dos músculos do assoalho pélvico (MAP e músculos abdominais. Quanto à gestação e puerpério, ainda faltam evidências sobre possíveis alterações da ativação elétrica dos MAP nesses períodos.Surface electromyography has clinical and research importance for the physiotherapist. Although capturing electrical activity promoted by recruitment of motor units, there is a good correlation between the number of activated units and muscle strength. This is one of the methods of higher specificity in pelvic floor evaluation, although the lack of consensus regarding its application. The aim of this literature review was to cluster information regarding to the use of surface electromyography in the evaluation of pelvic floor. Papers were searched in Medline, Pubmed Lilacs, SciELO and Cochrane Library. Were selected papers which methods used surface electromyography to evaluate the

Dynamical Coordination of Hand Intrinsic Muscles for Precision Grip in Diabetes Mellitus.

Science.gov (United States)

Li, Ke; Wei, Na; Cheng, Mei; Hou, Xingguo; Song, Jun

2018-03-12

This study investigated the effects of diabetes mellitus (DM) on dynamical coordination of hand intrinsic muscles during precision grip. Precision grip was tested using a custom designed apparatus with stable and unstable loads, during which the surface electromyographic (sEMG) signals of the abductor pollicis brevis (APB) and first dorsal interosseous (FDI) were recorded simultaneously. Recurrence quantification analysis (RQA) was applied to quantify the dynamical structure of sEMG signals of the APB and FDI; and cross recurrence quantification analysis (CRQA) was used to assess the intermuscular coupling between the two intrinsic muscles. This study revealed that the DM altered the dynamical structure of muscle activation for the FDI and the dynamical intermuscular coordination between the APB and FDI during precision grip. A reinforced feedforward mechanism that compensates the loss of sensory feedbacks in DM may be responsible for the stronger intermuscular coupling between the APB and FDI muscles. Sensory deficits in DM remarkably decreased the capacity of online motor adjustment based on sensory feedback, rendering a lower adaptability to the uncertainty of environment. This study shed light on inherent dynamical properties underlying the intrinsic muscle activation and intermuscular coordination for precision grip and the effects of DM on hand sensorimotor function.

Comparison of Muscle Onset Activation Sequences between a Golf or Tennis Swing and Common Training Exercises Using Surface Electromyography: A Pilot Study

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John M. Vasudevan

2016-01-01

Full Text Available Aim. The purpose of this pilot study is to use surface electromyography to determine an individual athlete’s typical muscle onset activation sequence when performing a golf or tennis forward swing and to use the method to assess to what degree the sequence is reproduced with common conditioning exercises and a machine designed for this purpose. Methods. Data for 18 healthy male subjects were collected for 15 muscles of the trunk and lower extremities. Data were filtered and processed to determine the average onset of muscle activation for each motion. A Spearman correlation estimated congruence of activation order between the swing and each exercise. Correlations of each group were pooled with 95% confidence intervals using a random effects meta-analytic strategy. Results. The averaged sequences differed among each athlete tested, but pooled correlations demonstrated a positive association between each exercise and the participants’ natural muscle onset activation sequence. Conclusion. The selected training exercises and Turning Point™ device all partially reproduced our athletes’ averaged muscle onset activation sequences for both sports. The results support consideration of a larger, adequately powered study using this method to quantify to what degree each of the selected exercises is appropriate for use in both golf and tennis.

Recognition of Handwriting from Electromyography

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Linderman, Michael; Lebedev, Mikhail A.; Erlichman, Joseph S.

2009-01-01

Handwriting – one of the most important developments in human culture – is also a methodological tool in several scientific disciplines, most importantly handwriting recognition methods, graphology and medical diagnostics. Previous studies have relied largely on the analyses of handwritten traces or kinematic analysis of handwriting; whereas electromyographic (EMG) signals associated with handwriting have received little attention. Here we show for the first time, a method in which EMG signals generated by hand and forearm muscles during handwriting activity are reliably translated into both algorithm-generated handwriting traces and font characters using decoding algorithms. Our results demonstrate the feasibility of recreating handwriting solely from EMG signals – the finding that can be utilized in computer peripherals and myoelectric prosthetic devices. Moreover, this approach may provide a rapid and sensitive method for diagnosing a variety of neurogenerative diseases before other symptoms become clear. PMID:19707562

EOG-sEMG Human Interface for Communication.

Science.gov (United States)

Tamura, Hiroki; Yan, Mingmin; Sakurai, Keiko; Tanno, Koichi

2016-01-01

The aim of this study is to present electrooculogram (EOG) and surface electromyogram (sEMG) signals that can be used as a human-computer interface. Establishing an efficient alternative channel for communication without overt speech and hand movements is important for increasing the quality of life for patients suffering from amyotrophic lateral sclerosis, muscular dystrophy, or other illnesses. In this paper, we propose an EOG-sEMG human-computer interface system for communication using both cross-channels and parallel lines channels on the face with the same electrodes. This system could record EOG and sEMG signals as "dual-modality" for pattern recognition simultaneously. Although as much as 4 patterns could be recognized, dealing with the state of the patients, we only choose two classes (left and right motion) of EOG and two classes (left blink and right blink) of sEMG which are easily to be realized for simulation and monitoring task. From the simulation results, our system achieved four-pattern classification with an accuracy of 95.1%.

A model for generating Surface EMG signal of m. Tibialis Anterior.

Science.gov (United States)

Siddiqi, Ariba; Kumar, Dinesh; Arjunan, Sridhar P

2014-01-01

A model that simulates surface electromyogram (sEMG) signal of m. Tibialis Anterior has been developed and tested. This has a firing rate equation that is based on experimental findings. It also has a recruitment threshold that is based on observed statistical distribution. Importantly, it has considered both, slow and fast type which has been distinguished based on their conduction velocity. This model has assumed that the deeper unipennate half of the muscle does not contribute significantly to the potential induced on the surface of the muscle and has approximated the muscle to have parallel structure. The model was validated by comparing the simulated and the experimental sEMG signal recordings. Experiments were conducted on eight subjects who performed isometric dorsiflexion at 10, 20, 30, 50, 75, and 100% maximal voluntary contraction. Normalized root mean square and median frequency of the experimental and simulated EMG signal were computed and the slopes of the linearity with the force were statistically analyzed. The gradients were found to be similar (p>0.05) for both experimental and simulated sEMG signal, validating the proposed model.

Region-dependent hamstrings activity in Nordic hamstring exercise and stiff-leg deadlift defined with high-density electromyography.

Science.gov (United States)

Hegyi, A; Péter, A; Finni, T; Cronin, N J

2018-03-01

Recent studies suggest region-specific metabolic activity in hamstring muscles during injury prevention exercises, but the neural representation of this phenomenon is unknown. The aim of this study was to examine whether regional differences are evident in the activity of biceps femoris long head (BFlh) and semitendinosus (ST) muscles during two common injury prevention exercises. Twelve male participants without a history of hamstring injury performed the Nordic hamstring exercise (NHE) and stiff-leg deadlift (SDL) while BFlh and ST activities were recorded with high-density electromyography (HD-EMG). Normalized activity was calculated from the distal, middle, and proximal regions in the eccentric phase of each exercise. In NHE, ST overall activity was substantially higher than in BFlh (d = 1.06 ± 0.45), compared to trivial differences between muscles in SDL (d = 0.19 ± 0.34). Regional differences were found in NHE for both muscles, with different proximal-distal patterns: The distal region showed the lowest activity level in ST (regional differences, d range = 0.55-1.41) but the highest activity level in BFlh (regional differences, d range = 0.38-1.25). In SDL, regional differences were smaller in both muscles (d range = 0.29-0.67 and 0.16-0.63 in ST and BFlh, respectively) than in NHE. The use of HD-EMG in hamstrings revealed heterogeneous hamstrings activity during typical injury prevention exercises. High-density EMG might be useful in future studies to provide a comprehensive overview of hamstring muscle activity in other exercises and high-injury risk tasks. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

A INFLUÊNCIA DA APLICAÇÃO DE EXERCÍCIOS DE TRÍCEPS SOBRE A ESTIMULAÇÃO DO PEITORAL NO EXERCÍCIO SUPINO RETO - UM ESTUDO ELETROMIOGRÁFICO

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Daiane da Rosa

2014-04-01

Full Text Available Objective: To investigate the difference electromyography registers of the pectorals major muscle in the bench press exercise with or without prior triceps fatigued. Materials and Methods: The study included four male subjects aged 22-25 years with intermediate level training in bodybuilding, with goals in muscle hypertrophy, without any infirmity presented. The subjects performed 10 maximal repetitions in bench for electromyography evaluation. The procedure used for the analysis was the gathering of the electromyography signal of the pectorals major during movement execution of the bench press exercise without the exercises for triceps and their implementation on different days, with 80 hours apart. Results: It was found that changes were found in the electromyography signal in bench press exercise when compared with the burden versus performing triceps exercises before the bench press exercise. Conclusion: Thus differences were found when relating the load imposed on the bench press exercise to perform the same on the stimulation of the pectorals major, whether this is done before or after exercise for the triceps.

Reliability of surface electromyography activity of gluteal and hamstring muscles during sub-maximal and maximal voluntary isometric contractions.

Science.gov (United States)

Bussey, Melanie D; Aldabe, Daniela; Adhia, Divya; Mani, Ramakrishnan

2018-04-01

Normalizing to a reference signal is essential when analysing and comparing electromyography signals across or within individuals. However, studies have shown that MVC testing may not be as reliable in persons with acute and chronic pain. The purpose of this study was to compare the test-retest reliability of the muscle activity in the biceps femoris and gluteus maximus between a novel sub-MVC and standard MVC protocols. This study utilized a single individual repeated measures design with 12 participants performing multiple trials of both the sub-MVC and MVC tasks on two separate days. The participant position in the prone leg raise task was standardised with an ultrasonic sensor to improve task precession between trials/days. Day-to-day and trial-to-trial reliability of the maximal muscle activity was examined using ICC and SEM. Day-to-day and trial-to-trial reliability of the EMG activity in the BF and GM were high (0.70-0.89) to very high (≥0.90) for both test procedures. %SEM was <5-10% for both tests on a given day but higher in the day-to-day comparisons. The lower amplitude of the sub-MVC is a likely contributor to increased %SEM (8-13%) in the day-to-day comparison. The findings show that the sub-MVC modified prone double leg raise results in GM and BF EMG measures similar in reliability and precision to the standard MVC tasks. Therefore, the modified prone double leg raise may be a useful substitute for traditional MVC testing for normalizing EMG signals of the BF and GM. Copyright © 2017 Elsevier Ltd. All rights reserved.

Effects of Push-ups Plus Sling Exercise on Muscle Activation and Cross-sectional Area of the Multifidus Muscle in Patients with Low Back Pain.

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Kim, Gye-Yeop; Kin, Se-Hun

2013-12-01

[Purpose] The purpose of this study was to examine the effect of lumbar stability exercises on chronic low back pain by using sling exercise and push-ups. [Subjects] Thirty adult subjects with chronic back pain participated, with 10 adults being assigned to each of 3 exercise groups: general physical therapy (PT), lumbar stability using sling exercises (Sling Ex), and sling exercise plus push-ups (Sling Ex+PU). Each group trained for 30 minutes 3 times a week for 6 weeks. The Oswestry Disability Index (ODI), surface electromyographic (sEMG) activity of the lumbar muscles, and cross-sectional area of the multifidus muscle on computed tomography (CT) were evaluated before and at 2, 4, and 6 weeks of therapy. [Results] A significant decrease in ODI was seen in all therapy groups, and this change was greater in the Sling Ex and Sling Ex+PU groups than in the PT group. No changes in sEMG activity were noted in the PT group, whereas significant increases in the sEMG activities of all lumbar muscles were found in the other 2 groups. The increases in the sEMG activities of the rectus abdominis and internal and external oblique muscles of the abdomen were greater in the Sling Ex+PU group than in the other 2 groups. [Conclusion] These findings demonstrate that Sling Ex+PU, similar to normal lumbar stabilization exercise, is effective in activating and improving the function of the lumbar muscles. These results suggest that Sling Ex+PU has a positive impact on stabilization of the lumbar region.

Cervico-mandibular muscle activity in females with chronic cervical pain

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T. Lang

2013-12-01

Full Text Available Pathophysiological mechanisms behind pain in chroniccervical musculoskeletal conditions (MSC in office workers remainunclear. Chronic cervical pain has established links with temporomandibular(TM disorders. Yet there is no current published evidence to reportwhether individuals with cervical dysfunction exhibit altered masseterand cervical extensor (CE muscle activity. Objective: To explore CE andmasseter surface electromyographic (sEMG activity and teeth clenchinghabits in females with chronic cervical dysfunction and no TM disorder.Design: Descriptive cross-sectional correlational study with singleblinding.Participants: University students and staff with or without chroniccervical pain and no TM involvement. Methods: Descriptive and paindata captured from Research Diagnostic Criteria for TM disorders, NeckDisability Index, Computer Usage, Brief Pain Inventory, and EuroQoL-5Dquestionnaires. Female participants allocated to a chronic cervical (n = 20 and a control group (n = 22. Investigator blindedto the study groups recorded sEMG of bilateral masseter and CE muscles (C4/5 level at rest and during light teeth clenching.Results: No differences in socio-demographic profile; or in masseter or CE sEMG activity at rest or during light clench betweengroups. The pain group had higher scores for pain, reported a daytime teeth clenching habit, and had worse scores for the healthrelatedquality of life (HRQoL sub-sections for pain, anxiety/depression, and lower scores for perceived health status. Conclusion:No relationship established between cervico-mandibular sEMG activity and reported disability in females with chronic cervicaldysfunction and no TM disorder. Association between biopsychosocial factors of teeth clenching and anxiety/depression highlightscomplex pathophysiological mechanisms in chronic recurrent cervical pain.

