Muscle synergy extraction during arm reaching movements at different speeds.

Science.gov (United States)

Sabzevari, Vahid Reza; Jafari, Amir Homayoun; Boostani, Reza

2017-01-01

Muscle synergy is the activation of a group of muscles that contribute to a particular movement. The goal of the present study is to examine the hypothesis that human reaching movements at different speeds share similar muscle synergies and to investigate the kinesiology basis and innervation of muscles. Electromyographic activity from six muscles of the upper limb and shoulder girdle were recorded during three movements at different speeds, i.e. slow, moderate and fast. The effect of window length on the RMS signal of the EMG was analyzed and then EMG envelope signals were decomposed using non-negative matrix factorization. For each of the ten subjects, three synergies were extracted which accounted for at least 99% of the VAF. For each movement, the muscle synergies and muscle activation coefficients of all participants were clustered in to three partitions. Investigation showed a high similarity and dependency of cluster members due to the cosine similarity and mutual information in muscle synergy clustering. For further verification, the EMG envelope signals for all subjects were reconstructed. The results indicated a lower reconstruction error using the center of the muscle synergy clusters in comparison with the average of the activation coefficients, which confirms the current research's hypothesis.

A new teaching model for demonstrating the movement of the extraocular muscles.

Science.gov (United States)

Iwanaga, Joe; Refsland, Jason; Iovino, Lee; Holley, Gary; Laws, Tyler; Oskouian, Rod J; Tubbs, R Shane

2017-09-01

The extraocular muscles consist of the superior, inferior, lateral, and medial rectus muscles and the superior and inferior oblique muscles. This study aimed to create a new teaching model for demonstrating the function of the extraocular muscles. A coronal section of the head was prepared and sutures attached to the levator palpebral superioris muscle and six extraocular muscles. Tension was placed on each muscle from a posterior approach and movement of the eye documented from an anterior view. All movements were clearly seen less than that of the inferior rectus muscle. To our knowledge, this is the first cadaveric teaching model for demonstrating the movements of the extraocular muscles. Clin. Anat. 30:733-735, 2017. © 2017Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

Charge movement and depolarization-contraction coupling in arthropod vs. vertebrate skeletal muscle.

OpenAIRE

Scheuer, T; Gilly, W F

1986-01-01

Voltage-dependent charge movement has been characterized in arthropod skeletal muscle. Charge movement in scorpion (Centuroides sculpturatus) muscle is distinguishable from that in vertebrate skeletal muscle by criteria of kinetics, voltage dependence, and pharmacology. The function of scorpion charge movement is gating of calcium channels in the sarcolemma, and depolarization-contraction coupling relies on calcium influx through these channels.

Patterns of arm muscle activation involved in octopus reaching movements.

Science.gov (United States)

Gutfreund, Y; Flash, T; Fiorito, G; Hochner, B

1998-08-01

The extreme flexibility of the octopus arm allows it to perform many different movements, yet octopuses reach toward a target in a stereotyped manner using a basic invariant motor structure: a bend traveling from the base of the arm toward the tip (Gutfreund et al., 1996a). To study the neuronal control of these movements, arm muscle activation [electromyogram (EMG)] was measured together with the kinematics of reaching movements. The traveling bend is associated with a propagating wave of muscle activation, with maximal muscle activation slightly preceding the traveling bend. Tonic activation was occasionally maintained afterward. Correlation of the EMG signals with the kinematic variables (velocities and accelerations) reveals that a significant part of the kinematic variability can be explained by the level of muscle activation. Furthermore, the EMG level measured during the initial stages of movement predicts the peak velocity attained toward the end of the reaching movement. These results suggest that feed-forward motor commands play an important role in the control of movement velocity and that simple adjustment of the excitation levels at the initial stages of the movement can set the velocity profile of the whole movement. A simple model of octopus arm extension is proposed in which the driving force is set initially and is then decreased in proportion to arm diameter at the bend. The model qualitatively reproduces the typical velocity profiles of octopus reaching movements, suggesting a simple control mechanism for bend propagation in the octopus arm.

The neuromechanical functional contractile properties of the thigh muscles measured using tensiomyography in male athletes and non-athletes

Directory of Open Access Journals (Sweden)

Toskić Lazar

2016-01-01

Full Text Available Involuntary neuromechanical muscle contractile properties, especially of the extensor muscles and knee joint flexors as the largest muscle groups of the caudal part of the body, play an important role in both everyday movement and sport. Based on these data we can obtain important information on the functional properties of muscles. The basic means of evaluation of the functional involuntary neuromechanical muscles contractile properties is the non-invasive tensiomyographic method (TMG. The aim of this study was to determine the differences between the involuntary neuromechanical contractile properties of the thigh muscles measured using the TMG method on a sample of male athletes and non-athletes. The sample of participants was made up of 17 athletes and 10 non-athletes. By applying the multivariate analysis of variance (MANOVA and the t-test, we achieved results which indicate that of the overall 30 variables, a difference was determined among 13 of them. Most of the differences were determined for the extensor muscles of the right knee, especially of the rectus femoris muscle. It was also shown that in addition to the main knee joint extensor muscle (rectus femoris the main knee joint flexor muscle (biceps femoris also takes part in the definition of the difference between athletes and non-athletes. The results have shown that the following variables: contraction time (Tc and delay contraction time (Td are the functional parameters for which the highest difference between athletes and non-athletes were determined (from t = -2.284, p < 0.05 for the vastus lateralis of the right leg to t = -4.018, p < 0.01 for the rectus femoris of the left leg. These results have shown that it is possible to determine the differences in the functional involuntary neuromechanical contractile properties of the thigh muscles among trained and untrained individuals using the tensiomyographic method, but at the same time indicated that these differences were very

Charge movements and transverse tubular ultrastructure in organ cultured skeletal muscle.

Science.gov (United States)

Cullen, M J; Hollingworth, S; Marshall, M W; Robson, E

1990-04-01

A study was made of charge movements and the transverse tubular systems in rat EDL and soleus muscle fibres maintained for up to five days in organ culture. In the cultured EDL muscle the maximum amount of charge moved was about one third of that in innervated muscle. Charge movements in innervated soleus fibres are small, less than 10 nC/microF, and difficult to resolve. They remain small following organ culturing. The ultrastructural study examined the concentration of junctional feet because of their proposed key role in excitation-contraction coupling. The general architecture of the triads and the spacing of the feet in both muscle types was largely unchanged by culturing. In cultured EDL muscles the small changes in feet concentration did not parallel the large fall in charge movement. The results reported here support a previous conclusion that, in mammalian muscle, there is not a simple relation between charge and feet. The stimulation of cultured soleus muscles with a fast twitch pattern of electrical activity produced no observable changes in morphology.

Eugenics and Involuntary Sterilization: 1907-2015.

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Reilly, Philip R

2015-01-01

In England during the late nineteenth century, intellectuals, especially Francis Galton, called for a variety of eugenic policies aimed at ensuring the health of the human species. In the United States, members of the Progressive movement embraced eugenic ideas, especially immigration restriction and sterilization. Indiana enacted the first eugenic sterilization law in 1907, and the US Supreme Court upheld such laws in 1927. State programs targeted institutionalized, mentally disabled women. Beginning in the late 1930s, proponents rationalized involuntary sterilization as protecting vulnerable women from unwanted pregnancy. By World War II, programs in the United States had sterilized approximately 60,000 persons. After the horrific revelations concerning Nazi eugenics (German Hereditary Health Courts approved at least 400,000 sterilization operations in less than a decade), eugenic sterilization programs in the United States declined rapidly. Simplistic eugenic thinking has faded, but coerced sterilization remains widespread, especially in China and India. In many parts of the world, involuntary sterilization is still intermittently used against minority groups.

Trunk muscle activity increases with unstable squat movements.

Science.gov (United States)

Anderson, Kenneth; Behm, David G

2005-02-01

The objective of this study was to determine differences in electromyographic (EMG) activity of the soleus (SOL), vastus lateralis (VL), biceps femoris (BF), abdominal stabilizers (AS), upper lumbar erector spinae (ULES), and lumbo-sacral erector spinae (LSES) muscles while performing squats of varied stability and resistance. Stability was altered by doing the squat movement on a Smith machine, a free squat, and while standing on two balance discs. Fourteen male subjects performed the movements. Activities of the SOL, AS, ULES, and LSES were highest during the unstable squat and lowest with the Smith machine protocol (p squats on unstable surfaces may permit a training adaptation of the trunk muscles responsible for supporting the spinal column (i.e., erector spinae) as well as the muscles most responsible for maintaining posture (i.e., SOL).

[A case of respiratory dyskinesia due to clebopride malate].

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Kawasaki, H; Yamamoto, M; Okayasu, H; Wakayama, Y

1991-08-01

Clebopride malate is therapeutically used for the treatment of peptic ulcer. This drug has potent antidopaminergic activity that causes acute dystonic reaction, parkinsonism and tardive dyskinesia as adverse effects. Here, we have reported an 86-year-old man who developed abnormal involuntary movement of respiratory muscles and lower limb muscles after this drug had been given for four months. This involuntary movement appeared spontaneously at resting state and disappeared during sleep. Surface EMG demonstrated a synchronous grouping discharge in m. orbicularis oris, m. sternocleidomastoideus and m. interstales which synchronized with diaphragmatic movement on cinefluorography. Involuntary movement of the lower limbs was synchronous bilaterally and had little relationship with diaphragmatic movement. This involuntary movement was irregular not only in rhythm but also in duration. According to this irregular nature, we diagnosed this involuntary movement as respiratory dyskinesia with limb dyskinesia that belongs to tardive dyskinesia. After cessation of clebopride malate limb dyskinesia disappeared rapidly and respiratory dyskinesia markedly decreased. We emphasize that respiratory dyskinesia should be differentiated from psychogenic hyperventilation as easily misdiagnosed on initial examination.

Movement amplitude on the Functional Re-adaptive Exercise Device: deep spinal muscle activity and movement control.

Science.gov (United States)

Winnard, A; Debuse, D; Wilkinson, M; Samson, L; Weber, T; Caplan, Nick

2017-08-01

Lumbar multifidus (LM) and transversus abdominis (TrA) show altered motor control, and LM is atrophied, in people with low-back pain (LBP). The Functional Re-adaptive Exercise Device (FRED) involves cyclical lower-limb movement against minimal resistance in an upright posture. It has been shown to recruit LM and TrA automatically, and may have potential as an intervention for non-specific LBP. However, no studies have yet investigated the effects of changes in FRED movement amplitude on the activity of these muscles. This study aimed to assess the effects of different FRED movement amplitudes on LM and TrA muscle thickness and movement variability, to inform an evidence-based exercise prescription. Lumbar multifidus and TrA thickness of eight healthy male volunteers were examined using ultrasound imaging during FRED exercise, normalised to rest at four different movement amplitudes. Movement variability was also measured. Magnitude-based inferences were used to compare each amplitude. Exercise at all amplitudes recruited LM and TrA more than rest, with thickness increases of approximately 5 and 1 mm, respectively. Larger amplitudes also caused increased TrA thickness, LM and TrA muscle thickness variability and movement variability. The data suggests that all amplitudes are useful for recruiting LM and TrA. A progressive training protocol should start in the smallest amplitude, increasing the setting once participants can maintain a consistent movement speed, to continue to challenge the motor control system.

Muscle activation patterns in acceleration-based phases during reach-to-grasp movement.

Science.gov (United States)

Tokuda, Keisuke; Lee, Bumsuk; Shiihara, Yasufumi; Takahashi, Kazuhiro; Wada, Naoki; Shirakura, Kenji; Watanabe, Hideomi

2016-11-01

[Purpose] An earlier study divided reaching activity into characteristic phases based on hand velocity profiles. By synchronizing muscle activities and the acceleration profile, a phasing approach for reaching movement, based on hand acceleration profiles, was attempted in order to elucidate the roles of individual muscle activities in the different phases of the acceleration profile in reaching movements. [Subjects and Methods] Ten healthy volunteer subjects participated in this study. The aim was to electromyographically evaluate muscles around the shoulder, the upper trapezius, the anterior deltoid, the biceps brachii, and the triceps brachii, most of which have been used to evaluate arm motion, as well as the acceleration of the upper limb during simple reaching movement in the reach-to-grasp task. [Results] Analysis showed the kinematic trajectories of the acceleration during a simple biphasic profile of the reaching movement could be divided into four phases: increasing acceleration (IA), decreasing acceleration (DA), increasing deceleration (ID), and decreasing deceleration (DD). Muscles around the shoulder showed different activity patterns, which were closely associated with these acceleration phases. [Conclusion] These results suggest the important role of the four phases, derived from the acceleration trajectory, in the elucidation of the muscular mechanisms which regulate and coordinate the muscles around the shoulder in reaching movements.

Transversus abdominis is part of a global not local muscle synergy during arm movement.

Science.gov (United States)

Morris, S L; Lay, B; Allison, G T

2013-10-01

The trunk muscle transversus abdominis (TrA) is thought to be controlled independently of the global trunk muscles. Methodological issues in the 1990s research such as unilateral electromyography and a limited range of arm movements justify a re-examination of this theory. The hypothesis tested is that TrA bilateral co-contraction is a typical muscle synergy during arm movement. The activity of 6 pairs of trunk and lower limb muscles was recorded using bilateral electromyography during anticipatory postural adjustments (APAs) associated with the arm movements. The integrated APA electromyographical signals were analyzed for muscle synergy using Principle Component Analysis. TrA does not typically bilaterally co-contract during arm movements (1 out of 6 participants did). APA muscle activity of all muscles during asymmetrical arm movements typically reflected a direction specific diagonal pattern incorporating a twisting motion to transfer energy from the ground up. This finding is not consistent with the hypothesis that TrA plays a unique role providing bilateral, feedforward, multidirectional stiffening of the spine. This has significant implications to the theories underlying the role of TrA in back pain and in the training of isolated bilateral co-contraction of TrA in the prophylaxis of back pain. Crown Copyright © 2013. Published by Elsevier B.V. All rights reserved.

Economy, Movement Dynamics, and Muscle Activity of Human Walking at Different Speeds

DEFF Research Database (Denmark)

Raffalt, Peter Christian; Guul, Martin Kjær; Nielsen, A. N.

2017-01-01

The complex behaviour of human walking with respect to movement variability, economy and muscle activity is speed dependent. It is well known that a U-shaped relationship between walking speed and economy exists. However, it is an open question if the movement dynamics of joint angles and centre...... of mass and muscle activation strategy also exhibit a U-shaped relationship with walking speed. We investigated the dynamics of joint angle trajectories and the centre of mass accelerations at five different speeds ranging from 20 to 180% of the predicted preferred speed (based on Froude speed) in twelve...... healthy males. The muscle activation strategy and walking economy were also assessed. The movement dynamics was investigated using a combination of the largest Lyapunov exponent and correlation dimension. We observed an intermediate stage of the movement dynamics of the knee joint angle and the anterior...

Glossary of ALS-Related Medical and Scientific Terms

Science.gov (United States)

... dyskinesia An involuntary movement including athetosis and chorea. dysphagia Difficulty in swallowing. dystonia A slow movement or ... Paralysis of a muscle or group of muscles. Parkinson's Disease The most common form of Parkinson's is ...

Trunk Muscle Activation at the Initiation and Braking of Bilateral Shoulder Flexion Movements of Different Amplitudes.

Directory of Open Access Journals (Sweden)

M Eriksson Crommert

Full Text Available The aim of this study was to investigate if trunk muscle activation patterns during rapid bilateral shoulder flexions are affected by movement amplitude. Eleven healthy males performed shoulder flexion movements starting from a position with arms along sides (0° to either 45°, 90° or 180°. EMG was measured bilaterally from transversus abdominis (TrA, obliquus internus (OI with intra-muscular electrodes, and from rectus abdominis (RA, erector spinae (ES and deltoideus with surface electrodes. 3D kinematics was recorded and inverse dynamics was used to calculate the reactive linear forces and torque about the shoulders and the linear and angular impulses. The sequencing of trunk muscle onsets at the initiation of arm movements was the same across movement amplitudes with ES as the first muscle activated, followed by TrA, RA and OI. All arm movements induced a flexion angular impulse about the shoulders during acceleration that was reversed during deceleration. Increased movement amplitude led to shortened onset latencies of the abdominal muscles and increased level of activation in TrA and ES. The activation magnitude of TrA was similar in acceleration and deceleration where the other muscles were specific to acceleration or deceleration. The findings show that arm movements need to be standardized when used as a method to evaluate trunk muscle activation patterns and that inclusion of the deceleration of the arms in the analysis allow the study of the relationship between trunk muscle activation and direction of perturbing torque during one and the same arm movement.

Experience of action depends on intention, not body movement: an experiment on memory for mens rea.

Science.gov (United States)

Jensen, Mads; Vagnoni, Eleonora; Overgaard, Morten; Haggard, Patrick

2014-03-01

How do we know whether our own actions were voluntary or involuntary? Intentional theories of sense of agency suggest that we consciously perceive the intentions that accompany our actions, but reconstructive theories suggest that we perceive our actions only through the body movements and other effects that they produce. Intentions would then be mere confabulations, and not bona fide experiences. Previous work on voluntary action has focused on immediate experiences of authorship, and few studies have considered memory for voluntary actions. We devised an experiment in which both voluntary action and involuntary movement always occurred at the same time, but could either involve the same hand (congruent condition), or different hands (incongruent condition). When signals from the voluntary and involuntary movements involved different hands, they could therefore potentially interfere in memory. We found that recall of a voluntary action was unaffected by an incongruent involuntary movement. In contrast, recall of an involuntary movement was strongly influenced by an incongruent voluntary action. Our results demonstrate an "intentional capture" of body movement by voluntary actions, in support of intentional theories of agency, but contrary to reconstructive theories. When asked to recall both actions and movements, people's responses are shaped by memory of what they intended to do, rather than by how their body moved. Copyright © 2013 The Authors. Published by Elsevier Ltd.. All rights reserved.

A comparison of muscle activity in concentric and counter movement maximum bench press.

Science.gov (United States)

van den Tillaar, Roland; Ettema, Gertjan

2013-01-01

The purpose of this study was to compare the kinematics and muscle activation patterns of regular free-weight bench press (counter movement) with pure concentric lifts in the ascending phase of a successful one repetition maximum (1-RM) attempt in the bench press. Our aim was to evaluate if diminishing potentiation could be the cause of the sticking region. Since diminishing potentiation cannot occur in pure concentric lifts, the occurrence of a sticking region in this type of muscle actions would support the hypothesis that the sticking region is due to a poor mechanical position. Eleven male participants (age 21.9 ± 1.7 yrs, body mass 80.7 ± 10.9 kg, body height 1.79 ± 0.07 m) conducted 1-RM lifts in counter movement and in pure concentric bench presses in which kinematics and EMG activity were measured. In both conditions, a sticking region occurred. However, the start of the sticking region was different between the two bench presses. In addition, in four of six muscles, the muscle activity was higher in the counter movement bench press compared to the concentric one. Considering the findings of the muscle activity of six muscles during the maximal lifts it was concluded that the diminishing effect of force potentiation, which occurs in the counter movement bench press, in combination with a delayed muscle activation unlikely explains the existence of the sticking region in a 1-RM bench press. Most likely, the sticking region is the result of a poor mechanical force position.

Realization of masticatory movement by 3-dimensional simulation of the temporomandibular joint and the masticatory muscles.

Science.gov (United States)

Park, Jong-Tae; Lee, Jae-Gi; Won, Sung-Yoon; Lee, Sang-Hee; Cha, Jung-Yul; Kim, Hee-Jin

2013-07-01

Masticatory muscles are closely involved in mastication, pronunciation, and swallowing, and it is therefore important to study the specific functions and dynamics of the mandibular and masticatory muscles. However, the shortness of muscle fibers and the diversity of movement directions make it difficult to study and simplify the dynamics of mastication. The purpose of this study was to use 3-dimensional (3D) simulation to observe the functions and movements of each of the masticatory muscles and the mandible while chewing. To simulate the masticatory movement, computed tomographic images were taken from a single Korean volunteer (30-year-old man), and skull image data were reconstructed in 3D (Mimics; Materialise, Leuven, Belgium). The 3D-reconstructed masticatory muscles were then attached to the 3D skull model. The masticatory movements were animated using Maya (Autodesk, San Rafael, CA) based on the mandibular motion path. During unilateral chewing, the mandible was found to move laterally toward the functional side by contracting the contralateral lateral pterygoid and ipsilateral temporalis muscles. During the initial mouth opening, only hinge movement was observed at the temporomandibular joint. During this period, the entire mandible rotated approximately 13 degrees toward the bicondylar horizontal plane. Continued movement of the mandible to full mouth opening occurred simultaneously with sliding and hinge movements, and the mandible rotated approximately 17 degrees toward the center of the mandibular ramus. The described approach can yield data for use in face animation and other simulation systems and for elucidating the functional components related to contraction and relaxation of muscles during mastication.

Plane of vertebral movement eliciting muscle lengthening history in the low back influences the decrease in muscle spindle responsiveness of the cat.

Science.gov (United States)

Ge, Weiqing; Cao, Dong-Yuan; Long, Cynthia R; Pickar, Joel G

2011-12-01

Proprioceptive feedback is thought to play a significant role in controlling both lumbopelvic and intervertebral orientations. In the lumbar spine, a vertebra's positional history along the dorsal-ventral axis has been shown to alter the position, movement, and velocity sensitivity of muscle spindles in the multifidus and longissimus muscles. These effects appear due to muscle history. Because spinal motion segments have up to 6 degrees of freedom for movement, we were interested in whether the axis along which the history is applied differentially affects paraspinal muscle spindles. We tested the null hypothesis that the loading axis, which creates a vertebra's positional history, has no effect on a lumbar muscle spindle's subsequent response to vertebral position or movement. Identical displacements were applied along three orthogonal axes directly at the L(6) spinous process using a feedback motor system under displacement control. Single-unit nerve activity was recorded from 60 muscle spindle afferents in teased filaments from L(6) dorsal rootlets innervating intact longissimus or multifidus muscles of deeply anesthetized cats. Muscle lengthening histories along the caudal-cranial and dorsal-ventral axis, compared with the left-right axis, produced significantly greater reductions in spindle responses to vertebral position and movement. The spinal anatomy suggested that the effect of a lengthening history is greatest when that history had occurred along an axis lying within the anatomical plane of the facet joint. Speculation is made that the interaction between normal spinal mechanics and the inherent thixotropic property of muscle spindles poses a challenge for feedback and feedforward motor control of the lumbar spine.

A comparative study of charge movement in rat and frog skeletal muscle fibres.

Science.gov (United States)

Hollingworth, S; Marshall, M W

1981-12-01

1. The middle of the fibre voltage--clamp technique (Adrian & Marshall, 1977), modified where necessary for electrically short muscle fibres, has been used to measure non-linear charge movements in mammalian fast twitch (rat extensor digitorum longus), mammalian slow twitch (rat soleus) and frog (sartorius) muscles. 2. The maximum amount of charge moved in mammalian fast twitch muscle at 2 degrees C in hypertonic solution, was 3--5 times greater than in slow twitch muscle. The voltage distribution of fast twitch charge was 10--15 mV more positive when compared to slow twitch. 3. In both mammalian muscle types hypertonic Ringer solution negatively shifted the voltage distribution of charge some 6 mV. The steepness of charge moved around mechanical threshold was unaffected by hypertonicity. 4. The amount of charge in frog sartorius fibres at 2 degrees C in hypertonic solution was about half of that in rat fast twitch muscle; the voltage distribution of the frog charge was similar to rat soleus muscle. 5. Warming between 2 and 15 degrees C had no effect on either the amount of steady-state distribution of charge in mammalian or frog muscles. 6. At 2 degrees C, the kinetics of charge movement in fast and slow twitch mammalian muscles were similar and 2--3 times faster than frog muscle at the same temperature. In fast and slow mammalian fibres at 2 degrees C similar times were taken to shift the same fractions of the total amount of charge. The Q10 of charge movement kinetics was between 1.2 and 2.0 in the three muscles studied.

An application of dynamic CT for diagnosis of abnormal external ocular muscle movement

International Nuclear Information System (INIS)

Tomita, Kazumi; Ogura, Yuuko; Takeshita, Gen; Koga, Sukehiko; Katada, Kazuhiro; Anno, Hirofumi.

1993-01-01

To evaluate the movements of retrobulbar structures radiologically, we have developed a new technique called 'external ocular muscle movement CT' (EOM CT), in which dynamic CT scanning is performed while the patient performs controlled eye movements. This new technique was applied in one volunteer and 72 patients with external ophthalmoplegia due to orbital mass lesion, hyperthyroid ophthalmopathy, blowout fracture, and other retrobulbar lesions. EOM CT permits the assessment of extraocular muscle contraction in cases of blowout fracture, the evaluation of muscular contraction in hypertrophy of the extraocular muscles, and the diagnosis of adhesions between the extraocular muscles and intraorbital masses. Radiation dose to the lens from EOM CT was measured using a phantom and TLD, and was compared with that of conventional CT scanning with a 5 mm slice thickness. The dose to the lens from EOM CT was three times higher than that for conventional CT in axial scanning, but in the coronal section of the retrobulbar region, the dose to the lens from EOM CT decreases to one twelfth of that of conventional CT. EOM CT promises to be a powerful modality for functional evaluation of the extraocular muscles and other retrobulbar structures. (author)

Ionic currents and charge movements in organ-cultured rat skeletal muscle.

Science.gov (United States)

Hollingworth, S; Marshall, M W; Robson, E

1984-12-01

The middle of the fibre voltage-clamp technique was used to measure ionic currents and non-linear charge movements in intact, organ-cultured (in vitro denervated) mammalian fast-twitch (rat extensor digitorum longus) muscle fibres. Muscle fibres organ cultured for 4 days can be used as electrophysiological and morphological models for muscles in vivo denervated for the same length of time. Sodium currents in organ-cultured muscle fibres are similar to innervated fibres except that in the temperature range 0-20 degrees C (a) in the steady state, the voltage distribution of inactivation in cultured fibres is shifted negatively some 20 mV; (b) at the same temperature and membrane potential, the time constant of inactivation in cultured fibres is about twice that of innervated fibres. Potassium currents in innervated and cultured fibres at 15 degrees C can be fitted with the Hodgkin-Huxley n variable raised to the second power. Despite the large range we would estimate that the maximum value of the steady-state potassium conductance of cultured fibres is about one-half that of innervated fibres. The estimated maximum amount of charge moved in cultured fibre is about one-third that in innervated fibres. Compared to innervated fibres, culturing doubles the kinetics of the decay phase of charge movement. The possibility of a negative shift of the voltage distribution of charge movements in cultured fibres is discussed.

Current concerns in involuntary and voluntary autobiographical memories

DEFF Research Database (Denmark)

Johannessen, Kim Berg; Berntsen, Dorthe

2010-01-01

Involuntary autobiographical memories are conscious memories of personal events that come to mind with no preceding attempts at retrieval. It is often assumed that such memories are closely related to current concerns - i.e., uncompleted personal goals. Here we examined involuntary versus volunta...... concern related involuntary and voluntary memories. The findings support the view that involuntary and voluntary remembering is subject to similar motivational constraints.......Involuntary autobiographical memories are conscious memories of personal events that come to mind with no preceding attempts at retrieval. It is often assumed that such memories are closely related to current concerns - i.e., uncompleted personal goals. Here we examined involuntary versus voluntary...... (deliberately retrieved) autobiographical memories in relation to earlier registered current concerns measured by the Personal Concern Inventory (PCI; Cox & Klinger, 2000). We found no differences between involuntary and voluntary memories with regard to frequency or characteristics of current concern related...

Creutzfeldt-Jakob disease versus anti-LGI1 limbic encephalitis in a patient with progressive cognitive dysfunction, psychiatric symptoms, involuntary facio-brachio-crural movement, and an abnormal electroencephalogram: a case report

Directory of Open Access Journals (Sweden)

Sun L

2015-06-01

Full Text Available Li Sun, Jie Cao, Chang Liu, Yudan LvDepartment of Neurology, The First Hospital of JiLin University, ChangChun, People’s Republic of ChinaAbstract: Diagnosis of Creutzfeldt-Jakob disease (CJD is often challenging in elderly individuals, not only because of its variable clinical features but also because of nonspecific changes on the electroencephalogram (EEG in the early stages of the disease. Here we report on a patient who presented with progressive cognitive dysfunction, psychiatric symptoms, involuntary facio-brachio-crural movement, and an abnormal EEG. We provide a detailed analysis and differential diagnosis between anti-leucine-rich glioma inactivated 1 (LGI1 limbic encephalitis versus CJD, in the hope of providing a new understanding of CJD. A 65-year-old Chinese man presented with slowly progressive cognitive decline with psychiatric symptoms. On admission, he presented with facial grimacing and brief left upper limb dystonic posturing lasting 1–2 seconds, with hyponatremia that was difficult to rectify. Neurological examination showed increased muscle tension in the left limb but without pathological reflexes. His early EEG showed focal periodic wave complexes. Diffusion-weighted magnetic resonance imaging showed a suspected “lace sign” in the occipital cortex. His cerebrospinal fluid was negative for LGI1 antibodies and positive for 14-3-3 brain protein. Therefore, we made a presumptive diagnosis of CJD. At the following visit, a second EEG showed paroxysmal sharp wave complexes, but the patient had a poor prognosis. Atypical facio-brachio-crural movement and nonspecific EEG changes may occasionally be found in patients with CJD or anti-LGI1 encephalitis. Clinicians should not be dissuaded from a diagnosis of CJD where the EEG does not show paroxysmal sharp wave complexes in the early stages but abnormal facio-brachio-crural movement is present.Keywords: abnormal facio-brachio-crural movement, hyponatremia, Creutzfeldt

Experience of action depends on intention, not body movement

DEFF Research Database (Denmark)

Jensen, Mads; Vagnoni, Eleonora; Overgaard, Morten

2014-01-01

in memory. We found that recall of a voluntary action was unaffected by an incongruent involuntary movement. In contrast, recall of an involuntary movement was strongly influenced by an incongruent voluntary action. Our results demonstrate an “intentional capture” of body movement by voluntary actions......, in support of intentional theories of agency, but contrary to reconstructive theories. When asked to recall both actions and movements, people's responses are shaped by memory of what they intended to do, rather than by how their body moved....... effects that they produce. Intentions would then be mere confabulations, and not bona fide experiences. Previous work on voluntary action has focused on immediate experiences of authorship, and few studies have considered memory for voluntary actions. We devised an experiment in which both voluntary...

Correlation between dopamine receptor D2 expression and presence of abnormal involuntary movements in Wistar rats with hemiparkinsonism and dyskinesia.

Science.gov (United States)

Caro Aponte, P A; Otálora, C A; Guzmán, J C; Turner, L F; Alcázar, J P; Mayorga, E L

2018-03-07

Parkinson's disease (PD) is characterised by motor alterations, which are commonly treated with L-DOPA. However, long-term L-DOPA use may cause dyskinesia. Although the pathogenic mechanism of L-DOPA-induced dyskinesia is unclear, the condition has been associated with alterations in dopamine receptors, among which D2 receptors (D2R) have received little attention. This study aims to: (i)develop and standardise an experimental model of L-DOPA-induced dyskinesia in rats with hemiparkinsonism; and (ii)evaluate the correlation between D2R expression and presence of abnormal involuntary movements (AIM). We allocated 21 male Wistar rats into 3 groups: intact controls, lesioned rats (with neurotoxin 6-OHDA), and dyskinetic rats (injected with L-DOPA for 19 days). Sensorimotor impairment was assessed with behavioural tests. Dyskinetic rats gradually developed AIMs during the treatment period; front leg AIMs were more severe and locomotor AIMs less severe (Pde Neurología. Publicado por Elsevier España, S.L.U. All rights reserved.

Fatigue-Induced Changes in Movement Pattern and Muscle Activity During Ballet Releve on Demi-Pointe.

Science.gov (United States)

Lin, Cheng-Feng; Lee, Wan-Chin; Chen, Yi-An; Hsue, Bih-Jen

2016-08-01

Fatigue in ballet dancers may lead to injury, particularly in the lower extremities. However, few studies have investigated the effects of fatigue on ballet dancers' performance and movement patterns. Thus, the current study examines the effect of fatigue on the balance, movement pattern, and muscle activities of the lower extremities in ballet dancers. Twenty healthy, female ballet dancers performed releve on demi-pointe before and after fatigue. The trajectory of the whole body movement and the muscle activities of the major lower extremity muscles were recorded continuously during task performance. The results show that fatigue increases the medial-lateral center of mass (COM) displacement and hip and trunk motion, but decreases the COM velocity and ankle motion. Moreover, fatigue reduces the activities of the hamstrings and tibialis anterior, but increases that of the soleus. Finally, greater proximal hip and trunk motions are applied to compensate for the effects of fatigue, leading to a greater COM movement. Overall, the present findings show that fatigue results in impaired movement control and may therefore increase the risk of dance injury.

Involuntary Neuromuscular Coupling between the Thumb and Finger of Stroke Survivors during Dynamic Movement.