A Biomechanical Comparison of Proportional Electromyography Control to Biological Torque Control Using a Powered Hip Exoskeleton

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Aaron J. Young

2017-06-01

Full Text Available BackgroundDespite a large increase in robotic exoskeleton research, there are few studies that have examined human performance with different control strategies on the same exoskeleton device. Direct comparison studies are needed to determine how users respond to different types of control. The purpose of this study was to compare user performance using a robotic hip exoskeleton with two different controllers: a controller that targeted a biological hip torque profile and a proportional myoelectric controller.MethodsWe tested both control approaches on 10 able-bodied subjects using a pneumatically powered hip exoskeleton. The state machine controller targeted a biological hip torque profile. The myoelectric controller used electromyography (EMG of lower limb muscles to produce a proportional control signal for the hip exoskeleton. Each subject performed two 30-min exoskeleton walking trials (1.0 m/s using each controller and a 10-min trial with the exoskeleton unpowered. During each trial, we measured subjects’ metabolic cost of walking, lower limb EMG profiles, and joint kinematics and kinetics (torques and powers using a force treadmill and motion capture.ResultsCompared to unassisted walking in the exoskeleton, myoelectric control significantly reduced metabolic cost by 13% (p = 0.005 and biological hip torque control reduced metabolic cost by 7% (p = 0.261. Subjects reduced muscle activity relative to the unpowered condition for a greater number of lower limb muscles using myoelectric control compared to the biological hip torque control. More subjects subjectively preferred the myoelectric controller to the biological hip torque control.ConclusionMyoelectric control had more advantages (metabolic cost and muscle activity reduction compared to a controller that targeted a biological torque profile for walking with a robotic hip exoskeleton. However, these results were obtained with a single exoskeleton device with specific

A Biomechanical Comparison of Proportional Electromyography Control to Biological Torque Control Using a Powered Hip Exoskeleton.

Science.gov (United States)

Young, Aaron J; Gannon, Hannah; Ferris, Daniel P

2017-01-01

Despite a large increase in robotic exoskeleton research, there are few studies that have examined human performance with different control strategies on the same exoskeleton device. Direct comparison studies are needed to determine how users respond to different types of control. The purpose of this study was to compare user performance using a robotic hip exoskeleton with two different controllers: a controller that targeted a biological hip torque profile and a proportional myoelectric controller. We tested both control approaches on 10 able-bodied subjects using a pneumatically powered hip exoskeleton. The state machine controller targeted a biological hip torque profile. The myoelectric controller used electromyography (EMG) of lower limb muscles to produce a proportional control signal for the hip exoskeleton. Each subject performed two 30-min exoskeleton walking trials (1.0 m/s) using each controller and a 10-min trial with the exoskeleton unpowered. During each trial, we measured subjects' metabolic cost of walking, lower limb EMG profiles, and joint kinematics and kinetics (torques and powers) using a force treadmill and motion capture. Compared to unassisted walking in the exoskeleton, myoelectric control significantly reduced metabolic cost by 13% ( p  = 0.005) and biological hip torque control reduced metabolic cost by 7% ( p  = 0.261). Subjects reduced muscle activity relative to the unpowered condition for a greater number of lower limb muscles using myoelectric control compared to the biological hip torque control. More subjects subjectively preferred the myoelectric controller to the biological hip torque control. Myoelectric control had more advantages (metabolic cost and muscle activity reduction) compared to a controller that targeted a biological torque profile for walking with a robotic hip exoskeleton. However, these results were obtained with a single exoskeleton device with specific control configurations while level walking at a

Determining Changes in Electromyography Indices when Measuring Maximum Acceptable Weight of Lift in Iranian Male Students.

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Salehi Sahl Abadi, A; Mazloumi, A; Nasl Saraji, G; Zeraati, H; Hadian, M R; Jafari, A H

2018-03-01

In spite of the increasing degree of automation in industry, manual material handling (MMH) is still performed in many occupational settings. The aim of the current study was to determine the maximum acceptable weight of lift using psychophysical and electromyography indices. This experimental study was conducted among 15 male students recruited from Tehran University of Medical Sciences. Each participant performed 18 different lifting tasks which involved three lifting frequencies, three lifting heights and two box sizes. Each set of experiments was conducted during the 20 min work period using free-style lifting technique and subjective as well as objective assessment methodologies. SPSS version 18 software was used for descriptive and analytical analyses by Friedman, Wilcoxon and Spearman correlation techniques. The results demonstrated that muscle activity increased with increasing frequency, height of lift and box size (P<0.05). Meanwhile, MAWLs obtained in this study are lower than those in Snook table (P<0.05). In this study, the level of muscle activity in percent MVC in relation to the erector spine muscles in L3 and T9 regions as well as left and right abdominal external oblique muscles were at 38.89%, 27.78%, 11.11% and 5.55% in terms of muscle activity is more than 70% MVC, respectively. The results of Wilcoxon test revealed that for both small and large boxes under all conditions, significant differences were detected between the beginning and end of the test values for MPF of erector spine in L3 and T9 regions, and left and right abdominal external oblique muscles (P<0.05). The results of Spearman correlation test showed that there was a significant relation between the MAWL, RMS and MPF of the muscles in all test conditions (P<0.05). Based on the results of this study, it was concluded if muscle activity is more than 70% of MVC, the values of Snook tables should be revisited. Furthermore, the biomechanical perspective should receive special attention

Fuzzy central tendency measure for time series variability analysis with application to fatigue electromyography signals.

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Xie, Hong-Bo; Dokos, Socrates

2013-01-01

A new method, namely fuzzy central tendency measure (fCTM) analysis, that could enable measurement of the variability of a time series, is presented in this study. Tests on simulated data sets show that fCTM is superior to the conventional central tendency measure (CTM) in several respects, including improved relative consistency and robustness to noise. The proposed fCTM method was applied to electromyograph (EMG) signals recorded during sustained isometric contraction for tracking local muscle fatigue. The results showed that the fCTM increased significantly during the development of muscle fatigue, and it was more sensitive to the fatigue phenomenon than mean frequency (MNF), the most commonly-used muscle fatigue indicator.

Eletromiografia laríngea em pacientes com disfonia e fechamento glótico incompleto Laryngeal electromyography in dysphonic patients with incomplete glottic closure

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Noemi Grigoletto De Biase

2012-12-01

Full Text Available O diagnóstico de comprometimento do nervo laríngeo superior e de ramos do laríngeo recorrente demanda eletromiografia, pois as alterações à laringoscopia são inespecíficas. OBJETIVO: Avaliar eletrofisiologicamente a função dos nervos laríngeo superior e inferior por meio da atividade elétrica dos músculos por eles inervados, em pacientes com disfonia com coaptação incompleta das pregas vocais à fonação. MÉTODO: Estudo prospectivo; 39 indivíduos com disfonia e fechamento glótico incompleto foram submetidos à eletromiografia dos músculos tireoaritenóideo, cricotireóideo e cricoaritenóideo lateral bilateralmente. Foram avaliadas atividade de inserção, no repouso (fibrilação, onda positiva e fasciculação e durante contração voluntária dos músculos (recrutamento, amplitude e duração do potencial e latência entre início da atividade elétrica e a sonorização. RESULTADOS: Não observamos alteração na atividade de inserção e no repouso. Nenhum paciente apresentou recrutamento alterado. A média da amplitude dos potenciais elétricos esteve compatível com a normalidade nos músculos testados, assim como a duração do potencial e o tempo de latência entre o início da atividade elétrica e a sonorização. CONCLUSÃO: Não observamos sinais de desnervação nos músculos tireoaritenóideo, cricotireóideo e cricoaritenóideo lateral bilateralmente nos pacientes estudados.The lack of specificity in laryngoscopical examination requires that the diagnosis of superior laryngeal and recurrent laryngeal nerve involvement be carried out with the aid of electromyography. OBJECTIVE: This study aims to assess the electrophysiological function of the superior and inferior laryngeal nerves by measuring the electrical activity of the muscles they innervate in dysphonic patients with incomplete closure of the vocal folds during phonation. METHOD: Thirty-nine patients with incomplete glottic closure were enrolled in a

Paracetamol 325 mg/tramadol 37.5 mg effect on pain during needle electromyography: a double-blind crossover clinical trial.

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Kalantar, Seyed Sadeq; Abbasi, Mehrshad; Faghihi-Kashani, Sara; Majedi, Hossein; Ahmadi, Mona; Agah, Elmira; Tafakhori, Abbas

2016-12-01

Needle insertion during electromyography (EMG) may cause varying levels of pain that could lead to inaccurate assessment and premature termination of the procedure. The aim of this study is to compare paracetamol 325 mg/tramadol 37.5 mg with placebo in relieving pain before EMG. This is a randomized, crossover, placebo-controlled, double-blind clinical trial; forty-four healthy individuals, including 27 males with a mean age of 35.3 years (range 18-59 years), entered this study. The needles were inserted unilaterally 2 h after administration of two analgesic tablets of paracetamol 325 mg/tramadol 37.5 mg or two placebo tablets. The pain was scored through a 100-mm visual analog scale (VAS) immediately and 2 h after the procedure. The side effects were also recorded. Within a week, the procedure was repeated on the other upper limb, changing the treatment and placebo. The immediate and 2-h VAS scores were notably lower after administration of treatment compared to placebo (immediate pain: 17.5 ± 12.8 vs. 32.1 ± 16.0, P pain: 1.6 ± 5.6 vs. 5.8 ± 7.9, P = 0. 002). There was a higher prevalence of side effects when treatment was used (48 vs. 9 %, P pain. Further application of this medication in patients with neuromuscular disorders would warrant additional clinical trials, particularly considering the adverse events.

Biomechanical analysis of double poling in elite cross-country skiers.

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Holmberg, Hans-Christer; Lindinger, Stefan; Stöggl, Thomas; Eitzlmair, Erich; Müller, Erich

2005-05-01

To further the understanding of double poling (DP) through biomechanical analysis of upper and lower body movements during DP in cross-country (XC) skiing at racing speed. Eleven elite XC skiers performed DP at 85% of their maximal DP velocity (V85%) during roller skiing at 1 degrees inclination on a treadmill. Pole and plantar ground reaction forces, joint angles (elbow, hip, knee, and ankle), cycle characteristics, and electromyography (EMG) of upper and lower body muscles were analyzed. 1) Pole force pattern with initial impact force peak and the following active force peak (PPF) correlated to V85%, (r = 0.66, P biomechanical aspects. Future research should further investigate the relationship between biomechanical and physiological variables and elaborate training models to improve DP performance.

Textile Electrodes Embedded in Clothing: A Practical Alternative to Traditional Surface Electromyography when Assessing Muscle Excitation during Functional Movements

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Steffi L. Colyer, Polly M. McGuigan

2018-03-01

Full Text Available Textile electromyography (EMG electrodes embedded in clothing allow muscle excitation to be recorded in previously inaccessible settings; however, their ability to accurately and reliably measure EMG during dynamic tasks remains largely unexplored. To quantify the validity and reliability of textile electrodes, 16 recreationally active males completed two identical testing sessions, within which three functional movements (run, cycle and squat were performed twice: once wearing EMG shorts (measuring quadriceps, hamstrings and gluteals myoelectric activity and once with surface EMG electrodes attached to the vastus lateralis, biceps femoris and gluteus maximus. EMG signals were identically processed to provide average rectified EMG (normalized to walking and excitation length. Results were compared across measurement systems and demonstrated good agreement between the magnitude of muscle excitation when EMG activity was lower, but agreement was poorer when excitation was higher. The length of excitation bursts was consistently longer when measured using textile vs. surface EMG electrodes. Comparable between-session (day-to-day repeatability was found for average rectified EMG (mean coefficient of variation, CV: 42.6 and 41.2% and excitation length (CV: 12.9 and 9.8% when using textile and surface EMG, respectively. Additionally, similar within-session repeatability (CV was recorded for average rectified EMG (13.8 and 14.1% and excitation length (13.0 and 12.7% for textile and surface electrodes, respectively. Generally, textile EMG electrodes appear to be capable of providing comparable muscle excitation information and reproducibility to surface EMG during dynamic tasks. Textile EMG shorts could therefore be a practical alternative to traditional laboratory-based methods allowing muscle excitation information to be collected in more externally-valid training environments.

Electromyography comparison of the effects of various footwear in the activity patterns of the peroneus longus and brevis muscles.

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Roca-Dols, Andrea; Losa-Iglesias, Marta Elena; Sánchez-Gómez, Rubén; López-López, Daniel; Becerro-de-Bengoa-Vallejo, Ricardo; Calvo-Lobo, César

2018-06-01

Peroneus longus and brevis (PLB) disorders are commonly in people with lateral ligamentous instability, ankle pain, lateral hindfoot pain and structures of the proximal compartment of the lower legs and their muscle activity is believed to be influenced by different footwear types. The proposal of this research is to evaluate the effects of five types of footwear with respect to the barefoot condition and analyze the activity patterns of PLB muscles in healthy subjects during the gait cycle. Thirty healthy subjects were recruited in a laboratory in this cross-sectional research design. While walking, electromyography (EMG) activity was measured from PLB via surface electrodes in six experimental conditions: 1) barefoot, 2) minimalist, 3) pronated control, 4) air chamber, 5) ethyl-vinyl-acetate (EVA) and 6) boost. These data were obtained and compared. The peroneus brevis showed significant reductions in the peak amplitude of the five footwear types (minimalist, pronation control, air chamber, EVA and boost) with respect to the barefoot condition in the propulsion phase of the gait cycle during walking (P = 0.034; P footwear types with respect to the barefoot condition in the propulsion phase of the gait cycle during running (P = 0.005; P = 0.038; P = 0.019; P = 0.025; P = 0.021). The EMG activity patterns of the PLB muscles may depend on the use of different types of sport shoes such as minimalist, pronation control, air chamber, EVA and boost footwear with respect the barefoot condition in different phases of the gait cycle during walking and running. Copyright © 2018 Elsevier Ltd. All rights reserved.