Science.gov (United States)

Jones, Christopher L; Kamper, Derek G

2018-01-01

Finger-thumb coordination is crucial to manual dexterity but remains incompletely understood, particularly following neurological injury such as stroke. While being controlled independently, the index finger and thumb especially must work in concert to perform a variety of tasks requiring lateral or palmar pinch. The impact of stroke on this functionally critical sensorimotor control during dynamic tasks has been largely unexplored. In this study, we explored finger-thumb coupling during close-open pinching motions in stroke survivors with chronic hemiparesis. Two types of perturbations were applied randomly to the index with a novel Cable-Actuated Finger Exoskeleton: a sudden joint acceleration stretching muscle groups of the index finger and a sudden increase in impedance in selected index finger joint(s). Electromyographic signals for specific thumb and index finger muscles, thumb tip trajectory, and index finger joint angles were recorded during each trial. Joint angle perturbations invoked reflex responses in the flexor digitorum superficialis (FDS), first dorsal interossei (FDI), and extensor digitorum communis muscles of the index finger and heteronymous reflex responses in flexor pollicis brevis of the thumb ( p  index finger joint impedance was suddenly increased, thumb tip movement was substantially increased, from 2 to 10 cm ( p  index finger impacting thumb activity. The degree of coupling modulated with the phase of motion. These findings reveal a potential mechanism for direct intervention to improve poststroke hand mobility and provide insight on prospective neurologically oriented therapies.

32 CFR 644.102 - Examples of involuntary acquisitions.

Science.gov (United States)

2010-07-01

... 32 National Defense 4 2010-07-01 2010-07-01 true Examples of involuntary acquisitions. 644.102... PROPERTY REAL ESTATE HANDBOOK Acquisition Involuntary Acquisition by the United States § 644.102 Examples... property, as prescribed by Pub. L. 91-646. Examples of involuntary acquisition are: (a) Damage to real...

Involuntary inter-prison transfer of prisoners in Denmark

DEFF Research Database (Denmark)

Kjær Minke, Linda

Involuntary inter prison transfer are for most prisoners very intrusive. In Denmark official record shows in average 669 incidences of involuntary inter prison transfers for disciplinary reasons in the period 2006-2013. Involuntary transfers because of prison capacity are not registered statistic....... A rule in Danish administrative law states that prisoners can be involuntary transferred from one prison to the other without prior notice, statement of reasons or hearing. In a legal protective perspective it is problematic that prisoners can be transferred without apparent reasons....

29 CFR 785.28 - Involuntary attendance.

Science.gov (United States)

2010-07-01

... 29 Labor 3 2010-07-01 2010-07-01 false Involuntary attendance. 785.28 Section 785.28 Labor... POLICY OR INTERPRETATION NOT DIRECTLY RELATED TO REGULATIONS HOURS WORKED Application of Principles Lectures, Meetings and Training Programs § 785.28 Involuntary attendance. Attendance is not voluntary, of...

Investigating reduction of dimensionality during single-joint elbow movements: a case study on muscle synergies

Directory of Open Access Journals (Sweden)

Enrico eChiovetto

2013-02-01

Full Text Available A long standing hypothesis in the neuroscience community is that the CNS generates the muscle activities to accomplish movements by combining a relatively small number of stereotyped patterns of muscle activations, often referred to as muscle synergies. Different definitions of synergies have been given in the literature. The most well-known are those of synchronous, time-varying and temporal muscle synergies. Each one of them is based on a different mathematical model used to factor some EMG array recordings collected during the execution of variety of motor tasks into a well-determined spatial, temporal or spatio-temporal organization. This plurality of definitions and their separate application to complex tasks have so far complicated the comparison and interpretation of the results obtained across studies, and it has always remained unclear why and when one synergistic decomposition should be preferred to another one. By using well-understood motor tasks such as elbow flexions and extensions, we aimed in this study to clarify better what are the motor features characterized by each kind of decomposition and to assess whether, when and why one of them should be preferred to the others. We found that three temporal synergies, each one of them accounting for specific temporal phases of the movements could account for the majority of the data variation. Similar performances could be achieved by two synchronous synergies, encoding the agonist-antagonist nature of the two muscles considered, and by two time-varying muscle synergies, encoding each one a task-related feature of the elbow movements, specifically their direction. Our findings support the notion that each EMG decomposition provides a set of well-interpretable muscle synergies, identifying reduction of dimensionality in different aspects of the movements. Taken together, our findings suggest that all decompositions are not equivalent and may imply different neurophysiological substrates

Relationship between frequency of involuntary autobiographical memories and cognitive failure.

Science.gov (United States)

Kamiya, Shunji

2014-01-01

Involuntary autobiographical memories are memories of personal experiences that pop into mind without a conscious attempt at their retrieval. This study investigated individual differences in the number of involuntary autobiographical memories, and explored the relationship between the frequency of occurrence in involuntary autobiographical memory and cognitive failures in everyday memory, as indexed by metamemory questionnaires. A total of 24 undergraduate students reported involuntary autobiographical memories in controlled field interviews, and completed the Everyday Memory Questionnaire and the Cognitive Failures Questionnaire. The results showed that, despite controlled conditions, considerable individual differences were observed in the number of involuntary autobiographical memories reported while walking along a prescribed route on the campus, and that reported memories were predominantly serving self function. In addition, the number of involuntary autobiographical memories was positively related to cognitive failures in everyday memory: participants who acknowledged more problems in everyday memory had a higher frequency of involuntary memories. The implications of these results are discussed in terms of the complementary function of involuntary autobiographical memory in everyday life.

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

Science.gov (United States)

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.

Post-stroke Movement Disorders: Clinical Manifestations and Pharmacological Management

OpenAIRE

Siniscalchi, Antonio; Gallelli, Luca; Labate, Angelo; Malferrari, Giovanni; Palleria, Caterina; Sarro, Giovambattista De

2012-01-01

Involuntary abnormal movements have been reported after ischaemic and haemorrhagic stroke. Post stroke movement disorders can appear as acute or delayed sequel. At the moment, for many of these disorders the knowledge of pharmacological treatment is still inadequate. Dopaminergic and GABAergic systems may be mainly involved in post-stroke movement disorders. This article provides a review on drugs commonly used in post-stroke movement disorders, given that some post-stroke movement disorders ...

Is muscle coordination affected by loading condition in ballistic movements?

Science.gov (United States)

Giroux, Caroline; Guilhem, Gaël; Couturier, Antoine; Chollet, Didier; Rabita, Giuseppe

2015-02-01

This study aimed to investigate the effect of loading on lower limb muscle coordination involved during ballistic squat jumps. Twenty athletes performed ballistic squat jumps on a force platform. Vertical force, velocity, power and electromyographic (EMG) activity of lower limb muscles were recorded during the push-off phase and compared between seven loading conditions (0-60% of the concentric-only maximal repetition). The increase in external load increased vertical force (from 1962 N to 2559 N; P=0.0001), while movement velocity decreased (from 2.5 to 1.6 ms(-1); P=0.0001). EMG activity of tibialis anterior first peaked at 5% of the push-off phase, followed by gluteus maximus (35%), vastus lateralis and soleus (45%), rectus femoris (55%), gastrocnemius lateralis (65%) and semitendinosus (75%). This sequence of activation (P=0.67) and the amplitude of muscle activity (P=0.41) of each muscle were not affected by loading condition. However, a main effect of muscle was observed on these parameters (peak value: Ppush-off phase. Our findings suggest that muscle coordination is not influenced by external load during a ballistic squat jump. Copyright © 2014 Elsevier Ltd. All rights reserved.

Association between maximal hamstring strength and hamstring muscle pre-activity during a movement associated with non-contact ACL injury

DEFF Research Database (Denmark)

Skov Husted, Rasmus; Bencke, Jesper; Thorborg, Kristian

2014-01-01

Introduction Reduced hamstring pre-activity during side-cutting may predispose for non-contact ACL injury. During the last decade resistance training of the lower limb muscles has become an integral part of ACL injury prevention in e.g. soccer and handball. However, it is not known whether a strong...... hamstring (ACL-agonist) musculature is associated with a high level of hamstring muscle pre-activity during high risk movements such as side-cutting. The purpose of this study was to examine the relationship between hamstring muscle pre-activity recorded during a standardized sidecutting maneuver...... translate into high levels of muscle pre-activity during movements like the sidecutting maneuver. Thus, other exercise modalities (i.e. neuromuscular training) are needed to optimize hamstring muscle pre-activity during movements associated with non-contact ACL injury....

The effects of tetracaine on charge movement in fast twitch rat skeletal muscle fibres.

Science.gov (United States)

Hollingworth, S; Marshall, M W; Robson, E

1990-02-01

1. The effects of tetracaine, a local anaesthetic that inhibits muscle contraction, on membrane potential and intramembrane charge movements were investigated in fast twitch rat muscle fibres (extensor digitorum longus). 2. The resting membrane potentials of surface fibres from muscles bathed in isotonic Ringer solution containing 2 mM-tetracaine were well maintained, but higher concentrations of tetracaine caused a time-dependent fall of potential. Muscle fibres bathed in hypertonic solutions containing 2 mM-tetracaine were rapidly depolarized. In both isotonic and hypertonic solutions, the depolarizing effect of tetracaine could not be reversed. 3. Charge movement measurements were made using the middle-of-the-fibre voltage clamp technique. The voltage dependence of charge movements measured in cold isotonic solutions was well fitted by a Boltzmann distribution (Q(V) = Qmax/(1 + exp(-(V-V)/k] where Qmax = 37.3 +/- 2.8 nC muF-1, V = -17.9 +/- 1.2 mV and k = 12.6 +/- 0.8 mV (n = 6, 2 degrees C; means +/- S.E. of means). Similar values were obtained when 2 mM-tetracaine was added to the isotonic bathing fluid (Qmax = 40.6 +/- 2.3 nC microF-1, V = -14.1 +/- 1.3 mV, k = 15.3 +/- 0.8 mV; n = 8, 2 degrees C). 4. Charge movements measured around mechanical threshold in muscle fibres bathed in hypertonic solutions were reduced when 2 mM-tetracaine was added to the bathing fluid. The tetracaine-sensitive component of charge was well fitted with an unconstrained Boltzmann distribution which gave: Qmax = 7.5 nC microF-1, V = -46.5 mV, k = 5.5 mV. The e-fold rise of the foot of the curve was 9.3 mV.

Special involuntary conversion situations involving timberland

Science.gov (United States)

William C. Siegal

2001-01-01

If standing timber is destroyed or stolen, or if forest land is condemned for public use, the owner may be entitled to take a deduction on his or her income tax return. These types of losses are called involuntary conversions. In previous National Woodlands articles I've discussed in detail casualty losses, which represent the major type of timber involuntary...

Simulating the activation, contraction and movement of skeletal muscles using the bidomain model.

Science.gov (United States)

Lopez Rincon, A; Cantu, C; Soto, R; Shimoda, S

2016-08-01

A simulation of the muscle activation, contraction and movement is here presented. This system was developed based on the Bidomain mathematical model of the electrical propagation in muscles. This study shows an electrical stimuli input to a muscle and how this behave. The comparison between healthy subject and patient with muscle activation impairment is depicted, depending on whether the signal reaches a threshold. A 3D model of a bicep muscle and a forearm bone connected was constructed using OpenGL. This platform could be used for development of controllers for biomechatronic systems in future works. This kind of bioinspired model could be used for a better understanding of the neuromotor system.

General Practitioners and Involuntary Admission

DEFF Research Database (Denmark)

Jepsen, Britta; Lomborg, Kirsten; Engberg, Marianne

2010-01-01

Background: In many countries, medical authorities are responsible for involuntary admissions of mentally ill patients. Nonetheless, very little is known about GPs' experiences with involuntary admission. Aim: The aim of the present study was to explore GP's experiences from participating....... They felt that sectioning patients was unpleasant, and felt nervous, but experienced relief and professional satisfaction if things went well. The GPs experienced the doctor-patient relationship to be at risk, but also reported that it could be improved. GPs felt that they were not taken seriously...

Evaluation of the effects of the Arm Light Exoskeleton on movement execution and muscle activities: a pilot study on healthy subjects.

Science.gov (United States)

Pirondini, Elvira; Coscia, Martina; Marcheschi, Simone; Roas, Gianluca; Salsedo, Fabio; Frisoli, Antonio; Bergamasco, Massimo; Micera, Silvestro

2016-01-23

Exoskeletons for lower and upper extremities have been introduced in neurorehabilitation because they can guide the patient's limb following its anatomy, covering many degrees of freedom and most of its natural workspace, and allowing the control of the articular joints. The aims of this study were to evaluate the possible use of a novel exoskeleton, the Arm Light Exoskeleton (ALEx), for robot-aided neurorehabilitation and to investigate the effects of some rehabilitative strategies adopted in robot-assisted training. We studied movement execution and muscle activities of 16 upper limb muscles in six healthy subjects, focusing on end-effector and joint kinematics, muscle synergies, and spinal maps. The subjects performed three dimensional point-to-point reaching movements, without and with the exoskeleton in different assistive modalities and control strategies. The results showed that ALEx supported the upper limb in all modalities and control strategies: it reduced the muscular activity of the shoulder's abductors and it increased the activity of the elbow flexors. The different assistive modalities favored kinematics and muscle coordination similar to natural movements, but the muscle activity during the movements assisted by the exoskeleton was reduced with respect to the movements actively performed by the subjects. Moreover, natural trajectories recorded from the movements actively performed by the subjects seemed to promote an activity of muscles and spinal circuitries more similar to the natural one. The preliminary analysis on healthy subjects supported the use of ALEx for post-stroke upper limb robotic assisted rehabilitation, and it provided clues on the effects of different rehabilitative strategies on movement and muscle coordination.

Post-stroke Movement Disorders: Clinical Manifestations and Pharmacological Management.

Science.gov (United States)

Siniscalchi, Antonio; Gallelli, Luca; Labate, Angelo; Malferrari, Giovanni; Palleria, Caterina; Sarro, Giovambattista De

2012-09-01

Involuntary abnormal movements have been reported after ischaemic and haemorrhagic stroke. Post stroke movement disorders can appear as acute or delayed sequel. At the moment, for many of these disorders the knowledge of pharmacological treatment is still inadequate. Dopaminergic and GABAergic systems may be mainly involved in post-stroke movement disorders. This article provides a review on drugs commonly used in post-stroke movement disorders, given that some post-stroke movement disorders have shown a partial benefit with pharmacological approach.

Impaired sense of agency in functional movement disorders: An fMRI study.

Directory of Open Access Journals (Sweden)

Fatta B Nahab

Full Text Available The sense of agency (SA is an established framework that refers to our ability to exert and perceive control over our own actions. Having an intact SA provides the basis for the human perception of voluntariness, while impairments in SA are hypothesized to lead to the perception of movements being involuntary that may be seen many neurological or psychiatric disorders. Individuals with functional movement disorders (FMD experience a lack of control over their movements, yet these movements appear voluntary by physiology. We used fMRI to explore whether alterations in SA in an FMD population could explain why these patients feel their movements are involuntary. We compared the FMD group to a control group that was previously collected using an ecologically valid, virtual-reality movement paradigm that could modulate SA. We found selective dysfunction of the SA neural network, whereby the dorsolateral prefrontal cortex and pre-supplementary motor area on the right did not respond differentially to the loss of movement control. These findings provide some of the strongest evidence to date for a physiological basis underlying these disabling disorders.

The influence of altered working-side occlusal guidance on masticatory muscles and related jaw movement.

Science.gov (United States)

Belser, U C; Hannam, A G

1985-03-01

The effect of four different occlusal situations (group function, canine guidance, working side occlusal interference, and hyperbalancing occlusal interference) on EMG activity in jaw elevator muscles and related mandibular movement was investigated on 12 subjects. With a computer-based system, EMG and displacement signals were collected simultaneously during specific functional (unilateral chewing) and parafunctional tasks (mandibular gliding movements and various tooth clenching efforts) and analyzed quantitatively. When a naturally acquired group function was temporarily and artificially changed into a dominant canine guidance, a significant general reduction of elevator muscle activity was observed when subjects exerted full isometric tooth-clenching efforts in a lateral mandibular position. The original muscular coordination pattern (relative contraction from muscle to muscle) remained unaltered during this test. With respect to unilateral chewing, no significant alterations in the activity or coordination of the muscles occurred when an artificial canine guidance was introduced. Introduction of a hyperbalancing occlusal contact caused significant alterations in muscle activity and coordination during maximal tooth clenching in a lateral mandibular position. A marked shift of temporal muscle EMG activity toward the side of the interference and unchanged bilateral activity of the two masseter muscles were observed. The results suggest that canine-protected occlusions do not significantly alter muscle activity during mastication but significantly reduce muscle activity during parafunctional clenching. They also suggest that non-working side contacts dramatically alter the distribution of muscle activity during parafunctional clenching, and that this redistribution may affect the nature of reaction forces at the temporomandibular joints.

Design of a Magnetic Resonance-Safe Haptic Wrist Manipulator for Movement Disorder Diagnostics

NARCIS (Netherlands)

Bode, Dyon; Mugge, Winfred; Schouten, Alfred C.; van Rootselaar, Anne-Fleur; Bour, Lo J.; van der Helm, Frans C. T.; Lammertse, Piet

2017-01-01

Tremor, characterized by involuntary and rhythmical movements, is the most common movement disorder. Tremor can have peripheral and central oscillatory components which properly assessed may improve diagnostics. A magnetic resonance (MR)-safe haptic wrist manipulator enables simultaneous measurement

Out of One's Mind: A Study of Involuntary Semantic Memories

Science.gov (United States)

Kvavilashvili, Lia; Mandler, George

2004-01-01

The study of memories that pop into one's mind without any conscious attempt to retrieve them began only recently. While there are some studies on involuntary autobiographical memories (e.g., Berntsen, 1996, 1998) research on involuntary semantic memories or mind-popping is virtually non-existent. The latter is defined as an involuntary conscious…

Altered striatal and pallidal connectivity in cervical dystonia

NARCIS (Netherlands)

Delnooz, C.C.S.; Pasman, J.W; Beckmann, C.F.; Warrenburg, B.P.C. van de

2015-01-01

Cervical dystonia is a neurological movement disorder characterized by involuntary, abnormal movements of the head and neck. Injecting the overactive muscles with botulinum toxin is the gold standard treatment, supported by good evidence (Delnooz and van de Warrenburg in Ther Adv Neurol Disord

Involuntary Absence from an Organizational Point of View

NARCIS (Netherlands)

J.M.P. de Kok (Jan)

1997-01-01

textabstractInvoluntary absence is often seen as an exogenous factor, but firms can take actions to reduce it. In this paper the notion that firms, especially SMEs, are faced with a single decision whether or not to undertake these actions is questioned. A firm model on involuntary absence measures

Neural mechanisms of voluntary and involuntary recall: a PET study.

Science.gov (United States)

Hall, Nicoline Marie; Gjedde, Albert; Kupers, Ron

2008-01-25

Neuropsychological and neuroimaging studies on episodic memory retrieval have primarily focused on volitional memory tasks. However, some conscious memories arise involuntarily, i.e. without a strategic retrieval attempt, yet little is known about the neural network underlying involuntary episodic memory. The aim of this study was to determine whether voluntary and involuntary recall are mediated by separate cortical networks. We used positron emission tomography (PET) to measure changes in regional cerebral blood flow (rCBF) in 12 healthy subjects during voluntary and involuntary cued recall of pictures and a control condition with no episodic memory requirements. Involuntary recall was elicited by using an incidental memory task. Compared to the control condition, voluntary and involuntary recall were both associated with significant regional cerebral blood flow (rCBF) increases in posterior cingulate gyrus (PCG; BA 23), left precuneus (BA 7), and right parahippocampal gyrus (BA 35/36). In addition, rCBF in right dorsolateral prefrontal cortex (PFC; BA 8/9) and left precuneus (BA 7) was significantly larger during voluntary compared to involuntary recall, while rCBF was enhanced in left dorsolateral PFC (BA 9) during involuntary recall. The findings corroborate an association of the right PFC with a strategic component of episodic memory retrieval. Moreover, they show for the first time that it is possible to activate the medial temporal lobe, the PCG, and the precuneus, regions normally associated with retrieval success, without this strategic element. The relatively higher activity in precuneus during voluntary compared to involuntary recall suggests that activity in this region co-varies not only with retrieval success but also with retrieval intentionality.

Dystonia and paroxysmal dyskinesias: under-recognized movement disorders in domestic animals? A comparison with human dystonia/paroxysmal dyskinesias.

Directory of Open Access Journals (Sweden)

Angelika eRichter

2015-11-01

Full Text Available Dystonia is defined as a neurological syndrome characterized by involuntary sustained or intermittent muscle contractions causing twisting, often repetitive movements and postures. Paroxysmal dyskinesias are episodic movement disorders encompassing dystonia, chorea, athetosis and ballism in conscious individuals. Several decades of research have enhanced the understanding of the etiology of human dystonia and dyskinesias that are associated with dystonia, but the pathophysiology remains largely unknown. The spontaneous occurrence of hereditary dystonia and paroxysmal dyskinesia is well documented in rodents used as animal models in basic dystonia research. Several hyperkinetic movement disorders, described in dogs, horses and cattle, show similarities to these human movement disorders. Although dystonia is regarded as the third most common movement disorder in humans, it is often misdiagnosed because of the heterogeneity of etiology and clinical presentation. Since these conditions are poorly known in veterinary practice, their prevalence may be underestimated in veterinary medicine. In order to attract attention to these movement disorders, i.e. dystonia and paroxysmal dyskinesias associated with dystonia, and to enhance interest in translational research, this review gives a brief overview of the current literature regarding dystonia/paroxysmal dyskinesia in humans, and summarizes similar hereditary movement disorders reported in domestic animals.

The incidence of spontaneous movements (myoclonus) in dogs undergoing total intravenous anaesthesia with propofol.

Science.gov (United States)

Cattai, Andrea; Rabozzi, Roberto; Natale, Valentina; Franci, Paolo

2015-01-01

To evaluate the incidence of myoclonus (involuntary movements during anaesthesia, unrelated to inadequate hypnosis or analgesia, and of sufficient severity to require treatment) in dogs anaesthetized with a TIVA of propofol with or without the use of fentanyl. Retrospective clinical study. Dogs, undergoing general anaesthesia for clinical procedures between January 2012 and January 2013 and subject to TIVA with propofol. A retrospective analysis reviewed the medical and anaesthetic records. Animals with existing or potential neurological or neuromuscular pathology in the anamnesis or upon clinical examination and cases with incomplete clinical records were excluded. Myoclonus was considered as involuntary muscle contractions which did not cease following a bolus administration of propofol or fentanyl and, due to their intensity and duration, made continuation of the procedure impracticable without other drug administration. Tremors, paddling or muscle spasms, explicable as insufficient hypnosis or analgesia, and transient excitatory phenomena only present during the awakening phase, were not considered as myoclonus. Out of a total of 492 dogs undergoing anaesthesia, six mixed breed dogs (1.2%), one male and five females, American Society of Anaesthesiologists (ASA) physical status I, median (range) weight 20.5 (7-37) kg and age 1.5 (1-5) years had myoclonus according to the aforementioned definition. In all subjects, myoclonus appeared within 20 minutes after induction of anaesthesia, and mainly involved the limb muscles. All subjects appeared to be in an adequate plane of anaesthesia before and during myoclonus. This study shows that 1.2% of dogs, undergoing TIVA with propofol with or without fentanyl administration, developed myoclonus, which required to be, and were treated successfully pharmacologically. The cause of this phenomenon is yet to be determined. © 2014 Association of Veterinary Anaesthetists and the American College of Veterinary Anesthesia and

Muscle Activation During ACL Injury Risk Movements in Young Female Athletes: A Narrative Review

Directory of Open Access Journals (Sweden)

Jesper Bencke

2018-05-01

Full Text Available Young, adolescent female athletes are at particular high risk of sustaining a non-contact anterior cruciate ligament (ACL injury during sport. Through the last decades much attention has been directed toward various anatomical and biomechanical risk factors for non-contact ACL injury, and important information have been retrieved about the influence of external loading factors on ACL injury risk during given sports-specific movements. However, much less attention has been given to the aspect of neuromuscular control during such movements and only sparse knowledge exists on the specific muscle activation patterns involved during specific risk conditions. Therefore, the aim of this narrative review was (1 to describe anatomical aspects, strength aspects and biomechanical aspects relevant for the understanding of ACL non-contact injury mechanisms in young female athletes, and (2 to review the existing literature on lower limb muscle activation in relation to risk of non-contact ACL-injury and prevention of ACL injury in young female athletes. Studies investigating muscle activity patterns associated with sports-specific risk situations were identified, comprising cohort studies, intervention studies and prospective studies. Based on the retrieved studies, clear gender-specific differences in muscle activation and coordination were identified demonstrating elevated quadriceps activity and reduced hamstring activity in young female athletes compared to their male counterparts, and suggesting young female athletes to be at elevated risk of non-contact ACL injury. Only few studies (n = 6 examined the effect of preventive exercise-based intervention protocols on lower limb muscle activation during sports-specific movements. A general trend toward enhanced hamstring activation was observed during selected injury risk situations (e.g., sidecutting and drop landings. Only a single study examined the association between muscle activation deficits and ACL

Muscle Activation During ACL Injury Risk Movements in Young Female Athletes: A Narrative Review.

Science.gov (United States)

Bencke, Jesper; Aagaard, Per; Zebis, Mette K

2018-01-01

Young, adolescent female athletes are at particular high risk of sustaining a non-contact anterior cruciate ligament (ACL) injury during sport. Through the last decades much attention has been directed toward various anatomical and biomechanical risk factors for non-contact ACL injury, and important information have been retrieved about the influence of external loading factors on ACL injury risk during given sports-specific movements. However, much less attention has been given to the aspect of neuromuscular control during such movements and only sparse knowledge exists on the specific muscle activation patterns involved during specific risk conditions. Therefore, the aim of this narrative review was (1) to describe anatomical aspects, strength aspects and biomechanical aspects relevant for the understanding of ACL non-contact injury mechanisms in young female athletes, and (2) to review the existing literature on lower limb muscle activation in relation to risk of non-contact ACL-injury and prevention of ACL injury in young female athletes. Studies investigating muscle activity patterns associated with sports-specific risk situations were identified, comprising cohort studies, intervention studies and prospective studies. Based on the retrieved studies, clear gender-specific differences in muscle activation and coordination were identified demonstrating elevated quadriceps activity and reduced hamstring activity in young female athletes compared to their male counterparts, and suggesting young female athletes to be at elevated risk of non-contact ACL injury. Only few studies ( n = 6) examined the effect of preventive exercise-based intervention protocols on lower limb muscle activation during sports-specific movements. A general trend toward enhanced hamstring activation was observed during selected injury risk situations (e.g., sidecutting and drop landings). Only a single study examined the association between muscle activation deficits and ACL injury risk

The relationship between abdominal muscle activity and pain, disability and fear of movement during standing postural tasks in females with chronic nonspecific low back pain

Directory of Open Access Journals (Sweden)

Fatemeh Ehsani

2016-10-01

Full Text Available Introduction: It appears that the level of fear of movement changes deep trunk muscle activity in the patients with low back pain (LBP. There is no study to investigate the relationship between deep trunk muscle activity and fear of movement in the patients with LBP. Thus, the purpose of this study was to assess the relationship between abdominal muscle activity and pain, disability and fear of movement during standing postural tasks in females with chronic nonspecific LBP. Materials and Methods: Forty four females participated were asked to maintain their balance during standing on the platform stability levels of Biodex Balance System (BBS. Concurrently, ultrasonography (US data about abdominal muscles thickness measurement were transferred and saved to process offline. The pain intensity, disability and fear of movement were assessed by valid scales and questionnaire. Results: There was not significant correlation between abdominal muscle thickness changes and pain and disability intensity (P>0.05, while significant and inverse correlation between deep abdominal muscle thickness changes and fear of movement was observed in the patients (P<0.05, although this correlation is weak (r= -0.36- -0.32. Conclusion: It seems that increases in fear of movement decrease significantly deep abdominal muscles activity in the patients with LBP. This relationship demonstrates the importance of cognitive behavioral therapy and controlling fear of movement on improvement of deep abdominal muscle activity in the patients with LBP

Priming involuntary autobiographical memories in the lab

OpenAIRE

Barzykowski, Krystian; Niedźwieńska, Agnieszka

2018-01-01

Involuntary autobiographical memories (IAMs) are recollections of personal past that frequently and spontaneously occur in daily life. Initial studies by Mace. Priming involuntary autobiographical memories. Showed that deliberately reminiscing about a certain lifetime period (e.g., high school) significantly increased the number of different IAMs from the same period in subsequent days, suggesting that priming may play a significant role in the retrieval of IAMs in everyday life. In the prese...

Improving mouse controlling and movement for people with Parkinson's disease and involuntary tremor using adaptive path smoothing technique via B-spline.

Science.gov (United States)

Hashem, Seyed Yashar Bani; Zin, Nor Azan Mat; Yatim, Noor Faezah Mohd; Ibrahim, Norlinah Mohamed

2014-01-01

Many input devices are available for interacting with computers, but the computer mouse is still the most popular device for interaction. People who suffer from involuntary tremor have difficulty using the mouse in the normal way. The target participants of this research were individuals who suffer from Parkinson's disease. Tremor in limbs makes accurate mouse movements impossible or difficult without any assistive technologies to help. This study explores a new assistive technique-adaptive path smoothing via B-spline (APSS)-to enhance mouse controlling based on user's tremor level and type. APSS uses Mean filtering and B-spline to provide a smoothed mouse trajectory. Seven participants who have unwanted tremor evaluated APSS. Results show that APSS is very promising and greatly increases their control of the computer mouse. Result of user acceptance test also shows that user perceived APSS as easy to use. They also believe it to be a useful tool and intend to use it once it is available. Future studies could explore the possibility of integrating APSS with one assistive pointing technique, such as the Bubble cursor or the Sticky target technique, to provide an all in one solution for motor disabled users.

The effects of voluntary, involuntary, and forced exercises on brain-derived neurotrophic factor and motor function recovery: a rat brain ischemia model.

Directory of Open Access Journals (Sweden)

Zheng Ke

Full Text Available BACKGROUND: Stroke rehabilitation with different exercise paradigms has been investigated, but which one is more effective in facilitating motor recovery and up-regulating brain neurotrophic factor (BDNF after brain ischemia would be interesting to clinicians and patients. Voluntary exercise, forced exercise, and involuntary muscle movement caused by functional electrical stimulation (FES have been individually demonstrated effective as stroke rehabilitation intervention. The aim of this study was to investigate the effects of these three common interventions on brain BDNF changes and motor recovery levels using a rat ischemic stroke model. METHODOLOGY/PRINCIPAL FINDINGS: One hundred and seventeen Sprague-Dawley rats were randomly distributed into four groups: Control (Con, Voluntary exercise of wheel running (V-Ex, Forced exercise of treadmill running (F-Ex, and Involuntary exercise of FES (I-Ex with implanted electrodes placed in two hind limb muscles on the affected side to mimic gait-like walking pattern during stimulation. Ischemic stroke was induced in all rats with the middle cerebral artery occlusion/reperfusion model and fifty-seven rats had motor deficits after stroke. Twenty-four hours after reperfusion, rats were arranged to their intervention programs. De Ryck's behavioral test was conducted daily during the 7-day intervention as an evaluation tool of motor recovery. Serum corticosterone concentration and BDNF levels in the hippocampus, striatum, and cortex were measured after the rats were sacrificed. V-Ex had significantly better motor recovery in the behavioral test. V-Ex also had significantly higher hippocampal BDNF concentration than F-Ex and Con. F-Ex had significantly higher serum corticosterone level than other groups. CONCLUSION/SIGNIFICANCE: Voluntary exercise is the most effective intervention in upregulating the hippocampal BDNF level, and facilitating motor recovery. Rats that exercised voluntarily also showed less

Motor unit firing rates during spasms in thenar muscles of spinal cord injured subjects

NARCIS (Netherlands)

Zijdewind, Inge; Bakels, Robert; Thomas, Christine K.

2014-01-01

Involuntary contractions of paralyzed muscles (spasms) commonly disrupt daily activities and rehabilitation after human spinal cord injury (SCI). Our aim was to examine the recruitment, firing rate modulation, and derecruitment of motor units that underlie spasms of thenar muscles after cervical

Active Bio-sensor System, Compatible with Arm Muscle Movement or Blinking Signals in BCI Application

Directory of Open Access Journals (Sweden)

Saeid Mehrkanoon

2008-05-01

Full Text Available This paper addresses a bionic active sensor system for the BCI application. Proposed system involves analog and digital parts. Two types of accurate sensors are used to pickup the blinking and muscle movement signals. A precision micro-power instrumentation amplifier with the adjustable gain, a sixth order low pass active filter with cutoff frequency 0.1 Hz, and a sixth order band pas filter with the bandwidth of 2-6 Hz are constructed to provide the clean blinking and arm muscle movement signals. TMS320C25 DSP processor is used for independent and unique command signals which are prepared for BCI application by a power amplifier and driver.

Radiation-induced camptocormia and dropped head syndrome. Review and case report of radiation-induced movement disorders

International Nuclear Information System (INIS)

Seidel, Clemens; Kuhnt, Thomas; Kortmann, Rolf-Dieter; Hering, Kathrin

2015-01-01

In recent years, camptocormia and dropped head syndrome (DHS) have gained attention as particular forms of movement disorders. Camptocormia presents with involuntary forward flexion of the thoracolumbar spine that typically increases during walking or standing and may severely impede walking ability. DHS is characterized by weakness of the neck extensors and a consecutive inability to extend the neck; in severe cases the head is fixed in a ''chin to chest position.'' Many diseases may underlie these conditions, and there have been some reports about radiation-induced camptocormia and DHS. A PubMed search with the keywords ''camptocormia,'' ''dropped head syndrome,'' ''radiation-induced myopathy,'' ''radiation-induced neuropathy,'' and ''radiation-induced movement disorder'' was carried out to better characterize radiation-induced movement disorders and the radiation techniques involved. In addition, the case of a patient developing camptocormia 23 years after radiation therapy of a non-Hodgkin's lymphoma of the abdomen is described. In total, nine case series of radiation-induced DHS (n = 45 patients) and - including our case - three case reports (n = 3 patients) about radiogenic camptocormia were retrieved. Most cases (40/45 patients) occurred less than 15 years after radiotherapy involving extended fields for Hodgkin's disease. The use of wide radiation fields including many spinal segments with paraspinal muscles may lead to radiation-induced movement disorders. If paraspinal muscles and the thoracolumbar spine are involved, the clinical presentation can be that of camptocormia. DHS may result if there is involvement of the cervical spine. To prevent these disorders, sparing of the spine and paraspinal muscles is desirable. (orig.) [de

Exercise-induced rib stress fractures: potential risk factors related to thoracic muscle co-contraction and movement pattern

DEFF Research Database (Denmark)

Vinther-Knudsen, Archibald; Kanstrup, I-L; Christiansen, E

2006-01-01

The etiology of exercise-induced rib stress fractures (RSFs) in elite rowers is unclear. The purpose of the study was to investigate thoracic muscle activity, movement patterns and muscle strength in elite rowers. Electromyographic (EMG) and 2-D video analysis were performed during ergometer rowing...

28 CFR 549.43 - Involuntary psychiatric treatment and medication.

Science.gov (United States)

2010-07-01

... 28 Judicial Administration 2 2010-07-01 2010-07-01 false Involuntary psychiatric treatment and... INSTITUTIONAL MANAGEMENT MEDICAL SERVICES Administrative Safeguards for Psychiatric Treatment and Medication § 549.43 Involuntary psychiatric treatment and medication. Title 18 U.S.C. 4241-4247 and federal court...

Prolonging the duration of masseter muscle reduction by adjusting the masticatory movements after the treatment of masseter muscle hypertrophy with botulinum toxin type a injection.

Science.gov (United States)

Wei, Jiao; Xu, Hua; Dong, Jiasheng; Li, Qingfeng; Dai, Chuanchang

2015-01-01

Botulinum toxin type A (BTX-A) is widely used for the clinical treatment of masseteric hypertrophy. Until now, few reports have discussed how to prolong the duration of its effectiveness. This study evaluated that purposely adjusting the masticatory movements is possible of postponing the masseter muscle rehypertrophy. Ninety-eight patients were randomly and equally divided into 2 groups, and 35 U BTX-A per side was injected into the masseters. The thickness and volume of the masticatory muscles were measured by ultrasound and computerized tomography, respectively. Patients in Group 1 were instructed to strengthen their masticatory effort during the denervated atrophic stage of the masseter (the interval was evaluated by real-time ultrasound monitoring), whereas patients in Group 2 were not given this instruction. When the masseter muscle began to recover, patients in both groups were instructed to reduce their chewing. The duration of the masseter muscle rehypertrophy was significantly prolonged in Group 1 patients. The thickness and the volume of the other masticatory muscles were significantly increased in Group 1 but were either slightly decreased or insignificantly different in Group 2. Purposely strengthening masticatory muscle movement during the denervated atrophic stage of the masseter can prolong the duration of masseter rehypertrophy.

26 CFR 1.381(c)(13)-1 - Involuntary conversions.

Science.gov (United States)

2010-04-01

... 26 Internal Revenue 4 2010-04-01 2010-04-01 false Involuntary conversions. 1.381(c)(13)-1 Section 1.381(c)(13)-1 Internal Revenue INTERNAL REVENUE SERVICE, DEPARTMENT OF THE TREASURY (CONTINUED) INCOME TAX (CONTINUED) INCOME TAXES Insolvency Reorganizations § 1.381(c)(13)-1 Involuntary conversions...

Ways of sampling voluntary and involuntary autobiographical memories in daily life.

Science.gov (United States)

Rasmussen, Anne S; Johannessen, Kim B; Berntsen, Dorthe

2014-11-01

Cognitive psychologists have often equaled retrieval of personal events with voluntary recall from autobiographical memory, but more recent research shows that autobiographical memories often come to mind involuntarily-that is, with no retrieval effort. Voluntary memories have been studied in numerous laboratory experiments in response to word-prompts, whereas involuntary memories primarily have been examined in an everyday living context, using a structured diary procedure. However, it remains unclear how voluntary memories sampled in the laboratory map onto self-prompted voluntary memories in daily life. Here, we used a structured diary procedure to compare different types of voluntary autobiographical memories to their involuntary counterparts. The results replicated previous findings with regard to differences between word-prompted voluntary and involuntary memories, whereas there were fewer differences between self-prompted voluntary and involuntary memories. The findings raise the question as to what is the best way of sampling voluntary memories and the best comparison for involuntary memories. Copyright © 2014 Elsevier Inc. All rights reserved.

Involuntary transfer of Intellectual property

Directory of Open Access Journals (Sweden)

Saeed habiba

2011-07-01

Full Text Available IPR owners have a right about voluntary transfer but sometimes Intellectual property right transfer by force and thus, there are challenge that this article regard for its. IPR shall be devolved to their legitimate heirs after their death unless, owner indicate otherwise in their wills. The heirs have the exclusive right to exercise economic and moral rights, they decide upon publication of the work and in general do every exploitation. But, they shall exercise The decisive manner that IPR of holder intended before his death. On other hand, IPR may be liable to seizure or IPR have been used in mortgage loan. Thus they can be transfer to new person.Here, we regard to Involuntary transfer.This article highlight subject of involuntary transfer and analysis on aspects

Muscle Activation During ACL Injury Risk Movements in Young Female Athletes

DEFF Research Database (Denmark)

Bencke, Jesper; Aagaard, Per; Zebis, Mette K

2018-01-01

, and important information have been retrieved about the influence of external loading factors on ACL injury risk during given sports-specific movements. However, much less attention has been given to the aspect of neuromuscular control during such movements and only sparse knowledge exists on the specific......, intervention studies and prospective studies. Based on the retrieved studies, clear gender-specific differences in muscle activation and coordination were identified demonstrating elevated quadriceps activity and reduced hamstring activity in young female athletes compared to their male counterparts......Young, adolescent female athletes are at particular high risk of sustaining a non-contact anterior cruciate ligament (ACL) injury during sport. Through the last decades much attention has been directed toward various anatomical and biomechanical risk factors for non-contact ACL injury...

Slow movement resistance training using body weight improves muscle mass in the elderly: A randomized controlled trial.

Science.gov (United States)

Tsuzuku, S; Kajioka, T; Sakakibara, H; Shimaoka, K

2018-04-01

To examine the effect of a 12-week slow movement resistance training using body weight as a load (SRT-BW) on muscle mass, strength, and fat distribution in healthy elderly people. Fifty-three men and 35 women aged 70 years old or older without experience in resistance training participated, and they were randomly assigned to a SRT-BW group or control group. The control group did not receive any intervention, but participants in this group underwent a repeat measurement 12 weeks later. The SRT-BW program consisted of 3 different exercises (squat, tabletop push-up, and sit-up), which were designed to stimulate anterior major muscles. Initially, these exercises were performed by 2 sets of 10 repetitions, and subsequently, the number of repetitions was increased progressively by 2 repetitions every 4 weeks. Participants were instructed to perform each eccentric and concentric phase of movement slowly (spending 4 seconds on each movement), covering the full range of motion. We evaluated muscle mass, strength, and fat distribution at baseline and after 12 weeks of training. Changes over 12 weeks were significantly greater in the SRT-BW group than in the control group, with a decrease in waist circumference, hip circumference, and abdominal preperitoneal and subcutaneous fat thickness, and an increase in thigh muscle thickness, knee extension strength, and hip flexion strength. In conclusion, relatively short-term SRT-BW was effective in improving muscle mass, strength, and fat distribution in healthy elderly people. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

The Welfare Effects of Involuntary Part-time Work

DEFF Research Database (Denmark)

Borowczyk-Martins, Daniel; Lalé, Etienne

2018-01-01

Employed individuals in the USA are increasingly more likely to move to involuntarily part-time work than to unemployment. Spells of involuntary part-time work are different from unemployment spells: a full-time worker who takes on a part-time job suffers an earnings loss while remaining employed......, and is unlikely to receive income compensation from publicly provided insurance programmes. We analyse these differences through the lens of an incomplete-market, job-search model featuring unemployment risk alongside an additional risk of involuntary part-time employment. A calibration of the model consistent...... with US institutions and labour market dynamics shows that involuntary part-time work generates lower welfare losses relative to unemployment. This finding relies critically on the much higher probability to return to full-time employment from part-time work. We interpret it as a premium in access to full...

Charge Movement in a Fast Twitch Skeletal Muscle from Rat

OpenAIRE

Simon, B. J.; Beam, K. G.

1983-01-01

Voltage-dependent charge movement in the rat omohyoid muscle was investigated using the three microelectrode voltage clamp technique. The charge that moved during a depolarization from the holding potential (-90 mV) to the test potential, V, increased with increasing V, saturating around 0 mV. The charge vs. voltage relationship was well fitted by Q = Qmax/{1 + exp[-(V - V)/k]}, with Qmax = 28.5 nC/μF, V = -34.2 mV, and k = 8.7 mV. Repolarization of the fiber from the test potential back to t...

Contribution of elastic tissues to the mechanics and energetics of muscle function during movement.

Science.gov (United States)

Roberts, Thomas J

2016-01-01

Muscle force production occurs within an environment of tissues that exhibit spring-like behavior, and this elasticity is a critical determinant of muscle performance during locomotion. Muscle force and power output both depend on the speed of contraction, as described by the isotonic force-velocity curve. By influencing the speed of contractile elements, elastic structures can have a profound effect on muscle force, power and work. In very rapid movements, elastic mechanisms can amplify muscle power by storing the work of muscle contraction slowly and releasing it rapidly. When energy must be dissipated rapidly, such as in landing from a jump, energy stored rapidly in elastic elements can be released more slowly to stretch muscle contractile elements, reducing the power input to muscle and possibly protecting it from damage. Elastic mechanisms identified so far rely primarily on in-series tendons, but many structures within muscles exhibit spring-like properties. Actomyosin cross-bridges, actin and myosin filaments, titin, and the connective tissue scaffolding of the extracellular matrix all have the potential to store and recover elastic energy during muscle contraction. The potential contribution of these elements can be assessed from their stiffness and estimates of the strain they undergo during muscle function. Such calculations provide boundaries for the possible roles these springs might play in locomotion, and may help to direct future studies of the uses of elastic elements in muscle. © 2016. Published by The Company of Biologists Ltd.

Facial Muscle Coordination in Monkeys During Rhythmic Facial Expressions and Ingestive Movements

Science.gov (United States)

Shepherd, Stephen V.; Lanzilotto, Marco; Ghazanfar, Asif A.

2012-01-01

Evolutionary hypotheses regarding the origins of communication signals generally, and primate orofacial communication signals in particular, suggest that these signals derive by ritualization of noncommunicative behaviors, notably including ingestive behaviors such as chewing and nursing. These theories are appealing in part because of the prominent periodicities in both types of behavior. Despite their intuitive appeal, however, there are little or no data with which to evaluate these theories because the coordination of muscles innervated by the facial nucleus has not been carefully compared between communicative and ingestive movements. Such data are especially crucial for reconciling neurophysiological assumptions regarding facial motor control in communication and ingestion. We here address this gap by contrasting the coordination of facial muscles during different types of rhythmic orofacial behavior in macaque monkeys, finding that the perioral muscles innervated by the facial nucleus are rhythmically coordinated during lipsmacks and that this coordination appears distinct from that observed during ingestion. PMID:22553017

Risk factors for readmission in schizophrenia patients following involuntary admission.

Directory of Open Access Journals (Sweden)

Yu-Yuan Hung

Full Text Available Individuals with schizophrenia who are involuntarily admitted may have poorer prognosis, including higher readmission rates, than those voluntarily admitted. However, little is known about the risk factors for readmission in those schizophrenia patients who are involuntarily admitted.We aim to explore the risk factors for readmission in this population.We enrolled 138 schizophrenia patients with involuntary admission from July 2008 to June 2013 and followed those patients for readmission outcomes at 3 months and at 1 year.The one-year and 3-months readmission rates were 33.3% and 15.2%, respectively. Unmarried status (adjusted odds ratio (aOR = 6.28, 95% CI: 1.48-26.62, previous history of involuntary admission (aOR = 4.08, 95% CI: 1.19-14.02, longer involuntary admission days (aOR = 1.04, 95% CI: 1.01-1.07 and shorter total admission days (aOR = 1.03, 95% CI: 1.01-1.05 were associated with increased risk for 1-year readmission. Younger age (aOR = 1.10, 95% CI 1.02-1.18 was associated with increased risk for 3-months readmission.Unmarried status, prior history of involuntary admission, longer involuntary admission days and shorter total admission days were associated with increased risk for 1-year readmission. Healthcare providers may need to focus on patients with these risk factors to reduce subsequent readmissions.

Risk factors for readmission in schizophrenia patients following involuntary admission.

Science.gov (United States)

Hung, Yu-Yuan; Chan, Hung-Yu; Pan, Yi-Ju

2017-01-01

Individuals with schizophrenia who are involuntarily admitted may have poorer prognosis, including higher readmission rates, than those voluntarily admitted. However, little is known about the risk factors for readmission in those schizophrenia patients who are involuntarily admitted. We aim to explore the risk factors for readmission in this population. We enrolled 138 schizophrenia patients with involuntary admission from July 2008 to June 2013 and followed those patients for readmission outcomes at 3 months and at 1 year. The one-year and 3-months readmission rates were 33.3% and 15.2%, respectively. Unmarried status (adjusted odds ratio (aOR) = 6.28, 95% CI: 1.48-26.62), previous history of involuntary admission (aOR = 4.08, 95% CI: 1.19-14.02), longer involuntary admission days (aOR = 1.04, 95% CI: 1.01-1.07) and shorter total admission days (aOR = 1.03, 95% CI: 1.01-1.05) were associated with increased risk for 1-year readmission. Younger age (aOR = 1.10, 95% CI 1.02-1.18) was associated with increased risk for 3-months readmission. Unmarried status, prior history of involuntary admission, longer involuntary admission days and shorter total admission days were associated with increased risk for 1-year readmission. Healthcare providers may need to focus on patients with these risk factors to reduce subsequent readmissions.

Warm-up with weighted bat and adjustment of upper limb muscle activity in bat swinging under movement correction conditions.

Science.gov (United States)

Ohta, Yoichi; Ishii, Yasumitsu; Ikudome, Sachi; Nakamoto, Hiroki

2014-02-01

The effects of weighted bat warm-up on adjustment of upper limb muscle activity were investigated during baseball bat swinging under dynamic conditions that require a spatial and temporal adjustment of the swinging to hit a moving target. Seven male college baseball players participated in this study. Using a batting simulator, the task was to swing the standard bat coincident with the arrival timing and position of a moving target after three warm-up swings using a standard or weighted bat. There was no significant effect of weighted bat warm-up on muscle activity before impact associated with temporal or spatial movement corrections. However, lower inhibition of the extensor carpi ulnaris muscle activity was observed in a velocity-changed condition in the weighted bat warm-up, as compared to a standard bat warm-up. It is suggested that weighted bat warm-up decreases the adjustment ability associated with inhibition of muscle activation under movement correction conditions.

Stochastic Signatures of Involuntary Head Micro-movements Can Be Used to Classify Females of ABIDE into Different Subtypes of Neurodevelopmental Disorders

Directory of Open Access Journals (Sweden)

Elizabeth B. Torres

2017-06-01

Full Text Available Background: The approximate 5:1 male to female ratio in clinical detection of Autism Spectrum Disorder (ASD prevents research from characterizing the female phenotype. Current open access repositories [such as those in the Autism Brain Imaging Data Exchange (ABIDE I-II] contain large numbers of females to help begin providing a new characterization of females on the autistic spectrum. Here we introduce new methods to integrate data in a scale-free manner from continuous biophysical rhythms of the nervous systems and discrete (ordinal observational scores.Methods: New data-types derived from image-based involuntary head motions and personalized statistical platform were combined with a data-driven approach to unveil sub-groups within the female cohort. Further, to help refine the clinical DSM-based ASD vs. Asperger's Syndrome (AS criteria, distributional analyses of ordinal score data from Autism Diagnostic Observation Schedule (ADOS-based criteria were used on both the female and male phenotypes.Results: Separate clusters were automatically uncovered in the female cohort corresponding to differential levels of severity. Specifically, the AS-subgroup emerged as the most severely affected with an excess level of noise and randomness in the involuntary head micro-movements. Extending the methods to characterize males of ABIDE revealed ASD-males to be more affected than AS-males. A thorough study of ADOS-2 and ADOS-G scores provided confounding results regarding the ASD vs. AS male comparison, whereby the ADOS-2 rendered the AS-phenotype worse off than the ASD-phenotype, while ADOS-G flipped the results. Females with AS scored higher on severity than ASD-females in all ADOS test versions and their scores provided evidence for significantly higher severity than males. However, the statistical landscapes underlying female and male scores appeared disparate. As such, further interpretation of the ADOS data seems problematic, rather suggesting the

The Frequency of Voluntary and Involuntary Autobiographical Memories across the Lifespan

Science.gov (United States)

Rubin, David C.; Berntsen, Dorthe

2011-01-01

Ratings of the memory of an important event from the last week on the frequency of voluntary and involuntary retrieval, belief in its accuracy, visual imagery, auditory imagery, setting, emotional intensity, valence, narrative coherence, and centrality to the life story were obtained from 988 adults whose age ranged from 15 to over 90. Another 992 adults provided the same ratings for a memory from their confirmation day when they were about age 14. The frequencies of involuntary and voluntary retrieval were similar. Both frequencies were predicted by emotional intensity and centrality to the life story. The results from this study, which is the first to measure the frequency of voluntary and involuntary retrieval for the same events, are counter to both cognitive and clinical theories, which consistently claim that involuntary memories are infrequent compared to voluntary memories. Age and gender differences are noted. PMID:19487759

How the mind shapes action: Offline contexts modulate involuntary episodic retrieval.

Science.gov (United States)

Frings, Christian; Koch, Iring; Moeller, Birte

2017-11-01

Involuntary retrieval of previous stimulus-response episodes is a centerpiece of many theories of priming, episodic binding, and action control. Typically it is assumed that by repeating a stimulus from trial n-1 to trial n, involuntary retrieval is triggered in a nearly automatic fashion, facilitating (or interfering with) the to-be-executed action. Here we argue that changes in the offline context weaken the involuntary retrieval of previous episodes (the offline context is defined to be the information presented before or after the focal stimulus). In four conditions differing in cue modality and target modality, retrieval was diminished if participants changed the target selection criterion (as indicated by a cue presented before the selection took place) while they still performed the same task. Thus, solely through changes in the offline context (cue or selection criterion), involuntary retrieval can be weakened in an effective way.

Dopamine receptors genes polymorphisms in Parkinson patients with levodopa-induced dyskinesia

NARCIS (Netherlands)

Pozhidaev, I.; Alifirova, V.M.; Freidin, M.B.; Zhukova, I.A.; Fedorenko, O.Y.; Osmanova, D.Z.; Mironova, Y.S.; Wilffert, B.; Ivanova, S.A.; Loonen, A.J.M.

2017-01-01

Introduction: Long-term levodopa treatment of Parkinson's disease (PD) is frequently complicated by spontaneously occur ring involuntary muscle movements called levodopa-induced dyskinesia (LID). LID are a substantial barrier to effective symptomatic management of Parkinson's disease (PD), as up to

Dissimilar mechanistic background of peripheral and orofacial hyperkinesia in patients with Parkinson’s disease and levodopa-induced dyskinesia

NARCIS (Netherlands)

Ivanova, Svetlana A.; Fedorenko, Olga Yu.; Freidin, Maxim B.; Alifirova, Valentina M.; Zhukova, Natalia G.; Zhukova, Irina A.; Al Hadithy, Asmar F. Y.; Brouwers, Jacobus R. B. J.; Bokhan, Nikolay A.; Wilffert, Bob; Loonen, Anton J. M.

2015-01-01

Introduction: Long-term levodopa treatment of Parkinson’s disease (PD) is frequently complicated by spontaneously occurring involuntary muscle movements called dyskinesia. The exact pathological mechanism of this complication has not yet been elucidated. We have previously demonstrated that in PD

Botulinum toxin as treatment for focal dystonia : a systematic review of the pharmaco-therapeutic and pharmaco-economic value

NARCIS (Netherlands)

Zoons, E.; Dijkgraaf, M. G. W.; Dijk, J. M.; van Schaik, I. N.; Tijssen, M. A.

2012-01-01

Focal dystonia is a common, invalidating neurologic condition characterized by involuntary, sustained muscle contractions causing twisting movements and abnormal postures in one body part. Currently, botulinum toxin is the treatment of first choice. We performed a systematic review towards the

Botulinum toxin as treatment for focal dystonia: a systematic review of the pharmaco-therapeutic and pharmaco-economic value

NARCIS (Netherlands)

Zoons, E.; Dijkgraaf, M. G. W.; Dijk, J. M.; van Schaik, I. N.; Tijssen, M. A.

2012-01-01

Focal dystonia is a common, invalidating neurologic condition characterized by involuntary, sustained muscle contractions causing twisting movements and abnormal postures in one body part. Currently, botulinum toxin is the treatment of first choice. We performed a systematic review towards the

26 CFR 1.1033(a)-1 - Involuntary conversions; nonrecognition of gain.

Science.gov (United States)

2010-04-01

... 26 Internal Revenue 11 2010-04-01 2010-04-01 true Involuntary conversions; nonrecognition of gain... Involuntary conversions; nonrecognition of gain. (a) In general. Section 1033 applies to cases where property... property. Section 1033 provides that, under certain specified circumstances, any gain which is realized...

An improved method to determine neuromuscular properties using force laws - From single muscle to applications in human movements.

Science.gov (United States)

Siebert, T; Sust, M; Thaller, S; Tilp, M; Wagner, H

2007-04-01

We evaluate an improved method for individually determining neuromuscular properties in vivo. The method is based on Hill's equation used as a force law combined with Newton's equation of motion. To ensure the range of validity of Hill's equation, we first perform detailed investigations on in vitro single muscles. The force-velocity relation determined with the model coincides well with results obtained by standard methods (r=.99) above 20% of the isometric force. In addition, the model-predicted force curves during work loop contractions very well agree with measurements (mean difference: 2-3%). Subsequently, we deduce theoretically under which conditions it is possible to combine several muscles of the human body to model muscles. This leads to a model equation for human leg extension movements containing parameters for the muscle properties and for the activation. To numerically determine these invariant neuromuscular properties we devise an experimental method based on concentric and isometric leg extensions. With this method we determine individual muscle parameters from experiments such that the simulated curves agree well with experiments (r=.99). A reliability test with 12 participants revealed correlations r=.72-.91 for the neuromuscular parameters (p<.01). Predictions of similar movements under different conditions show mean errors of about 5%. In addition, we present applications in sports practise and theory.

Neck movement and muscle activity characteristics in female office workers with neck pain.

Science.gov (United States)

Johnston, V; Jull, G; Souvlis, T; Jimmieson, N L

2008-03-01

Cross-sectional study. To explore aspects of cervical musculoskeletal function in female office workers with neck pain. Evidence of physical characteristics that differentiate computer workers with and without neck pain is sparse. Patients with chronic neck pain demonstrate reduced motion and altered patterns of muscle control in the cervical flexor and upper trapezius (UT) muscles during specific tasks. Understanding cervical musculoskeletal function in office workers will better direct intervention and prevention strategies. Measures included neck range of motion; superficial neck flexor muscle activity during a clinical test, the craniocervical flexion test; and a motor task, a unilateral muscle coordination task, to assess the activity of both the anterior and posterior neck muscles. Office workers with and without neck pain were formed into 3 groups based on their scores on the Neck Disability Index. Nonworking women without neck pain formed the control group. Surface electromyographic activity was recorded bilaterally from the sternocleidomastoid, anterior scalene (AS), cervical extensor (CE) and UT muscles. Workers with neck pain had reduced rotation range and increased activity of the superficial cervical flexors during the craniocervical flexion test. During the coordination task, workers with pain demonstrated greater activity in the CE muscles bilaterally. On completion of the task, the UT and dominant CE and AS muscles demonstrated an inability to relax in workers with pain. In general, there was a linear relationship between the workers' self-reported levels of pain and disability and the movement and muscle changes. These results are consistent with those found in other cervical musculoskeletal disorders and may represent an altered muscle recruitment strategy to stabilize the head and neck. An exercise program including motor reeducation may assist in the management of neck pain in office workers.

Determinants of disability in cervical dystonia

NARCIS (Netherlands)

van den Dool, J.; Tijssen, M. A. J.; Koelman, J. H. T. M.; Engelbert, R. H. H.; Visser, B.

Background: Cervical dystonia (CD) is characterized by involuntary muscle contractions causing abnormal postures and/or twisting movements of the head and neck. These motor symptoms can have a major impact on disability. Treatment with botulinum toxin injections aims to reduce motor symptoms, and

The frequency of involuntary autobiographical memories and future thoughts in relation to daydreaming, emotional distress, and age.

Science.gov (United States)

Berntsen, Dorthe; Rubin, David C; Salgado, Sinue

2015-11-01

We introduce a new scale, the Involuntary Autobiographical Memory Inventory (IAMI), for measuring the frequency of involuntary autobiographical memories and involuntary future thoughts. Using the scale in relation to other psychometric and demographic measures provided three important, novel findings. First, the frequency of involuntary and voluntary memories and future thoughts are similarly related to general measures of emotional distress. This challenges the idea that the involuntary mode is uniquely associated with emotional distress. Second, the frequency of involuntary autobiographical remembering does not decline with age, whereas measures of daydreaming, suppression of unwanted thoughts and dissociative experiences all do. Thus, involuntary autobiographical remembering relates differently to aging than daydreaming and other forms of spontaneous and uncontrollable thoughts. Third, unlike involuntary autobiographical remembering, the frequency of future thoughts does decrease with age. This finding underscores the need for examining past and future mental time travel in relation to aging and life span development. Copyright © 2015 Elsevier Inc. All rights reserved.

Control of leg movements driven by EMG activity of shoulder muscles

Directory of Open Access Journals (Sweden)

Valentina eLa Scaleia

2014-10-01

Full Text Available During human walking there exists a functional neural coupling between arms and legs, and between cervical and lumbosacral pattern generators. Here we present a novel approach for associating the electromyographic (EMG activity from upper limb muscles with leg kinematics. Our methodology takes advantage of the high involvement of shoulder muscles in most locomotor-related movements and of the natural coordination between arms and legs. Nine healthy subjects were asked to walk at different constant and variable speeds (3-5 km/h, while EMG activity of shoulder (deltoid muscles and the kinematics of walking were recorded. To ensure a high level of EMG activity in deltoid, the subjects performed slightly larger arm swinging than they usually do. The temporal structure of the burst-like EMG activity was used to predict the spatiotemporal kinematic pattern of the forthcoming step. A comparison of actual and predicted stride leg kinematics showed a high degree of correspondence (r>0.9. This algorithm has been also implemented in pilot experiments for controlling avatar walking in a virtual reality setup and an exoskeleton during overground stepping. The proposed approach may have important implications for the design of human-machine interfaces and neuroprosthetic technologies such as those of assistive lower limb exoskeletons.

Functional Movement Disorder

Science.gov (United States)

... Publications Patient Organizations International Parkinson and Movement Disorder Society National Institute of Mental Health (NIMH) See all related organizations Publications Order NINDS Publications Definition Psychogenic movement is an unwanted muscle movement such ...

Movement - uncoordinated

Science.gov (United States)

... Loss of coordination; Coordination impairment; Ataxia; Clumsiness; Uncoordinated movement ... Smooth graceful movement requires a balance between different muscle groups. A part of the brain called the cerebellum manages this balance.

The association of visually-assessed quality of movement during jump-landing with ankle dorsiflexion range-of-motion and hip abductor muscle strength among healthy female athletes.

Science.gov (United States)

Rabin, Alon; Einstein, Ofira; Kozol, Zvi

2018-05-01

To explore the association between ankle dorsiflexion (DF) range of motion (ROM), and hip abductor muscle strength, to visually-assessed quality of movement during jump-landing. Cross-sectional. Gymnasium of participating teams. 37 female volleyball players. Quality of movement in the frontal-plane, sagittal-plane, and overall (both planes) was visually rated as "good/moderate" or "poor". Weight-bearing Ankle DF ROM and hip abductor muscle strength were compared between participants with differing quality of movement. Weight-bearing DF ROM on both sides was decreased among participants with "poor" sagittal-plane quality of movement (dominant side: 50.8° versus 43.6°, P = .02; non-dominant side: 54.6° versus 45.9°, P = .01), as well as among participants with an overall "poor" quality of movement (dominant side: 51.8° versus 44.0°, P movement (53.9° versus 46.0°, P = .02). No differences in hip abductor muscle strength were noted between participants with differing quality of movement. Visual assessment of jump-landing can detect differences in quality of movement that are associated with ankle DF ROM. Clinicians observing a poor quality of movement may wish to assess ankle DF ROM. Copyright © 2018 Elsevier Ltd. All rights reserved.

The Use of Functional Electrical Stimulation on the Upper Limb and Interscapular Muscles of Patients with Stroke for the Improvement of Reaching Movements: A Feasibility Study

Directory of Open Access Journals (Sweden)

Alicia Cuesta-Gómez

2017-05-01

Full Text Available IntroductionReaching movements in stroke patients are characterized by decreased amplitudes at the shoulder and elbow joints and greater displacements of the trunk, compared to healthy subjects. The importance of an appropriate and specific contraction of the interscapular and upper limb (UL muscles is crucial to achieving proper reaching movements. Functional electrical stimulation (FES is used to activate the paretic muscles using short-duration electrical pulses.ObjectiveTo evaluate whether the application of FES in the UL and interscapular muscles of stroke patients with motor impairments of the UL modifies patients’ reaching patterns, measured using instrumental movement analysis systems.DesignA cross-sectional study was carried out.SettingThe VICON Motion System® was used to conduct motion analysis.ParticipantsTwenty-one patients with chronic stroke.InterventionThe Compex® electric stimulator was used to provide muscle stimulation during two conditions: a placebo condition and a FES condition.Main outcome measuresWe analyzed the joint kinematics (trunk, shoulder, and elbow from the starting position until the affected hand reached the glass.ResultsParticipants receiving FES carried out the movement with less trunk flexion, while shoulder flexion elbow extension was increased, compared to placebo conditions.ConclusionThe application of FES to the UL and interscapular muscles of stroke patients with motor impairment of the UL has improved reaching movements.

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

Science.gov (United States)

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.

Polymorphisms of DRD2, DRD3, DRD4 and HTR2C genes in levodopa-induced dyskinesias in Parkinson's disease

NARCIS (Netherlands)

Ivanova, S.A.; Alifirova, V.M.; Fedorenko, O.Y.; Freidin, M.B.; Bokhan, N.A.; Zhukova, I.; Al Hadithy, A.F.Y.; Brouwers, J.R.B.J.; Wilffert, B.; Loonen, A.J.M.

2015-01-01

Levodopa-induced dyskinesias (LID) are involuntary muscle movements that occur as a consequence of chronic levodopa (L-DOPA) treatment. LID are a substantial barrier to effective symptomatic management of Parkinson's disease (PD), up to 45% of L-DOPA users develop LID within 5 years [1]. Clinical

[Involuntary psychiatric care for inmates in France: Only for "dangerous" patients?

Science.gov (United States)

Fovet, T; Bertrand, M; Horn, M; Si Mohammed, W; Dandelot, D; Dalle, M-C; Thomas, P; Amad, A

2017-11-27

The unités hospitalières spécialement aménagées (UHSA) are full-time inpatient psychiatric units for inmates in France. Their creation has been associated with several advances in access to psychiatric care for inmates in recent years. However, there is still only one means of involuntary hospitalization for prisoners in France: care by decision of a representative of the state (les soins sur décision d'un représentant de l'état [SDRE]). Interestingly, for SDRE to be recognized as legal by the French judge, the patient must be "a danger to himself or to the others". Thus, there is a major difference with involuntary hospitalization outside the prison, and there are specific criteria for involuntary psychiatric hospitalization for inmates in France. This situation questions the general framework of involuntary psychiatric care and is very inconsistent with French law. Indeed, the goal of the loi n o  94-43 du 18 janvier 1994 relating to public health and social protection is to ensure equivalent care for all patients, incarcerated or not. Copyright © 2017 L'Encéphale, Paris. Published by Elsevier Masson SAS. All rights reserved.

Pilot study on quantitative assessment of muscle imbalance: differences of muscle synergies, equilibrium-point trajectories, and endpoint stiffness in normal and pathological upper-limb movements.

Science.gov (United States)

Oku, Takanori; Uno, Kanna; Nishi, Tomoki; Kageyama, Masayuki; Phatiwuttipat, Pipatthana; Koba, Keitaro; Yamashita, Yuto; Murakami, Kenta; Uemura, Mitsunori; Hirai, Hiroaki; Miyazaki, Fumio; Naritomi, Hiroaki

2014-01-01

This paper proposes a novel method for assessment of muscle imbalance based on muscle synergy hypothesis and equilibrium point (EP) hypothesis of motor control. We explain in detail the method for extracting muscle synergies under the concept of agonist-antagonist (AA) muscle pairs and for estimating EP trajectories and endpoint stiffness of human upper limbs in a horizontal plane using an electromyogram. The results of applying this method to the reaching movement of one normal subject and one hemiplegic subject suggest that (1) muscle synergies (the balance among coactivation of AA muscle pairs), particularly the synergies that contributes to the angular directional kinematics of EP and the limb stiffness, are quite different between the normal subject and the hemiplegic subject; (2) the concomitant EP trajectory is also different between the normal and hemiplegic subjects, corresponding to the difference of muscle synergies; and (3) the endpoint (hand) stiffness ellipse of the hemiplegic subject becomes more elongated and orientation of the major axis rotates clockwise more than that of the normal subject. The level of motor impairment would be expected to be assessed from a comparison of these differences of muscle synergies, EP trajectories, and endpoint stiffness among normal and pathological subjects using the method.