Effect of rest-pause vs. traditional bench press training on muscle strength, electromyography, and lifting volume in randomized trial protocols.

Science.gov (United States)

Korak, J Adam; Paquette, Max R; Brooks, Justin; Fuller, Dana K; Coons, John M

2017-09-01

Rest-pause (4-s unloaded rest between repetitions) training effects on one repetition maximum (1 RM), lifting volume, and neural activation via electromyography (EMG) are currently vague in the literature and can benefit strength and conditioning professionals for resistance training programme design. Therefore, this study compared 1 RM, neural activation via (EMG), and volume differences between rest-pause vs. traditional resistance training. Trained males (N = 20) were randomly assigned to either a rest-pause or a traditional training group. Pre- and post-1 RM testing was recorded. Training sessions were completed twice a week for 4 weeks and consisted of four sets of bench press to volitional fatigue at 80% of pre-test 1 RM with a 2-min rest between sets. Total volume completed was recorded on each training day. Neural activation of the pectoralis major was measured on the first and last training days. A two-way repeated-measures ANOVA indicated both groups significantly increased their 1 RMs following the 4-week training protocol (p  .05). An independent samples t test indicated that total volume lifted was significantly higher for the rest-pause group (56,778 vs. 38,315 lbs; p < .05) throughout the protocol and independently during weeks 2, 3, and 4. While strength and neural activation changes did not differ between groups, both increased 1 RMs and the rest-pause group achieved greater increases in volume than the traditional group. If volume is the focus of training, the rest-pause method should be utilized.

Vocal fold paresis - a debilitating and underdiagnosed condition.

Science.gov (United States)

Harris, G; O'Meara, C; Pemberton, C; Rough, J; Darveniza, P; Tisch, S; Cole, I

2017-07-01

To review the clinical signs of vocal fold paresis on laryngeal videostroboscopy, to quantify its impact on patients' quality of life and to confirm the benefit of laryngeal electromyography in its diagnosis. Twenty-nine vocal fold paresis patients were referred for laryngeal electromyography. Voice Handicap Index 10 results were compared to 43 patients diagnosed with vocal fold paralysis. Laryngeal videostroboscopy analysis was conducted to determine side of paresis. Blinded laryngeal electromyography confirmed vocal fold paresis in 92.6 per cent of cases, with vocal fold lag being the most common diagnostic sign. The laryngology team accurately predicted side of paresis in 76 per cent of cases. Total Voice Handicap Index 10 responses were not significantly different between vocal fold paralysis and vocal fold paresis groups (26.08 ± 0.21 and 22.93 ± 0.17, respectively). Vocal fold paresis has a significant impact on quality of life. This study shows that laryngeal electromyography is an important diagnostic tool. Patients with persisting dysphonia and apparently normal vocal fold movement, who fail to respond to appropriate speech therapy, should be investigated for a diagnosis of vocal fold paresis.

Analysis of musle fatigue induced by isometric vibration exercise at varying frequencies

NARCIS (Netherlands)

Mischi, M.; Rabotti, C.; Cardinale, M. (Marco)

2012-01-01

An increase in neuromuscular activity, measured by electromyography (EMG), is usually observed during vibration exercise. The underlying mechanisms are however unclear, limiting the possibilities to introduce and exploit vibration training in rehabilitation programs. In this study, a new training

Age-Associated Changes in the Spectral and Statistical Parameters of Surface Electromyogram of Tibialis Anterior

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Ariba Siddiqi

2016-01-01

Full Text Available Age-related neuromuscular change of Tibialis Anterior (TA is a leading cause of muscle strength decline among the elderly. This study has established the baseline for age-associated changes in sEMG of TA at different levels of voluntary contraction. We have investigated the use of Gaussianity and maximal power of the power spectral density (PSD as suitable features to identify age-associated changes in the surface electromyogram (sEMG. Eighteen younger (20–30 years and 18 older (60–85 years cohorts completed two trials of isometric dorsiflexion at four different force levels between 10% and 50% of the maximal voluntary contraction. Gaussianity and maximal power of the PSD of sEMG were determined. Results show a significant increase in sEMG’s maximal power of the PSD and Gaussianity with increase in force for both cohorts. It was also observed that older cohorts had higher maximal power of the PSD and lower Gaussianity. These age-related differences observed in the PSD and Gaussianity could be due to motor unit remodelling. This can be useful for noninvasive tracking of age-associated neuromuscular changes.

A novel spatiotemporal muscle activity imaging approach based on the Extended Kalman Filter.

Science.gov (United States)

Wang, Jing; Zhang, Yingchun; Zhu, Xiangjun; Zhou, Ping; Liu, Chenguang; Rymer, William Z

2012-01-01

A novel spatiotemporal muscle activity imaging (sMAI) approach has been developed using the Extended Kalman Filter (EKF) to reconstruct internal muscle activities from non-invasive multi-channel surface electromyogram (sEMG) recordings. A distributed bioelectric dipole source model is employed to describe the internal muscle activity space, and a linear relationship between the muscle activity space and the sEMG measurement space is then established. The EKF is employed to recursively solve the ill-posed inverse problem in the sMAI approach, in which the weighted minimum norm (WMN) method is utilized to calculate the initial state and a new nonlinear method is developed based on the propagating features of muscle activities to predict the recursive state. A series of computer simulations was conducted to test the performance of the proposed sMAI approach. Results show that the localization error rapidly decreases over 35% and the overlap ratio rapidly increases over 45% compared to the results achieved using the WMN method only. The present promising results demonstrate the feasibility of utilizing the proposed EKF-based sMAI approach to accurately reconstruct internal muscle activities from non-invasive sEMG recordings.

ECG artifact cancellation in surface EMG signals by fractional order calculus application.

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Miljković, Nadica; Popović, Nenad; Djordjević, Olivera; Konstantinović, Ljubica; Šekara, Tomislav B

2017-03-01

New aspects for automatic electrocardiography artifact removal from surface electromyography signals by application of fractional order calculus in combination with linear and nonlinear moving window filters are explored. Surface electromyography recordings of skeletal trunk muscles are commonly contaminated with spike shaped artifacts. This artifact originates from electrical heart activity, recorded by electrocardiography, commonly present in the surface electromyography signals recorded in heart proximity. For appropriate assessment of neuromuscular changes by means of surface electromyography, application of a proper filtering technique of electrocardiography artifact is crucial. A novel method for automatic artifact cancellation in surface electromyography signals by applying fractional order calculus and nonlinear median filter is introduced. The proposed method is compared with the linear moving average filter, with and without prior application of fractional order calculus. 3D graphs for assessment of window lengths of the filters, crest factors, root mean square differences, and fractional calculus orders (called WFC and WRC graphs) have been introduced. For an appropriate quantitative filtering evaluation, the synthetic electrocardiography signal and analogous semi-synthetic dataset have been generated. The examples of noise removal in 10 able-bodied subjects and in one patient with muscle dystrophy are presented for qualitative analysis. The crest factors, correlation coefficients, and root mean square differences of the recorded and semi-synthetic electromyography datasets showed that the most successful method was the median filter in combination with fractional order calculus of the order 0.9. Statistically more significant (p ECG peak reduction was obtained by the median filter application compared to the moving average filter in the cases of low level amplitude of muscle contraction compared to ECG spikes. The presented results suggest that the

Leg and trunk muscle coordination and postural sway during increasingly difficult standing balance tasks in young and older adults.

Science.gov (United States)

Donath, Lars; Kurz, Eduard; Roth, Ralf; Zahner, Lukas; Faude, Oliver

2016-09-01

Ageing impairs body balance and increases older adults' fall risk. Balance training can improve intrinsic fall risk factors. However, age comparisons of muscle activity responses during balance tasks are lacking. This study investigated relative muscle activity, muscle coordination and postural sway during various recommended static balance training tasks. Muscle activity (%MVC), amplitude ratios (AR) and co-activity (CAI) were determined during standing tasks for 30s (1: double limb stance on a foam surface, eyes open; 2: double limb stance on firm ground, eyes closed; 3: double limb stance, feet in step position on a foam surface, eyes open; 4: double limb stance, feet in step position on firm ground, eyes closed; 5: single limb stance on firm ground, eyes open) in 20 healthy young adults (24±2 y) and 20 older adults (73±6 y). Surface electromyography (SEMG) was applied (SENIAM guidelines) to ankle (tibialis anterior, soleus, medial gastrocnemius, peroneus longus) and thigh (vastus lateralis, vastus medialis, biceps femoris, semitendinosus) muscles (non-dominant leg). Electrodes over trunk (multifidus and internal oblique) muscles were applied bilaterally. Two- to six-fold higher levels of relative muscle activity were found in older adults for ankle (0.0002adults for the trunk (0.001older adults for the ankle (0.009Older adults had higher electrophysiological costs for all stance conditions. Muscle coordination showed inverse activity patterns at the ankle and trunk. Optimal balance and strength training programs should take into account age-specific alterations in muscle activity. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

The lower body muscle activation of intermediate to experienced kayakers when navigating white water.

Science.gov (United States)

Murtagh, Misha; Brooks, Darrell; Sinclair, Jonathan; Atkins, Stephen

2016-11-01

In white-water kayaking, the legs play a vital part in turning, stabilising and bracing actions. To date, there has been no reported information on neuromuscular activation of the legs in an authentic white-water environment. The aim of the current study was to identify lower body muscle activation, using 'in-boat' electromyography (EMG), whilst navigating a white-water run. Ten experienced male kayakers (age 31.5 ± 12.5 yr, intermediate to advanced experience) completed three successful runs of an international standard white-water course (grade 3 rapids), targeting right and left sides of the course, in a zigzag formation. Surface EMG (sEMG) outputs were generated, bilaterally, for the rectus femoris (RF), vastus lateralis, biceps femoris and gastrocnemius, expressed as a percentage of a dynamic maximal voluntary contraction (dMVC). Only RF showed significantly higher activation than any muscle on the left side of the body, and only on the left side of the course (P = .004; ETA(2) = 0.56). Other results showed no significant difference between muscle activation in the right and left legs during each run, nor when assessed at either the right or left side of the course (P > .05). These findings indicate that contralateral symmetry in lower limb muscle activation is evident during white-water kayaking. This symmetry may provide a stable base to allow more asymmetrical upper body and trunk movements to be fully optimised. Lower body symmetry development should be considered useful in targeted training programmes for white-water kayakers.

Active pauses induce more variable electromyographic pattern of the trapezius muscle activity during computer work

DEFF Research Database (Denmark)

Samani, Afshin; Holtermann, Andreas; Søgaard, Karen

2009-01-01

, with passive (relax) and active (30% maximum voluntary contraction of shoulder elevation) pauses given every 2 min at two different work paces (low/high). Bipolar SEMG from four parts of the trapezius muscle was recorded. The relative rest time was higher for the lower parts compared with the upper......The aim of this laboratory study was to evaluate effects of active and passive pauses and investigate the distribution of the trapezius surface electromyographic (SEMG) activity during computer mouse work. Twelve healthy male subjects performed four sessions of computer work for 10 min in one day...... of the trapezius (pwork with active pause compared with passive one (p

siGnum: graphical user interface for EMG signal analysis.

Science.gov (United States)

Kaur, Manvinder; Mathur, Shilpi; Bhatia, Dinesh; Verma, Suresh

2015-01-01

Electromyography (EMG) signals that represent the electrical activity of muscles can be used for various clinical and biomedical applications. These are complicated and highly varying signals that are dependent on anatomical location and physiological properties of the muscles. EMG signals acquired from the muscles require advanced methods for detection, decomposition and processing. This paper proposes a novel Graphical User Interface (GUI) siGnum developed in MATLAB that will apply efficient and effective techniques on processing of the raw EMG signals and decompose it in a simpler manner. It could be used independent of MATLAB software by employing a deploy tool. This would enable researcher's to gain good understanding of EMG signal and its analysis procedures that can be utilized for more powerful, flexible and efficient applications in near future.

Analysis of High-Density Surface EMG and Finger Pressure in the Left Forearm of Violin Players: A Feasibility Study.

Science.gov (United States)

Cattarello, Paolo; Merletti, Roberto; Petracca, Francesco

2017-09-01

Wrist and finger flexor muscles of the left hand were evaluated using high-density surface EMG (HDsEMG) in 17 violin players. Pressure sensors also were mounted below the second string of the violin to evaluate, simultaneously, finger pressure. Electrode grid size was 110x70 mm (12x8 electrodes with interelectrode distance=10 mm and Ø=3 mm). The study objective was to observe the activation patterns of these muscles while the violinists sequentially played four notes--SI (B), DO# (C#), RE (D), MI (E)--at 2 bows/s (one bow up in 0.5 s and one down in 0.5 s) and 4 bows/s on the second string, while producing a constant (CONST) or ramp (RAMP) sound volume. HDsEMG images obtained while playing the notes were compared with those obtained during isometric radial or ulnar flexion of the wrist or fingers. Two image descriptors provided information on image differences. Results showed that the technique was reliable and provided reliable signals, and that recognizably different sEMG images could be associated with the four notes tested, despite the variability within and between subjects playing the same note. sEMG activity of the left hand muscles and pressure on the string in the RAMP task were strongly affected in some individuals by the sound volume (controlled by the right hand) and much less in other individuals. These findings question whether there is an individual or generally optimal way of pressing violin strings with the left hand. The answer to this question might substantially modify the teaching of string instruments.

Humeral external rotation handling by using the Bobath concept approach affects trunk extensor muscles electromyography in children with cerebral palsy.

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Grazziotin Dos Santos, C; Pagnussat, Aline S; Simon, A S; Py, Rodrigo; Pinho, Alexandre Severo do; Wagner, Mário B

2014-10-20

This study aimed to investigate the electromyographic activity of cervical and trunk extensors muscles in children with cerebral palsy during two handlings according to the Bobath concept. A crossover trial involving 40 spastic diplegic children was conducted. Electromyography (EMG) was used to measure muscular activity at sitting position (SP), during shoulder internal rotation (IR) and shoulder external rotation (ER) handlings, which were performed using the elbow joint as key point of control. Muscle recordings were performed at the fourth cervical (C4) and at the tenth thoracic (T10) vertebral levels. The Gross Motor Function Classification System (GMFCS) was used to assess whether muscle activity would vary according to different levels of severity. Humeral ER handling induced an increase on EMG signal of trunk extensor muscles at the C4 (P=0.007) and T10 (P<0.001) vertebral levels. No significant effects were observed between SP and humeral IR handling at C4 level; However at T10 region, humeral IR handling induced an increase of EMG signal (P=0.019). Humeral ER resulted in an increase of EMG signal at both levels, suggesting increase of extensor muscle activation. Furthermore, the humeral ER handling caused different responses on EMG signal at T10 vertebra level, according to the GMFCS classification (P=0.017). In summary, an increase of EMG signal was observed during ER handling in both evaluated levels, suggesting an increase of muscle activation. These results indicate that humeral ER handling can be used for diplegic CP children rehabilitation to facilitate cervical and trunk extensor muscles activity in a GMFCS level-dependent manner. Copyright © 2014 Elsevier Ltd. All rights reserved.

Surface electromyographic evaluation of jaw muscles in children with unilateral crossbite and lateral shift in the early mixed dentition. Sexual dimorphism

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Lenguas, Leticia; Alarcón, José-Antonio; Venancio, Filipa; Kassem, Marta

2012-01-01

Objectives: To examine the activity of jaw muscles at rest and during maximal voluntary clenching (MVC) in children with unilateral posterior crossbite (UPXB) and functional lateral shift in the early mixed dentition and to evaluate sex differences. Material and Methods: The sample included 30 children (15 males, 15 females) aged 6 to 10 years old, with UPXB and functional mandibular lateral shift (≥1.5 mm) in the early mixed dentition. sEMG activity coming from the muscle areas (anterior temporalis [AT], posterior temporalis [PT], masseter [MA] and suprahyoid [SH]) were obtained from both the crossbite (XB) and noncrossbite (NONXB) sides at mandibular rest position. sEMG acti-vity of the bilateral AT and MA muscles sides was obtained during MVC. Asymmetry and activity indexes were calculated for each muscle area at rest and during MVC; the MA/TA ratio during MVC was also determined. Results: At rest, no differences were found between sexes for any muscle areas or asymmetry and activity indexes. No differences were found between XB and NONXB sides. During MVC, however, significant sex differences were found in AT and MA activity, with higher sEMG values in males than in females, on both XB and NONXB sides. Asymmetry indexes, activity indexes and MA/AT ratios did not show significant differences between the sexes. Activity was symmetric both in males and in females. Conclusions: At rest, no sex differences were found, but during MVC males showed higher activity than did females in both XB and NONXB AT and MA muscle areas. Muscular activity was symmetrical at rest and during MVC in both sexes. Sexual dimorphism should be considered in the diagnosis and treatment of UPXB and lateral shift in the early mixed dentition. Key words:Unilateral crossbite, mandibular shift, jaw muscles, sEMG, early mixed dentition. PMID:22926468

Image analysis software for following progression of peripheral neuropathy

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Epplin-Zapf, Thomas; Miller, Clayton; Larkin, Sean; Hermesmeyer, Eduardo; Macy, Jenny; Pellegrini, Marco; Luccarelli, Saverio; Staurenghi, Giovanni; Holmes, Timothy

2009-02-01

A relationship has been reported by several research groups [1 - 4] between the density and shapes of nerve fibers in the cornea and the existence and severity of peripheral neuropathy. Peripheral neuropathy is a complication of several prevalent diseases or conditions, which include diabetes, HIV, prolonged alcohol overconsumption and aging. A common clinical technique for confirming the condition is intramuscular electromyography (EMG), which is invasive, so a noninvasive technique like the one proposed here carries important potential advantages for the physician and patient. A software program that automatically detects the nerve fibers, counts them and measures their shapes is being developed and tested. Tests were carried out with a database of subjects with levels of severity of diabetic neuropathy as determined by EMG testing. Results from this testing, that include a linear regression analysis are shown.

Simultaneous Force Regression and Movement Classification of Fingers via Surface EMG within a Unified Bayesian Framework.

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Baldacchino, Tara; Jacobs, William R; Anderson, Sean R; Worden, Keith; Rowson, Jennifer

2018-01-01

This contribution presents a novel methodology for myolectric-based control using surface electromyographic (sEMG) signals recorded during finger movements. A multivariate Bayesian mixture of experts (MoE) model is introduced which provides a powerful method for modeling force regression at the fingertips, while also performing finger movement classification as a by-product of the modeling algorithm. Bayesian inference of the model allows uncertainties to be naturally incorporated into the model structure. This method is tested using data from the publicly released NinaPro database which consists of sEMG recordings for 6 degree-of-freedom force activations for 40 intact subjects. The results demonstrate that the MoE model achieves similar performance compared to the benchmark set by the authors of NinaPro for finger force regression. Additionally, inherent to the Bayesian framework is the inclusion of uncertainty in the model parameters, naturally providing confidence bounds on the force regression predictions. Furthermore, the integrated clustering step allows a detailed investigation into classification of the finger movements, without incurring any extra computational effort. Subsequently, a systematic approach to assessing the importance of the number of electrodes needed for accurate control is performed via sensitivity analysis techniques. A slight degradation in regression performance is observed for a reduced number of electrodes, while classification performance is unaffected.

A eletromiografia como auxílio na conduta terapêutica após cirurgia de craniotomia fronto-temporal: relato de caso Electromyography as an aid in therapeutic behavior after fronto-temporal craniotomy surgery: case report

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Maristella Cecco Oncins

2009-01-01

Full Text Available TEMA: eletromiografia e conduta terapêutica. PROCEDIMENTOS: este estudo foi realizado com uma paciente de 45 anos de idade, após 4 meses ser submetida a craniotomia fronto-temporal proveniente de um aneurisma. O músculo temporal anterior direito foi retirado da sua origem móvel e após a cirurgia, a paciente apresentou disfunção do músculo temporal e da articulação temporomandibular, com redução da abertura de boca, dor ao falar e comer. Utilizou-se a eletromiografia para registrar quantitativamente a atividade elétrica dos músculos temporais e masseteres na avaliação e durante o processo terapêutico. Registraram-se, na posição de repouso, oclusão máxima e mastigação habitual provocada. Fez-se terapia miofuncional durante todo o processo. RESULTADOS: dados dos exames mostraram um aumento significativo da atividade elétrica do músculo temporal anterior direito e uma redução da atividade do músculo temporal anterior esquerdo, o que no primeiro registro mostrava uma atividade elétrica rebaixada do lado direito em comparação com o lado esquerdo. Com a seleção dos exercícios miofuncionais houve uma participação mais efetiva do músculo temporal anterior direito, abertura de boca maior, sem dor, facilitando a função da mastigação e da fala, harmonizando o sistema estomatognático. CONCLUSÃO: registros comparativos dos exames de eletromiografia em diferentes etapas do processo terapêutico auxiliaram e direcionaram a melhor conduta terapêutica fonoaudiológica. Conseguiu-se atingir um equilíbrio das funções de respiração, sucção, mastigação, deglutição e fala relacionadas ao sistema estomatognático, considerando as limitações do caso.BACKGROUND: electromyography and therapeutic behavior. PROCEDURES: this study was carried out with a woman, 45year old, after 4 months from being submitted to fronto-temporal craniotomy originated an aneurysm. The right anterior temporal muscle was removed from its

Testing of motor unit synchronization model for localized muscle fatigue.

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Naik, Ganesh R; Kumar, Dinesh K; Yadav, Vivek; Wheeler, Katherine; Arjunan, Sridhar

2009-01-01

Spectral compression of surface electromyogram (sEMG) is associated with onset of localized muscle fatigue. The spectral compression has been explained based on motor unit synchronization theory. According to this theory, motor units are pseudo randomly excited during muscle contraction, and with the onset of muscle fatigue the recruitment pattern changes such that motor unit firings become more synchronized. While this is widely accepted, there is little experimental proof of this phenomenon. This paper has used source dependence measures developed in research related to independent component analysis (ICA) to test this theory.

Fractal and twin SVM-based handgrip recognition for healthy subjects and trans-radial amputees using myoelectric signal.

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Arjunan, Sridhar Poosapadi; Kumar, Dinesh Kant; Jayadeva J

2016-02-01

Identifying functional handgrip patterns using surface electromygram (sEMG) signal recorded from amputee residual muscle is required for controlling the myoelectric prosthetic hand. In this study, we have computed the signal fractal dimension (FD) and maximum fractal length (MFL) during different grip patterns performed by healthy and transradial amputee subjects. The FD and MFL of the sEMG, referred to as the fractal features, were classified using twin support vector machines (TSVM) to recognize the handgrips. TSVM requires fewer support vectors, is suitable for data sets with unbalanced distributions, and can simultaneously be trained for improving both sensitivity and specificity. When compared with other methods, this technique resulted in improved grip recognition accuracy, sensitivity, and specificity, and this improvement was significant (κ=0.91).

Location versus task relevance: The impact of differing internal focus of attention instructions on motor performance.

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Pelleck, Valerie; Passmore, Steven R

2017-05-01

Impaired performance while executing a motor task is attributed to a disruption of normal automatic processes when an internal focus of attention is used. What remains unclear is whether the specificity of internally focused task instructions may impact task performance. The present study assessed the implications of changing the attentional focus of novice and skilled golfers by measuring behavioural, neurophysiological and kinematic changes during a golf putting task. Over six blocks of ten putting trials each, attention was directed either externally (towards the target) or internally in one of two ways: 1) proximal (keeping the elbows extended and the hands gripping the putter); or 2) distal (keeping the weight evenly distributed between both legs) to the critical elements of the task. Results provided evidence that when novice participants use an internal focus of attention more closely associated with task performance that their: 1) execution; 2) accuracy; 3) variability of surface electromyography (sEMG) activity; and 4) kinematics of the putter movement are all adversely affected. Skilled golfers are much more resilient to changes in attentional focus, while all participants interpret a distal internal focus of attention similar to an external focus. All participants produced decreased activity in the muscle (tibialis anterior) associated with the distal (less task relevant) focus of attention even when the "internal" focus was on the lower extremity. Our results provide evidence that the skill level of the participant and the distance of the internal focus of attention from the key elements of a motor skill directly impact the execution, muscle activity, and movement kinematics associated with skilled motor task performance. Copyright © 2017 Elsevier B.V. All rights reserved.

Comparison of symptoms, physical examination and electromyography findings, with the results of surgery of carpal tunnel release, in patients treated between January 2007 and December 2008, at the Hospital Calderon Guardia

International Nuclear Information System (INIS)

Chavarria Alvarado, Manuel

2010-01-01

A comparison of the preoperative findings was performed in patients with the diagnosis of carpal tunnel syndrome, with functional outcomes and postoperative residual pain, using the scale Patient Rate Wrist Evaluation (PRWE). All patients have had clinical history, physical examination and electromyography studies. They were operated by minimally invasive open surgery. The information was collected in an Excel table and patients have located via telephone. 100% of the evaluated patients have engaged in activities that involve trauma or repetitive wrist movements. The physical sign with predicative positive value for suspect of carpal tunnel syndrome has been the Phalen, present in over 70% of cases. The amount of physical signs present preoperatively and postoperative results were found without correlation. The mixed lesion, both sensory and motor has been the most found in electrodiagnostic studies. Patients whose studies have been negative, postoperative results have showed less favorable. Only 69% of patients operated in the orthopedic service of the Hospital Rafael Angel Calderon Guardia (HCG), have had favorable postoperative results. (author) [es

Muscle Fatigue in the Three Heads of the Triceps Brachii During a Controlled Forceful Hand Grip Task with Full Elbow Extension Using Surface Electromyography.

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Ali, Asraf; Sundaraj, Kenneth; Badlishah Ahmad, R; Ahamed, Nizam Uddin; Islam, Anamul; Sundaraj, Sebastian

2015-06-27

The objective of the present study was to investigate the time to fatigue and compare the fatiguing condition among the three heads of the triceps brachii muscle using surface electromyography during an isometric contraction of a controlled forceful hand grip task with full elbow extension. Eighteen healthy subjects concurrently performed a single 90 s isometric contraction of a controlled forceful hand grip task and full elbow extension. Surface electromyographic signals from the lateral, long and medial heads of the triceps brachii muscle were recorded during the task for each subject. The changes in muscle activity among the three heads of triceps brachii were measured by the root mean square values for every 5 s period throughout the total contraction period. The root mean square values were then analysed to determine the fatiguing condition for the heads of triceps brachii muscle. Muscle fatigue in the long, lateral, and medial heads of the triceps brachii started at 40 s, 50 s, and 65 s during the prolonged contraction, respectively. The highest fatiguing rate was observed in the long head (slope = -2.863), followed by the medial head (slope = -2.412) and the lateral head (slope = -1.877) of the triceps brachii muscle. The results of the present study concurs with previous findings that the three heads of the triceps brachii muscle do not work as a single unit, and the fiber type/composition is different among the three heads.