Contemplated Suicide Among Voluntary and Involuntary Retirees

Science.gov (United States)

Peretti, Peter O.; Wilson, Cedric

1978-01-01

This study explored anomic and egoistic dimensions of contemplated suicide among voluntary and involuntary retired males. Results indicated a direct relationship between anomie and egoism on the one hand, and contemplation of suicide on the other. (Author)

[Factors associated with involuntary hospital admissions in technology-dependent children].

Science.gov (United States)

Okido, Aline Cristiane Cavicchioli; Pina, Juliana Coelho; Lima, Regina Aparecida Garcia

2016-02-01

To identify the factors associated with involuntary hospital admissions of technology-dependent children, in the municipality of Ribeirão Preto, São Paulo State, Brazil. A cross-sectional study, with a quantitative approach. After an active search, 124 children who qualified under the inclusion criteria, that is to say, children from birth to age 12, were identified. Data was collected in home visits to mothers or the people responsible for the children, through the application of a questionnaire. Analysis of the data followed the assumptions of the Generalized Linear Models technique. 102 technology-dependent children aged between 6 months and 12 years participated in the study, of whom 57% were male. The average number of involuntary hospital admissions in the previous year among the children studied was 0.71 (±1.29). In the final model the following variables were significantly associated with the outcome: age (OR=0.991; CI95%=0.985-0.997), and the number of devices (OR=0.387; CI95%=0.219-0.684), which were characterized as factors of protection and quantity of medications (OR=1.532; CI95%=1.297-1.810), representing a risk factor for involuntary hospital admissions in technology-dependent children. The results constitute input data for consideration of the process of care for technology-dependent children by supplying an explanatory model for involuntary hospital admissions for this client group.

The Emotional Response to Everyday Involuntary and Voluntary Memories in Dysphoria and Non-Dysphoria

DEFF Research Database (Denmark)

del Palacio Gonzalez, Adriana; Watson, Lynn; Berntsen, Dorthe

Retrieving personal memories may cause emotional reactions and thus a need for emotion regulation. Past research indicates that involuntary memories have a greater effect on mood that the voluntary counterparts. However, different dimensions of the emotional response (i.e., intensity and regulation...... regulation strategies in response to both involuntary and voluntary memories. The between-group differences were not accounted for by the individuals’ mood preceding memory retrieval or the valence of the remembered events. The results suggest an important effect of retrieval mode in the emotion regulation......) upon retrieval of both involuntary and voluntary personal memories have not been thoroughly examined. We examined individuals’ emotional intensity and regulation of everyday involuntary and voluntary memories during dysphoria and non-depression. Twenty dysphoric individuals and 23 non...

Changes in Lumbopelvic Movement and Muscle Recruitment Associated with Prolonged Deep Squatting: A Pilot Study

Directory of Open Access Journals (Sweden)

Tim K. S. Lui

2018-05-01

Full Text Available This study examined the changes in spinal kinematics and muscle recruitment of the lumbopelvic region associated with prolonged squatting. Eight subjects with chronic nonspecific low back pain (LBP and eight asymptomatic subjects (AS performed squat-to-stand and reverse movements, before and immediately after 15 min deep-squatting. Within-group and between-group differences in lumbopelvic kinematics and electromyographic activity acquired in lumbar erector spinae (ES, gluteus maximus (GM, and vastus lateralis (VL were analyzed. During squat-to-stand after squatting, the LBP group showed slower then faster lumbar movement in the second and third quartiles, respectively. In the second quartile, the AS group moved with a significantly greater lumbar angle. However, significantly greater bilateral GM activity (+4–4.5% was found in the LBP group only. A more profound decrease in bilateral ES activity (−10% was also shown in the LBP group, yet this was nonsignificant compared to the AS group (−4%. In the third quartile, only the LBP group moved with a significantly greater lumbar angle, together with a significant increase in bilateral ES (+6–8% and GM muscle (+2–3% activity. The findings of the altered pattern of joint kinematics and recruitment of the key lumbopelvic muscles displayed in the LBP group inform on the possible mechanisms that may contribute to the increased risk of developing lumbar dysfunctions for people who work in prolonged squatting postures.

Comparison of rhythmic masticatory muscle activity during non-rapid eye movement sleep in guinea pigs and humans.

Science.gov (United States)

Kato, Takafumi; Toyota, Risa; Haraki, Shingo; Yano, Hiroyuki; Higashiyama, Makoto; Ueno, Yoshio; Yano, Hiroshi; Sato, Fumihiko; Yatani, Hirofumi; Yoshida, Atsushi

2017-09-27

Rhythmic masticatory muscle activity can be a normal variant of oromotor activity, which can be exaggerated in patients with sleep bruxism. However, few studies have tested the possibility in naturally sleeping animals to study the neurophysiological mechanisms of rhythmic masticatory muscle activity. This study aimed to investigate the similarity of cortical, cardiac and electromyographic manifestations of rhythmic masticatory muscle activity occurring during non-rapid eye movement sleep between guinea pigs and human subjects. Polysomnographic recordings were made in 30 freely moving guinea pigs and in eight healthy human subjects. Burst cycle length, duration and activity of rhythmic masticatory muscle activity were compared with those for chewing. The time between R-waves in the electrocardiogram (RR interval) and electroencephalogram power spectrum were calculated to assess time-course changes in cardiac and cortical activities in relation to rhythmic masticatory muscle activity. In animals, in comparison with chewing, rhythmic masticatory muscle activity had a lower burst activity, longer burst duration and longer cycle length (P motor activation in comparison to human subjects. © 2017 European Sleep Research Society.

Abnormally Small Neuromuscular Junctions in the Extraocular Muscles From Subjects With Idiopathic Nystagmus and Nystagmus Associated With Albinism.

Science.gov (United States)

McLoon, Linda K; Willoughby, Christy L; Anderson, Jill S; Bothun, Erick D; Stager, David; Felius, Joost; Lee, Helena; Gottlob, Irene

2016-04-01

Infantile nystagmus syndrome (INS) is often associated with abnormalities of axonal outgrowth and connectivity. To determine if this manifests in extraocular muscle innervation, specimens from children with idiopathic INS or INS and albinism were examined and compared to normal age-matched control extraocular muscles. Extraocular muscles removed during normal surgery on children with idiopathic INS or INS and albinism were immunostained for neuromuscular junctions, myofiber type, the immature form of the acetylcholine receptor, and brain-derived neurotrophic factor (BDNF) and compared to age-matched controls. Muscles from both the idiopathic INS and INS and albinism groups had neuromuscular junctions that were 35% to 71% smaller based on myofiber area and myofiber perimeter than found in age-matched controls, and this was seen on both fast and slow myosin heavy chain isoform-expressing myofibers (all P albinism showed a 7-fold increase in neuromuscular junction numbers on fast myofibers expressing the immature gamma subunit of the acetylcholine receptor. The extraocular muscles from both INS subgroups showed a significant increase in the number and size of slow myofibers compared to age-matched controls. Brain-derived neurotrophic factor was expressed in control muscle but was virtually absent in the INS muscles. These studies suggest that, relative to the final common pathway, INS is not the same between different patient etiologies. It should be possible to modulate these final common pathway abnormalities, via exogenous application of appropriate drugs, with the hope that this type of treatment may reduce the involuntary oscillatory movements in these children.

Involuntary psychiatric hospitalisation, stigma stress and recovery: a 2-year study.

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Xu, Z; Lay, B; Oexle, N; Drack, T; Bleiker, M; Lengler, S; Blank, C; Müller, M; Mayer, B; Rössler, W; Rüsch, N

2018-01-31

Compulsory admission can be experienced as devaluing and stigmatising by people with mental illness. Emotional reactions to involuntary hospitalisation and stigma-related stress may affect recovery, but longitudinal data are lacking. We, therefore, examined the impact of stigma-related emotional reactions and stigma stress on recovery over a 2-year period. Shame and self-contempt as emotional reactions to involuntary hospitalisation, stigma stress, self-stigma and empowerment, as well as recovery were assessed among 186 individuals with serious mental illness and a history of recent involuntary hospitalisation. More shame, self-contempt and stigma stress at baseline were correlated with increased self-stigma and reduced empowerment after 1 year. More stigma stress at baseline was associated with poor recovery after 2 years. In a longitudinal path analysis more stigma stress at baseline predicted poorer recovery after 2 years, mediated by decreased empowerment after 1 year, controlling for age, gender, symptoms and recovery at baseline. Stigma stress may have a lasting detrimental effect on recovery among people with mental illness and a history of involuntary hospitalisation. Anti-stigma interventions that reduce stigma stress and programs that enhance empowerment could improve recovery. Future research should test the effect of such interventions on recovery.

Effects of multidimensional pelvic floor muscle training in healthy young women.

Science.gov (United States)

Talasz, Helena; Kalchschmid, Elisabeth; Kofler, Markus; Lechleitner, Monika

2012-03-01

Cross-sectional and interventional study to assess pelvic floor muscle (PFM) function in healthy young nulliparous women and to determine the effects of a 3-month PFM training program with emphasis on co-contraction of PFM and anterolateral abdominal muscles and on correctly performed coughing patterns. PFM function was assessed by digital vaginal palpation in 40 volunteers and graded according to the 6-point Oxford grading scale. The PFM training program was comprised theoretical instruction, as well as verbal feedback during hands-on instruction and repeated training sessions focussing on strengthening PFM and anterolateral abdominal muscle co-contraction during forced expiration and coughing. At baseline, 30 women (75%) were able to perform normal PFM contractions at rest (Oxford scale score ≥ 3); only 4 of them (10%) presented additional involuntary PFM contractions before and during coughing. The remaining 10 women (25%) were unable to perform voluntary or involuntary PFM contractions. Mean Oxford scale score in the whole group was 3.3 ± 1.7. After completing the PFM training program, 29 women (72.5%) performed cough-related PFM contractions and group mean Oxford scale score increased significantly to 4.2 ± 1.0. The study shows that PFM dysfunction may be detected even in healthy young women. Multidimensional training, however, may significantly improve PFM function.

Modulation of Muscle Tone and Sympathovagal Balance in Cervical Dystonia Using Percutaneous Stimulation of the Auricular Vagus Nerve.

Science.gov (United States)

Kampusch, Stefan; Kaniusas, Eugenijus; Széles, Jozsef C

2015-10-01

Primary cervical dystonia is characterized by abnormal, involuntary, and sustained contractions of cervical muscles. Current ways of treatment focus on alleviating symptomatic muscle activity. Besides pharmacological treatment, in severe cases patients may receive neuromodulative intervention such as deep brain stimulation. However, these (highly invasive) methods have some major drawbacks. For the first time, percutaneous auricular vagus nerve stimulation (pVNS) was applied in a single case of primary cervical dystonia. Auricular vagus nerve stimulation was already shown to modulate the (autonomous) sympathovagal balance of the body and proved to be an effective treatment in acute and chronic pain, epilepsy, as well as major depression. pVNS effects on cervical dystonia may be hypothesized to rely upon: (i) the alteration of sensory input to the brain, which affects structures involved in the genesis of motoric and nonmotoric dystonic symptoms; and (ii) the alteration of the sympathovagal balance with a sustained impact on involuntary movement control, pain, quality of sleep, and general well-being. The presented data provide experimental evidence that pVNS may be a new alternative and minimally invasive treatment in primary cervical dystonia. One female patient (age 50 years) suffering from therapy refractory cervical dystonia was treated with pVNS over 20 months. Significant improvement in muscle pain, dystonic symptoms, and autonomic regulation as well as a subjective improvement in motility, sleep, and mood were achieved. A subjective improvement in pain recorded by visual analog scale ratings (0-10) was observed from 5.42 to 3.92 (medians). Muscle tone of the mainly affected left and right trapezius muscle in supine position was favorably reduced by about 96%. Significant reduction of muscle tone was also achieved in sitting and standing positions of the patient. Habituation to stimulation leading to reduced stimulation efficiency was observed and

Involuntary psychiatric admission based on risk rather than need for treatment: report from the Dublin Involuntary Admission Study (DIAS).

LENUS (Irish Health Repository)

Kelly, BD

2018-04-01

Involuntary psychiatric admission in Ireland is based on the presence of mental disorder plus serious risk to self\\/others and\\/or need for treatment. This study aimed to examine differences between use of risk and treatment criteria, about which very little is known.

Involuntary treatment of psychiatric patients in South Africa

African Journals Online (AJOL)

When such a person refuses treatment, it may cause significant distress ... public safety. Patients, on the other hand, understandably have had mixed feelings about involuntary treatment. ... people with mental illness and intellectual disability.

Effects of pushing height on trunk posture and trunk muscle activity when a cart suddenly starts or stops moving.

Science.gov (United States)

Lee, Yun-Ju; Hoozemans, Marco J M; van Dieën, Jaap H

2012-01-01

Unexpected sudden (un)loading of the trunk may induce inadequate responses of trunk muscles and uncontrolled trunk motion. These unexpected perturbations may occur in pushing tasks, when the cart suddenly starts moving (unloading) or is blocked by an obstacle (loading). In pushing, handle height affects the user's working posture, which may influence trunk muscle activity and trunk movement in response to the perturbation. Eleven healthy male subjects pushed a 200 kg cart with handles at shoulder and hip height in a start condition (sudden release of brakes) and a stop condition (bumping into an obstacle). Before the perturbation, the baseline of the trunk inclination, internal moment and trunk extensor muscle activity were significantly higher when pushing at hip height than at shoulder height. After the perturbation, the changes in trunk inclination and internal moment were significantly larger when pushing at shoulder height than at hip height in both conditions. The opposite directions of changes in trunk inclination and internal moment suggest that the unexpected perturbations caused uncontrolled trunk motion. Pushing at shoulder height may impose a high risk of low-back injury due to the low trunk stiffness and large involuntary trunk motion occurring after carts suddenly move or stop.

[Involuntary treatment of mental patients in the community: legal and ethical dilemmas].

Science.gov (United States)

Mitrossili, M

2014-01-01

This article focuses on the measure of involuntary treatment of mental patients in the community, not only with regard to human rights and more specifically those of persons with mental disorders, but also with regard to ethics and deontology in mental healthcare delivery service. In this light, the important role of informed consent in psychiatry with regard to the psychiatric act is examined. Informed consent of mental patients in treatment when they are in need of voluntary or involuntary hospitalization is further examined, while emphasis is being put on the case of involuntary treatment. The Convention for Human Rights and Biomedicine (Convention of Οviedo), the European Convention of Human Rights, other documents of International Organizations (UN) and specialized national legislation (A. 2071/1992, Chapter vi, Greek law) constitute basic reference and interpretation points. The examination of consent and the demarcation of the exceptions are important issues that need to be approached. More particularly, our interest lies with the article 7 of the Convention for Human Rights and Biomedicine, which specifically refers to the protection of person who suffers from a mental disorder. The opinion that informed consent in psychiatric treatment and involuntary treatment are concepts and processes which are distinct but not always mutually exclusive is enhanced. In any case, involuntary treatment causes major dilemmas as far as informed consent in the psychiatric act is concerned, as it raises issues that affect the autonomy of the person. Today, however, there are many factors which influence public politics towards the adoption of the measure of involuntary treatment within the community. How is it that this paradoxical link is legitimized and justified: involuntary treatment and community? The enactment of the above mentioned measure in many European and North American countries has created new paths in the practice of contemporary psychiatry. Nonetheless, it

[Quality of involuntary hospital administration in Switzerland].

Science.gov (United States)

Jäger, Matthias; Ospelt, Isabelle; Kawohl, Wolfram; Theodoridou, Anastasia; Rössler, Wulf; Hoff, Paul

2014-05-21

This study aims at investigating the formal and content-related quality of medical certificates directing compulsory hospital admissions before the scheduled alteration of the Swiss civil legislation in January 2013. A comparison between physicians with different professional backgrounds concerning certificates and patients was conducted. Retrospective investigation of medical records of involuntary inpatients at the University Hospital of Psychiatry in Zurich during a period of six months (N=489). Considerable deficits concerning formal and particularly content-related aspects of the certificates were found. Psychiatrists issued certificates of the highest quality followed by emergency physicians, hospital doctors and general practitioners. Patients differed with respect to several sociodemographic and clinical variables. The quality of certificates directing involuntary hospital admission has to be improved considering the impact on the individual concerned. The consequences of the new legislation on the quality of the admission practices should be inquired in order to improve professional training on the issue.

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.

Development's Collateral Damage : The World Bank, involuntary resettlement and human rights

OpenAIRE

Martin, Deirdre Christine

2011-01-01

Each year millions of people throughout the world are forced from their homes to make way for new roads, dams and other infrastructure developments. The World Bank funds many of these projects in developing countries and has been both harshly criticised for its track record with involuntary resettlement and a global leader in producing guidelines aimed at ensuring those forced to relocate are not harmed by the process. The Bank’s policy on involuntary resettlement is backed up by an Inspecti...

Inverse relations in the patterns of muscle and center of pressure dynamics during standing still and movement postures.

Science.gov (United States)

Morrison, S; Hong, S L; Newell, K M

2007-08-01

The aim of this study was to investigate the postural center of pressure (COP) and surface muscle (EMG) dynamics of young adult participants under conditions where they were required to voluntarily produce random and regular sway motions in contrast to that of standing still. Frequency, amplitude and regularity measures of the COP excursion and EMG activity were assessed, as were measures of the coupling relations between the COP and EMG outputs. The results demonstrated that, even when standing still, there was a high degree of regularity in the COP output, with little difference in the modal frequency dynamics between standing still and preferred motion. Only during random conditions was a significantly greater degree of irregularity observed in the COP measures. The random-like movements were also characterized by a decrease in the level of synchrony between COP motion on the anterior-posterior (AP) and medio-lateral (ML) axes. In contrast, at muscle level, the random task resulted in the highest level of regularity (decreased ApEn) for the EMG output for soleus and tibialis anterior. The ability of individuals to produce a random motion was achieved through the decoupling of the COP motion in each dimension. This decoupling strategy was reflected by increased regularity of the EMG output as opposed to any significant change in the synchrony in the firing patterns of the muscles examined. Increased regularity across the individual muscles was accompanied by increased irregularity in COP dynamics, which can be characterized as a complexity tradeoff. Collectively, these findings support the view that the dynamics of muscle firing patterns does not necessarily map directly to the dynamics at the movement task level and vice versa.

Treatment or Involuntary Euthanasia for Severely Handicapped Newborns: Issues of Philosophy and Public Policy.

Science.gov (United States)

Powell, T. Hennessy; And Others

1982-01-01

Recent reports have indicated that parents and/or physicians occasionally decide not to provide life-sustaining treatment (referred to as involuntary euthanasia), thus ensuring that the severely handicapped newborn will die. The issues involved relative to treatment or involuntary euthanasia are reviewed from two opposing perspectives…

Individual differences in recognising involuntary autobiographical memories: impact on the reporting of abstract cues.

Science.gov (United States)

Mace, John H; Bernas, Ronan S; Clevinger, Amanda

2015-01-01

This study examined individual differences in the ability to recognise involuntary autobiographical memories. We hypothesised that individuals may not always recognise involuntary memories which are cued by abstract experiences (e.g., thoughts or language), while they are better able to recognise those which are cued by concrete sensory/perpetual experiences. We hypothesised that individuals without formal training in psychology would be more prone to these recognition failures than individuals with training in psychology. We tested the hypothesis by comparing the results of general first-year undergraduate students, graduate students in psychology and graduates students in other disciplines after each had participated in a two-week diary study of their naturally occurring involuntary memories. The results showed undergraduate participants and non-psychology graduate participants reporting fewer involuntary memories being triggered by abstract cues than the graduate psychology participants, while the groups did not differ in the report of memories triggered by sensory/perpetual cues. The implications of the findings are discussed.

In response to community violence: coping strategies and involuntary stress responses among Latino adolescents.

Science.gov (United States)

Epstein-Ngo, Quyen; Maurizi, Laura K; Bregman, Allyson; Ceballo, Rosario

2013-01-01

Among poor, urban adolescents, high rates of community violence are a pressing public health concern. This study relies on a contextual framework of stress and coping to investigate how coping strategies and involuntary stress responses may both mediate and moderate the relation between exposure to community violence and psychological well-being. Our sample consists of 223 ninth grade Latino adolescents from poor, urban families. In response to community violence, these adolescents reported using an array of coping strategies as well as experiencing a number of involuntary stress responses; the most frequent coping responses were turning to religion and seeking social support. Hierarchical regression analyses demonstrated that involuntary stress responses mediated the relations between both witnessing or being victimized by violence and poorer psychological functioning, while coping strategies moderated these relations. These findings suggest that the negative psychological effects of exposure to community violence may, in part, be explained by involuntary stress responses, while religious-based coping may serve as a protective factor.

How involuntary commitment impacts on the burden of care of the family.

Science.gov (United States)

Hallam, Larissa

2007-08-01

Little research has examined how, or if, involuntary commitment has impacted on the burden experienced by the family. This paper reports a qualitative study which explored how involuntary commitment under the Mental Health Act (MHA) 2000 in Queensland, Australia impacted on families of people with mental illness. Family members of a person with a mental illness, under involuntary commitment at the time or in the previous 12 months, participated in focus groups. Thematic analysis was used to determine the themes. It was apparent from the views of the family that the use of the involuntary commitment was influenced greatly by the pressures experienced by the mental health services (MHS). The MHA did little to assist the family in gaining access to MHS. It was not until after the family made repeated attempts that they were taken seriously. Often the family had few options other than to use deceit and threats to obtain the necessary treatment required. In view of this, the inherit nature of what involuntary commitment implies for persons under it, such as refusing treatment and management difficulties, indicates the family with such an individual experience more hardship in trying to obtain assistance for that person. Thus, the MHA in Queensland has not met its goals of increasing access to MHS. Family members perceive that they were not being listened to and their concerns were not acted upon. The current culture of the MHS appears to serve, to a large degree, to estrange the family from the consumer making relationships difficult and time-consuming to repair. The mental health profession is urged to consider the culture within their workplace and move towards constructive involvement of the family.

Pelvic floor muscle exercise therapy with myofeedback for women with stress urinary incontinence : A meta-analysis

NARCIS (Netherlands)

De Kruif, Yvette P.; Van Wegen, Erwin E.H.

1996-01-01

Involuntary urine loss can be a major social and hygienic problem for women suffering from stress urinary incontinence (SUI). A frequently applied treatment method for these women is pelvic floor muscle exercise therapy (PFE), either with or without EMG-biofeedback (myofeedback). This paper attempts

Electrical stimulation to the trigeminal proprioceptive fibres that innervate the mechanoreceptors in Müller's muscle induces involuntary reflex contraction of the frontalis muscles.

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Matsuo, Kiyoshi; Osada, Yoshiro; Ban, Ryokuya

2013-02-01

The levator and frontalis muscles lack interior muscle spindles, despite consisting of slow-twitch fibres that involuntarily sustain eyelid-opening and eyebrow-raising against gravity. To compensate for this anatomical defect, this study hypothetically proposes that initial voluntary contraction of the levator fast-twitch muscle fibres stretches the mechanoreceptors in Müller's muscle and evokes proprioception, which continuously induces reflex contraction of slow-twitch fibres of the levator and frontalis muscles. This study sought to determine whether unilateral transcutaneous electrical stimulation to the trigeminal proprioceptive fibres that innervate the mechanoreceptors in Müller's muscle could induce electromyographic responses in the frontalis muscles, with monitoring responses in the orbicularis oculi muscles. The study population included 27 normal subjects and 23 subjects with aponeurotic blepharoptosis, who displayed persistently raised eyebrows on primary gaze and light eyelid closure. The stimulation induced a short-latency response in the ipsilateral frontalis muscle of all subjects and long-latency responses in the bilateral frontalis muscles of normal subjects. However, it did not induce long-latency responses in the bilateral frontalis muscles of subjects with aponeurotic blepharoptosis. The orbicularis oculi muscles showed R1 and/or R2 responses. The stimulation might reach not only the proprioceptive fibres, but also other sensory fibres related to the blink or corneal reflex. The experimental system can provoke a monosynaptic short-latency response in the ipsilateral frontalis muscle, probably through the mesencephalic trigeminal proprioceptive neuron and the frontalis motor neuron, and polysynaptic long-latency responses in the bilateral frontalis muscles through an unknown pathway. The latter neural circuit appeared to be engaged by the circumstances of aponeurotic blepharoptosis.

Involuntary admission may support treatment outcome and motivation in patients receiving assertive community treatment.

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Kortrijk, Hans Erik; Staring, A B P; van Baars, A W B; Mulder, C L

2010-02-01

Patients with severe mental illness who are treated in assertive community treatment (ACT) teams are sometimes involuntarily admitted when they are dangerous to themselves or others, and are not motivated for treatment. However, the consequences of involuntary admission in terms of psychosocial outcome and treatment motivation are largely unknown. We hypothesized that involuntary admission would improve psychosocial outcome and not adversely affect their treatment motivation. In the context of routine 6-monthly outcome monitoring in the period January 2003-March 2008, we used the Health of the Nation Outcome Scales (HoNOS) and a motivation-for-treatment scale to assess 260 severely mentally ill patients at risk for involuntary admission. Mixed models with repeated measures were used for data analyses. During the observation period, 77 patients (30%) were involuntarily admitted. Relative to patients who were not involuntarily admitted, these patients improved significantly in HoNOS total scores (F = 17,815, df = 1, p < 0.001) and in motivation for treatment (F = 28.139, df = 1, p < 0.001). Patients who were not involuntarily admitted had better HoNOS and motivation scores at baseline, but did not improve. Involuntary admission in the context of ACT was associated with improvements in psychosocial outcome and motivation for treatment. There are no indications that involuntary admission leads to deterioration in psychosocial outcome or worsening of motivation for treatment.

Impairment of gradual muscle adjustment during wrist circumduction in Parkinson's disease.

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Carolien M Toxopeus

Full Text Available Purposeful movements are attained by gradually adjusted activity of opposite muscles, or synergists. This requires a motor system that adequately modulates initiation and inhibition of movement and selectively activates the appropriate muscles. In patients with Parkinson's disease (PD initiation and inhibition of movements are impaired which may manifest itself in e.g. difficulty to start and stop walking. At single-joint level, impaired movement initiation is further accompanied by insufficient inhibition of antagonist muscle activity. As the motor symptoms in PD primarily result from cerebral dysfunction, quantitative investigation of gradually adjusted muscle activity during execution of purposeful movement is a first step to gain more insight in the link between impaired modulation of initiation and inhibition at the levels of (i cerebrally coded task performance and (ii final execution by the musculoskeletal system. To that end, the present study investigated changes in gradual adjustment of muscle synergists using a manipulandum that enabled standardized smooth movement by continuous wrist circumduction. Differences between PD patients (N = 15, off-medication and healthy subjects (N = 16 concerning the relation between muscle activity and movement performance in these groups were assessed using kinematic and electromyographic (EMG recordings. The variability in the extent to which a particular muscle was active during wrist circumduction--defined as muscle activity differentiation--was quantified by EMG. We demonstrated that more differentiated muscle activity indeed correlated positively with improved movement performance, i.e. higher movement speed and increased smoothness of movement. Additionally, patients employed a less differentiated muscle activity pattern than healthy subjects. These specific changes during wrist circumduction imply that patients have a decreased ability to gradually adjust muscles causing a decline in

Hypoglossal-Facial Nerve Reconstruction Using a Y-Tube-Conduit Reduces Aberrant Synkinetic Movements of the Orbicularis Oculi and Vibrissal Muscles in Rats

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Yasemin Kaya

2014-01-01

Full Text Available The facial nerve is the most frequently damaged nerve in head and neck trauma. Patients undergoing facial nerve reconstruction often complain about disturbing abnormal synkinetic movements of the facial muscles (mass movements, synkinesis which are thought to result from misguided collateral branching of regenerating motor axons and reinnervation of inappropriate muscles. Here, we examined whether use of an aorta Y-tube conduit during reconstructive surgery after facial nerve injury reduces synkinesis of orbicularis oris (blink reflex and vibrissal (whisking musculature. The abdominal aorta plus its bifurcation was harvested (N = 12 for Y-tube conduits. Animal groups comprised intact animals (Group 1, those receiving hypoglossal-facial nerve end-to-end coaptation alone (HFA; Group 2, and those receiving hypoglossal-facial nerve reconstruction using a Y-tube (HFA-Y-tube, Group 3. Videotape motion analysis at 4 months showed that HFA-Y-tube group showed a reduced synkinesis of eyelid and whisker movements compared to HFA alone.

Hypoglossal-facial nerve reconstruction using a Y-tube-conduit reduces aberrant synkinetic movements of the orbicularis oculi and vibrissal muscles in rats.

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Kaya, Yasemin; Ozsoy, Umut; Turhan, Murat; Angelov, Doychin N; Sarikcioglu, Levent

2014-01-01

The facial nerve is the most frequently damaged nerve in head and neck trauma. Patients undergoing facial nerve reconstruction often complain about disturbing abnormal synkinetic movements of the facial muscles (mass movements, synkinesis) which are thought to result from misguided collateral branching of regenerating motor axons and reinnervation of inappropriate muscles. Here, we examined whether use of an aorta Y-tube conduit during reconstructive surgery after facial nerve injury reduces synkinesis of orbicularis oris (blink reflex) and vibrissal (whisking) musculature. The abdominal aorta plus its bifurcation was harvested (N = 12) for Y-tube conduits. Animal groups comprised intact animals (Group 1), those receiving hypoglossal-facial nerve end-to-end coaptation alone (HFA; Group 2), and those receiving hypoglossal-facial nerve reconstruction using a Y-tube (HFA-Y-tube, Group 3). Videotape motion analysis at 4 months showed that HFA-Y-tube group showed a reduced synkinesis of eyelid and whisker movements compared to HFA alone.

A cardiorespiratory classifier of voluntary and involuntary electrodermal activity

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Sejdic Ervin

2010-02-01

Full Text Available Abstract Background Electrodermal reactions (EDRs can be attributed to many origins, including spontaneous fluctuations of electrodermal activity (EDA and stimuli such as deep inspirations, voluntary mental activity and startling events. In fields that use EDA as a measure of psychophysiological state, the fact that EDRs may be elicited from many different stimuli is often ignored. This study attempts to classify observed EDRs as voluntary (i.e., generated from intentional respiratory or mental activity or involuntary (i.e., generated from startling events or spontaneous electrodermal fluctuations. Methods Eight able-bodied participants were subjected to conditions that would cause a change in EDA: music imagery, startling noises, and deep inspirations. A user-centered cardiorespiratory classifier consisting of 1 an EDR detector, 2 a respiratory filter and 3 a cardiorespiratory filter was developed to automatically detect a participant's EDRs and to classify the origin of their stimulation as voluntary or involuntary. Results Detected EDRs were classified with a positive predictive value of 78%, a negative predictive value of 81% and an overall accuracy of 78%. Without the classifier, EDRs could only be correctly attributed as voluntary or involuntary with an accuracy of 50%. Conclusions The proposed classifier may enable investigators to form more accurate interpretations of electrodermal activity as a measure of an individual's psychophysiological state.

A dual contribution to the involuntary semantic processing of unexpected spoken words.

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Parmentier, Fabrice B R; Turner, Jacqueline; Perez, Laura

2014-02-01

Sounds are a major cause of distraction. Unexpected to-be-ignored auditory stimuli presented in the context of an otherwise repetitive acoustic background ineluctably break through selective attention and distract people from an unrelated visual task (deviance distraction). This involuntary capture of attention by deviant sounds has been hypothesized to trigger their semantic appraisal and, in some circumstances, interfere with ongoing performance, but it remains unclear how such processing compares with the automatic processing of distractors in classic interference tasks (e.g., Stroop, flanker, Simon tasks). Using a cross-modal oddball task, we assessed the involuntary semantic processing of deviant sounds in the presence and absence of deviance distraction. The results revealed that some involuntary semantic analysis of spoken distractors occurs in the absence of deviance distraction but that this processing is significantly greater in its presence. We conclude that the automatic processing of spoken distractors reflects 2 contributions, one that is contingent upon deviance distraction and one that is independent from it.

Lifestyles and routine activities of South African teenagers at risk of being trafficked for involuntary prostitution.

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Lutya, Thozama Mandisa

2010-12-01

The United Nations estimates that 79% of teenage girls trafficked globally every year are forced into involuntary prostitution. About 247 000 South African children work in exploitative conditions; about 40 000 South African female teenagers work as prostitutes. This paper investigates lifestyles and routine activities of teenagers at risk of being trafficked for involuntary prostitution. The key concepts involuntary prostitution, intergenerational sex and exploitative conditions are defined in relation to the lifestyles and routine activities of South African female teenagers. Human trafficking for involuntary prostitution is described, based on a literature review. Lifestyle exposure and routine activities theories help to explain the potential victimisation of these teenagers in human trafficking for involuntary prostitution. Actual lifestyle and routine activities of South African teenagers and risky behaviours (substance abuse, intergenerational sex and child prostitution) are discussed as factors that make teens vulnerable to such trafficking. This paper recommends that human trafficking prevention efforts (awareness programmes and information campaigns) be directed at places frequented by human traffickers and teenagers in the absence of a capable guardian to reduce victimisation, as traffickers analyse the lifestyles and routine activities of their targets. South Africa should also interrogate entrenched practices such as intergenerational sex.