The Effects of Upper-Limb Training Assisted with an Electromyography-Driven Neuromuscular Electrical Stimulation Robotic Hand on Chronic Stroke

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Chingyi Nam

2017-12-01

Full Text Available BackgroundImpaired hand dexterity is a major disability of the upper limb after stroke. An electromyography (EMG-driven neuromuscular electrical stimulation (NMES robotic hand was designed previously, whereas its rehabilitation effects were not investigated.ObjectivesThis study aims to investigate the rehabilitation effectiveness of the EMG-driven NMES-robotic hand-assisted upper-limb training on persons with chronic stroke.MethodA clinical trial with single-group design was conducted on chronic stroke participants (n = 15 who received 20 sessions of EMG-driven NMES-robotic hand-assisted upper-limb training. The training effects were evaluated by pretraining, posttraining, and 3-month follow-up assessments with the clinical scores of the Fugl-Meyer Assessment (FMA, the Action Research Arm Test (ARAT, the Wolf Motor Function Test, the Motor Functional Independence Measure, and the Modified Ashworth Scale (MAS. Improvements in the muscle coordination across the sessions were investigated by EMG parameters, including EMG activation level and Co-contraction Indexes (CIs of the target muscles in the upper limb.ResultsSignificant improvements in the FMA shoulder/elbow and wrist/hand scores (P < 0.05, the ARAT (P < 0.05, and in the MAS (P < 0.05 were observed after the training and sustained 3 months later. The EMG parameters indicated a significant decrease of the muscle activation level in flexor digitorum (FD and biceps brachii (P < 0.05, as well as a significant reduction of CIs in the muscle pairs of FD and triceps brachii and biceps brachii and triceps brachii (P < 0.05.ConclusionThe upper-limb training integrated with the assistance from the EMG-driven NMES-robotic hand is effective for the improvements of the voluntary motor functions and the muscle coordination in the proximal and distal joints. Furthermore, the motor improvement after the training could be maintained till 3 months later.Trial registration

The Effects of Upper-Limb Training Assisted with an Electromyography-Driven Neuromuscular Electrical Stimulation Robotic Hand on Chronic Stroke.

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Nam, Chingyi; Rong, Wei; Li, Waiming; Xie, Yunong; Hu, Xiaoling; Zheng, Yongping

2017-01-01

Impaired hand dexterity is a major disability of the upper limb after stroke. An electromyography (EMG)-driven neuromuscular electrical stimulation (NMES) robotic hand was designed previously, whereas its rehabilitation effects were not investigated. This study aims to investigate the rehabilitation effectiveness of the EMG-driven NMES-robotic hand-assisted upper-limb training on persons with chronic stroke. A clinical trial with single-group design was conducted on chronic stroke participants ( n  = 15) who received 20 sessions of EMG-driven NMES-robotic hand-assisted upper-limb training. The training effects were evaluated by pretraining, posttraining, and 3-month follow-up assessments with the clinical scores of the Fugl-Meyer Assessment (FMA), the Action Research Arm Test (ARAT), the Wolf Motor Function Test, the Motor Functional Independence Measure, and the Modified Ashworth Scale (MAS). Improvements in the muscle coordination across the sessions were investigated by EMG parameters, including EMG activation level and Co-contraction Indexes (CIs) of the target muscles in the upper limb. Significant improvements in the FMA shoulder/elbow and wrist/hand scores ( P  < 0.05), the ARAT ( P  < 0.05), and in the MAS ( P  < 0.05) were observed after the training and sustained 3 months later. The EMG parameters indicated a significant decrease of the muscle activation level in flexor digitorum (FD) and biceps brachii ( P  < 0.05), as well as a significant reduction of CIs in the muscle pairs of FD and triceps brachii and biceps brachii and triceps brachii ( P  < 0.05). The upper-limb training integrated with the assistance from the EMG-driven NMES-robotic hand is effective for the improvements of the voluntary motor functions and the muscle coordination in the proximal and distal joints. Furthermore, the motor improvement after the training could be maintained till 3 months later. ClinicalTrials.gov. NCT02117089; date of registration: April

Work related perceived stress and muscle activity during standardized computer work among female computer users

DEFF Research Database (Denmark)

Larsman, P; Thorn, S; Søgaard, K

2009-01-01

The current study investigated the associations between work-related perceived stress and surface electromyographic (sEMG) parameters (muscle activity and muscle rest) during standardized simulated computer work (typing, editing, precision, and Stroop tasks). It was part of the European case......-control study, NEW (Neuromuscular assessment in the Elderly Worker). The present cross-sectional study was based on a questionnaire survey and sEMG measurements among Danish and Swedish female computer users aged 45 or older (n=49). The results show associations between work-related perceived stress...... and trapezius muscle activity and rest during standardized simulated computer work, and provide partial empirical support for the hypothesized pathway of stress induced muscle activity in the association between an adverse psychosocial work environment and musculoskeletal symptoms in the neck and shoulder....

Effects of electroacupuncture therapy for Bell's palsy from acute stage: study protocol for a randomized controlled trial.

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Liu, Zhi-dan; He, Jiang-bo; Guo, Si-si; Yang, Zhi-xin; Shen, Jun; Li, Xiao-yan; Liang, Wei; Shen, Wei-dong

2015-08-25

Although many patients with facial paralysis have obtained benefits or completely recovered after acupuncture or electroacupuncture therapy, it is still difficult to list intuitive evidence besides evaluation using neurological function scales and a few electrophysiologic data. Hence, the aim of this study is to use more intuitive and reliable detection techniques such as facial nerve magnetic resonance imaging (MRI), nerve electromyography, and F waves to observe changes in the anatomic morphology of facial nerves and nerve conduction before and after applying acupuncture or electroacupuncture, and to verify their effectiveness by combining neurological function scales. A total of 132 patients with Bell's palsy (grades III and IV in the House-Brackmann [HB] Facial Nerve Grading System) will be randomly divided into electroacupuncture, manual acupuncture, non-acupuncture, and medicine control groups. All the patients will be given electroacupuncture treatment after the acute period, except for patients in the medicine control group. The acupuncture or electroacupuncture treatments will be performed every 2 days until the patients recover or withdraw from the study. The primary outcome is analysis based on facial nerve functional scales (HB scale and Sunnybrook facial grading system), and the secondary outcome is analysis based on MRI, nerve electromyography and F-wave detection. All the patients will undergo MRI within 3 days after Bell's palsy onset for observation of the signal intensity and facial nerve swelling of the unaffected and affected sides. They will also undergo facial nerve electromyography and F-wave detection within 1 week after onset of Bell's palsy. Nerve function will be evaluated using the HB scale and Sunnybrook facial grading system at each hospital visit for treatment until the end of the study. The MRI, nerve electromyography, and F-wave detection will be performed again at 1 month after the onset of Bell's palsy. Chinese Clinical Trials

Validity of Estimation of Pelvic Floor Muscle Activity from Transperineal Ultrasound Imaging in Men.

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Ryan E Stafford

Full Text Available To investigate the relationship between displacement of pelvic floor landmarks observed with transperineal ultrasound imaging and electromyography of the muscles hypothesised to cause the displacements.Three healthy men participated in this study, which included ultrasound imaging of the mid-urethra, urethra-vesical junction, ano-rectal junction and bulb of the penis. Fine-wire electromyography electrodes were inserted into the puborectalis and bulbocavernosus muscles and a transurethral catheter electrode recorded striated urethral sphincter electromyography. A nasogastric sensor recorded intra-abdominal pressure. Tasks included submaximal and maximal voluntary contractions, and Valsalva. The relationship between each of the parameters measured from ultrasound images and electromyography or intra-abdominal pressure amplitudes was described with nonlinear regression.Strong, non-linear relationships were calculated for each predicted landmark/muscle pair for submaximal contractions (R2-0.87-0.95. The relationships between mid-urethral displacement and striated urethral sphincter electromyography, and bulb of the penis displacement and bulbocavernosus electromyography were strong during maximal contractions (R2-0.74-0.88. Increased intra-abdominal pressure prevented shortening of puborectalis, which resulted in weak relationships between electromyography and anorectal and urethravesical junction displacement during all tasks.Displacement of landmarks in transperineal ultrasound imaging provides meaningful measures of activation of individual pelvic floor muscles in men during voluntary contractions. This method may aid assessment of muscle function or feedback for training.

Latent Factors Limiting the Performance of sEMG-Interfaces

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Sergey Lobov

2018-04-01

Full Text Available Recent advances in recording and real-time analysis of surface electromyographic signals (sEMG have fostered the use of sEMG human–machine interfaces for controlling personal computers, prostheses of upper limbs, and exoskeletons among others. Despite a relatively high mean performance, sEMG-interfaces still exhibit strong variance in the fidelity of gesture recognition among different users. Here, we systematically study the latent factors determining the performance of sEMG-interfaces in synthetic tests and in an arcade game. We show that the degree of muscle cooperation and the amount of the body fatty tissue are the decisive factors in synthetic tests. Our data suggest that these factors can only be adjusted by long-term training, which promotes fine-tuning of low-level neural circuits driving the muscles. Short-term training has no effect on synthetic tests, but significantly increases the game scoring. This implies that it works at a higher decision-making level, not relevant for synthetic gestures. We propose a procedure that enables quantification of the gestures’ fidelity in a dynamic gaming environment. For each individual subject, the approach allows identifying “problematic” gestures that decrease gaming performance. This information can be used for optimizing the training strategy and for adapting the signal processing algorithms to individual users, which could be a way for a qualitative leap in the development of future sEMG-interfaces.

An isometric muscle force estimation framework based on a high-density surface EMG array and an NMF algorithm

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Huang, Chengjun; Chen, Xiang; Cao, Shuai; Qiu, Bensheng; Zhang, Xu

2017-08-01

Objective. To realize accurate muscle force estimation, a novel framework is proposed in this paper which can extract the input of the prediction model from the appropriate activation area of the skeletal muscle. Approach. Surface electromyographic (sEMG) signals from the biceps brachii muscle during isometric elbow flexion were collected with a high-density (HD) electrode grid (128 channels) and the external force at three contraction levels was measured at the wrist synchronously. The sEMG envelope matrix was factorized into a matrix of basis vectors with each column representing an activation pattern and a matrix of time-varying coefficients by a nonnegative matrix factorization (NMF) algorithm. The activation pattern with the highest activation intensity, which was defined as the sum of the absolute values of the time-varying coefficient curve, was considered as the major activation pattern, and its channels with high weighting factors were selected to extract the input activation signal of a force estimation model based on the polynomial fitting technique. Main results. Compared with conventional methods using the whole channels of the grid, the proposed method could significantly improve the quality of force estimation and reduce the electrode number. Significance. The proposed method provides a way to find proper electrode placement for force estimation, which can be further employed in muscle heterogeneity analysis, myoelectric prostheses and the control of exoskeleton devices.

Effects of experimental occlusal interference on body posture: an optoelectronic stereophotogrammetric analysis.

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Marini, I; Gatto, M R; Bartolucci, M L; Bortolotti, F; Alessandri Bonetti, G; Michelotti, A

2013-07-01

In recent years, there has been increasing interest in the relationship between dental occlusion and body posture both among people and in scientific literature. The aim of the present longitudinal study is to investigate the effects of an experimental occlusal interference on body posture by means of a force platform and an optoelectronic stereophotogrammetric analysis. An occlusal interference of a 0- to 2-mm-thick glass composite was prepared to disturb the intercuspal position while not creating interference during lateral or protrusive mandibular excursions. Frontal and sagittal kinematic parameters, dynamic gait measurements and superficial electromyographic (SEMG) activity of head and neck muscles were performed on 12 healthy subjects. Measurements were taken 10 days before the application of the occlusal interference, and then immediately before the application, the day after it, and at a distance of 7 and 14 days under four different exteroceptive conditions. The outcomes of this study show that an occlusal interference does not modify significantly over time static and dynamic parameters of body posture under different exteroceptive conditions. It has a minimal influence only on the frontal kinematic parameters related to mandibular position, and it induces a transient increase of the activity of masticatory muscles. In this study, the experimental occlusal interference did not significantly influence the body posture during a 14-day follow-up period. © 2013 John Wiley & Sons Ltd.

Analysis of EMG Signals in Aggressive and Normal Activities by Using Higher-Order Spectra

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Necmettin Sezgin

2012-01-01

Full Text Available The analysis and classification of electromyography (EMG signals are very important in order to detect some symptoms of diseases, prosthetic arm/leg control, and so on. In this study, an EMG signal was analyzed using bispectrum, which belongs to a family of higher-order spectra. An EMG signal is the electrical potential difference of muscle cells. The EMG signals used in the present study are aggressive or normal actions. The EMG dataset was obtained from the machine learning repository. First, the aggressive and normal EMG activities were analyzed using bispectrum and the quadratic phase coupling of each EMG episode was determined. Next, the features of the analyzed EMG signals were fed into learning machines to separate the aggressive and normal actions. The best classification result was 99.75%, which is sufficient to significantly classify the aggressive and normal actions.

Analysis of EMG Signals in Aggressive and Normal Activities by Using Higher-Order Spectra

Science.gov (United States)

Sezgin, Necmettin

2012-01-01

The analysis and classification of electromyography (EMG) signals are very important in order to detect some symptoms of diseases, prosthetic arm/leg control, and so on. In this study, an EMG signal was analyzed using bispectrum, which belongs to a family of higher-order spectra. An EMG signal is the electrical potential difference of muscle cells. The EMG signals used in the present study are aggressive or normal actions. The EMG dataset was obtained from the machine learning repository. First, the aggressive and normal EMG activities were analyzed using bispectrum and the quadratic phase coupling of each EMG episode was determined. Next, the features of the analyzed EMG signals were fed into learning machines to separate the aggressive and normal actions. The best classification result was 99.75%, which is sufficient to significantly classify the aggressive and normal actions. PMID:23193379

The utility of EMG interference pattern analysis in botulinum toxin treatment of torticollis: A randomised, controlled and blinded study

DEFF Research Database (Denmark)

Werdelin, L; Dalager, T; Fuglsang-Frederiksen, Anders

2011-01-01

OBJECTIVE: The significance of electromyography (EMG) guidance in botulinum toxin (BT) treatment has been much debated. The aim of this study was to evaluate if EMG guidance in the treatment of torticollis in BT-naive patients had a better outcome than treatment after clinical evaluation alone...

Muscle activity during endotracheal intubation using 4 laryngoscopes (Macintosh laryngoscope, Intubrite, TruView Evo2 and King Vision – A comparative study

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Tomasz Gaszyński

2016-04-01

Full Text Available Background: Successful endotracheal intubation requires mental activity and no less important physical activity from the anesthesiologist, so ergonomics of used devices is important. The aim of our study has been to compare 4 laryngoscopes regarding an operator’s activity of selected muscles of the upper limb, an operator’s satisfaction with used devices and an operator’s fatigue during intubation attempts. Material and Methods: The study included 13 anesthesiologists of similar seniority. To measure muscle activity MyoPlus 2 with 2-channel surface ElectroMyoGraphy (sEMG test device was used. Participant’s satisfaction with studied devices was evaluated using Visual Analog Scale. An operator’s fatigue during intubation efforts was evaluated by means of the modified Borg’s scale. Results: The highest activity of all the studied muscles was observed for the Intubrite laryngoscope, followed by the Mackintosh, TruView Evo2 and the lowest one – for the King Vision video laryngoscope. A significant statistical difference was observed for the King Vision and the rest of laryngoscopes (p 0.05. The shortest time of intubation was achieved using the standard Macintosh blade laryngoscope. The highest satisfaction was noted for the King Vision video laryngoscope, and the lowest for – the TruView Evo2. The Intubrite was the most demanding in terms of workload, in the opinion of the participants’, and the least demanding was the King Vision video laryngoscope. Conclusions: Muscle activity, namely the force used for intubation, is the smallest when the King Vision video laryngoscope is used with the highest satisfaction and lowest workload, and the highest muscle activity was proven for the Intubrite laryngoscope with the highest workload. Med Pr 2016;67(2:155–162

Myoelectric manifestations of jaw elevator muscle fatigue and recovery in healthy and TMD subjects.

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Castroflorio, T; Falla, D; Tartaglia, G M; Sforza, C; Deregibus, A

2012-09-01

The effects of muscle pain and fatigue on the control of jaw elevator muscles are not well known. Furthermore, the myoelectric manifestations of fatigue and recovery from fatigue in the masticatory muscles are not reported in literature. The main aims of this study were (i) to evaluate the possible use of surface electromyography (sEMG) as an objective measure of fatigue of the jaw elevator muscles, (ii) to compare the myoelectric manifestations of fatigue in the temporalis anterior and masseter muscles bilaterally, (iii) to assess recovery of the investigated muscles after an endurance test and (iv) to compare fatigue and recovery of the jaw elevator muscles in healthy subjects and patients with muscle-related temporomandibular disorders (TMD). The study was performed on twenty healthy volunteers and eighteen patients with muscle-related TMD. An intra-oral compressive-force sensor was used to measure the voluntary contraction forces close to the intercuspal position and to provide visual feedback of submaximal forces to the subject. Surface EMG signals were recorded with linear electrode arrays during isometric contractions at 20%, 40%, 60% and 80% of the maximum voluntary contraction force, during an endurance test and during the recovery phase. The results showed that (i) the slope of the mean power spectral frequency (MNF) and the initial average rectified value (ARV) could be used to monitor fatigue of the jaw elevators, (ii) the temporalis anterior and masseter muscle show the same myoelectric manifestations of fatigue and recovery and (iii) the initial values of MNF and ARV were lower in patients with muscle-related TMD. The assessment of myoelectric manifestations of fatigue in the masticatory muscles may assist in the clinical assessment of TMDs. © 2012 Blackwell Publishing Ltd.

Activation of Neck and Low-Back Muscles Is Reduced with the Use of a Neck Balance System Together with a Lumbar Support in Urban Drivers.

Directory of Open Access Journals (Sweden)

Federica Menotti

Full Text Available Driving is associated with high activation of low-back and neck muscles due to the sitting position and perturbations imposed by the vehicle. The aim of this study was to investigate the use of a neck balance system together with a lumbar support on the activation of low-back and neck muscles during driving. Twelve healthy male subjects (age 32±6.71 years were asked to drive in two conditions: 1 with devices; 2 without devices. During vehicle accelerations and decelerations root mean square (RMS of surface electromyography (sEMG was recorded from the erector spinae, semispinalis capitis and sternocleidomastoid muscles and expressed as a percentage of maximal voluntary contraction (MVC. The pitch of the head was obtained by means of an inertial sensor placed on the subjects' head. A visual analog scale (VAS was used to assess the level of perceived comfort. RMS of the low back muscles was lower with than without devices during both acceleration and deceleration of the vehicle (1.40±0.93% vs 29 2.32±1.90% and 1.88±1.45% vs 2.91±2.33%, respectively, while RMS of neck extensor muscles was reduced only during acceleration (5.18±1.96% vs 5.91±2.16%. There were no differences between the two conditions in RMS of neck flexor muscles, the pitch of the head and the VAS score. The use of these two ergonomic devices is therefore effective in reducing the activation of low-back and neck muscles during driving with no changes in the level of perceived comfort, which is likely due to rebalancing weight on the neck and giving a neutral position to lumbar segments.

Biomedical sensor design using analog compressed sensing

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Balouchestani, Mohammadreza; Krishnan, Sridhar

2015-05-01

The main drawback of current healthcare systems is the location-specific nature of the system due to the use of fixed/wired biomedical sensors. Since biomedical sensors are usually driven by a battery, power consumption is the most important factor determining the life of a biomedical sensor. They are also restricted by size, cost, and transmission capacity. Therefore, it is important to reduce the load of sampling by merging the sampling and compression steps to reduce the storage usage, transmission times, and power consumption in order to expand the current healthcare systems to Wireless Healthcare Systems (WHSs). In this work, we present an implementation of a low-power biomedical sensor using analog Compressed Sensing (CS) framework for sparse biomedical signals that addresses both the energy and telemetry bandwidth constraints of wearable and wireless Body-Area Networks (BANs). This architecture enables continuous data acquisition and compression of biomedical signals that are suitable for a variety of diagnostic and treatment purposes. At the transmitter side, an analog-CS framework is applied at the sensing step before Analog to Digital Converter (ADC) in order to generate the compressed version of the input analog bio-signal. At the receiver side, a reconstruction algorithm based on Restricted Isometry Property (RIP) condition is applied in order to reconstruct the original bio-signals form the compressed bio-signals with high probability and enough accuracy. We examine the proposed algorithm with healthy and neuropathy surface Electromyography (sEMG) signals. The proposed algorithm achieves a good level for Average Recognition Rate (ARR) at 93% and reconstruction accuracy at 98.9%. In addition, The proposed architecture reduces total computation time from 32 to 11.5 seconds at sampling-rate=29 % of Nyquist rate, Percentage Residual Difference (PRD)=26 %, Root Mean Squared Error (RMSE)=3 %.

Early Stroke Rehabilitation of the Upper Limb Assisted with an Electromyography-Driven Neuromuscular Electrical Stimulation-Robotic Arm

Directory of Open Access Journals (Sweden)

Qiuyang Qian

2017-09-01

Full Text Available BackgroundEffective poststroke motor rehabilitation depends on repeated limb practice with voluntary efforts. An electromyography (EMG-driven neuromuscular electrical stimulation (NMES-robot arm was designed for the multi-joint physical training on the elbow, the wrist, and the fingers.ObjectivesTo investigate the training effects of the device-assisted approach on subacute stroke patients and to compare the effects with those achieved by the traditional physical treatments.MethodThis study was a pilot randomized controlled trial with a 3-month follow-up. Subacute stroke participants were randomly assigned into two groups, and then received 20-session upper limb training with the EMG-driven NMES-robotic arm (NMES-robot group, n = 14 or the time-matched traditional therapy (the control, n = 10. For the evaluation of the training effects, clinical assessments including Fugl-Meyer Assessment (FMA, Modified Ashworth Score (MAS, Action Research Arm Test (ARAT, and Function Independence Measurement (FIM were conducted before, after the rehabilitation training, and 3 months later. Session-by-session EMG parameters in the NMES-robot group, including normalized co-contraction Indexes (CI and EMG activation level of target muscles, were used to monitor the progress in muscular coordination patterns.ResultsSignificant improvements were obtained in FMA (full score and shoulder/elbow, ARAT, and FIM [P < 0.001, effect sizes (EFs > 0.279] for both groups. Significant improvement in FMA wrist/hand was only observed in the NMES-robot group (P < 0.001, EFs = 0.435 after the treatments. Significant reduction in MAS wrist was observed in the NMES-robot group after the training (P < 0.05, EFs = 0.145 and the effects were maintained for 3 months. MAS scores in the control group were elevated following training (P < 0.05, EFs > 0.24, and remained at an elevated level when assessed 3 months later. The EMG parameters

Tremor Detection Using Parametric and Non-Parametric Spectral Estimation Methods : A Comparison with Clinical Assessment

NARCIS (Netherlands)

Martinez Manzanera, Octavio; Elting, Jan Willem; van der Hoeven, Johannes H; Maurits, Natasha M

2016-01-01

In the clinic, tremor is diagnosed during a time-limited process in which patients are observed and the characteristics of tremor are visually assessed. For some tremor disorders, a more detailed analysis of these characteristics is needed. Accelerometry and electromyography can be used to obtain a

Effects of evidence-based prevention training on neuromuscular and biomechanical risk factors for ACL injury in adolescent female athletes

DEFF Research Database (Denmark)

Zebis, Mette K.; Andersen, Lars L.; Brandt, Mikkel

2016-01-01

training 3 times weekly for 12 weeks. The CON group completed their regular warm-up exercise programme before training. Players were tested while performing a side cutting movement at baseline and 12-week follow-up, using surface electromyography (EMG) and three-dimensional movement analysis. We calculated...

The Value of Biomechanical Research in Dance.

Science.gov (United States)

Ranney, D. A.

Simple observation of dance movement, while very useful, can lead to misconceptions, about the physical realities of dance movement, that make learning difficult. This gap between reality and understanding can be reduced by the application of biomechanical techniques such as cinematography, electromyography, and force-plate analysis. Biomechanical…

Myoeletric indices of fatigue adopting different rest intervals during leg press sets.

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Miranda, Humberto; Maia, Marianna; de Oliveira, Carlos G; Farias, Déborah; da Silva, Jurandir B; Lima, Vicente P; Willardson, Jeffrey M; Paz, Gabriel A

2018-01-01

The purpose of this study was to examine the acute effect of different rest intervals between multiple sets of the 45° angled leg press exercise (LP45) on surface electromyographic (SEMG) spectral and amplitude indices of fatigue. Fifteen recreationally trained females performed three protocols in a randomized crossover design; each consisting of four sets of 10 repetitions with 1 (P1), 3 (P3), or 5 (P5) minute rest intervals between sets. Each set was performed with 70% of the LP45 ten-repetition maximum load. The SEMG data for biceps femoris (BF), vastus lateralis (VL), vastus medialis (VM), and rectus femoris (RF) muscles was then evaluated. The SEMG amplitude change in the time coefficient (CRMS) and spectral fatigue index (Cf5) indicated higher levels of fatigue for all muscles evaluated during the P3 protocol versus the P1 and P5 protocols (p ≤ 0.05), respectively. The RF and VL muscles showed greater fatigue levels by the second and third sets; whereas, greater fatigue was shown in the VM and BF muscles by the fourth set (p ≤ 0.05). A three-minute rest interval between sets might represent a neuromuscular window between a fatigue stated and fully recovered state in the context of neural activation. Moreover, a three minute rest interval between sets might allow for consistent recruitment of high threshold motor units over multiple sets, and thus promote a more effective stimulus for strength gains. Copyright © 2017 Elsevier Ltd. All rights reserved.

Tremor Detection Using Parametric and Non-Parametric Spectral Estimation Methods: A Comparison with Clinical Assessment

Science.gov (United States)

Martinez Manzanera, Octavio; Elting, Jan Willem; van der Hoeven, Johannes H.; Maurits, Natasha M.