Muscle as a secretory organ

DEFF Research Database (Denmark)

Pedersen, Bente K

2013-01-01

Skeletal muscle is the largest organ in the body. Skeletal muscles are primarily characterized by their mechanical activity required for posture, movement, and breathing, which depends on muscle fiber contractions. However, skeletal muscle is not just a component in our locomotor system. Recent e...... proteins produced by skeletal muscle are dependent upon contraction. Therefore, it is likely that myokines may contribute in the mediation of the health benefits of exercise.......Skeletal muscle is the largest organ in the body. Skeletal muscles are primarily characterized by their mechanical activity required for posture, movement, and breathing, which depends on muscle fiber contractions. However, skeletal muscle is not just a component in our locomotor system. Recent...... evidence has identified skeletal muscle as a secretory organ. We have suggested that cytokines and other peptides that are produced, expressed, and released by muscle fibers and exert either autocrine, paracrine, or endocrine effects should be classified as "myokines." The muscle secretome consists...

Skeletal muscle mechanics: questions, problems and possible solutions.

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Herzog, Walter

2017-09-16

Skeletal muscle mechanics have been studied ever since people have shown an interest in human movement. However, our understanding of muscle contraction and muscle mechanical properties has changed fundamentally with the discovery of the sliding filament theory in 1954 and associated cross-bridge theory in 1957. Nevertheless, experimental evidence suggests that our knowledge of the mechanisms of contraction is far from complete, and muscle properties and muscle function in human movement remain largely unknown.In this manuscript, I am trying to identify some of the crucial challenges we are faced with in muscle mechanics, offer possible solutions to questions, and identify problems that might be worthwhile exploring in the future. Since it is impossible to tackle all (worthwhile) problems in a single manuscript, I identified three problems that are controversial, important, and close to my heart. They may be identified as follows: (i) mechanisms of muscle contraction, (ii) in vivo whole muscle mechanics and properties, and (iii) force-sharing among synergistic muscles. These topics are fundamental to our understanding of human movement and movement control, and they contain a series of unknowns and challenges to be explored in the future.It is my hope that this paper may serve as an inspiration for some, may challenge current beliefs in selected areas, tackle important problems in the area of muscle mechanics, physiology and movement control, and may guide and focus some of the thinking of future muscle mechanics research.

The validity and reliability of modelled neural and tissue properties of the ankle muscles in children with cerebral palsy

NARCIS (Netherlands)

Sloot, L.H.; van der Krogt, M.M.; de Gooijer-van Groep, K.; van Eesbeek, S.; de Groot, J.; Buizer, A.I.; Meskers, C.; Becher, J.G.; de Vlugt, E.; Harlaar, J.

2015-01-01

Spastic cerebral palsy (CP) is characterized by increased joint resistance, caused by a mix of increased tissue stiffness, as well as involuntary reflex and background muscle activity. These properties can be quantified using a neuromechanical model of the musculoskeletal complex and instrumented

Definition and classification of negative motor signs in childhood.

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Sanger, Terence D; Chen, Daofen; Delgado, Mauricio R; Gaebler-Spira, Deborah; Hallett, Mark; Mink, Jonathan W

2006-11-01

In this report we describe the outcome of a consensus meeting that occurred at the National Institutes of Health in Bethesda, Maryland, March 12 through 14, 2005. The meeting brought together 39 specialists from multiple clinical and research disciplines including developmental pediatrics, neurology, neurosurgery, orthopedic surgery, physical therapy, occupational therapy, physical medicine and rehabilitation, neurophysiology, muscle physiology, motor control, and biomechanics. The purpose of the meeting was to establish terminology and definitions for 4 aspects of motor disorders that occur in children: weakness, reduced selective motor control, ataxia, and deficits of praxis. The purpose of the definitions is to assist communication between clinicians, select homogeneous groups of children for clinical research trials, facilitate the development of rating scales to assess improvement or deterioration with time, and eventually to better match individual children with specific therapies. "Weakness" is defined as the inability to generate normal voluntary force in a muscle or normal voluntary torque about a joint. "Reduced selective motor control" is defined as the impaired ability to isolate the activation of muscles in a selected pattern in response to demands of a voluntary posture or movement. "Ataxia" is defined as an inability to generate a normal or expected voluntary movement trajectory that cannot be attributed to weakness or involuntary muscle activity about the affected joints. "Apraxia" is defined as an impairment in the ability to accomplish previously learned and performed complex motor actions that is not explained by ataxia, reduced selective motor control, weakness, or involuntary motor activity. "Developmental dyspraxia" is defined as a failure to have ever acquired the ability to perform age-appropriate complex motor actions that is not explained by the presence of inadequate demonstration or practice, ataxia, reduced selective motor control

Bio-inspired Hybrid Carbon Nanotube Muscles

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Kim, Tae Hyeob; Kwon, Cheong Hoon; Lee, Changsun; An, Jieun; Phuong, Tam Thi Thanh; Park, Sun Hwa; Lima, Márcio D.; Baughman, Ray H.; Kang, Tong Mook; Kim, Seon Jeong

2016-05-01

There has been continuous progress in the development for biomedical engineering systems of hybrid muscle generated by combining skeletal muscle and artificial structure. The main factor affecting the actuation performance of hybrid muscle relies on the compatibility between living cells and their muscle scaffolds during cell culture. Here, we developed a hybrid muscle powered by C2C12 skeletal muscle cells based on the functionalized multi-walled carbon nanotubes (MWCNT) sheets coated with poly(3,4-ethylenedioxythiophene) (PEDOT) to achieve biomimetic actuation. This hydrophilic hybrid muscle is physically durable in solution and responds to electric field stimulation with flexible movement. Furthermore, the biomimetic actuation when controlled by electric field stimulation results in movement similar to that of the hornworm by patterned cell culture method. The contraction and relaxation behavior of the PEDOT/MWCNT-based hybrid muscle is similar to that of the single myotube movement, but has faster relaxation kinetics because of the shape-maintenance properties of the freestanding PEDOT/MWCNT sheets in solution. Our development provides the potential possibility for substantial innovation in the next generation of cell-based biohybrid microsystems.

The Relationship Between Postural and Movement Stability.

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Feldman, Anatol G

2016-01-01

Postural stabilization is provided by stretch reflexes, intermuscular reflexes, and intrinsic muscle properties. Taken together, these posture-stabilizing mechanisms resist deflections from the posture at which balance of muscle and external forces is maintained. Empirical findings suggest that for each muscle, these mechanisms become functional at a specific, spatial threshold-the muscle length or respective joint angle at which motor units begin to be recruited. Empirical data suggest that spinal and supraspinal centers can shift the spatial thresholds for a group of muscles that stabilized the initial posture. As a consequence, the same stabilizing mechanisms, instead of resisting motion from the initial posture, drive the body to another stable posture. In other words by shifting spatial thresholds, the nervous system converts movement resisting to movement-producing mechanisms. It is illustrated that, contrary to conventional view, this control strategy allows the system to transfer body balance to produce locomotion and other actions without loosing stability at any point of them. It also helps orient posture and movement with the direction of gravity. It is concluded that postural and movement stability is provided by a common mechanism.

The impossibility of involuntary unemployment in an overlapping generations model with rational expectation

DEFF Research Database (Denmark)

Schultz, Christian

1992-01-01

If there is unemployment no matter how low the wage rate becomes, one speaks of involuntary unemployment. This phenomenon has been shown to arise in a variety of temporary or atemporal macro models with imperfect competition in the goods markets. In this paper we investigate whether the phenomeno...... of involuntary unemployment arises in a Hartian overlapping generations model with rational expectations. It does not, neither in the short nor in the long run...

MOTOR UNIT FIRING RATES DURING SPASMS IN THENAR MUSCLES OF SPINAL CORD INJURED SUBJECTS

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Inge eZijdewind

2014-11-01

Full Text Available Abstract Involuntary contractions of paralyzed muscles (spasms commonly disrupt daily activities and rehabilitation after human spinal cord injury. Our aim was to examine the recruitment, firing rate modulation, and derecruitment of motor units that underlie spasms of thenar muscles after cervical spinal cord injury. Intramuscular electromyographic activity (EMG, surface EMG, and force were recorded during thenar muscle spasms that occurred spontaneously or that were triggered by movement of a shoulder or leg. Most spasms were submaximal (mean: 39%, SD: 33 of the force evoked by median nerve stimulation at 50 Hz with strong relationships between EMG and force (R2>0.69. Unit recruitment occurred over a wide force range (0.2-103% of 50 Hz force. Significant unit rate modulation occurred during spasms (frequency at 25% maximal force: 8.8 Hz, 3.3 SD; at maximal force: 16.1 Hz, 4.1 SD. Mean recruitment frequency (7.1 Hz, 3.2 SD was significantly higher than derecruitment frequency (5.4 Hz, 2.4 SD. Coactive unit pairs that fired for more than 4 s showed high (R2>0.7, n=4 or low (R2:0.3-0.7, n=12 rate-rate correlations, and derecruitment reversals (21 pairs, 29%. Later recruited units had higher or lower maximal firing rates than lower threshold units. These discrepant data show that coactive motoneurons are driven by both common inputs and by synaptic inputs from different sources during muscle spasms. Further, thenar motoneurons can still fire at high rates in response to various peripheral inputs after spinal cord injury, supporting the idea that low maximal voluntary firing rates and forces in thenar muscles result from reduced descending drive.

Movement and personality development

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Aida M. Aylamazyan

2017-06-01

Full Text Available The paper discusses the role of the movement in the process of shaping the personality, its importance as a mechanism for personality development is considered. The issue of the movement has always occupied a central place in Russian psychology. However, subsequently the movement began to be considered primarily as an executive action in human life. The role of movement in personality development can vary depending on the level it occupies in the hierarchical structure of activity, and also on the type of movement, its character, and the way it is constructed. Under certain conditions, the movement can express the attitude of the subject to the surrounding world and people. Many foreign and Russian psychologists point to a special place of the postural tonic component of the motor movement, the posture in personal regulation. The posture reflects his/her personal attitudes, the system of relationships, and, above all, the emotional attitude or emotional assessment of the current situation, the interest in the actions performed. Mastering the tonic level of motor management is based on the emotional regulation, so the ability to regulate one’s own pose is an important stage in the personality development. Posture tonic regulation of motor movements in humans reveals a qualitatively different character than in animals, this being due to the person’s facing the task of mastering his’her posture, arbitrary retention of the body in one or another position. Maintaining a vertical posture requires constant activity at an arbitrary and involuntary level of mental regulation. Mastering the posture of an unstable equilibrium presupposes the emergence of the «I» and is the last stage of the development. The way a person solves the motor task of maintaining the vertical position of the body reflects his/her specific personal strategy or attitude.

Muscle Recruitment and Coordination following Constraint-Induced Movement Therapy with Electrical Stimulation on Children with Hemiplegic Cerebral Palsy: A Randomized Controlled Trial.

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Kaishou Xu

Full Text Available To investigate changes of muscle recruitment and coordination following constraint-induced movement therapy, constraint-induced movement therapy plus electrical stimulation, and traditional occupational therapy in treating hand dysfunction.In a randomized, single-blind, controlled trial, children with hemiplegic cerebral palsy were randomly assigned to receive constraint-induced movement therapy (n = 22, constraint-induced movement therapy plus electrical stimulation (n = 23, or traditional occupational therapy (n = 23. Three groups received a 2-week hospital-based intervention and a 6-month home-based exercise program following hospital-based intervention. Constraint-induced movement therapy involved intensive functional training of the involved hand during which the uninvolved hand was constrained. Electrical stimulation was applied on wrist extensors of the involved hand. Traditional occupational therapy involved functional unimanual and bimanual training. All children underwent clinical assessments and surface electromyography (EMG at baseline, 2 weeks, 3 and 6 months after treatment. Surface myoelectric signals were integrated EMG, root mean square and cocontraction ratio. Clinical measures were grip strength and upper extremity functional test.Constraint-induced movement therapy plus electrical stimulation group showed both a greater rate of improvement in integrated EMG of the involved wrist extensors and cocontraction ratio compared to the other two groups at 3 and 6 months, as well as improving in root mean square of the involved wrist extensors than traditional occupational therapy group (p<0.05. Positive correlations were found between both upper extremity functional test scores and integrated EMG of the involved wrist as well as grip strength and integrated EMG of the involved wrist extensors (p<0.05.Constraint-induced movement therapy plus electrical stimulation is likely to produce the best outcome in improving muscle recruitment

Fiducial marker-based correction for involuntary motion in weight-bearing C-arm CT scanning of knees. Part I. Numerical model-based optimization.

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Choi, Jang-Hwan; Fahrig, Rebecca; Keil, Andreas; Besier, Thor F; Pal, Saikat; McWalter, Emily J; Beaupré, Gary S; Maier, Andreas

2013-09-01

Human subjects in standing positions are apt to show much more involuntary motion than in supine positions. The authors aimed to simulate a complicated realistic lower body movement using the four-dimensional (4D) digital extended cardiac-torso (XCAT) phantom. The authors also investigated fiducial marker-based motion compensation methods in two-dimensional (2D) and three-dimensional (3D) space. The level of involuntary movement-induced artifacts and image quality improvement were investigated after applying each method. An optical tracking system with eight cameras and seven retroreflective markers enabled us to track involuntary motion of the lower body of nine healthy subjects holding a squat position at 60° of flexion. The XCAT-based knee model was developed using the 4D XCAT phantom and the optical tracking data acquired at 120 Hz. The authors divided the lower body in the XCAT into six parts and applied unique affine transforms to each so that the motion (6 degrees of freedom) could be synchronized with the optical markers' location at each time frame. The control points of the XCAT were tessellated into triangles and 248 projection images were created based on intersections of each ray and monochromatic absorption. The tracking data sets with the largest motion (Subject 2) and the smallest motion (Subject 5) among the nine data sets were used to animate the XCAT knee model. The authors defined eight skin control points well distributed around the knees as pseudo-fiducial markers which functioned as a reference in motion correction. Motion compensation was done in the following ways: (1) simple projection shifting in 2D, (2) deformable projection warping in 2D, and (3) rigid body warping in 3D. Graphics hardware accelerated filtered backprojection was implemented and combined with the three correction methods in order to speed up the simulation process. Correction fidelity was evaluated as a function of number of markers used (4-12) and marker distribution

32 CFR Appendix C to Part 113 - Sample DD Form 2653, “Involuntary Allotment Application”

Science.gov (United States)

2010-07-01

... 32 National Defense 1 2010-07-01 2010-07-01 false Sample DD Form 2653, âInvoluntary Allotment Applicationâ C Appendix C to Part 113 National Defense Department of Defense OFFICE OF THE SECRETARY OF DEFENSE... Part 113—Sample DD Form 2653, “Involuntary Allotment Application” ER05JA95.002 ER05JA95.003 ...

Does Involuntary Mental Time Travel Make Sense in Prospective Teachers' Feelings and Behaviors during Lessons?

Science.gov (United States)

Eren, Altay; Yesilbursa, Amanda

2013-01-01

This study examined the effects of involuntary mental time travel into the past and into the future on prospective teachers' feelings and behaviors during the period of a class hour. A total of 110 prospective teachers participated voluntarily in the study. The results of the present study showed that (a) the involuntary mental time travel into…

Cognitive Control of Involuntary Distraction by Deviant Sounds

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Parmentier, Fabrice B. R.; Hebrero, Maria

2013-01-01

It is well established that a task-irrelevant sound (deviant sound) departing from an otherwise repetitive sequence of sounds (standard sounds) elicits an involuntary capture of attention and orienting response toward the deviant stimulus, resulting in the lengthening of response times in an ongoing task. Some have argued that this type of…

Psychiatric patients' views on why their involuntary hospitalisation was right or wrong: a qualitative study.

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Katsakou, Christina; Rose, Diana; Amos, Tim; Bowers, Len; McCabe, Rosemarie; Oliver, Danielle; Wykes, Til; Priebe, Stefan

2012-07-01

To explore involuntary patients' retrospective views on why their hospitalisation was right or wrong. Involuntary patients were recruited from 22 hospitals in England and interviewed in-depth. The study drew on grounded theory and thematic analysis. Most of the patients felt mentally unwell before admission and out of control during their treatment. Despite these common experiences, three groups of patients with distinct views on their involuntary hospitalisation were identified: those who believed that it was right, those who thought it was wrong and those with ambivalent views. Those with retrospectively positive views believed that hospitalisation ensured that they received treatment, averted further harm and offered them the opportunity to recover in a safe place. They felt that coercion was necessary, as they could not recognise that they needed help when acutely unwell. Those who believed that involuntary admission was wrong thought that their problems could have been managed through less coercive interventions, and experienced hospitalisation as an unjust infringement of their autonomy, posing a permanent threat to their independence. Patients with ambivalent views believed that they needed acute treatment and that hospitalisation averted further harm. Nonetheless, they thought that their problems might have been managed through less coercive community interventions or a shorter voluntary hospitalisation. The study illustrates why some patients view their involuntary hospitalisation positively, whereas others believe it was wrong. This knowledge could inform the development of interventions to improve patients' views and treatment experiences.

Fetal muscle-type nicotinic acetylcholine receptor activation in TE-671 cells and inhibition of fetal movement in a day 40 pregnant goat model by optical isomers of the piperidine alkaloid coniine.

Science.gov (United States)

Green, Benedict T; Lee, Stephen T; Welch, Kevin D; Pfister, James A; Panter, Kip E

2013-01-01

Coniine is an optically active toxic piperidine alkaloid and nicotinic acetylcholine receptor (nAChR) agonist found in poison hemlock (Conium maculatum L.). Coniine teratogenicity is hypothesized to be attributable to the binding, activation, and prolonged desensitization of fetal muscle-type nAChR, which results in the complete inhibition of fetal movement. However, pharmacological evidence of coniine actions at fetal muscle-type nAChR is lacking. The present study compared (-)-coniine, (+)-coniine, and nicotine for the ability to inhibit fetal movement in a day 40 pregnant goat model and in TE-671 cells that express fetal muscle-type nAChR. Furthermore, α-conotoxins (CTx) EI and GI were used to antagonize the actions of (+)- and (-)-coniine in TE-671 cells. (-)-Coniine was more effective at eliciting electrical changes in TE-671 cells and inhibiting fetal movement than was (+)-coniine, suggesting stereoselectivity by the receptor. The pyridine alkaloid nicotine did not inhibit fetal movement in a day 40 pregnant goat model, suggesting agonist specificity for the inhibition of fetal movement. Low concentrations of both CTxs potentiated the TE-671 cell response and higher concentrations of CTx EI, and GI antagonized the actions of both coniine enantiomers demonstrating concentration-dependent coagonism and selective antagonism. These results provide pharmacological evidence that the piperidine alkaloid coniine is acting at fetal muscle-type nAChR in a concentration-dependent manner.

Can fast-twitch muscle fibres be selectively recruited during lengthening contractions? Review and applications to sport movements.

Science.gov (United States)

Chalmers, Gordon R

2008-01-01

Literature examining the recruitment order of motor units during lengthening (eccentric) contractions was reviewed to determine if fast-twitch motor units can be active while lower threshold slow-twitch motor units are not active. Studies utilizing surface electromyogram (EMG) amplitude, single motor unit activity, spike amplitude-frequency analyses, EMG power spectrum, mechanomyographic, and phosphocreatine-to-creatine ratio (PCr/Cr) techniques were reviewed. Only single motor unit and PCr/Cr data were found to be suitable to address the goals of this review. Nine of ten single motor unit studies, examining joint movement velocities up to 225 degrees/s and forces up to 53% of a maximum voluntary contraction, found that the size principle of motor unit recruitment applied during lengthening contractions. Deviation from the size principle was demonstrated by one study examining movements within a small range of low velocities and modest forces, although other studies examining similar low forces and lengthening velocities reported size-ordered recruitment. The PCr/Cr data demonstrated the activation of all fibre types in lengthening maximal contractions. Most evidence indicates that for lengthening contractions of a wide range of efforts and speeds, fast-twitch muscle fibres cannot be selectively recruited without activity of the slow-twitch fibres of the same muscle.

Different corticospinal control between discrete and rhythmic movement of the ankle.

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Goto, Yumeno; Jono, Yasutomo; Hatanaka, Ryota; Nomura, Yoshifumi; Tani, Keisuke; Chujo, Yuta; Hiraoka, Koichi

2014-01-01

We investigated differences in corticospinal and spinal control between discrete and rhythmic ankle movements. Motor evoked potentials (MEPs) in the tibialis anterior and soleus muscles and soleus H-reflex were elicited in the middle of the plantar flexion phase during discrete ankle movement or in the initial or later cycles of rhythmic ankle movement. The H-reflex was evoked at an intensity eliciting a small M-wave and MEPs were elicited at an intensity of 1.2 times the motor threshold of the soleus MEPs. Only trials in which background EMG level, ankle angle, and ankle velocity were similar among the movement conditions were included for data analysis. In addition, only trials with a similar M-wave were included for data analysis in the experiment evoking H-reflexes. Results showed that H reflex and MEP amplitudes in the soleus muscle during discrete movement were not significantly different from those during rhythmic movement. MEP amplitude in the tibialis anterior muscle during the later cycles of rhythmic movement was significantly larger than that during the initial cycle of the rhythmic movement or during discrete movement. Higher corticospinal excitability in the tibialis anterior muscle during the later cycles of rhythmic movement may reflect changes in corticospinal control from the initial cycle to the later cycles of rhythmic movement.

Voluntary "involuntary" commitment--the briar-patch syndrome.

Science.gov (United States)

Miller, R D

1980-01-01

Szasz and others have pointed out that many so-called voluntary admissions to mental hospitals have various elements of coercion involved, and are thus not truly voluntary. The author contends that the converse situation is also true, that many patients admitted under involuntary commitment papers arrange for their own commitments. Reasons for such choices are discussed in the context of a review of the literature and several case histories.

I want to move, but cannot: characteristics of involuntary stayers and associations with health among Canadian seniors.

Science.gov (United States)

Strohschein, Lisa

2012-08-01

The purpose of this study was to investigate characteristics of seniors in the Canadian population who are involuntary stayers and to assess associations with health. Data come from the 1994 Canadian National Population Health Survey, with the sample restricted to those 65 and older (N = 2,551). Nearly 1 in 10 seniors identified as an involuntary stayer. Seniors with few socioeconomic resources, poor health, greater need for assistance, and low social involvement were more likely to identify as an involuntary stayer. Furthermore, seniors who were involuntary stayers report significantly more distress and greater odds of low self-rated health than other seniors. This study brings into visibility an understudied segment of the elderly population: seniors who are unable to move from their present location despite their desire to do so. Further research and policy responses assisting seniors to age in a setting of their own choosing are needed.

Acceleration of the sliding movement of actin filaments with the use of a non-motile mutant myosin in in vitro motility assays driven by skeletal muscle heavy meromyosin.

Directory of Open Access Journals (Sweden)

Kohei Iwase

Full Text Available We examined the movement of an actin filament sliding on a mixture of normal and genetically modified myosin molecules that were attached to a glass surface. For this purpose, we used a Dictyostelium G680V mutant myosin II whose release rates of Pi and ADP were highly suppressed relative to normal myosin, leading to a significantly extended life-time of the strongly bound state with actin and virtually no motility. When the mixing ratio of G680V mutant myosin II to skeletal muscle HMM (heavy myosin was 0.01%, the actin filaments moved intermittently. When they moved, their sliding velocities were about two-fold faster than the velocity of skeletal HMM alone. Furthermore, sliding movements were also faster when the actin filaments were allowed to slide on skeletal muscle HMM-coated glass surfaces in the motility buffer solution containing G680V HMM. In this case no intermittent movement was observed. When the actin filaments used were copolymerized with a fusion protein consisting of Dictyostelium actin and Dictyostelium G680V myosin II motor domain, similar faster sliding movements were observed on skeletal muscle HMM-coated surfaces. The filament sliding velocities were about two-fold greater than the velocities of normal actin filaments. We found that the velocity of actin filaments sliding on skeletal muscle myosin molecules increased in the presence of a non-motile G680V mutant myosin motor.

Muscle fibre types of fishes : structural and functional specialization

NARCIS (Netherlands)

Akster, H.A.

1984-01-01

Muscles of fishes are active in a variety of movements that differ in velocity, duration and excursion length. To investigate how muscles meet the, often conflicting, demands imposed upon them by these movements, the fibre type composition of several muscles was determined. The ultrastructural and

Who cares for involuntary clients?

Science.gov (United States)

Soliman, Soheil; Pollack, Harold A; Alexander, Jeffrey A

2009-01-01

The objectives of this study were to compare characteristics of outpatient substance abuse treatment (OSAT) units that serve high proportions of involuntary clients (ICs) with those that serve a low percentage of such clients. The authors analyze unit-level 1995-2005 data from the National Drug Abuse Treatment System Survey (NDATSS). Approximately 1/6 of OSAT units draw the dominant majority of their clients from involuntary referrals. OSAT units that treat a high proportion of ICs are less likely to be accredited by professional organizations, have fewer treatment staff with advanced degrees, and have shorter average treatment duration than do OSAT units that serve few ICs. OSAT units that serve ICs are more likely to offer legal and domestic violence services but are less likely to offer mental health services or aftercare. OSAT units that serve ICs are less likely to be hospital-affiliated than are other units. Clients at such facilities are more likely to be convicted of driving while intoxicated (DWI), are younger, are less likely to have received prior treatment, are more likely to remain abstinent after treatment, but are more likely to be remanded back to courts. The authors conclude that ICs are an important market niche in OSAT care. DWI is by far the most common offense reported in units that specialize in ICs. Aside from legal and domestic violence services, units with a high proportion of ICs appear to offer somewhat less intensive and professionalized services than do other facilities; however, clients at these units are more likely to be abstinent at the end of treatment and but more likely to be remanded back to the courts.

Sarcopenia, cachexia, and muscle performance in heart failure: Review update 2016.

Science.gov (United States)

Saitoh, Masakazu; Ishida, Junichi; Doehner, Wolfram; von Haehling, Stephan; Anker, Markus S; Coats, Andrew J S; Anker, Stefan D; Springer, Jochen

2017-07-01

Cachexia in the context of heart failure (HF) has been termed cardiac cachexia, and represents a progressive involuntary weight loss. Cachexia is mainly the result of an imbalance in the homeostasis of muscle protein synthesis and degradation due to a lower activity of protein synthesis pathways and an over-activation of protein degradation. In addition, muscle wasting leads to of impaired functional capacity, even after adjusting for clinical relevant variables in patients with HF. However, there is no sufficient therapeutic strategy in muscle wasting in HF patients and very few studies in animal models. Exercise training represents a promising intervention that can prevent or even reverse the process of muscle wasting, and worsening the muscle function and performance in HF with muscle wasting and cachexia. The pathological mechanisms and effective therapeutic approach of cardiac cachexia remain uncertain, because of the difficulty to establish animal cardiac cachexia models, thus novel animal models are warranted. Furthermore, the use of improved animal models will lead to a better understanding of the pathways that modulate muscle wasting and therapeutics of muscle wasting of cardiac cachexia. Copyright © 2017 Elsevier B.V. All rights reserved.

Locomotor-like leg movements evoked by rhythmic arm movements in humans.

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Francesca Sylos-Labini

Full Text Available Motion of the upper limbs is often coupled to that of the lower limbs in human bipedal locomotion. It is unclear, however, whether the functional coupling between upper and lower limbs is bi-directional, i.e. whether arm movements can affect the lumbosacral locomotor circuitry. Here we tested the effects of voluntary rhythmic arm movements on the lower limbs. Participants lay horizontally on their side with each leg suspended in an unloading exoskeleton. They moved their arms on an overhead treadmill as if they walked on their hands. Hand-walking in the antero-posterior direction resulted in significant locomotor-like movements of the legs in 58% of the participants. We further investigated quantitatively the responses in a subset of the responsive subjects. We found that the electromyographic (EMG activity of proximal leg muscles was modulated over each cycle with a timing similar to that of normal locomotion. The frequency of kinematic and EMG oscillations in the legs typically differed from that of arm oscillations. The effect of hand-walking was direction specific since medio-lateral arm movements did not evoke appreciably leg air-stepping. Using externally imposed trunk movements and biomechanical modelling, we ruled out that the leg movements associated with hand-walking were mainly due to the mechanical transmission of trunk oscillations. EMG activity in hamstring muscles associated with hand-walking often continued when the leg movements were transiently blocked by the experimenter or following the termination of arm movements. The present results reinforce the idea that there exists a functional neural coupling between arm and legs.

Involuntary masturbation and hemiballismus after bilateral anterior cerebral artery infarction.

Science.gov (United States)

Bejot, Yannick; Caillier, Marie; Osseby, Guy-Victor; Didi, Roy; Ben Salem, Douraied; Moreau, Thibault; Giroud, Maurice

2008-02-01

Ischemia of the areas supplied by the anterior cerebral artery is relatively uncommon. In addition, combined hemiballismus and masturbation have rarely been reported in patients with cerebrovascular disease. We describe herein a 62-year-old right-handed man simultaneously exhibiting right side hemiballismus and involuntary masturbation with the left hand after bilateral infarction of the anterior cerebral artery territory. Right side hemiballismus was related to the disruption of afferent fibers from the left frontal lobe to the left subthalamic nucleus. Involuntary masturbation using the left hand was exclusively linked to a callosal type of alien hand syndrome secondary to infarction of the right side of the anterior corpus callosum. After 2 weeks, these abnormal behaviours were completely extinguished. This report stresses the wide diversity of clinical manifestations observed after infarction of the anterior cerebral artery territory.

Graves' ophthalmopathy evaluated by infrared eye-movement recordings

International Nuclear Information System (INIS)

Feldon, S.E.; Unsoeld, R.

1982-01-01

Thirteen patients with varying degrees of Graves' ophthalmopathy were examined using high-resolution infrared oculography to determine peak velocities for horizontal eye movements between 3 degrees and 30 degrees. As severity of the orbital disease increased, peak velocities became substantially lower. Vertical-muscle surgery failed to have any effect on peak velocity of horizontal eye movements. In contrast, orbital decompression caused notable improvement in peak velocity of eye movements. Eye-movement recordings, which provide a measure of extraocular muscle function rather than structure, may provide a safe, sensitive, and accurate method for classifying and following up patients with Graves' ophthalmopathy

Probing muscle myosin motor action: x-ray (m3 and m6) interference measurements report motor domain not lever arm movement.

Science.gov (United States)

Knupp, Carlo; Offer, Gerald; Ranatunga, K W; Squire, John M

2009-07-10

The key question in understanding how force and movement are produced in muscle concerns the nature of the cyclic interaction of myosin molecules with actin filaments. The lever arm of the globular head of each myosin molecule is thought in some way to swing axially on the actin-attached motor domain, thus propelling the actin filament past the myosin filament. Recent X-ray diffraction studies of vertebrate muscle, especially those involving the analysis of interference effects between myosin head arrays in the two halves of the thick filaments, have been claimed to prove that the lever arm moves at the same time as the sliding of actin and myosin filaments in response to muscle length or force steps. It was suggested that the sliding of myosin and actin filaments, the level of force produced and the lever arm angle are all directly coupled and that other models of lever arm movement will not fit the X-ray data. Here, we show that, in addition to interference across the A-band, which must be occurring, the observed meridional M3 and M6 X-ray intensity changes can all be explained very well by the changing diffraction effects during filament sliding caused by heads stereospecifically attached to actin moving axially relative to a population of detached or non-stereospecifically attached heads that remain fixed in position relative to the myosin filament backbone. Crucially, and contrary to previous interpretations, the X-ray interference results provide little direct information about the position of the myosin head lever arm; they are, in fact, reporting relative motor domain movements. The implications of the new interpretation are briefly assessed.

[German practice of involuntary commitment at both federal and state level after introduction of the Guardianship law (1992-2009)].

Science.gov (United States)

Valdes-Stauber, J; Deinert, H; Kilian, R

2012-05-01

Given the steady rise of psychiatric coercive measures in Germany, the question arises whether this development is significantly influenced by the corresponding legal basis or through epidemiological, socio-economic or socio-structural factors. Based on full surveys of the Federal Ministry of Justice we examined the development and associations of 10 indicators of coercive psychiatric measures over a period of 18 years. Time trends of all indicators have been descriptively analysed. Statistical associations between time trends and between involuntary and admissions economic indicators were analysed by regression models. All annual involuntary commitment rates have increased, judicial ordered physical restraint measures particularly strongly (848%). The rate of judicial rejections of applied involuntary measures showed the lowest increase. On the other hand, quotas of involuntary admissions remained stable. In former East Germany, the involuntary admission rates are only a third of those in the former West Germany. Results of regression analyses indicate an excess increase of physical coercive measures in psychiatric hospitals in relation to the increase of psychiatric admissions. In former East Germany the rate of involuntary admissions at the federal state level is negatively correlated with the average gross income. The continuous increase of coercive psychiatric measures in consequence to the change in the Guardianship law suggests that this change has influenced the practice. The differences at federal and state levels, and the sharper rise in the former East Germany by lower rates in comparison to the former West Germany need an explanation, as well as the fact that the rate of involuntary admissions is associated at least in the former East Germany with economic conditions. © Georg Thieme Verlag KG Stuttgart · New York.