2016-01-01

In the clinic, tremor is diagnosed during a time-limited process in which patients are observed and the characteristics of tremor are visually assessed. For some tremor disorders, a more detailed analysis of these characteristics is needed. Accelerometry and electromyography can be used to obtain a better insight into tremor. Typically, routine clinical assessment of accelerometry and electromyography data involves visual inspection by clinicians and occasionally computational analysis to obtain objective characteristics of tremor. However, for some tremor disorders these characteristics may be different during daily activity. This variability in presentation between the clinic and daily life makes a differential diagnosis more difficult. A long-term recording of tremor by accelerometry and/or electromyography in the home environment could help to give a better insight into the tremor disorder. However, an evaluation of such recordings using routine clinical standards would take too much time. We evaluated a range of techniques that automatically detect tremor segments in accelerometer data, as accelerometer data is more easily obtained in the home environment than electromyography data. Time can be saved if clinicians only have to evaluate the tremor characteristics of segments that have been automatically detected in longer daily activity recordings. We tested four non-parametric methods and five parametric methods on clinical accelerometer data from 14 patients with different tremor disorders. The consensus between two clinicians regarding the presence or absence of tremor on 3943 segments of accelerometer data was employed as reference. The nine methods were tested against this reference to identify their optimal parameters. Non-parametric methods generally performed better than parametric methods on our dataset when optimal parameters were used. However, one parametric method, employing the high frequency content of the tremor bandwidth under consideration

Cross Time-Frequency Analysis of Gastrocnemius Electromyographic Signals in Hypertensive and Nonhypertensive Subjects

Science.gov (United States)

Mitchell, Patrick; Krotish, Debra; Shin, Yong-June; Hirth, Victor

2010-12-01

The effects of hypertension are chronic and continuous; it affects gait, balance, and fall risk. Therefore, it is desirable to assess gait health across hypertensive and nonhypertensive subjects in order to prevent or reduce the risk of falls. Analysis of electromyography (EMG) signals can identify age related changes of neuromuscular activation due to various neuropathies and myopathies, but it is difficult to translate these medical changes to clinical diagnosis. To examine and compare geriatrics patients with these gait-altering diseases, we acquire EMG muscle activation signals, and by use of a timesynchronized mat capable of recording pressure information, we localize the EMG data to the gait cycle, ensuring identical comparison across subjects. Using time-frequency analysis on the EMG signal, in conjunction with several parameters obtained from the time-frequency analyses, we can determine the statistical discrepancy between diseases. We base these parameters on physiological manifestations caused by hypertension, as well as other comorbities that affect the geriatrics community. Using these metrics in a small population, we identify a statistical discrepancy between a control group and subjects with hypertension, neuropathy, diabetes, osteoporosis, arthritis, and several other common diseases which severely affect the geriatrics community.

Temporary-tattoo for long-term high fidelity biopotential recordings.

Science.gov (United States)

Bareket, Lilach; Inzelberg, Lilah; Rand, David; David-Pur, Moshe; Rabinovich, David; Brandes, Barak; Hanein, Yael

2016-05-12

Electromyography is a non-invasive method widely used to map muscle activation. For decades, it was commonly accepted that dry metallic electrodes establish poor electrode-skin contact, making them impractical for skin electromyography applications. Gelled electrodes are therefore the standard in electromyography with their use confined, almost entirely, to laboratory settings. Here we present novel dry electrodes, exhibiting outstanding electromyography recording along with excellent user comfort. The electrodes were realized using screen-printing of carbon ink on a soft support. The conformity of the electrodes helps establish direct contact with the skin, making the use of a gel superfluous. Plasma polymerized 3,4-ethylenedioxythiophene was used to enhance the impedance of the electrodes. Cyclic voltammetry measurements revealed an increase in electrode capacitance by a factor of up to 100 in wet conditions. Impedance measurements show a reduction factor of 10 in electrode impedance on human skin. The suitability of the electrodes for long-term electromyography recordings from the hand and from the face is demonstrated. The presented electrodes are ideally-suited for many applications, such as brain-machine interfacing, muscle diagnostics, post-injury rehabilitation, and gaming.

Temporary-tattoo for long-term high fidelity biopotential recordings

Science.gov (United States)

Bareket, Lilach; Inzelberg, Lilah; Rand, David; David-Pur, Moshe; Rabinovich, David; Brandes, Barak; Hanein, Yael

2016-05-01

Electromyography is a non-invasive method widely used to map muscle activation. For decades, it was commonly accepted that dry metallic electrodes establish poor electrode-skin contact, making them impractical for skin electromyography applications. Gelled electrodes are therefore the standard in electromyography with their use confined, almost entirely, to laboratory settings. Here we present novel dry electrodes, exhibiting outstanding electromyography recording along with excellent user comfort. The electrodes were realized using screen-printing of carbon ink on a soft support. The conformity of the electrodes helps establish direct contact with the skin, making the use of a gel superfluous. Plasma polymerized 3,4-ethylenedioxythiophene was used to enhance the impedance of the electrodes. Cyclic voltammetry measurements revealed an increase in electrode capacitance by a factor of up to 100 in wet conditions. Impedance measurements show a reduction factor of 10 in electrode impedance on human skin. The suitability of the electrodes for long-term electromyography recordings from the hand and from the face is demonstrated. The presented electrodes are ideally-suited for many applications, such as brain-machine interfacing, muscle diagnostics, post-injury rehabilitation, and gaming.

Muscle synergy analysis in children with cerebral palsy

Science.gov (United States)

Tang, Lu; Li, Fei; Cao, Shuai; Zhang, Xu; Wu, De; Chen, Xiang

2015-08-01

Objective. To explore the mechanism of lower extremity dysfunction of cerebral palsy (CP) children through muscle synergy analysis. Approach. Twelve CP children were involved in this study, ten adults (AD) and eight typically developed (TD) children were recruited as a control group. Surface electromyographic (sEMG) signals were collected bilaterally from eight lower limb muscles of the subjects during forward walking at a comfortable speed. A nonnegative matrix factorization algorithm was used to extract muscle synergies. In view of muscle synergy differences in number, structure and symmetry, a model named synergy comprehensive assessment (SCA) was proposed to quantify the abnormality of muscle synergies. Main results. There existed larger variations between the muscle synergies of the CP group and the AD group in contrast with the TD group. Fewer mature synergies were recruited in the CP group, and many abnormal synergies specific to the CP group appeared. Specifically, CP children were found to recruit muscle synergies with a larger difference in structure and symmetry between two legs of one subject and different subjects. The proposed SCA scale demonstrated its great potential to quantitatively assess the lower-limb motor dysfunction of CP children. SCA scores of the CP group (57.00 ± 16.78) were found to be significantly less (p < 0.01) than that of the control group (AD group: 95.74 ± 2.04; TD group: 84.19 ± 11.76). Significance. The innovative quantitative results of this study can help us to better understand muscle synergy abnormality in CP children, which is related to their motor dysfunction and even the physiological change in their nervous system.

The reliability of a maximal isometric hip strength and simultaneous surface EMG screening protocol in elite, junior rugby league athletes.

Science.gov (United States)

Charlton, Paula C; Mentiplay, Benjamin F; Grimaldi, Alison; Pua, Yong-Hao; Clark, Ross A

2017-02-01

Firstly to describe the reliability of assessing maximal isometric strength of the hip abductor and adductor musculature using a hand held dynamometry (HHD) protocol with simultaneous wireless surface electromyographic (sEMG) evaluation of the gluteus medius (GM) and adductor longus (AL). Secondly, to describe the correlation between isometric strength recorded with the HHD protocol and a laboratory standard isokinetic device. Reliability and correlational study. A sample of 24 elite, male, junior, rugby league athletes, age 16-20 years participated in repeated HHD and isometric Kin-Com (KC) strength testing with simultaneous sEMG assessment, on average (range) 6 (5-7) days apart by a single assessor. Strength tests included; unilateral hip abduction (ABD) and adduction (ADD) and bilateral ADD assessed with squeeze (SQ) tests in 0 and 45° of hip flexion. HHD demonstrated good to excellent inter-session reliability for all outcome measures (ICC (2,1) =0.76-0.91) and good to excellent association with the laboratory reference KC (ICC (2,1) =0.80-0.88). Whilst intra-session, inter-trial reliability of EMG activation and co-activation outcome measures ranged from moderate to excellent (ICC (2,1) =0.70-0.94), inter-session reliability was poor (all ICC (2,1) Isometric strength testing of the hip ABD and ADD musculature using HHD may be measured reliably in elite, junior rugby league athletes. Due to the poor inter-session reliability of sEMG measures, it is not recommended for athlete screening purposes if using the techniques implemented in this study. Copyright © 2016 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.

Seizure Onset Detection based on one sEMG channel

DEFF Research Database (Denmark)

Conradsen, Isa; Beniczky, Sandor; Hoppe, Karsten

2011-01-01

with a Butterworth filter with a cut-off frequency of 150 Hz. The number of zero-crossings with a hysteresis of ±50μV is the only feature extracted. The number of counts in a window of 1 second and the number of windows to make a detection is tested with a leave-one-out method. On 6 patients the method performs...

Bilateral neuromuscular and force differences during a plyometric task.

Science.gov (United States)

Ball, Nick B; Scurr, Joanna C

2009-08-01

The purpose of this article is to compare the bilateral neuromuscular and force contribution during a plyometric bounce drop jump task and to assess the affects of nonsimultaneous foot placement. Sixteen male participants performed bounce drop jumps from a height of 0.4 m. Mean peak electromyography activity of the soleus, medial, and lateral gastrocnemius of both legs was recorded from each phase of the drop jump and normalized to a reference dynamic muscle action. Resultant ground reaction force, ground contact time, and duration of the drop jumps were recorded from each leg. Multivariate analysis of variance was used to compare bilateral electromyographic activity, resultant peak ground reaction force, and contact duration. Pearson's correlations (r) ascertained relationships between normalized electromyographic activity and contact time. Significant differences were shown between left and right triceps surae normalized electromyography during precontact and contact40ms (p 0.01). Significant differences were found between normalized soleus electromyography and both gastrocnemii for both legs during precontact (p 0.01). Weak relationships were found between normalized electromyographic activity and nonsimultaneous foot contact (r < 0.2). This study showed differences between left and right triceps surae in neuromuscular strategies engaged in the early stages of a drop jump task. Differences in contact time initiation were present; however, they are not significant enough to cause neuromuscular differences in the plantar flexor muscles.

A kinematic and metabolic analysis of the first Lu of Tai Chi in experts and beginners.

Science.gov (United States)

Zorzi, Elena; Nardello, Francesca; Fracasso, Enrico; Franchi, Sara; Clauti, Anna; Cesari, Paola; Zamparo, Paola

2015-10-01

The aim of this study was to compare movement kinematics, cocontraction times, and metabolic data in expert and nonexpert Tai Chi practitioners. Significant differences were observed for all kinematic parameters: experts moved smoothly (lower jerk) and with a lower frequency. No differences in metabolic and electromyography data were observed but for the breathing pattern (experts breathed slowly and deeply). Movement frequency and breathing pattern are thus the main features that distinguish expert and nonexpert practitioners.

Tennis players show a lower coactivation of the elbow antagonist muscles during isokinetic exercises.

Science.gov (United States)

Bazzucchi, Ilenia; Riccio, Maria Elena; Felici, Francesco

2008-10-01

Previous studies have suggested that muscle coactivation could be reduced by a recurrent activity (training, daily activities). If this was correct, skilled athletes should show a specific muscle activation pattern with a low level of coactivation of muscles which are typically involved in their discipline. In particular, the aim of this study was to verify the hypothesis that the amount of antagonist activation of biceps brachii (BB) and triceps brachii (TB) is different between tennis players and non-players individuals during maximal isokinetic contractions. Ten young healthy men and eight male tennis players participated in the study. The surface electromyographic signals (sEMG) were recorded from the BB and TB muscles during three maximal voluntary isometric contractions (MVC) of elbow flexors and extensors and a set of three maximal elbow flexions and extensions at 15 degrees , 30 degrees , 60 degrees , 120 degrees , 180 degrees and 240 degrees /s. Normalized root mean square (RMS) of sEMG was calculated as an index of sEMG amplitude. Antagonist activation (%RMSmax) of TB was significantly lower in tennis players (from 14.0+/-7.9% at MVC to 16.3+/-8.9% at 240 degrees /s) with respect to non-players (from 27.7+/-19.7% at MVC to 38.7+/-17.6% at 240 degrees /s) at all angular velocities. Contrary to non-players, tennis players did not show any difference in antagonist activation between BB and TB muscles. Tennis players, with a constant practice in controlling forces around the elbow joint, learn how to reduce coactivation of muscles involved in the control of this joint. This has been shown by the lower antagonist muscular activity of triceps brachii muscle during isokinetic elbow flexion found in tennis players with respect to non-players.

Relationship between oxygen uptake slow component and surface EMG during heavy exercise in humans: influence of pedal rate.

Science.gov (United States)

Vercruyssen, Fabrice; Missenard, Olivier; Brisswalter, Jeanick

2009-08-01

The aim of this study was to test the hypothesis that extreme pedal rates contributed to the slow component of oxygen uptake (VO(2) SC) in association with changes in surface electromyographic (sEMG) during heavy-cycle exercise. Eight male trained cyclists performed two square-wave transitions at 50 and 110 rpm at a work rate that would elicit a VO(2) corresponding to 50% of the difference between peak VO(2) and the ventilatory threshold. Pulmonary gas exchange was measured breath-by-breath and sEMG was obtained from the vastus lateralis and medialis muscles. Integrated EMG flow (QiEMG) and mean power frequency (MPF) were computed. The relative amplitude of the VO(2) SC was significantly higher during the 110-rpm bout (556+/-186 ml min(-1), Pexercise only during the 110-rpm bout and were associated with the greater amplitude of the VO(2) SC observed for this condition (Pmotor units recruitment pattern, muscle energy turnover and muscle temperature have been suggested to explain the different VO(2) SC to heavy pedal rate bouts.