PELVIC FLOOR MUSCLE TRAINING IN THE TREATMENT OF URINARY INCONTINENCE AFTER RADICAL PROSTATECTOMY

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Yu. L. Demidko

2014-07-01

Full Text Available The incidence of urinary incontinence after radical prostatectomy is 0.8 to 87%. This category of patients has pelvic floor muscle weakness and reduced perineal reflex. The treatment of these patients uses a pelvic floor exercise system that is to enhance muscle tone and to develop strong reflex contraction in response to a sudden rise in intraabdominal pressure. Pelvic floor muscle training belongs to first-line therapy for urinary incontinence occurring within 6 to 12 months after prostatectomy. The ability to control pelvic floor muscle knowingly and to train them allows one not only to increase the closing capability of sphincter mechanisms, but also to suppress involuntary detrusor contractions. We used this method in 9 patients who had undergone radical prostatectomy. The duration of pelvic floor muscle training under control was up to 25 weeks. During this period, the symptoms of incontinence were relieved. No contraindications or adverse reactions have put this method in first-line therapy for post-prostatectomy urinary incontinence.

PELVIC FLOOR MUSCLE TRAINING IN THE TREATMENT OF URINARY INCONTINENCE AFTER RADICAL PROSTATECTOMY

Directory of Open Access Journals (Sweden)

Yu. L. Demidko

2010-01-01

Full Text Available The incidence of urinary incontinence after radical prostatectomy is 0.8 to 87%. This category of patients has pelvic floor muscle weakness and reduced perineal reflex. The treatment of these patients uses a pelvic floor exercise system that is to enhance muscle tone and to develop strong reflex contraction in response to a sudden rise in intraabdominal pressure. Pelvic floor muscle training belongs to first-line therapy for urinary incontinence occurring within 6 to 12 months after prostatectomy. The ability to control pelvic floor muscle knowingly and to train them allows one not only to increase the closing capability of sphincter mechanisms, but also to suppress involuntary detrusor contractions. We used this method in 9 patients who had undergone radical prostatectomy. The duration of pelvic floor muscle training under control was up to 25 weeks. During this period, the symptoms of incontinence were relieved. No contraindications or adverse reactions have put this method in first-line therapy for post-prostatectomy urinary incontinence.

32 CFR Appendix D to Part 113 - Sample DD Form 2654, “Involuntary Allotment Notice and Processing”

Science.gov (United States)

2010-07-01

... 32 National Defense 1 2010-07-01 2010-07-01 false Sample DD Form 2654, âInvoluntary Allotment Notice and Processingâ D Appendix D to Part 113 National Defense Department of Defense OFFICE OF THE..., App. D Appendix D to Part 113—Sample DD Form 2654, “Involuntary Allotment Notice and Processing...

Does the cerebellum initiate movement?

Science.gov (United States)

Thach, W T

2014-02-01

Opinion is divided on what the exact function of the cerebellum is. Experiments are summarized that support the following views: (1) the cerebellum is a combiner of multiple movement factors; (2) it contains anatomically fixed permanent focal representation of individual body parts (muscles and segments) and movement modes (e.g., vestibular driven vs. cognitive driven); (3) it contains flexible changing representations/memory of physical properties of the body parts including muscle strength, segment inertia, joint viscosity, and segmental interaction torques (dynamics); (4) it contains mechanisms for learning and storage of the properties in item no. 3 through trial-and-error practice; (5) it provides for linkage of body parts, motor modes, and motordynamics via the parallel fiber system; (6) it combines and integrates the many factors so as to initiate coordinated movements of the many body parts; (7) it is thus enabled to play the unique role of initiating coordinated movements; and (8) this unique causative role is evidenced by the fact that: (a) electrical stimulation of the cerebellum can initiate compound coordinated movements; (b) in naturally initiated compound movements, cerebellar discharge precedes that in downstream target structures such as motor cerebral cortex; and (c) cerebellar ablation abolishes the natural production of compound movements in the awake alert individuals.

Extraocular muscle architecture in hawks and owls.

Science.gov (United States)

Plochocki, Jeffrey H; Segev, Tamar; Grow, Wade; Hall, Margaret I

2018-02-06

A complete and accurate understanding of extraocular muscle function is important to the veterinary care of the avian eye. This is especially true for birds of prey, which rely heavily on vision for survival and yet are prone to ocular injury and disease. To better understand the function of extraocular muscles in birds of prey, we studied extraocular muscle architecture grossly and histologically. This sample was composed of two each of the following species: red-tailed hawk (Buteo jamaicensis), Harris's hawk (Parabuteo unicinctus), great horned owl (Bubo virginianus), and barn owl (Tyto alba). All extraocular muscles were dissected and weighed. To analyze muscle fiber architecture, the superior oblique and quadratus muscles were dissected, weighed, and sectioned at 5 μm thickness in the transverse plane. We calculated the physiologic cross-sectional area and the ratio of muscle mass to predicted effective maximum tetanic tension. Hawk and owl extraocular muscles exhibit significant physiological differences that play roles in ocular movements and closure of the nictitating membrane. Owls, which do not exhibit extraocular movement, have muscle architecture suited to stabilize the position of a massive, tubular eye that protrudes significantly from the orbit. Hawks, which have a more globose eye that is largely contained within the orbit, do not require as much muscular stability and instead have muscle architecture that facilitates rapid eye movement. © 2018 American College of Veterinary Ophthalmologists.

Nuclear Positioning in Muscle Development and Disease

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Eric eFolker

2013-12-01

Full Text Available Muscle disease as a group is characterized by muscle weakness, muscle loss, and impaired muscle function. Although the phenotype is the same, the underlying cellular pathologies, and the molecular causes of these pathologies, are diverse. One common feature of many muscle disorders is the mispositioning of myonuclei. In unaffected individuals myonuclei are spaced throughout the periphery of the muscle fiber such that the distance between nuclei is maximized. However, in diseased muscles, the nuclei are often clustered within the center of the muscle cell. Although this phenotype has been acknowledged for several decades, it is often ignored as a contributor to muscle weakness. Rather, these nuclei are taken only as a sign of muscle repair. Here we review the evidence that mispositioned myonuclei are not merely a symptom of muscle disease but also a cause. Additionally, we review the working models for how myonuclei move from two different perspectives, from that of the nucleus and from that of the cytoskeleton. We further compare and contrast these mechanisms with the mechanisms of nuclear movement in other cell types both to draw general themes for nuclear movement and to identify muscle-specific considerations. Finally, we focus on factors that can be linked to muscle disease and find that genes that regulate myonuclear movement and positioning have been linked to muscular dystrophy. Although the cause-effect relationship is largely speculative, recent data indicate that the position of nuclei should no longer be considered only a means to diagnose muscle disease.

Validated Predictions of Metabolic Energy Consumption for Submaximal Effort Movement

OpenAIRE

Tsianos, George A.; MacFadden, Lisa N.

2016-01-01

Author Summary Muscles consume metabolic energy to generate movement. Performing a movement over a long period of time or at a high intensity strains the respiratory and cardiovascular systems that need to replenish the energy reserves in muscle. Furthermore, consuming and replenishing metabolic energy involves biochemical reactions with byproducts that cause muscle fatigue. These biochemical reactions also produce heat that increases body temperature, potentially causing central fatigue. A m...

Involuntary sterilization among HIV-positive Garifuna women from Honduras seeking asylum in the United States: Two case reports.

Science.gov (United States)

Atkinson, Holly G; Ottenheimer, Deborah

2018-05-01

Voluntary sterilization is one of the most widely used forms of contraception by women worldwide; however, involuntary sterilization is considered a violation of multiple human rights and grounds for asylum in the United States. Women have been disproportionately affected by this practice. We report two cases of involuntary sterilization in HIV-positive Garifuna women from Honduras who sought asylum in America and were medically evaluated at the request of their attorneys. Key lessons can be drawn from these cases with regard to the importance of medical evaluations in establishing persecution. These include the need for a detailed account of the events surrounding sterilization, radiologic proof of tubal blockage if at all possible, and confirmation of significant and enduring mental distress as a result of the involuntary sterilization. Immigration attorneys and medical evaluators need to be attuned to the possibility of a history of involuntary sterilization among at risk women seeking asylum in the United States. Copyright © 2018 The Authors. Published by Elsevier Ltd.. All rights reserved.

Involuntary outpatient treatment (IOT) in Spain.

Science.gov (United States)

Hernández-Viadel, M; Cañete-Nicolás, C; Bellido-Rodriguez, C; Asensio-Pascual, P; Lera-Calatayud, G; Calabuig-Crespo, R; Leal-Cercós, C

2015-01-01

In recent decades there have been significant legislative changes in Spain. Society develops faster than laws, however, and new challenges have emerged. In 2004, the Spanish Association of Relatives of the Mentally Ill (FEAFES) proposed amending the existing legislation to allow for the implementation of involuntary outpatient treatment (IOT) for patients with severe mental illness. Currently, and after having made several attempts at change, there is no specific legislation governing the application of this measure. Although IOT may be implemented in local programmes, we consider legal regulation to be needed in this matter. Copyright © 2015 Elsevier Ltd. All rights reserved.

Sleep-related movement disorders.

Science.gov (United States)

Merlino, Giovanni; Gigli, Gian Luigi

2012-06-01

Several movement disorders may occur during nocturnal rest disrupting sleep. A part of these complaints is characterized by relatively simple, non-purposeful and usually stereotyped movements. The last version of the International Classification of Sleep Disorders includes these clinical conditions (i.e. restless legs syndrome, periodic limb movement disorder, sleep-related leg cramps, sleep-related bruxism and sleep-related rhythmic movement disorder) under the category entitled sleep-related movement disorders. Moreover, apparently physiological movements (e.g. alternating leg muscle activation and excessive hypnic fragmentary myoclonus) can show a high frequency and severity impairing sleep quality. Clinical and, in specific cases, neurophysiological assessments are required to detect the presence of nocturnal movement complaints. Patients reporting poor sleep due to these abnormal movements should undergo non-pharmacological or pharmacological treatments.

Relationships among hamstring muscle optimal length and hamstring flexibility and strength

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Xianglin Wan

2017-09-01

Conclusion: Hamstring flexibility may affect hamstring muscle maximum strain in movements. With similar hamstring flexibility, hamstring muscle maximal strain in a given movement may be different between genders. Hamstring muscle lengths in standing should not be used as an approximation of their optimal lengths in calculation of hamstring muscle strain in musculoskeletal system modeling.

Muscle Sensor Model Using Small Scale Optical Device for Pattern Recognitions

Directory of Open Access Journals (Sweden)

Kreangsak Tamee

2013-01-01

Full Text Available A new sensor system for measuring contraction and relaxation of muscles by using a PANDA ring resonator is proposed. The small scale optical device is designed and configured to perform the coupling effects between the changes in optical device phase shift and human facial muscle movement, which can be used to form the relationship between optical phase shift and muscle movement. By using the Optiwave and MATLAB programs, the results obtained have shown that the measurement of the contraction and relaxation of muscles can be obtained after the muscle movements, in which the unique pattern of individual muscle movement from facial expression can be established. The obtained simulation results, that is, interference signal patterns, can be used to form the various pattern recognitions, which are useful for the human machine interface and the human computer interface application and discussed in detail.

A systematic review of the frequency, duration, type and effect of involuntary treatment for people with anorexia nervosa, and an analysis of patient characteristics

DEFF Research Database (Denmark)

Clausen, Loa; Jones, Allan

2014-01-01

observed between involuntary and voluntary patient-groups together with findings of higher co-morbidity, more preadmissions, longer duration of illness and more incidences of self-harm for involuntary patients suggest that involuntary treatment is not a reaction to the severity of eating disorder symptoms...

An Objective Functional Characterisation of Head Movement Impairment in Individuals with Neck Muscle Weakness Due to Amyotrophic Lateral Sclerosis.

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Silvia Pancani

Full Text Available Neck muscle weakness and head drop are well recognised in patients with Amyotrophic lateral sclerosis (ALS, but an objective characterisation of the consequent head movement impairment is lacking. The aim of this study was to quantitatively characterise head movements in ALS compared to aged matched controls.We evaluated two groups, one of thirteen patients with ALS and one of thirteen age-matched controls, during the execution of a series of controlled head movements, performed while wearing two inertial sensors attached on the forehead and sternum, respectively. We quantified the differences between the two groups from the sensor data using indices of velocity, smoothness and movement coupling (intended as a measure of undesired out of plane movements.Results confirmed a general limitation in the ability of the ALS patients to perform and control head movements. High inter-patient variability was observed due to a wide range of observed functional impairment levels. The ability to extend the head backward and flex it laterally were the most compromised, with significantly lower angular velocity (P 0.8, reduced smoothness and greater presence of coupled movements with respect to the controls. A significant reduction of angular velocity (P 0.8 in extension, axial rotation and lateral flexion was observed when patients were asked to perform the movements as fast as possible.This pilot study is the first study providing a functional objective quantification of head movements in ALS. Further work involving different body areas and correlation with existing methods of evaluating neuromuscular function, such as dynamometry and EMG, is needed to explore the use of this approach as a marker of disease progression in ALS.

Long-term consequences of youth volunteering: Voluntary versus involuntary service.

Science.gov (United States)

Kim, Jinho; Morgül, Kerem

2017-09-01

Despite the renewed interest in youth volunteering in recent years, there remain major gaps in our knowledge of its consequences. Drawing data from the National Longitudinal Study of Adolescent to Adult Health, we examine the long-term effects of youth volunteering on the civic and personal aspects of volunteers' lives. Our results suggest that youth volunteering has a positive return on adult volunteering only when it is voluntary, and that net of contextual factors neither voluntary nor involuntary youth service has a significant effect on adult voting. Regarding personal outcomes, our findings indicate that the psychological benefits of youth volunteering accrue only to voluntary participants, whereas both voluntary and involuntary youth service are positively associated with educational attainment and earnings in young adulthood. Taken together, these results lend support to the case for youth volunteer programs, though the civic benefits of these programs appear to be less dramatic than generally suggested. Copyright © 2017 Elsevier Inc. All rights reserved.

Thoughts on selected movement disorder terminology and a plea for clarity.

Science.gov (United States)

Walker, Ruth H

2013-01-01

Description of the phenomenology of movement disorders requires precise and accurate terminology. Many of the terms that have been widely used in the literature are imprecise and open to interpretation. An examination of these terms and the assumptions implicit in their usage is important to improve communication and hence the definition, diagnosis, and treatment of movement disorders. I recommend that the term dyskinesia should be used primarily in the settings of Parkinson's disease and tardive dyskinesia, in which its clinical implications are relatively clear; it should not be used in other situations where a precise description could more usefully facilitate diagnosis and treatment. In general dyskinesia should be used in the singular form. Extrapyramidal is based upon obsolete anatomical concepts, is uninformative, and should be discarded. The term abnormal involuntary movements (AIMs) is similarly vague and uninformative, although is unlikely to be eliminated from the psychiatric literature. Movement disorder neurologists as teachers, clinicians, article reviewers, and journal editors have the responsibility to educate our colleagues regarding appropriate usage and the importance of employing correct descriptors.

Thoughts on Selected Movement Disorders Terminology and a Plea for Clarity

Directory of Open Access Journals (Sweden)

Ruth H. Walker

2013-12-01

Full Text Available Description of the phenomenology of movement disorders requires precise and accurate terminology. Many of the terms that have been widely used in the literature are imprecise and open to interpretation. An examination of these terms and the assumptions implicit in their usage is important to improve communication and hence the definition, diagnosis, and treatment of movement disorders. I recommend that the term dyskinesia should be used primarily in the settings of Parkinson's disease and tardive dyskinesia, in which its clinical implications are relatively clear; it should not be used in other situations where a precise description could more usefully facilitate diagnosis and treatment. In general dyskinesia should be used in the singular form. Extrapyramidal is based upon obsolete anatomical concepts, is uninformative, and should be discarded. The term abnormal involuntary movements (AIMs is similarly vague and uninformative, although is unlikely to be eliminated from the psychiatric literature. Movement disorder neurologists as teachers, clinicians, article reviewers, and journal editors have the responsibility to educate our colleagues regarding appropriate usage and the importance of employing correct descriptors.

Effect of cooling on thixotropic position-sense error in human biceps muscle.

Science.gov (United States)

Sekihara, Chikara; Izumizaki, Masahiko; Yasuda, Tomohiro; Nakajima, Takayuki; Atsumi, Takashi; Homma, Ikuo

2007-06-01

Muscle temperature affects muscle thixotropy. However, it is unclear whether changes in muscle temperature affect thixotropic position-sense errors. We studied the effect of cooling on thixotropic position-sense errors induced by short-length muscle contraction (hold-short conditioning) in the biceps of 12 healthy men. After hold-short conditioning of the right biceps muscle in a cooled (5.0 degrees C) or control (36.5 degrees C) environment, subjects perceived greater extension of the conditioned forearm at 5.0 degrees C. The angle differences between the two forearms following hold-short conditioning of the right biceps muscle in normal or cooled conditions were significantly different (-3.335 +/- 1.680 degrees at 36.5 degrees C vs. -5.317 +/- 1.096 degrees at 5.0 degrees C; P=0.043). Induction of a tonic vibration reflex in the biceps muscle elicited involuntary forearm elevation, and the angular velocities of the elevation differed significantly between arms conditioned in normal and cooled environments (1.583 +/- 0.326 degrees /s at 36.5 degrees C vs. 3.100 +/- 0.555 degrees /s at 5.0 degrees C, P=0.0039). Thus, a cooled environment impairs a muscle's ability to provide positional information, potentially leading to poor muscle performance.

Qualitative exploration of stakeholders' perspectives of involuntary admission under the Mental Health Act 2001 in Ireland.

Science.gov (United States)

Smyth, Siobhán; Casey, Dympna; Cooney, Adeline; Higgins, Agnes; McGuinness, David; Bainbridge, Emma; Keys, Mary; Georgieva, Irina; Brosnan, Liz; Beecher, Claire; Hallahan, Brian; McDonald, Colm; Murphy, Kathy

2017-12-01

There is international interest in, and continued concern about, the potential long-term impact of involuntary admission to psychiatric institutions, and the effect this coercive action has on a person's well-being and human rights. Involuntary detention in hospital remains a controversial process that involves stakeholders with competing concerns and who often describe negative experiences of the process, which can have long-lasting effects on the therapeutic relationship with service users. The aim of the present study was to explore the perspectives of key stakeholders involved in the involuntary admission and detention of people under the Mental Health Act 2001 in Ireland. Focus groups were used to collect data. Stakeholders interviewed were service users, relatives, general practitioners, psychiatrists, mental health nurses, solicitors, tribunal members, and police. Data were analysed using a general inductive approach. Three key categories emerged: (i) getting help; (ii) detention under the Act; and (iii) experiences of the tribunal process. This research highlights gaps in information and uncertainty about the involuntary admission process for stakeholders, but particularly for service users who are most affected by inadequate processes and supports. Mental health law has traditionally focussed on narrower areas of detention and treatment, but human rights law requires a greater refocussing on supporting service users to ensure a truly voluntary approach to care. The recent human rights treaty, the UN Convention on the Rights of Persons with Disabilities, is to guarantee a broad range of fundamental rights, such as liberty and integrity, which can be affected by coercive processes of involuntary admission and treatment. © 2016 Australian College of Mental Health Nurses Inc.

26 CFR 1.1033(c)-1 - Disposition of excess property within irrigation project deemed to be involuntary conversion.

Science.gov (United States)

2010-04-01

... project deemed to be involuntary conversion. 1.1033(c)-1 Section 1.1033(c)-1 Internal Revenue INTERNAL... Nontaxable Exchanges § 1.1033(c)-1 Disposition of excess property within irrigation project deemed to be... project or division shall be treated as an involuntary conversion to which the provisions of section 1033...

Dynamic model of the octopus arm. I. Biomechanics of the octopus reaching movement.

Science.gov (United States)

Yekutieli, Yoram; Sagiv-Zohar, Roni; Aharonov, Ranit; Engel, Yaakov; Hochner, Binyamin; Flash, Tamar

2005-08-01

The octopus arm requires special motor control schemes because it consists almost entirely of muscles and lacks a rigid skeletal support. Here we present a 2D dynamic model of the octopus arm to explore possible strategies of movement control in this muscular hydrostat. The arm is modeled as a multisegment structure, each segment containing longitudinal and transverse muscles and maintaining a constant volume, a prominent feature of muscular hydrostats. The input to the model is the degree of activation of each of its muscles. The model includes the external forces of gravity, buoyancy, and water drag forces (experimentally estimated here). It also includes the internal forces generated by the arm muscles and the forces responsible for maintaining a constant volume. Using this dynamic model to investigate the octopus reaching movement and to explore the mechanisms of bend propagation that characterize this movement, we found the following. 1) A simple command producing a wave of muscle activation moving at a constant velocity is sufficient to replicate the natural reaching movements with similar kinematic features. 2) The biomechanical mechanism that produces the reaching movement is a stiffening wave of muscle contraction that pushes a bend forward along the arm. 3) The perpendicular drag coefficient for an octopus arm is nearly 50 times larger than the tangential drag coefficient. During a reaching movement, only a small portion of the arm is oriented perpendicular to the direction of movement, thus minimizing the drag force.

Multi-Joint Dynamics and the Development of Movement Control

Directory of Open Access Journals (Sweden)

E. Otten

2005-01-01

Full Text Available The movement control of articulated limbs in humans has been explained in terms of equilibrium points and moving equilibrium points or virtual trajectories. One hypothesis is that the nervous system controls multi-segment limbs by simply planning in terms of these equilibrium points and trajectories. The present paper describes a planar computer simulation of an articulated three-segment limb, controlled by pairs of muscles. The shape of the virtual trajectory is analyzed when the limb is required to make fast movements with endpoint movements along a straight line with bell-shaped velocity profiles. Apparently, the faster the movement, the more the virtual trajectory deviates from the real trajectory and becomes up to eight times longer. The complexity of the shape of the virtual trajectories and its length in these fast movements makes it unlikely that the nervous system plans using these trajectories. it seems simpler to set up the required bursts of muscle activation, coupled in the nervous system to the direction of movement, the s peed, and the place in workspace. Finally, it is argued that the two types of explanation do not contradict each other: when a relation is established in the nervous system between muscle activation and movements, equilibrium points and virtual trajectories are necessarily part of that relation.

Changing Artificial Playback Speed and Real Movement Velocity Do Not Differentially Influence the Excitability of Primary Motor Cortex during Observation of a Repetitive Finger Movement

Directory of Open Access Journals (Sweden)

Takefumi Moriuchi

2017-11-01

Full Text Available Action observation studies have investigated whether changing the speed of the observed movement affects the action observation network. There are two types of speed-changing conditions; one involves “changes in actual movement velocity,” and the other is “manipulation of video speed.” Previous studies have investigated the effects of these conditions separately, but to date, no study has directly investigated the differences between the effects of these conditions. In the “movement velocity condition,” increased velocity is associated with increased muscle activity; however, this change of muscle activities is not shown in the “video speed condition.” Therefore, a difference in the results obtained under these conditions could be considered to reflect a difference in muscle activity of actor in the video. The aim of the present study was to investigate the effects of different speed-changing conditions and spontaneous movement tempo (SMT on the excitability of primary motor cortex (M1 during action observation, as assessed by motor-evoked potentials (MEPs amplitudes induced by transcranial magnetic stimulation (TMS. A total of 29 healthy subjects observed a video clip of a repetitive index or little finger abduction movement under seven different speed conditions. The video clip in the movement velocity condition showed repetitive finger abduction movements made in time with an auditory metronome, at frequencies of 0.5, 1, 2, and 3 Hz. In the video speed condition, playback of the 1-Hz movement velocity condition video clip was modified to show movement frequencies of 0.5, 2, or 3 Hz (Hz-Fake. TMS was applied at the time of maximal abduction and MEPs were recorded from two right-hand muscles. There were no differences in M1 excitability between the movement velocity and video speed conditions. Moreover, M1 excitability did not vary across the speed conditions for either presentation condition. Our findings suggest that changing

Patient-specific fibre-based models of muscle wrapping

Science.gov (United States)

Kohout, J.; Clapworthy, G. J.; Zhao, Y.; Tao, Y.; Gonzalez-Garcia, G.; Dong, F.; Wei, H.; Kohoutová, E.

2013-01-01

In many biomechanical problems, the availability of a suitable model for the wrapping of muscles when undergoing movement is essential for the estimation of forces produced on and by the body during motion. This is an important factor in the Osteoporotic Virtual Physiological Human project which is investigating the likelihood of fracture for osteoporotic patients undertaking a variety of movements. The weakening of their skeletons makes them particularly vulnerable to bone fracture caused by excessive loading being placed on the bones, even in simple everyday tasks. This paper provides an overview of a novel volumetric model that describes muscle wrapping around bones and other muscles during movement, and which includes a consideration of how the orientations of the muscle fibres change during the motion. The method can calculate the form of wrapping of a muscle of medium size and visualize the outcome within tenths of seconds on commodity hardware, while conserving muscle volume. This makes the method suitable not only for educational biomedical software, but also for clinical applications used to identify weak muscles that should be strengthened during rehabilitation or to identify bone stresses in order to estimate the risk of fractures. PMID:24427519

Single motor unit firing behaviour in the right trapezius muscle during rapid movement of right or left index finger.

Directory of Open Access Journals (Sweden)

Karen eSøgaard

2014-11-01

Full Text Available Computer work is associated with low level sustained activity in the trapezius muscle that may cause myalgia. The activity may be attention related or part of a general multijoint motor program providing stabilization of the shoulder girdle for precise finger manipulation. This study examines single motor unit (MU firing pattern in the right trapezius muscle during fast movements of ipsi or contralateral index finger. Modulated firing rate would support a general multi joint motor program, while a generally increased and continuous firing rate would support attention related activation. 12 healthy female subjects were seated at a computer work place with elbows and forearms supported. Ten double clicks (DC were performed with right and left index finger on a computer mouse instrumented with a trigger.Surface EMG was recorded from right and left trapezius muscle. Intramuscular EMG was recorded with a quadripolar wire electrode in the right trapezius.Surface EMG was analysed as %MVE. The intramuscular EMG was decomposed into individual MU action potential trains. Instantaneous firing rate (IFR was calculated from inter-spike interval with ISI shorter than 20 ms defined as doublets. IFR was averaged across 10 DC to show IFR modulation.Surface EMG in both right and left trapezius was 1.8-2.5%MVE. During right hand DC a total of 32 MUs were identified. Four subjects showed no activity. Four showed MU activity with weak or no variations related to the timing of DC. Four subjects showed large modulation in IFR with temporal relation to DC. During left hand DC 15 MUs were identified in 4 subjects, for two of the subjects with IFR modulations related to DC. Doublets was found as an integrated part of MU activation in the trapezius muscle and for one subject temporarily related to DC. In conclusion, DC with ipsi- and contralateral fast movements of the index finger was found to evoke biomechanically as well as attention related activity pattern in the

Compulsory outpatient treatment can prevent involuntary commitment

DEFF Research Database (Denmark)

Hansen, Lene Nørregård; Svensson, Eva Maria Birgitta; Brandt-Christensen, Anne Mette

2014-01-01

Compulsory outpatient treatment (co-pt) has been possible in Denmark since 2010. The aim is to secure necessary treatment, reduce involuntary commitment and improve quality of life for patients with a severe psychiatric illness. Co-pt has been brought into use in 33 cases. This case report...... describes a patient with paranoid schizophrenia who several times developed severe psychotic symptoms shortly after discharge due to lack of compliance with treatment. Within one year of co-pt the patient was not admitted to hospital and improved in overall functioning. After terminating co-pt the patient...

Brain activation associated with eccentric movement: A narrative review of the literature.

Science.gov (United States)

Perrey, Stéphane

2018-02-01

The movement occurring when a muscle exerts tension while lengthening is known as eccentric muscle action. Literature contains limited evidence on how our brain controls eccentric movement. However, how the cortical regions in the motor network are activated during eccentric muscle actions may be critical for understanding the underlying control mechanism of eccentric movements encountered in daily tasks. This is a novel topic that has only recently begun to be investigated through advancements in neuroimaging methods (electroencephalography, EEG; functional magnetic resonance imaging, fMRI). This review summarizes a selection of seven studies indicating mainly: longer time and higher cortical signal amplitude (EEG) for eccentric movement preparation and execution, greater magnitude of cortical signals with wider activated brain area (EEG, fMRI), and weaker brain functional connectivity (fMRI) between primary motor cortex (M1) and other cortical areas involved in the motor network during eccentric muscle actions. Only some differences among studies due to the forms of movement with overload were observed in the contralateral (to the active hand) M1 activity during eccentric movement. Altogether, the findings indicate an important challenge to the brain for controlling the eccentric movement. However, our understanding remains limited regarding the acute effects of eccentric exercise on cortical regions and their cooperation as functional networks that support motor functions. Further analysis and standardized protocols will provide deeper insights into how different cortical regions of the underlying motor network interplay with each other in increasingly demanding muscle exertions in eccentric mode.

On the origin of muscle synergies: invariant balance in the co-activation of agonist and antagonist muscle pairs

Directory of Open Access Journals (Sweden)

Hiroaki eHirai

2015-11-01

Full Text Available Investigation of neural representation of movement planning has attracted the attention of neuroscientists, as it may reveal the sensorimotor transformation essential to motor control. The analysis of muscle synergies based on the activity of agonist-antagonist (AA muscle pairs may provide insight into such transformations, especially for a reference frame in the muscle space. In this study, we examined the AA concept using the following explanatory variables: the AA ratio, which is related to the equilibrium-joint angle, and the AA sum, which is associated with joint stiffness. We formulated muscle synergies as a function of AA sums, positing that muscle synergies are composite units of mechanical impedance. The AA concept can be regarded as another form of the equilibrium-point (EP hypothesis, and it can be extended to the concept of EP-based synergies. We introduce here a novel tool for analyzing the neurological and motor functions underlying human movements and review some initial insights from our results about the relationships between muscle synergies, endpoint stiffness, and virtual trajectories (time series of EP. Our results suggest that (1 muscle synergies reflect an invariant balance in the co-activation of AA muscle pairs; (2 each synergy represents the basis for the radial, tangential, and null movements of the virtual trajectory in the polar coordinates centered on the specific joint at the base of the body; and (3 the alteration of muscle synergies (for example, due to spasticity or rigidity following neurological injury results in significant distortion of endpoint stiffness and concomitant virtual trajectories. These results indicate that muscle synergies (i.e., the balance of muscle mechanical impedance are essential for motor control.

On the Origin of Muscle Synergies: Invariant Balance in the Co-activation of Agonist and Antagonist Muscle Pairs.

Science.gov (United States)

Hirai, Hiroaki; Miyazaki, Fumio; Naritomi, Hiroaki; Koba, Keitaro; Oku, Takanori; Uno, Kanna; Uemura, Mitsunori; Nishi, Tomoki; Kageyama, Masayuki; Krebs, Hermano Igo

2015-01-01

Investigation of neural representation of movement planning has attracted the attention of neuroscientists, as it may reveal the sensorimotor transformation essential to motor control. The analysis of muscle synergies based on the activity of agonist-antagonist (AA) muscle pairs may provide insight into such transformations, especially for a reference frame in the muscle space. In this study, we examined the AA concept using the following explanatory variables: the AA ratio, which is related to the equilibrium-joint angle, and the AA sum, which is associated with joint stiffness. We formulated muscle synergies as a function of AA sums, positing that muscle synergies are composite units of mechanical impedance. The AA concept can be regarded as another form of the equilibrium-point (EP) hypothesis, and it can be extended to the concept of EP-based synergies. We introduce, here, a novel tool for analyzing the neurological and motor functions underlying human movements and review some initial insights from our results about the relationships between muscle synergies, endpoint stiffness, and virtual trajectories (time series of EP). Our results suggest that (1) muscle synergies reflect an invariant balance in the co-activation of AA muscle pairs; (2) each synergy represents the basis for the radial, tangential, and null movements of the virtual trajectory in the polar coordinates centered on the specific joint at the base of the body; and (3) the alteration of muscle synergies (for example, due to spasticity or rigidity following neurological injury) results in significant distortion of endpoint stiffness and concomitant virtual trajectories. These results indicate that muscle synergies (i.e., the balance of muscle mechanical impedance) are essential for motor control.

The Welfare Effects of Involuntary Part-Time Work

OpenAIRE

Borowczyk-Martins, Daniel; Lalé, Etienne

2016-01-01

Employed individuals in the U.S. are increasingly more likely to work part-time involuntarily than to be unemployed. Spells of involuntary part-time work are different from unemployment spells: a full-time worker who takes on a part-time job suffers an earnings loss while remaining employed, and is unlikely to receive income compensation from publicly-provided insurance programs.We analyze these differences through the lens of an incomplete-market, job-search model featuring unemployment risk...

A simple method for assessment of muscle force, velocity, and power producing capacities from functional movement tasks.

Science.gov (United States)

Zivkovic, Milena Z; Djuric, Sasa; Cuk, Ivan; Suzovic, Dejan; Jaric, Slobodan

2017-07-01

A range of force (F) and velocity (V) data obtained from functional movement tasks (e.g., running, jumping, throwing, lifting, cycling) performed under variety of external loads have typically revealed strong and approximately linear F-V relationships. The regression model parameters reveal the maximum F (F-intercept), V (V-intercept), and power (P) producing capacities of the tested muscles. The aim of the present study was to evaluate the level of agreement between the routinely used "multiple-load model" and a simple "two-load model" based on direct assessment of the F-V relationship from only 2 external loads applied. Twelve participants were tested on the maximum performance vertical jumps, cycling, bench press throws, and bench pull performed against a variety of different loads. All 4 tested tasks revealed both exceptionally strong relationships between the parameters of the 2 models (median R = 0.98) and a lack of meaningful differences between their magnitudes (fixed bias below 3.4%). Therefore, addition of another load to the standard tests of various functional tasks typically conducted under a single set of mechanical conditions could allow for the assessment of the muscle mechanical properties such as the muscle F, V, and P producing capacities.

Mechanical modeling of skeletal muscle functioning

NARCIS (Netherlands)

van der Linden, B.J.J.J.

1998-01-01

For movement of body or body segments is combined effort needed of the central nervous system and the muscular-skeletal system. This thesis deals with the mechanical functioning of skeletal muscle. That muscles come in a large variety of geometries, suggest the existence of a relation between muscle

The involuntary nature of music-evoked autobiographical memories in Alzheimer's disease

NARCIS (Netherlands)

El Haj, M.; Fasotti, L.; Allain, P.

2012-01-01

The main objective of this paper was to examine the involuntary nature of music-evoked autobiographical memories. For this purpose, young adults, older adults, and patients with a clinical diagnosis of probable Alzheimer’s disease (AD) were asked to remember autobiographical events in two

Muscle Contraction.

Science.gov (United States)

Sweeney, H Lee; Hammers, David W

2018-02-01

SUMMARYMuscle cells are designed to generate force and movement. There are three types of mammalian muscles-skeletal, cardiac, and smooth. Skeletal muscles are attached to bones and move them relative to each other. Cardiac muscle comprises the heart, which pumps blood through the vasculature. Skeletal and cardiac muscles are known as striated muscles, because the filaments of actin and myosin that power their contraction are organized into repeating arrays, called sarcomeres, that have a striated microscopic appearance. Smooth muscle does not contain sarcomeres but uses the contraction of filaments of actin and myosin to constrict blood vessels and move the contents of hollow organs in the body. Here, we review the principal molecular organization of the three types of muscle and their contractile regulation through signaling mechanisms and discuss their major structural and functional similarities that hint at the possible evolutionary relationships between the cell types. Copyright © 2018 Cold Spring Harbor Laboratory Press; all rights reserved.

Does retrieval intentionality really matter? Similarities and differences between involuntary memories and directly and generatively retrieved voluntary memories

DEFF Research Database (Denmark)

Barzykowski, Krystian; Staugaard, Søren Risløv

2016-01-01

differences between the characteristics of involuntary and directly retrieved memories. The results imply that retrieval intention seems to differentiate how a memory appears in a person’s mind. Furthermore, we argue that these differences in part could result from differences in encoding and consolidation.......Theories of autobiographical memory distinguish between involuntary and voluntary retrieval as a consequence of conscious intention (i.e., wanting to remember). Another distinction can be made between direct and generative retrieval, which reflects the effort involved (i.e., trying to remember......). However, it is unclear how intention and effort interacts. For example, involuntary memories and directly retrieved memories have been used interchangeably in the literature to refer to the same phenomenon of effortless, nonstrategic retrieval. More recent theoretical advances suggest...

Voluntary and Involuntary Singlehood and Young Adults' Mental Health: an Investigation of Mediating Role of Romantic Loneliness.

Science.gov (United States)

Adamczyk, Katarzyna

2017-01-01

The present study tested the hypothesis that single young adults who perceive their singlehood as voluntary would report a higher level of positive mental health (i.e., emotional, psychological and social well-being), lower levels of mental health illness (i.e., somatic symptoms, anxiety, social dysfunction, severe depression) and romantic loneliness in comparison to young adults who perceive their singlehood as involuntary. This paper also investigated whether romantic loneliness mediates the relationship between voluntary and involuntary singlehood, positive mental health, and mental health illness. The study sample included 151 participants (86 females and 65 males) aged 20-26 ( M  = 22.48, SD  = 2.01) from Poland. The main findings were that voluntarily single young adults reported a lower level of romantic loneliness compared to involuntarily single young adults. The two groups differed neither in regard to positive mental health nor in regard to mental health problems. In addition, gender differences were observed solely in the domain of romantic loneliness, with women reporting greater romantic loneliness than men. The mediation analysis revealed that romantic loneliness does not mediate the relationship between voluntary and involuntary singlehood, positive mental health, and mental health illness. Voluntary and involuntary singlehood was predictive of somatic symptoms, anxiety and insomnia, severe depression, and romantic loneliness.

The timing of control signals underlying fast point-to-point arm movements.

Science.gov (United States)

Ghafouri, M; Feldman, A G

2001-04-01

It is known that proprioceptive feedback induces muscle activation when the facilitation of appropriate motoneurons exceeds their threshold. In the suprathreshold range, the muscle-reflex system produces torques depending on the position and velocity of the joint segment(s) that the muscle spans. The static component of the torque-position relationship is referred to as the invariant characteristic (IC). According to the equilibrium-point (EP) hypothesis, control systems produce movements by changing the activation thresholds and thus shifting the IC of the appropriate muscles in joint space. This control process upsets the balance between muscle and external torques at the initial limb configuration and, to regain the balance, the limb is forced to establish a new configuration or, if the movement is prevented, a new level of static torques. Taken together, the joint angles and the muscle torques generated at an equilibrium configuration define a single variable called the EP. Thus by shifting the IC, control systems reset the EP. Muscle activation and movement emerge following the EP resetting because of the natural physical tendency of the system to reach equilibrium. Empirical and simulation studies support the notion that the control IC shifts and the resulting EP shifts underlying fast point-to-point arm movements are gradual rather than step-like. However, controversies exist about the duration of these shifts. Some studies suggest that the IC shifts cease with the movement offset. Other studies propose that the IC shifts end early in comparison to the movement duration (approximately, at peak velocity). The purpose of this study was to evaluate the duration of the IC shifts underlying fast point-to-point arm movements. Subjects made fast (hand peak velocity about 1.3 m/s) planar arm movements toward different targets while grasping a handle. Hand forces applied to the handle and shoulder/elbow torques were, respectively, measured from a force sensor placed

Mending new communities after involuntary resettlement in the Philippines and Indonesia

NARCIS (Netherlands)

Quetulio-Navarra, M.

2014-01-01

Displacement of poor families contribute to the worsening of their poverty situation yet involuntary resettlement still takes place. According to the latest Report of the Indonesian Centre on Housing Rights and Eviction, more than 12,000 people were reportedly evicted in August 2008 to give way

The involuntary nature of music-evoked autobiographical memories in Alzheimer's disease.

Science.gov (United States)

El Haj, Mohamad; Fasotti, Luciano; Allain, Philippe

2012-03-01

The main objective of this paper was to examine the involuntary nature of music-evoked autobiographical memories. For this purpose, young adults, older adults, and patients with a clinical diagnosis of probable Alzheimer's disease (AD) were asked to remember autobiographical events in two conditions: after being exposed to their own chosen music, and in silence. Compared to memories evoked in silence, memories evoked in the "Music" condition were found to be more specific, accompanied by more emotional content and impact on mood, and retrieved faster. In addition, these memories engaged less executive processes. Thus, with all these characteristics and the fact that they are activated by a perceptual cue (i.e., music), music-evoked autobiographic memories have all the features to be considered as involuntary memories. Our paper reveals several characteristics of music-evoked autobiographical memories in AD patients and offers a theoretical background for this phenomenon. Copyright © 2012 Elsevier Inc. All rights reserved.

Classics in psychiatry and the law: Francis Wharton on involuntary confessions.

Science.gov (United States)

Weiss, Kenneth J

2012-01-01

Philadelphia attorney Francis Wharton was a key intellectual figure in linking the sciences of medicine and law. In 1860, he published a monograph on involuntary confessions, which represented the closing chapter of Wharton and Stillé's Treatise on Medical Jurisprudence. He had already published A Monograph on Mental Unsoundness in 1855, the first book of the Treatise in its first edition. Wharton was convinced that many criminals had an inner compulsion to confess or to be caught, explained as divine jurisprudence. His remarks on confessions include a typology spanning psychodynamics to police tactics, using contemporaneous, historical, and literary examples. This remarkable document provides insight into the dynamics of unintended and involuntary confessions and is compatible, in part, with current scholarship. The author contrasts Wharton's schema with those of his English predecessor Jeremy Bentham, the psychoanalyst Theodore Reik, and others, and concludes that it represents an important transition toward a psychological approach to the criminology of confessions.

Voluntary eye movements direct attention on the mental number space.

Science.gov (United States)

Ranzini, Mariagrazia; Lisi, Matteo; Zorzi, Marco

2016-05-01

Growing evidence suggests that orienting visual attention in space can influence the processing of numerical magnitude, with leftward orienting speeding up the processing of small numbers relative to larger ones and the converse for rightward orienting. The manipulation of eye movements is a convenient way to direct visuospatial attention, but several aspects of the complex relationship between eye movements, attention orienting and number processing remain unexplored. In a previous study, we observed that inducing involuntary, reflexive eye movements by means of optokinetic stimulation affected number processing only when numerical magnitude was task relevant (i.e., during magnitude comparison, but not during parity judgment; Ranzini et al., in J Cogn Psychol 27, 459-470, (2015). Here, we investigated whether processing of task-irrelevant numerical magnitude can be modulated by voluntary eye movements, and whether the type of eye movements (smooth pursuit vs. saccades) would influence this interaction. Participants tracked with their gaze a dot while listening to a digit. The numerical task was to indicate whether the digit was odd or even through non-spatial, verbal responses. The dot could move leftward or rightward either continuously, allowing tracking by smooth pursuit eye movements, or in discrete steps across a series of adjacent locations, triggering a sequence of saccades. Both smooth pursuit and saccadic eye movements similarly affected number processing and modulated response times for large numbers as a function of direction of motion. These findings suggest that voluntary eye movements redirect attention in mental number space and highlight that eye movements should play a key factor in the investigation of number-space interactions.

Mind-muscle connection training principle: influence of muscle strength and training experience during a pushing movement.

Science.gov (United States)

Calatayud, Joaquin; Vinstrup, Jonas; Jakobsen, Markus D; Sundstrup, Emil; Colado, Juan Carlos; Andersen, Lars L

2017-07-01

To investigate the effect of different attentional focus conditions on muscle activity during the push-up exercise and to assess the possible influence of muscle strength and training experience. Eighteen resistance-trained men performed 1RM bench press testing and were familiarized with the procedure during the first session. In the second session, three different conditions were randomly performed: regular push-up and push-up focusing on using the pectoralis major and triceps brachii muscles, respectively. Surface electromyography (EMG) was recorded and analyzed (EMG normalized to max; nEMG) for the triceps brachii and pectoralis major muscles. Participants had on average 8 (SD 6) years of training experience and 1RM of 1.25 (SD 0.28) kg per kg bodyweight. Focusing on using pectoralis major increased activity in this muscle by 9% nEMG (95% CI 5-13; Cohen's d 0.60) compared with the regular condition. Triceps activity was not significantly influenced by triceps focus although borderline significant, with a mean difference of 5% nEMG (95% CI 0-10; Cohen's d 0.30). However, years of training experience was positively associated with the ability to selectively activate the triceps (β = 0.41, P = 0.04), but not the pectoralis. Bench press 1RM was not significantly associated with the ability to selectively activate the muscles. Pectoralis activity can be increased when focusing on using this muscle during push-ups, whereas the ability to do this for the triceps is dependent on years of training experience. Maximal muscle strength does not appear to be a decisive factor for the ability to selectively activate these muscles.

(Re)Constructing Career Strategies After Experiencing Involuntary Job Loss

OpenAIRE

Mulhall, Sue

2014-01-01

This research article focuses on experiences of involuntary job loss following organisational change as occasions for career (re)construction. Using narrative inquiry, it explores the career stories of four former professionals on an Irish active labour market programme assisting the long-term unemployed to transition to employment. The article portrays how, and in what ways, the participants respond when confronted with transformation. Offering an empirically grounded understanding of the ch...

Effects of slip-induced changes in ankle movement on muscle activity and ground reaction forces during running acceleration

DEFF Research Database (Denmark)

Ketabi, Shahin; Kersting, Uwe G.

2013-01-01

Ground contact in running is always linked to a minimum amount of slipping, e.g., during the early contact phase when horizontal forces are high compared to vertical forces. Studies have shown altered muscular activation when expecting slips [2-4]. It is not known what the mechanical effect of su...... of such slip episodes are on joint loading or performance. The aim of the present study was to examine the effect of changes in ankle movement on ankle joint loading, muscle activity, and ground reaction forces during linear acceleration....

Involuntary psychiatric holds - the structure of admissions on the example of Institute of Psychiatry and Neurology in Warsaw.

Science.gov (United States)

Markiewicz, Inga; Heitzman, Janusz; Gardyńska-Ziemba, Ewa

2016-01-01

The aim of the study was to analyse the structure of involuntary psychiatric holds in Institute of Psychiatry and Neurology in Warsaw, throughout the year. Our research interests included socio-demographic profiles of the patients, time of admissions (time of a day/night/ season), type of diagnoses at admission and suicide attempts preceding the admission. We also analysed the normative aspect of involuntary admissions, i.e. which Articles of the Polish Mental Health Act constituted the basis for these patients admission, and if the choice of articles was justifiable by a diagnosis of the mental disorder. The primary research tool consisted of an original questionnaire allowing for the collection of relevant data. The material was submitted to statistical analysis, using primarily simple percentage methods. Involuntary psychiatric holds constituted 15.8% of the total number of admissions to the Institute of Psychiatry and Neurology (3,498 persons) in 2012. 522 persons with mental disorders were subject to involuntary admission on emergency basis (292 women and 260 men). Majority of patients was over 40 years old. The number of patients admitted to the Institute of Psychiatry and Neurology on emergency basis without the consent ranged from 38 to 62 people per month. Season did not differentiate significantly the number of admitted persons, majority of patients was admitted during the day (82%). Among the diagnosed patients, paranoid schizophrenia was the most frequent illness (43%), delirium tremens (7%), bipolar disorders (6%), dementia (5%), other psychotic disorders (5%), paranoid syndrome (5%), schizoaffective disorder (5%), other diagnoses (less than 1%). 4% of admissions to the Institute of Psychiatry and Neurology were due to attempted suicide. 37% of patients were admitted to the Institute of Psychiatry and Neurology under Article 23.1 of the Mental Health Act, 34% under Article 22.2, in accordance with Article 24.1 - only 7% of patients. Invoking Article 28

Muscle Co-activation: Definitions, Mechanisms, and Functions.

Science.gov (United States)

Latash, Mark L

2018-03-28

The phenomenon of agonist-antagonist muscle co-activation is discussed with respect to its consequences for movement mechanics (such as increasing joint apparent stiffness, facilitating faster movements, and effects on action stability), implication for movement optimization, and involvement of different neurophysiological structures. Effects of co-activation on movement stability are ambiguous and depend on the effector representing a kinematic chain with a fixed origin or free origin. Further, co-activation is discussed within the framework of the equilibrium-point hypothesis and the idea of hierarchical control with spatial referent coordinates. Relations of muscle co-activation to changes in one of the basic commands, the c-command, are discussed and illustrated. A hypothesis is suggested that agonist-antagonist co-activation reflects a deliberate neural control strategy to preserve effector-level control and avoid making it degenerate and facing the necessity to control at the level of signals to individual muscles. This strategy, in particular, allows stabilizing motor actions by co-varied adjustments in spaces of control variables. This hypothesis is able to account for higher levels of co-activation in young healthy persons performing challenging tasks and across various populations with movement impairments.

Physiological modules for generating discrete and rhythmic movements: component analysis of EMG signals.

Science.gov (United States)

Bengoetxea, Ana; Leurs, Françoise; Hoellinger, Thomas; Cebolla, Ana Maria; Dan, Bernard; Cheron, Guy; McIntyre, Joseph

2014-01-01

A central question in Neuroscience is that of how the nervous system generates the spatiotemporal commands needed to realize complex gestures, such as handwriting. A key postulate is that the central nervous system (CNS) builds up complex movements from a set of simpler motor primitives or control modules. In this study we examined the control modules underlying the generation of muscle activations when performing different types of movement: discrete, point-to-point movements in eight different directions and continuous figure-eight movements in both the normal, upright orientation and rotated 90°. To test for the effects of biomechanical constraints, movements were performed in the frontal-parallel or sagittal planes, corresponding to two different nominal flexion/abduction postures of the shoulder. In all cases we measured limb kinematics and surface electromyographic activity (EMG) signals for seven different muscles acting around the shoulder. We first performed principal component analysis (PCA) of the EMG signals on a movement-by-movement basis. We found a surprisingly consistent pattern of muscle groupings across movement types and movement planes, although we could detect systematic differences between the PCs derived from movements performed in each shoulder posture and between the principal components associated with the different orientations of the figure. Unexpectedly we found no systematic differences between the figure eights and the point-to-point movements. The first three principal components could be associated with a general co-contraction of all seven muscles plus two patterns of reciprocal activation. From these results, we surmise that both "discrete-rhythmic movements" such as the figure eight, and discrete point-to-point movement may be constructed from three different fundamental modules, one regulating the impedance of the limb over the time span of the movement and two others operating to generate movement, one aligned with the

Changes in muscle coordination with training.

Science.gov (United States)

Carson, Richard G

2006-11-01

Three core concepts, activity-dependent coupling, the composition of muscle synergies, and Hebbian adaptation, are discussed with a view to illustrating the nature of the constraints imposed by the organization of the central nervous system on the changes in muscle coordination induced by training. It is argued that training invoked variations in the efficiency with which motor actions can be generated influence the stability of coordination by altering the potential for activity-dependent coupling between the cortical representations of the focal muscles recruited in a movement task and brain circuits that do not contribute directly to the required behavior. The behaviors that can be generated during training are also constrained by the composition of existing intrinsic muscle synergies. In circumstances in which attempts to produce forceful or high velocity movements would otherwise result in the generation of inappropriate actions, training designed to promote the development of control strategies specific to the desired movement outcome may be necessary to compensate for protogenic muscle recruitment patterns. Hebbian adaptation refers to processes whereby, for neurons that release action potentials at the same time, there is an increased probability that synaptic connections will be formed. Neural connectivity induced by the repetition of specific muscle recruitment patterns during training may, however, inhibit the subsequent acquisition of new skills. Consideration is given to the possibility that, in the presence of the appropriate sensory guidance, it is possible to gate Hebbian plasticity and to promote greater subsequent flexibility in the recruitment of the trained muscles in other task contexts.

Dynamic modulation of corticospinal excitability and short-latency afferent inhibition during onset and maintenance phase of selective finger movement.

Science.gov (United States)

Cho, Hyun Joo; Panyakaew, Pattamon; Thirugnanasambandam, Nivethida; Wu, Tianxia; Hallett, Mark

2016-06-01

During highly selective finger movement, corticospinal excitability is reduced in surrounding muscles at the onset of movement but this phenomenon has not been demonstrated during maintenance of movement. Sensorimotor integration may play an important role in selective movement. We sought to investigate how corticospinal excitability and short-latency afferent inhibition changes in active and surrounding muscles during onset and maintenance of selective finger movement. Using transcranial magnetic stimulation (TMS) and paired peripheral stimulation, input-output recruitment curve and short-latency afferent inhibition (SAI) were measured in the first dorsal interosseus and abductor digiti minimi muscles during selective index finger flexion. Motor surround inhibition was present only at the onset phase, but not at the maintenance phase of movement. SAI was reduced at onset but not at the maintenance phase of movement in both active and surrounding muscles. Our study showed dynamic changes in corticospinal excitability and sensorimotor modulation for active and surrounding muscles in different movement states. SAI does not appear to contribute to motor surround inhibition at the movement onset phase. Also, there seems to be different inhibitory circuit(s) other than SAI for the movement maintenance phase in order to delineate the motor output selectively when corticospinal excitability is increased in both active and surrounding muscles. This study enhances our knowledge of dynamic changes in corticospinal excitability and sensorimotor interaction in different movement states to understand normal and disordered movements. Published by Elsevier Ireland Ltd.

The Moving Rubber Hand Illusion Reveals that Explicit Sense of Agency for Tapping Movements Is Preserved in Functional Movement Disorders

Directory of Open Access Journals (Sweden)

Angela Marotta

2017-06-01

Full Text Available Functional movement disorders (FMD are characterized by motor symptoms (e.g., tremor, gait disorder, and dystonia that are not compatible with movement abnormalities related to a known organic cause. One key clinical feature of FMD is that motor symptoms are similar to voluntary movements but are subjectively experienced as involuntary by patients. This gap might be related to abnormal self-recognition of bodily action, which involves two main components: sense of agency and sense of body ownership. The aim of this study was to systematically investigate whether this function is altered in FMD, specifically focusing on the subjective feeling of agency, body ownership, and their interaction during normal voluntary movements. Patients with FMD (n = 21 and healthy controls (n = 21 underwent the moving Rubber Hand Illusion (mRHI, in which passive and active movements can differentially elicit agency, ownership or both. Explicit measures of agency and ownership were obtained via a questionnaire. Patients and controls showed a similar pattern of response: when the rubber hand was in a plausible posture, active movements elicited strong agency and ownership; implausible posture of the rubber hand abolished ownership but not agency; passive movements suppressed agency but not ownership. These findings suggest that explicit sense of agency and body ownership are preserved in FMD. The latter finding is shared by a previous study in FMD using a static version of the RHI, whereas the former appears to contrast with studies demonstrating altered implicit measures of agency (e.g., sensory attenuation. Our study extends previous findings by suggesting that in FMD: (i the sense of body ownership is retained also when interacting with the motor system; (ii the subjective experience of agency for voluntary tapping movements, as measured by means of mRHI, is preserved.

Feed-forward motor control of ultrafast, ballistic movements.

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Kagaya, K; Patek, S N

2016-02-01

To circumvent the limits of muscle, ultrafast movements achieve high power through the use of springs and latches. The time scale of these movements is too short for control through typical neuromuscular mechanisms, thus ultrafast movements are either invariant or controlled prior to movement. We tested whether mantis shrimp (Stomatopoda: Neogonodactylus bredini) vary their ultrafast smashing strikes and, if so, how this control is achieved prior to movement. We collected high-speed images of strike mechanics and electromyograms of the extensor and flexor muscles that control spring compression and latch release. During spring compression, lateral extensor and flexor units were co-activated. The strike initiated several milliseconds after the flexor units ceased, suggesting that flexor activity prevents spring release and determines the timing of strike initiation. We used linear mixed models and Akaike's information criterion to serially evaluate multiple hypotheses for control mechanisms. We found that variation in spring compression and strike angular velocity were statistically explained by spike activity of the extensor muscle. The results show that mantis shrimp can generate kinematically variable strikes and that their kinematics can be changed through adjustments to motor activity prior to the movement, thus supporting an upstream, central-nervous-system-based control of ultrafast movement. Based on these and other findings, we present a shishiodoshi model that illustrates alternative models of control in biological ballistic systems. The discovery of feed-forward control in mantis shrimp sets the stage for the assessment of targets, strategic variation in kinematics and the role of learning in ultrafast animals. © 2016. Published by The Company of Biologists Ltd.

Sociodemographic and medical characteristics of involuntary psychiatric inpatients--retrospective study of five-year experience with Croatian Act on Mental Health.

Science.gov (United States)

Potkonjak, Jelena; Karlović, Dalibor

2008-09-01

The aim of this study was to analyze sociodemographic and medical characteristics of involuntary psychiatric inpatients treated during the five-year period of implementation of the Croatian Act on Mental Health. Data on involuntarily hospitalized patients according to the Croatian Act on Mental Health were singled out from the pool of inpatients treated at University Department of Psychiatry, Sestre milosrdnice University Hospital from January 1, 1998 till December 31, 2002. Data were collected from medical records. Patients were diagnosed according to the International Classification of Diseases, 10th revision criteria. The prevalence of involuntary hospitalization was 2%, including a comparative number of male and female patients. Most patients had secondary school, were living alone, were unmarried, widowed or divorced, and did not work at the time of hospitalization; however, most patients had some kind of health insurance. Schizophrenia was the most common diagnosis in involuntary psychiatric inpatients. In conclusion, scientific evaluation of involuntary hospitalization poses a major problem because of the many different factors that can influence the prevalence of involuntary hospitalization. Some of this factors are type of institution (psychiatric hospital or psychiatry department at a general hospital), organization of psychiatric care in the region, psychiatric morbidity and dynamics of changes in psychiatric morbidity in a specific region, public opinion about people with mental disorders, legal provisions on this very sensitive topic, etc.

An ocular biomechanic model for dynamic simulation of different eye movements.

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Iskander, J; Hossny, M; Nahavandi, S; Del Porto, L

2018-04-11

Simulating and analysing eye movement is useful for assessing visual system contribution to discomfort with respect to body movements, especially in virtual environments where simulation sickness might occur. It can also be used in the design of eye prosthesis or humanoid robot eye. In this paper, we present two biomechanic ocular models that are easily integrated into the available musculoskeletal models. The model was previously used to simulate eye-head coordination. The models are used to simulate and analyse eye movements. The proposed models are based on physiological and kinematic properties of the human eye. They incorporate an eye-globe, orbital suspension tissues and six muscles with their connective tissues (pulleys). Pulleys were incorporated in rectus and inferior oblique muscles. The two proposed models are the passive pulleys and the active pulleys models. Dynamic simulations of different eye movements, including fixation, saccade and smooth pursuit, are performed to validate both models. The resultant force-length curves of the models were similar to the experimental data. The simulation results show that the proposed models are suitable to generate eye movement simulations with results comparable to other musculoskeletal models. The maximum kinematic root mean square error (RMSE) is 5.68° and 4.35° for the passive and active pulley models, respectively. The analysis of the muscle forces showed realistic muscle activation with increased muscle synergy in the active pulley model. Copyright © 2018 Elsevier Ltd. All rights reserved.

Commercial sex behaviours among involuntary male bachelors: findings from a survey of migrants in Xi'an, China.

Science.gov (United States)

Yang, Xueyan; Li, Shuzhuo; Attané, Isabelle; Feldman, Marcus W

2015-06-01

The highly male-biased sex ratio at birth has produced a severe male 'marriage squeeze' in China. However, with an imbalanced sex ratio, the marriage-squeezed or involuntary bachelors can meet their sexual needs only through ways other than marriage. To investigate the commercial sex behaviours of involuntary bachelors, we conducted a survey on reproductive health and family living among male migrant bachelors in Xi'an City, the capital of Shaanxi Province, from December 2009 to January 2010. The prevalence of commercial sex use was 37.2% among unmarried men, 30.1% among married but separated men and 17.2% among married and cohabitating men (χ(2) = 31.33; P = 0.000; df = 2). Marital status, knowledge about acquired immunodeficiency syndrome (AIDS), age and income were associated with the prevalence and frequency of commercial sex behaviours. Condom use was less frequent among involuntary bachelors and was significantly associated with knowledge about AIDS and other sexually transmitted diseases, the frequency of commercial sex behaviours, marital status and age. The higher prevalence of commercial sex behaviours and the lower frequency of condom use indicate a higher risk of disease from commercial sex among involuntary bachelors, implicating both individual and public health. © The Author 2014. Published by Oxford University Press on behalf of Faculty of Public Health. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Investigation of Innervation Zone Shift with Continuous Dynamic Muscle Contraction

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Ken Nishihara

2013-01-01

Full Text Available Innervation zone (IZ has been identified as the origin of action potential propagation in isometric contraction. However, IZ shifts with changes in muscle length during muscle activity. The IZ shift has been estimated using raw EMG signals. This study aimed to investigate the movement of IZ location during continuous dynamic muscle contraction, using a computer program. Subjects flexed their elbow joint as repetitive dynamic muscle contractions. EMG signals were recorded from the biceps brachii muscle using an eight-channel surface electrode array. Approximately 100 peaks from EMG signals were detected for each channel and summed to estimate the IZ location. For each subject, the estimated IZ locations were subtracted from the IZ location during isometric contractions with the elbow flexed at 90°. The results showed that the IZ moved significantly with elbow joint movement from 45° to 135°. However, IZ movement was biased with only a 3.9 mm IZ shift on average when the elbow angle was acute but a 16 mm IZ shift on average when it was obtuse. The movement of IZ location during continuous dynamic muscle contraction can be investigated using this signal processing procedure without subjective judgment.

The scoring of movements in sleep.

Science.gov (United States)

Walters, Arthur S; Lavigne, Gilles; Hening, Wayne; Picchietti, Daniel L; Allen, Richard P; Chokroverty, Sudhansu; Kushida, Clete A; Bliwise, Donald L; Mahowald, Mark W; Schenck, Carlos H; Ancoli-Israel, Sonia

2007-03-15

The International Classification of Sleep Disorders (ICSD-2) has separated sleep-related movement disorders into simple, repetitive movement disorders (such as periodic limb movements in sleep [PLMS], sleep bruxism, and rhythmic movement disorder) and parasomnias (such as REM sleep behavior disorder and disorders of partial arousal, e.g., sleep walking, confusional arousals, night terrors). Many of the parasomnias are characterized by complex behaviors in sleep that appear purposeful, goal directed and voluntary but are outside the conscious awareness of the individual and therefore inappropriate. All of the sleep-related movement disorders described here have specific polysomnographic findings. For the purposes of developing and/or revising specifications and polysomnographic scoring rules, the AASM Scoring Manual Task Force on Movements in Sleep reviewed background literature and executed evidence grading of 81 relevant articles obtained by a literature search of published articles between 1966 and 2004. Subsequent evidence grading identified limited evidence for reliability and/or validity for polysomnographic scoring criteria for periodic limb movements in sleep, REM sleep behavior disorder, and sleep bruxism. Published scoring criteria for rhythmic movement disorder, excessive fragmentary myoclonus, and hypnagogic foot tremor/alternating leg muscle activation were empirical and based on descriptive studies. The literature review disclosed no published evidence defining clinical consequences of excessive fragmentary myoclonus or hypnagogic foot tremor/alternating leg muscle activation. Because of limited or absent evidence for reliability and/or validity, a standardized RAND/UCLA consensus process was employed for recommendation of specific rules for the scoring of sleep-associated movements.

Passive leg movement enhances interstitial VEGF protein, endothelial cell proliferation, and eNOS mRNA content in human skeletal muscle

DEFF Research Database (Denmark)

Hellsten, Ylva; Rufener, Nora; Nielsen, Jens J

2008-01-01

.05) in blood flow without a significant enhancement in oxygen uptake. Muscle interstitial fluid was sampled with microdialysis technique and analyzed for vascular endothelial growth factor (VEGF) protein and for the effect on endothelial cell proliferation. Biopsies obtained from the musculus vastus lateralis...... to cultured endothelial cells revealed that dialysate obtained during leg movement induced a 3.2-fold higher proliferation rate (P level fourfold above resting levels. VEGF mRNA and MMP-2 mRNA levels were...

ROLE OF HAMSTRING MUSCLES IN KNEE JOINT STABILITY PROVIDING AND INJURY PREVENTION

OpenAIRE

Pontaga, Inese

2016-01-01

The aim of our investigation was to determine the ratio of maximal torque values and the torques in the certain positions of range of movements (ROM) between hamstring (H) and quadriceps femoris (Q) muscles at medium and high velocity of movement in concentric (CC) and eccentric (ECC) action of hamstring muscles. The knee muscles of 15 amateur female short and middle distance runners were tested by the dynamometer system in the isokinetic movements with the angular velocity of 90º/s and 240º...

Evaluation of CHANGE, an Involuntary Cognitive Program for High-Risk Inmates

Science.gov (United States)

Hogan, Nancy L.; Lambert, Eric G.; Barton-Bellessa, Shannon M.

2012-01-01

Prison violence is a major concern in most correctional institutions. One intervention frequently used to reduce violent behavior is cognitive therapy. An involuntary cognitive program at a Midwestern state prison was evaluated for its impact on official misconduct. A total of 213 inmates were randomly assigned to the treatment (CHANGE) group (n =…

Modification of sudden onset auditory ERP by involuntary attention to visual stimuli.

Science.gov (United States)

Oray, Serkan; Lu, Zhong-Lin; Dawson, Michael E

2002-03-01

To investigate the cross-modal nature of the exogenous attention system, we studied how involuntary attention in the visual modality affects ERPs elicited by sudden onset of events in the auditory modality. Relatively loud auditory white noise bursts were presented to subjects with random and long inter-trial intervals. The noise bursts were either presented alone, or paired with a visual stimulus with a visual to auditory onset asynchrony of 120 ms. In a third condition, the visual stimuli were shown alone. All three conditions, auditory alone, visual alone, and paired visual/auditory, were randomly inter-mixed and presented with equal probabilities. Subjects were instructed to fixate on a point in front of them without task instructions concerning either the auditory or visual stimuli. ERPs were recorded from 28 scalp sites throughout every experimental session. Compared to ERPs in the auditory alone condition, pairing the auditory noise bursts with the visual stimulus reduced the amplitude of the auditory N100 component at Cz by 40% and the auditory P200/P300 component at Cz by 25%. No significant topographical change was observed in the scalp distributions of the N100 and P200/P300. Our results suggest that involuntary attention to visual stimuli suppresses early sensory (N100) as well as late cognitive (P200/P300) processing of sudden auditory events. The activation of the exogenous attention system by sudden auditory onset can be modified by involuntary visual attention in a cross-model, passive prepulse inhibition paradigm.