Design and validation of a morphing myoelectric hand posture controller based on principal component analysis of human grasping.

Science.gov (United States)

Segil, Jacob L; Weir, Richard F ff

2014-03-01

An ideal myoelectric prosthetic hand should have the ability to continuously morph between any posture like an anatomical hand. This paper describes the design and validation of a morphing myoelectric hand controller based on principal component analysis of human grasping. The controller commands continuously morphing hand postures including functional grasps using between two and four surface electromyography (EMG) electrodes pairs. Four unique maps were developed to transform the EMG control signals in the principal component domain. A preliminary validation experiment was performed by 10 nonamputee subjects to determine the map with highest performance. The subjects used the myoelectric controller to morph a virtual hand between functional grasps in a series of randomized trials. The number of joints controlled accurately was evaluated to characterize the performance of each map. Additional metrics were studied including completion rate, time to completion, and path efficiency. The highest performing map controlled over 13 out of 15 joints accurately.

Open-Box Muscle-Computer Interface: Introduction to Human-Computer Interactions in Bioengineering, Physiology, and Neuroscience Courses

Science.gov (United States)

Landa-Jiménez, M. A.; González-Gaspar, P.; Pérez-Estudillo, C.; López-Meraz, M. L.; Morgado-Valle, C.; Beltran-Parrazal, L.

2016-01-01

A Muscle-Computer Interface (muCI) is a human-machine system that uses electromyographic (EMG) signals to communicate with a computer. Surface EMG (sEMG) signals are currently used to command robotic devices, such as robotic arms and hands, and mobile robots, such as wheelchairs. These signals reflect the motor intention of a user before the…

FDG-PET/CT Brain Findings in a Patient With Macrophagic Myofasciitis

OpenAIRE

Van Der Gucht, Axel; Aoun-Sebaiti, Mehdi; Kauv, Paul; Guedj, Eric; Aouizerate, Jessie; Verger, Antoine; Gherardi, Romain K.; Bachoud-Levi, Anne-Catherine; Authier, Fran?ois-J?r?me; Itti, Emmanuel

2015-01-01

Brain Positron Emission Tomography/Computed Tomography with 18F-fluorodeoxyglucose (FDG PET/CT) was performed in a 44-year-old woman with marked cognitive impairment, diffuse myalgias, sensory, memory and visual disorders, and chronic fatigue, presenting with histopathological features of macrophagic myofasciitis (MMF) at deltoid muscle biopsy. Cerebromedullary Magnetic Resonance Imaging (MRI), electromyography, ophthalmic examination, and cerebrospinal fluid analysis were normal. Visual anal...

Influence of the "Slingshot" bench press training aid on bench press kinematics and neuromuscular activity in competitive powerlifters.

Science.gov (United States)

Dugdale, James H; Hunter, Angus; Di Virgilio, Thomas; Macgregor, Lewis J; Hamilton, D Lee

2017-02-13

This study examined the acute effects of the 'Slingshot' on bench-press performance, prime-mover surface electromyographic (sEMG) amplitude, and barbell velocity during maximal and submaximal bench-pressing in competitive male powerlifters. Fifteen male powerlifters (mean ± SD age: 27.05 ± 5.94 years; mass: 94.15kg; 1RM bench-press: 139.7 ± 16.79kg) participated in the study. Bench-press strength, average barbell velocity, and sEMG amplitude of the prime mover muscles (triceps brachii, pectoralis major and anterior deltoid) were measured during two conditions; 'Raw' (without use of any assistance) and 'Slingshot' [using the 'Slingshot' to perform both the weight achieved during 'Raw' 1RM testing (Raw max/SS), and absolute 1RM using the 'Slingshot' (SS)]. The results showed that the 'Slingshot' significantly increased bench press 1RM performance by a mean ± SD of 20.67kg ± 3.4kg. Barbell velocity and stick point analysis indicate that this improvement is likely driven by an increase in peak and pre-stick barbell velocity as triceps RMS was lower throughout all rep max phases with the 'Slingshot'. The 'Slingshot' also caused reductions in RMS, specifically of the triceps at all rep ranges but barbell velocity was better maintained in the last reps of all sets. These data indicate that the 'Slingshot' specifically de-loaded the triceps muscle throughout all rep ranges and provide assistance to maintaining barbell velocity under fatigue during later repetitions of multiple-repetition sets. The 'Slingshot' training aid could therefore be used in de-load phases of bench press training or as an over-reaching and velocity training aid.

Thermal-Signature-Based Sleep Analysis Sensor

Directory of Open Access Journals (Sweden)

Ali Seba

2017-10-01

Full Text Available This paper addresses the development of a new technique in the sleep analysis domain. Sleep is defined as a periodic physiological state during which vigilance is suspended and reactivity to external stimulations diminished. We sleep on average between six and nine hours per night and our sleep is composed of four to six cycles of about 90 min each. Each of these cycles is composed of a succession of several stages of sleep that vary in depth. Analysis of sleep is usually done via polysomnography. This examination consists of recording, among other things, electrical cerebral activity by electroencephalography (EEG, ocular movements by electrooculography (EOG, and chin muscle tone by electromyography (EMG. Recordings are made mostly in a hospital, more specifically in a service for monitoring the pathologies related to sleep. The readings are then interpreted manually by an expert to generate a hypnogram, a curve showing the succession of sleep stages during the night in 30s epochs. The proposed method is based on the follow-up of the thermal signature that makes it possible to classify the activity into three classes: “awakening,” “calm sleep,” and “restless sleep”. The contribution of this non-invasive method is part of the screening of sleep disorders, to be validated by a more complete analysis of the sleep. The measure provided by this new system, based on temperature monitoring (patient and ambient, aims to be integrated into the tele-medicine platform developed within the framework of the Smart-EEG project by the SYEL–SYstèmes ELectroniques team. Analysis of the data collected during the first surveys carried out with this method showed a correlation between thermal signature and activity during sleep. The advantage of this method lies in its simplicity and the possibility of carrying out measurements of activity during sleep and without direct contact with the patient at home or hospitals.

[Diagnosis of temporo-mandibular joint dysfunction caused by occlusion pathology and treatment of such patients].

Science.gov (United States)

Semkin, V A; Rabukhina, N A; Kravchenko, D V

2007-01-01

Patients with temporo-mandibular joint (TMJ) dysfunction need complex treatment that includes prosthetic treatment in intrajoint relation stabilization. In cases of TMJ pathology it is necessary to examine patients and make axiography, function analysis, MPI-analysis, magnetic resonance tomography and zonography of TMJ, electromyography of the masticatory muscles. The authors examined 47 patients with TMJ dysfunction, 43 of them had occlusion pathology. We managed to eliminate the dysfunction symptoms and to receive stable result of the treatment in all the patients.

Cervico-mandibular muscle activity in females with chronic cervical pain

OpenAIRE

T. Lang; R. Parker; T. Burgess

2013-01-01

Pathophysiological mechanisms behind pain in chroniccervical musculoskeletal conditions (MSC) in office workers remainunclear. Chronic cervical pain has established links with temporomandibular(TM) disorders. Yet there is no current published evidence to reportwhether individuals with cervical dysfunction exhibit altered masseterand cervical extensor (CE) muscle activity. Objective: To explore CE andmasseter surface electromyographic (sEMG) activity and teeth clenchinghabits in females with c...

Electrophysiological studies in healthy subjects involving caffeine

OpenAIRE

Carvalho, Mamede de; Marcelino, Erica; Mendonça, Alexandre de

2010-01-01

Copyright ©2012 IOS Press All rights reserved. We review the electrophysiological studies concerning the effects of caffeine on muscle, lower and upper motor neuron excitability and cognition. Several different methods have been used, such as electromyography, recruitment analysis, H-reflex, transcranial magnetic stimulation (TMS), electroencephalography and event-related potentials. The positive effect of caffeine on vigilance, attention, speed of reaction, information processing and arou...

Hip abductors and thigh muscles strength ratios and their relation to electromyography amplitude during split squat and walking lunge exercises

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Petr Stastny

2015-06-01

Full Text Available Background: The hip abductors (HAB, quadriceps (Q and hamstrings (H reciprocal strength ratios are predictors of electromyography (EMG amplitude during load carrying walking at moderate intensity. Therefore, these strength ratios might predict also the EMG during the exercises as walking lunge (WL or split squat (SSq at submaximal intensity. Objective: To determine whether the EMG amplitude of vastus mediali (VM, vastus laterali (VL, biceps femoris (BF and gluteus medius (Gmed is associated with muscle strength ratio during SSqs and WLs. To determine whether the EMG amplitude differs between individuals with HAB/H ratio above and below one and between individuals with H/Q or HAB/Q ratio above and below 0.5 during SSqs and WLs. Methods: 17 resistance-trained men (age 29.6 ± 4.6 years with at least 3 years of strength training performed in cross-sectional design 5 s maximal voluntary isometric contractions (MVIC on an isokinetic dynamometer for knee extension, knee flexion, and hip abduction. The MVIC was used to normalize the EMG signal and estimate the individual strength ratios. Than participants performed WL and SSq for a 5 repetition maximum, to find out muscle activity at submaximal intensity of exercise. Results: The H/Q ratio was associated by Kendall's tau (τ with VM (τ = .33 and BF (τ = -.71 amplitude, HAB/Q ratio was associated with BF (τ = -.43 and Gmed (τ = .38 amplitude, as well as HAB/H was associated with VM (τ = -.41 and Gmed (τ = .74 amplitude. ANOVA results showed significant differences between SSq and WL (F(4, 79 = 10, p < .001, ηp2 = .34 in Gmed amplitude, where WL resulted in higher Gmed amplitude compared to SSq. Other significant differences were found between H/Q groups (F(4, 29 = 3, p = .04, ηp2 = .28 in VM and Gmed amplitude, where group with H/Q > 0.5 showed higher VMO amplitude and lower Gmed amplitude. Furthermore, significant difference was found

Influence of wheel size on muscle activity and tri-axial accelerations during cross-country mountain biking.

Science.gov (United States)

Hurst, Howard Thomas; Sinclair, Jonathan; Atkins, Stephen; Rylands, Lee; Metcalfe, John

2017-07-01

This study aimed to investigate the influence of different mountain bike wheel diameters on muscle activity and whether larger diameter wheels attenuate muscle vibrations during cross-country riding. Nine male competitive mountain bikers (age 34.7 ± 10.7 years; stature 177.7 ± 5.6 cm; body mass 73.2 ± 8.6 kg) participated in the study. Riders performed one lap at race pace on 26, 27.5 and 29 inch wheeled mountain bikes. sEMG and acceleration (RMS) were recorded for the full lap and during ascent and descent phases at the gastrocnemius, vastus lateralis, biceps brachii and triceps brachii. No significant main effects were found by wheel size for each of the four muscle groups for sEMG or acceleration during the full lap and for ascent and descent (P > .05). When data were analysed between muscle groups, significant differences were found between biceps brachii and triceps brachii (P biking. However, more activity was observed in the biceps brachii during 26 inch wheel descending. This is possibly due to an increased need to manoeuvre the front wheel over obstacles.

Muscle activity characterization by laser Doppler Myography

Science.gov (United States)

Scalise, Lorenzo; Casaccia, Sara; Marchionni, Paolo; Ercoli, Ilaria; Primo Tomasini, Enrico

2013-09-01

Electromiography (EMG) is the gold-standard technique used for the evaluation of muscle activity. This technique is used in biomechanics, sport medicine, neurology and rehabilitation therapy and it provides the electrical activity produced by skeletal muscles. Among the parameters measured with EMG, two very important quantities are: signal amplitude and duration of muscle contraction, muscle fatigue and maximum muscle power. Recently, a new measurement procedure, named Laser Doppler Myography (LDMi), for the non contact assessment of muscle activity has been proposed to measure the vibro-mechanical behaviour of the muscle. The aim of this study is to present the LDMi technique and to evaluate its capacity to measure some characteristic features proper of the muscle. In this paper LDMi is compared with standard superficial EMG (sEMG) requiring the application of sensors on the skin of each patient. sEMG and LDMi signals have been simultaneously acquired and processed to test correlations. Three parameters has been analyzed to compare these techniques: Muscle activation timing, signal amplitude and muscle fatigue. LDMi appears to be a reliable and promising measurement technique allowing the measurements without contact with the patient skin.

Muscle activity characterization by laser Doppler Myography

International Nuclear Information System (INIS)

Scalise, Lorenzo; Casaccia, Sara; Marchionni, Paolo; Ercoli, Ilaria; Tomasini, Enrico Primo

2013-01-01

Electromiography (EMG) is the gold-standard technique used for the evaluation of muscle activity. This technique is used in biomechanics, sport medicine, neurology and rehabilitation therapy and it provides the electrical activity produced by skeletal muscles. Among the parameters measured with EMG, two very important quantities are: signal amplitude and duration of muscle contraction, muscle fatigue and maximum muscle power. Recently, a new measurement procedure, named Laser Doppler Myography (LDMi), for the non contact assessment of muscle activity has been proposed to measure the vibro-mechanical behaviour of the muscle. The aim of this study is to present the LDMi technique and to evaluate its capacity to measure some characteristic features proper of the muscle. In this paper LDMi is compared with standard superficial EMG (sEMG) requiring the application of sensors on the skin of each patient. sEMG and LDMi signals have been simultaneously acquired and processed to test correlations. Three parameters has been analyzed to compare these techniques: Muscle activation timing, signal amplitude and muscle fatigue. LDMi appears to be a reliable and promising measurement technique allowing the measurements without contact with the patient skin