A Neuro-Fuzzy System for Characterization of Arm Movements

Directory of Open Access Journals (Sweden)

Alexandre Balbinot

2013-02-01

Full Text Available The myoelectric signal reflects the electrical activity of skeletal muscles and contains information about the structure and function of the muscles which make different parts of the body move. Advances in engineering have extended electromyography beyond the traditional diagnostic applications to also include applications in diverse areas such as rehabilitation, movement analysis and myoelectric control of prosthesis. This paper aims to study and develop a system that uses myoelectric signals, acquired by surface electrodes, to characterize certain movements of the human arm. To recognize certain hand-arm segment movements, was developed an algorithm for pattern recognition technique based on neuro-fuzzy, representing the core of this research. This algorithm has as input the preprocessed myoelectric signal, to disclosed specific characteristics of the signal, and as output the performed movement. The average accuracy obtained was 86% to 7 distinct movements in tests of long duration (about three hours.

26 CFR 1.168(i)-6 - Like-kind exchanges and involuntary conversions.

Science.gov (United States)

2010-04-01

... this paragraph (c) are the only permissible methods of accounting for MACRS property within the scope... apply this section. (2) Effect of depreciation treatment of the replacement MACRS property by previous... exchange or an involuntary conversion, the depreciation treatment of the replacement MACRS property by...

Dual dimensionality reduction reveals independent encoding of motor features in a muscle synergy for insect flight control.

Science.gov (United States)

Sponberg, Simon; Daniel, Thomas L; Fairhall, Adrienne L

2015-04-01

What are the features of movement encoded by changing motor commands? Do motor commands encode movement independently or can they be represented in a reduced set of signals (i.e. synergies)? Motor encoding poses a computational and practical challenge because many muscles typically drive movement, and simultaneous electrophysiology recordings of all motor commands are typically not available. Moreover, during a single locomotor period (a stride or wingstroke) the variation in movement may have high dimensionality, even if only a few discrete signals activate the muscles. Here, we apply the method of partial least squares (PLS) to extract the encoded features of movement based on the cross-covariance of motor signals and movement. PLS simultaneously decomposes both datasets and identifies only the variation in movement that relates to the specific muscles of interest. We use this approach to explore how the main downstroke flight muscles of an insect, the hawkmoth Manduca sexta, encode torque during yaw turns. We simultaneously record muscle activity and turning torque in tethered flying moths experiencing wide-field visual stimuli. We ask whether this pair of muscles acts as a muscle synergy (a single linear combination of activity) consistent with their hypothesized function of producing a left-right power differential. Alternatively, each muscle might individually encode variation in movement. We show that PLS feature analysis produces an efficient reduction of dimensionality in torque variation within a wingstroke. At first, the two muscles appear to behave as a synergy when we consider only their wingstroke-averaged torque. However, when we consider the PLS features, the muscles reveal independent encoding of torque. Using these features we can predictably reconstruct the variation in torque corresponding to changes in muscle activation. PLS-based feature analysis provides a general two-sided dimensionality reduction that reveals encoding in high dimensional

Dual dimensionality reduction reveals independent encoding of motor features in a muscle synergy for insect flight control.

Directory of Open Access Journals (Sweden)

Simon Sponberg

2015-04-01

Full Text Available What are the features of movement encoded by changing motor commands? Do motor commands encode movement independently or can they be represented in a reduced set of signals (i.e. synergies? Motor encoding poses a computational and practical challenge because many muscles typically drive movement, and simultaneous electrophysiology recordings of all motor commands are typically not available. Moreover, during a single locomotor period (a stride or wingstroke the variation in movement may have high dimensionality, even if only a few discrete signals activate the muscles. Here, we apply the method of partial least squares (PLS to extract the encoded features of movement based on the cross-covariance of motor signals and movement. PLS simultaneously decomposes both datasets and identifies only the variation in movement that relates to the specific muscles of interest. We use this approach to explore how the main downstroke flight muscles of an insect, the hawkmoth Manduca sexta, encode torque during yaw turns. We simultaneously record muscle activity and turning torque in tethered flying moths experiencing wide-field visual stimuli. We ask whether this pair of muscles acts as a muscle synergy (a single linear combination of activity consistent with their hypothesized function of producing a left-right power differential. Alternatively, each muscle might individually encode variation in movement. We show that PLS feature analysis produces an efficient reduction of dimensionality in torque variation within a wingstroke. At first, the two muscles appear to behave as a synergy when we consider only their wingstroke-averaged torque. However, when we consider the PLS features, the muscles reveal independent encoding of torque. Using these features we can predictably reconstruct the variation in torque corresponding to changes in muscle activation. PLS-based feature analysis provides a general two-sided dimensionality reduction that reveals encoding in

Dual Dimensionality Reduction Reveals Independent Encoding of Motor Features in a Muscle Synergy for Insect Flight Control

Science.gov (United States)

Sponberg, Simon; Daniel, Thomas L.; Fairhall, Adrienne L.

2015-01-01

What are the features of movement encoded by changing motor commands? Do motor commands encode movement independently or can they be represented in a reduced set of signals (i.e. synergies)? Motor encoding poses a computational and practical challenge because many muscles typically drive movement, and simultaneous electrophysiology recordings of all motor commands are typically not available. Moreover, during a single locomotor period (a stride or wingstroke) the variation in movement may have high dimensionality, even if only a few discrete signals activate the muscles. Here, we apply the method of partial least squares (PLS) to extract the encoded features of movement based on the cross-covariance of motor signals and movement. PLS simultaneously decomposes both datasets and identifies only the variation in movement that relates to the specific muscles of interest. We use this approach to explore how the main downstroke flight muscles of an insect, the hawkmoth Manduca sexta, encode torque during yaw turns. We simultaneously record muscle activity and turning torque in tethered flying moths experiencing wide-field visual stimuli. We ask whether this pair of muscles acts as a muscle synergy (a single linear combination of activity) consistent with their hypothesized function of producing a left-right power differential. Alternatively, each muscle might individually encode variation in movement. We show that PLS feature analysis produces an efficient reduction of dimensionality in torque variation within a wingstroke. At first, the two muscles appear to behave as a synergy when we consider only their wingstroke-averaged torque. However, when we consider the PLS features, the muscles reveal independent encoding of torque. Using these features we can predictably reconstruct the variation in torque corresponding to changes in muscle activation. PLS-based feature analysis provides a general two-sided dimensionality reduction that reveals encoding in high dimensional

A pneumatic muscle hand therapy device.

Science.gov (United States)

Koeneman, E J; Schultz, R S; Wolf, S L; Herring, D E; Koeneman, J B

2004-01-01

Intensive repetitive therapy improves function and quality of life for stroke patients. Intense therapies to overcome upper extremity impairment are beneficial, however, they are expensive because, in part, they rely on individualized interaction between the patient and rehabilitation specialist. The development of a pneumatic muscle driven hand therapy device, the Mentortrade mark, reinforces the need for volitional activation of joint movement while concurrently offering knowledge of results about range of motion, muscle activity or resistance to movement. The device is well tolerated and has received favorable comments from stroke survivors, their caregivers, and therapists.

Myogenin regulates exercise capacity and skeletal muscle metabolism in the adult mouse.

Directory of Open Access Journals (Sweden)

Jesse M Flynn

2010-10-01

Full Text Available Although skeletal muscle metabolism is a well-studied physiological process, little is known about how it is regulated at the transcriptional level. The myogenic transcription factor myogenin is required for skeletal muscle development during embryonic and fetal life, but myogenin's role in adult skeletal muscle is unclear. We sought to determine myogenin's function in adult muscle metabolism. A Myog conditional allele and Cre-ER transgene were used to delete Myog in adult mice. Mice were analyzed for exercise capacity by involuntary treadmill running. To assess oxidative and glycolytic metabolism, we performed indirect calorimetry, monitored blood glucose and lactate levels, and performed histochemical analyses on muscle fibers. Surprisingly, we found that Myog-deleted mice performed significantly better than controls in high- and low-intensity treadmill running. This enhanced exercise capacity was due to more efficient oxidative metabolism during low- and high-intensity exercise and more efficient glycolytic metabolism during high-intensity exercise. Furthermore, Myog-deleted mice had an enhanced response to long-term voluntary exercise training on running wheels. We identified several candidate genes whose expression was altered in exercise-stressed muscle of mice lacking myogenin. The results suggest that myogenin plays a critical role as a high-level transcriptional regulator to control the energy balance between aerobic and anaerobic metabolism in adult skeletal muscle.

Movement-related and steady-state electromyographic activity of human elbow flexors in slow transition movements between two equilibrium states.

Science.gov (United States)

Tal'nov, A N; Cherkassky, V L; Kostyukov, A I

1997-08-01

The electromyograms were recorded in healthy human subjects by surface electrodes from the mm. biceps brachii (caput longum et. brevis), brachioradialis, and triceps brachii (caput longum) during slow transition movements in elbow joint against a weak extending torque. The test movements (flexion transitions between two steady-states) were fulfilled under visual control through combining on a monitor screen a signal from a joint angle sensor with a corresponding command generated by a computer. Movement velocities ranged between 5 and 80 degrees/s, subjects were asked to move forearm without activation of elbow extensors. Surface electromyograms were full-wave rectified, filtered and averaged within sets of 10 identical tests. Amplitudes of dynamic and steady-state components of the electromyograms were determined in dependence on a final value of joint angle, slow and fast movements were compared. An exponential-like increase of dynamic component was observed in electromyograms recorded from m. biceps brachii, the component had been increased with movement velocity and with load increment. In many experiments a statistically significant decrease of static component could be noticed within middle range of joint angles (40-60 degrees) followed by a well expressed increment for larger movements. This pattern of the static component in electromyograms could vary in different experiments even in the same subjects. A steady discharge in m. brachioradialis at ramp phase has usually been recorded only under a notable load. Variable and quite often unpredictable character of the static components of the electromyograms recorded from elbow flexors in the transition movements makes it difficult to use the equilibrium point hypothesis to describe the central processes of movement. It has been assumed that during active muscle shortening the dynamic components in arriving efferent activity should play a predominant role. A simple scheme could be proposed for transition to a

Advances in molecular genetic studies of primary dystonia

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MA Ling-yan

2013-07-01

Full Text Available Dystonias are heterogeneous hyperkinetic movement disorders characterized by involuntary muscle contractions which result in twisting, repetitive movements and abnormal postures. In recent years, there was a great advance in molecular genetic studies of primary dystonia. This paper will review the clinical characteristics and molecular genetic studies of primary dystonia, including early-onset generalized torsion dystonia (DYT1, whispering dysphonia (DYT4, dopa-responsive dystonia (DYT5, mixed-type dystonia (DYT6, paroxysmal kinesigenic dyskinesia (DYT10, myoclonus-dystonia syndrome (DYT11, rapid-onset dystonia parkinsonism (DYT12, adult-onset cervical dystonia (DYT23, craniocervical dystonia (DYT24 and primary torsion dystonia (DYT25.

Multimodal movement prediction - towards an individual assistance of patients.

Directory of Open Access Journals (Sweden)

Elsa Andrea Kirchner

Full Text Available Assistive devices, like exoskeletons or orthoses, often make use of physiological data that allow the detection or prediction of movement onset. Movement onset can be detected at the executing site, the skeletal muscles, as by means of electromyography. Movement intention can be detected by the analysis of brain activity, recorded by, e.g., electroencephalography, or in the behavior of the subject by, e.g., eye movement analysis. These different approaches can be used depending on the kind of neuromuscular disorder, state of therapy or assistive device. In this work we conducted experiments with healthy subjects while performing self-initiated and self-paced arm movements. While other studies showed that multimodal signal analysis can improve the performance of predictions, we show that a sensible combination of electroencephalographic and electromyographic data can potentially improve the adaptability of assistive technical devices with respect to the individual demands of, e.g., early and late stages in rehabilitation therapy. In earlier stages for patients with weak muscle or motor related brain activity it is important to achieve high positive detection rates to support self-initiated movements. To detect most movement intentions from electroencephalographic or electromyographic data motivates a patient and can enhance her/his progress in rehabilitation. In a later stage for patients with stronger muscle or brain activity, reliable movement prediction is more important to encourage patients to behave more accurately and to invest more effort in the task. Further, the false detection rate needs to be reduced. We propose that both types of physiological data can be used in an and combination, where both signals must be detected to drive a movement. By this approach the behavior of the patient during later therapy can be controlled better and false positive detections, which can be very annoying for patients who are further advanced in

Rat whisker movement after facial nerve lesion: evidence for autonomic contraction of skeletal muscle.

Science.gov (United States)

Heaton, James T; Sheu, Shu Hsien; Hohman, Marc H; Knox, Christopher J; Weinberg, Julie S; Kleiss, Ingrid J; Hadlock, Tessa A

2014-04-18

Vibrissal whisking is often employed to track facial nerve regeneration in rats; however, we have observed similar degrees of whisking recovery after facial nerve transection with or without repair. We hypothesized that the source of non-facial nerve-mediated whisker movement after chronic denervation was from autonomic, cholinergic axons traveling within the infraorbital branch of the trigeminal nerve (ION). Rats underwent unilateral facial nerve transection with repair (N=7) or resection without repair (N=11). Post-operative whisking amplitude was measured weekly across 10weeks, and during intraoperative stimulation of the ION and facial nerves at ⩾18weeks. Whisking was also measured after subsequent ION transection (N=6) or pharmacologic blocking of the autonomic ganglia using hexamethonium (N=3), and after snout cooling intended to elicit a vasodilation reflex (N=3). Whisking recovered more quickly and with greater amplitude in rats that underwent facial nerve repair compared to resection (Pfacial-nerve-mediated whisking was elicited by electrical stimulation of the ION, temporarily diminished following hexamethonium injection, abolished by transection of the ION, and rapidly and significantly (Pfacial nerve resection. This study provides the first behavioral and anatomical evidence of spontaneous autonomic innervation of skeletal muscle after motor nerve lesion, which not only has implications for interpreting facial nerve reinnervation results, but also calls into question whether autonomic-mediated innervation of striated muscle occurs naturally in other forms of neuropathy. Copyright © 2014 IBRO. Published by Elsevier Ltd. All rights reserved.

Behavioral variant of frontotemporal dementia mimicking Huntington's disease

DEFF Research Database (Denmark)

Nielsen, T Rune; Bruhn, Peter; Nielsen, Jørgen E

2010-01-01

Behavioral changes and cognitive decline are the core clinical manifestations in the behavioral variant of frontotemporal dementia (bv-FTD). The behavioral changes may include characteristic stereotypic movements. These movements, although without clear purpose, are not involuntary. Involuntary...

Decoding of Human Movements Based on Deep Brain Local Field Potentials Using Ensemble Neural Networks

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Mohammad S. Islam

2017-01-01

Full Text Available Decoding neural activities related to voluntary and involuntary movements is fundamental to understanding human brain motor circuits and neuromotor disorders and can lead to the development of neuromotor prosthetic devices for neurorehabilitation. This study explores using recorded deep brain local field potentials (LFPs for robust movement decoding of Parkinson’s disease (PD and Dystonia patients. The LFP data from voluntary movement activities such as left and right hand index finger clicking were recorded from patients who underwent surgeries for implantation of deep brain stimulation electrodes. Movement-related LFP signal features were extracted by computing instantaneous power related to motor response in different neural frequency bands. An innovative neural network ensemble classifier has been proposed and developed for accurate prediction of finger movement and its forthcoming laterality. The ensemble classifier contains three base neural network classifiers, namely, feedforward, radial basis, and probabilistic neural networks. The majority voting rule is used to fuse the decisions of the three base classifiers to generate the final decision of the ensemble classifier. The overall decoding performance reaches a level of agreement (kappa value at about 0.729±0.16 for decoding movement from the resting state and about 0.671±0.14 for decoding left and right visually cued movements.

Velocity-based planning of rapid elbow movements expands the control scheme of the equilibrium point hypothesis.

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Suzuki, Masataka; Yamazaki, Yoshihiko

2005-01-01

According to the equilibrium point hypothesis of voluntary motor control, control action of muscles is not explicitly computed, but rather arises as a consequence of interaction between moving equilibrium position, current kinematics and stiffness of the joint. This approach is attractive as it obviates the need to explicitly specify the forces controlling limb movements. However, many debatable aspects of this hypothesis remain in the manner of specification of the equilibrium point trajectory and muscle activation (or its stiffness), which elicits a restoring force toward the planned equilibrium trajectory. In this study, we expanded the framework of this hypothesis by assuming that the control system uses the velocity measure as the origin of subordinate variables scaling descending commands. The velocity command is translated into muscle control inputs by second order pattern generators, which yield reciprocal command and coactivation commands, and create alternating activation of the antagonistic muscles during movement and coactivation in the post-movement phase, respectively. The velocity command is also integrated to give a position command specifying a moving equilibrium point. This model is purely kinematics-dependent, since the descending commands needed to modulate the visco-elasticity of muscles are implicitly given by simple parametric specifications of the velocity command alone. The simulated movements of fast elbow single-joint movements corresponded well with measured data performed over a wide range of movement distances, in terms of both muscle excitations and kinematics. Our proposal on a synthesis for the equilibrium point approach and velocity command, may offer some insights into the control scheme of the single-joint arm movements.

Analysis of Facial Expression by Taste Stimulation

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Tobitani, Kensuke; Kato, Kunihito; Yamamoto, Kazuhiko

In this study, we focused on the basic taste stimulation for the analysis of real facial expressions. We considered that the expressions caused by taste stimulation were unaffected by individuality or emotion, that is, such expressions were involuntary. We analyzed the movement of facial muscles by taste stimulation and compared real expressions with artificial expressions. From the result, we identified an obvious difference between real and artificial expressions. Thus, our method would be a new approach for facial expression recognition.

Automatic gain control of neural coupling during cooperative hand movements.

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Thomas, F A; Dietz, V; Schrafl-Altermatt, M

2018-04-13

Cooperative hand movements (e.g. opening a bottle) are controlled by a task-specific neural coupling, reflected in EMG reflex responses contralateral to the stimulation site. In this study the contralateral reflex responses in forearm extensor muscles to ipsilateral ulnar nerve stimulation was analyzed at various resistance and velocities of cooperative hand movements. The size of contralateral reflex responses was closely related to the level of forearm muscle activation required to accomplish the various cooperative hand movement tasks. This indicates an automatic gain control of neural coupling that allows a rapid matching of corrective forces exerted at both sides of an object with the goal 'two hands one action'.

Involuntary memories of emotional scenes: The effects of cue discriminability and emotion over time

DEFF Research Database (Denmark)

Staugaard, Søren Risløv; Berntsen, Dorthe

2014-01-01

a range of clinical disorders, there is no broadly agreed upon explanation of their underlying mechanisms and no successful experimental simulations of their retrieval. In a series of experiments, we experimentally manipulated the activation of involuntary episodic memories for emotional and neutral...... scenes and predicted their activation on the basis of manipulations carried out at encoding and retrieval. Our findings suggest that the interplay between cue discriminability at the time of retrieval and emotional arousal at the time of encoding are crucial for explaining intrusive memories following...... negative events. While cue distinctiveness is important directly following encoding of the scenes, emotional intensity influences retrieval after delays of 24 hr and 1 week. Voluntary remembering follows the same pattern as involuntary remembering. Our results suggest an explanatory model of intrusive...

Muscle cocontraction following dynamics learning.

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Darainy, Mohammad; Ostry, David J

2008-09-01

Coactivation of antagonist muscles is readily observed early in motor learning, in interactions with unstable mechanical environments and in motor system pathologies. Here we present evidence that the nervous system uses coactivation control far more extensively and that patterns of cocontraction during movement are closely tied to the specific requirements of the task. We have examined the changes in cocontraction that follow dynamics learning in tasks that are thought to involve finely sculpted feedforward adjustments to motor commands. We find that, even following substantial training, cocontraction varies in a systematic way that depends on both movement direction and the strength of the external load. The proportion of total activity that is due to cocontraction nevertheless remains remarkably constant. Moreover, long after indices of motor learning and electromyographic measures have reached asymptotic levels, cocontraction still accounts for a significant proportion of total muscle activity in all phases of movement and in all load conditions. These results show that even following dynamics learning in predictable and stable environments, cocontraction forms a central part of the means by which the nervous system regulates movement.

Involuntary detention and treatment of the mentally ill: China's 2012 Mental Health Law.

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Ding, Chunyan

2014-01-01

The long-awaited Mental Health Law of China was passed on 26 October 2012 and took effect on 1 May 2013. Being the first national legislation on mental health, it establishes a basic legal framework to regulate mental health practice and recognizes the fundamental rights of persons with mental disorders. This article focuses on the system of involuntary detention and treatment of the mentally ill under the new law, which is expected to prevent the so-called "Being misidentified as mentally disordered" cases in China. A systematic examination of the new system demonstrates that the Mental Health Law of China implicitly holds two problematic assumptions and does not provide adequate protection of the fundamental rights of the involuntary patients. Administrative enactments and further national legislative efforts are needed to remedy these flaws in the new law. Copyright © 2014 Elsevier Ltd. All rights reserved.

Learned parametrized dynamic movement primitives with shared synergies for controlling robotic and musculoskeletal systems

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Elmar eRückert

2013-10-01

Full Text Available A salient feature of human motor skill learning is the ability to exploitsimilarities across related tasks.In biological motor control, it has been hypothesized that muscle synergies,coherent activations of groups of muscles, allow for exploiting shared knowledge.Recent studies have shown that a rich set of complex motor skills can be generated bya combination of a small number of muscle synergies.In robotics, dynamic movement primitives are commonlyused for motor skill learning. This machine learning approach implements a stable attractor systemthat facilitates learning and it can be used in high-dimensional continuous spaces. However, it does not allow for reusing shared knowledge, i.e. for each task an individual set of parameters has to be learned.We propose a novel movement primitive representationthat employs parametrized basis functions, which combines the benefits of muscle synergiesand dynamic movement primitives. For each task asuperposition of synergies modulates a stable attractor system.This approach leads to a compact representation of multiple motor skills andat the same time enables efficient learning in high-dimensional continuous systems.The movement representation supports discrete and rhythmic movements andin particular includes the dynamic movement primitive approach as a special case.We demonstrate the feasibility of the movement representation in three multi-task learning simulated scenarios.First, the characteristics of the proposed representation are illustrated in a point-mass task.Second, in complex humanoid walking experiments,multiple walking patterns with different step heights are learned robustly and efficiently.Finally, in a multi-directional reaching task simulated with a musculoskeletal modelof the human arm, we show how the proposed movement primitives can be used tolearn appropriate muscle excitation patterns and to generalize effectively to new reaching skills.

Dynamic study of ocular movement with MR imaging in orbital blow-out fracture

International Nuclear Information System (INIS)

Aibara, Ryuichi; Kawakita, Seiji; Matsumoto, Yasushi; Sadamoto, Masanori; Yumoto, Eiji.

1996-01-01

Operative indications for orbital blow-out fracture (OBF) remain controversial. One of the major sources of this controversy is that an accurate diagnosis of ocular movement disturbances can not be made by conventional procedures such as the Hess screen test, traction test, or CT scan. Disturbances in ocular movement resulting from OBF can occur not only with entrapment of the extraocular muscle but also with intraorbital bleeding, edema, and/or a variety of other unclear factors. To obtain a more accurate diagnosis and to assist in the choice of treatment, ocular movement was examined using orbital 'cine mode' MR imaging. MR images were obtained in multiple phases of vertical and horizontal ocular movements by using the 'fast SE' capabilities of the SIERRA, GE-YMS MR scanner (1.5 Tesla, superconductive). The fixed eye method was applied to two normal volunteers and to patients with 'pure' OBF. Five marks for binocular fixation were affixed to the inner wall of the gantry: one at the primary position and four at secondary positions. While keeping the subject's eye focused on each of these marks for about 30 sec, MR images (head coil) of the axial view and bilateral oblique sagittal view along the optic nerve were carried out. In the normal volunteers, a good demonstration of smooth movement of the eye ball, extraocular muscles, and the optic nerve could be obtained. In the OBF patients, it was clearly observed that the disturbance in ocular movement was caused by poor extension of the external ocular muscles, specifically the inferior rectus muscle in the orbital floor fracture, and the internal rectus muscle in the medial wall fracture. These observations suggested that dynamic orbital imaging with MR would be extremely valuable in the assessment of disturbances of ocular movement in OBF. (author)

Pelvic floor muscle strength and sexual function in women

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Cinara Sacomori

Full Text Available Abstract Introduction : Pelvic floor (PF muscles react to sexual stimuli with increased local blood circulation and involuntary contractions during orgasm. The training of the PF musculature helps in the improvement of the female sexual function. Objective : To verify the association between PF muscle strength and sexual function in women, controlling age and parity. Method : Cross-sectional study based on associations. The study included women who attended a reference center in Florianópolis, Santa Catarina, for a uterine cancer smear test. The Functional Evaluation of the Pelvic Floor and the Female Sexual Function Index questionnaire were used. Statistical procedures included Mann-Whitney U tests, Spearman correlation and Poisson Regression Analysis, with p < .05. Results : The mean age of the women (n = 177 was 39.05 years (SD = 13.3. Regarding PF function, 53.7% of participants presented weak or not palpable PF muscle function. Women with "good" muscle function (able to maintain contraction under examiner's resistance had significantly better indexes of sexual desire, excitement, lubrication and orgasm than women with weak/poor function. We identified that 52.5% of the women presented sexual dysfunction. Women with "poor" PF function and aged over 50 years had, respectively, 1.36 (CI95% 1.01 - 1.82 and 1.77 (CI95% 1.41 - 2.23 higher prevalence of sexual dysfunction than women with "good" PF function. Conclusions : Adult women with better PF muscle function also presented better sexual function.

Dynamic cardiomyoplasty using artificial muscle.

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Suzuki, Yasuyuki; Daitoku, Kazuyuki; Minakawa, Masahito; Fukui, Kozo; Fukuda, Ikuo

2008-01-01

Dynamic cardiomyoplasty using latissimus dorsi muscle was previously used to compensate for congestive heart failure. Now, however, this method is not acceptable because the long-term result was not as expected owing to fatigue of the skeletal muscle. BioMetal fiber developed by Toki Corporation is one of the artificial muscles activated by electric current. The behavior of this fiber is similar to that of organic muscle. We made an artificial muscle like the latissimus dorsi using BioMetal fiber and tested whether we could use this new muscle as a cardiac supporting device. Testing one Biometal fiber showed the following performance: practical use maximal generative force was 30 g, exercise variation was 50%, and the standard driving current was 220 mA. We created a 4 x 12-cm tabular artificial muscle using 8 BioMetal fibers as a cardiac support device. We also made a simulation circuit composed of a 6 x 8-cm soft bag with unidirectional valves, reservoir, and connecting tube. The simulation circuit was filled with water and the soft bag was wrapped with the artificial muscle device. After powering the device electrically at 9 V with a current of 220 mA for each fiber, we measured the inside pressure and observed the movement of the artificial device. The artificial muscle contracted in 0.5 s for peak time and squeezed the soft bag. The peak pressure inside the soft bag was measured as 10 mmHg. Although further work will be needed to enhance the speed of deformability and movement simulating contraction, we conclude that artificial muscle may be potentially useful as a cardiac assistance device that can be developed for dynamic cardiomyoplasty.

Paraneoplastic autoimmune movement disorders.

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Lim, Thien Thien

2017-11-01

To provide an overview of paraneoplastic autoimmune disorders presenting with various movement disorders. The spectrum of paraneoplastic autoimmune disorders has been expanding with the discovery of new antibodies against cell surface and intracellular antigens. Many of these paraneoplastic autoimmune disorders manifest as a form of movement disorder. With the discovery of new neuronal antibodies, an increasing number of idiopathic or neurodegenerative movement disorders are now being reclassified as immune-mediated movement disorders. These include anti-N-methyl-d-aspartate receptor (NMDAR) encephalitis which may present with orolingual facial dyskinesia and stereotyped movements, CRMP-5 IgG presenting with chorea, anti-Yo paraneoplastic cerebellar degeneration presenting with ataxia, anti-VGKC complex (Caspr2 antibodies) neuromyotonia, opsoclonus-myoclonus-ataxia syndrome, and muscle rigidity and episodic spasms (amphiphysin, glutamic acid decarboxylase, glycine receptor, GABA(A)-receptor associated protein antibodies) in stiff-person syndrome. Movement disorders may be a presentation for paraneoplastic autoimmune disorders. Recognition of these disorders and their common phenomenology is important because it may lead to the discovery of an occult malignancy. Copyright © 2017 Elsevier Ltd. All rights reserved.

Effect of finger motion on transverse median nerve movement in the carpal tunnel.

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Kang, Hyo Jung; Yoon, Joon Shik

2016-10-01

We used ultrasonography (US) to investigate the effects of finger motion on movement of the median nerve in patients with carpal tunnel syndrome (CTS) and the correlation between these US parameters and CTS severity. Ultrasonographic measures were performed in 23 control wrists and 22 CTS wrists in women. During first through third finger flexion and grip motion, median nerve movements were obtained using US and a tracing program. Nerve movements during third finger flexion in the dorsopalmar axis and grip motion in both axes, and during second finger flexion in the radioulnar axis, differed significantly between the control and CTS groups. US parameters correlated negatively with cross-sectional area. This study shows that transverse median nerve movements decreased during grip using US and correlated negatively with CTS severity. Muscle Nerve, 2016 Muscle Nerve 54: -, 2016 Muscle Nerve 54: 738-742, 2016. © 2016 Wiley Periodicals, Inc.

The punctum fixum-punctum mobile model: a neuromuscular principle for efficient movement generation?

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von Laßberg, Christoph; Rapp, Walter

2015-01-01

According to the "punctum fixum-punctum mobile model" that was introduced in prior studies, for generation of the most effective intentional acceleration of a body part the intersegmental neuromuscular onset succession has to spread successively from the rotation axis (punctum fixum) toward the body part that shall be accelerated (punctum mobile). The aim of the present study was to investigate whether this principle is, indeed, fundamental for any kind of efficient rotational accelerations in general, independent of the kind of movements, type of rotational axis, the current body position, or movement direction. Neuromuscular onset succession was captured by surface electromyography of relevant muscles of the anterior and posterior muscle chain in 16 high-level gymnasts during intentional accelerating movement phases while performing 18 different gymnastics elements (in various body positions to forward and backward, performed on high bar, parallel bars, rings and trampoline), as well as during non-sport specific pivot movements around the longitudinal axis. The succession patterns to generate the acceleration phases during these movements were described and statistically evaluated based on the onset time difference between the muscles of the corresponding muscle chain. In all the analyzed movement phases, the results clearly support the hypothesized succession pattern from punctum fixum to punctum mobile. This principle was further underlined by the finding that the succession patterns do change their direction running through the body when the rotational axis (punctum fixum) has been changed (e.g., high bar or rings [hands] vs. floor or trampoline [feet]). The findings improve our understanding of intersegmental neuromuscular coordination patterns to generate intentional movements most efficiently. This could help to develop more specific methods to facilitate such patterns in particular contexts, thus allowing for shorter motor learning procedures of context

The punctum fixum-punctum mobile model: a neuromuscular principle for efficient movement generation?

Directory of Open Access Journals (Sweden)

Christoph von Laßberg

Full Text Available According to the "punctum fixum-punctum mobile model" that was introduced in prior studies, for generation of the most effective intentional acceleration of a body part the intersegmental neuromuscular onset succession has to spread successively from the rotation axis (punctum fixum toward the body part that shall be accelerated (punctum mobile. The aim of the present study was to investigate whether this principle is, indeed, fundamental for any kind of efficient rotational accelerations in general, independent of the kind of movements, type of rotational axis, the current body position, or movement direction. Neuromuscular onset succession was captured by surface electromyography of relevant muscles of the anterior and posterior muscle chain in 16 high-level gymnasts during intentional accelerating movement phases while performing 18 different gymnastics elements (in various body positions to forward and backward, performed on high bar, parallel bars, rings and trampoline, as well as during non-sport specific pivot movements around the longitudinal axis. The succession patterns to generate the acceleration phases during these movements were described and statistically evaluated based on the onset time difference between the muscles of the corresponding muscle chain. In all the analyzed movement phases, the results clearly support the hypothesized succession pattern from punctum fixum to punctum mobile. This principle was further underlined by the finding that the succession patterns do change their direction running through the body when the rotational axis (punctum fixum has been changed (e.g., high bar or rings [hands] vs. floor or trampoline [feet]. The findings improve our understanding of intersegmental neuromuscular coordination patterns to generate intentional movements most efficiently. This could help to develop more specific methods to facilitate such patterns in particular contexts, thus allowing for shorter motor learning

The Punctum Fixum-Punctum Mobile Model: A Neuromuscular Principle for Efficient Movement Generation?

Science.gov (United States)

von Laßberg, Christoph; Rapp, Walter

2015-01-01

According to the “punctum fixum–punctum mobile model” that was introduced in prior studies, for generation of the most effective intentional acceleration of a body part the intersegmental neuromuscular onset succession has to spread successively from the rotation axis (punctum fixum) toward the body part that shall be accelerated (punctum mobile). The aim of the present study was to investigate whether this principle is, indeed, fundamental for any kind of efficient rotational accelerations in general, independent of the kind of movements, type of rotational axis, the current body position, or movement direction. Neuromuscular onset succession was captured by surface electromyography of relevant muscles of the anterior and posterior muscle chain in 16 high-level gymnasts during intentional accelerating movement phases while performing 18 different gymnastics elements (in various body positions to forward and backward, performed on high bar, parallel bars, rings and trampoline), as well as during non-sport specific pivot movements around the longitudinal axis. The succession patterns to generate the acceleration phases during these movements were described and statistically evaluated based on the onset time difference between the muscles of the corresponding muscle chain. In all the analyzed movement phases, the results clearly support the hypothesized succession pattern from punctum fixum to punctum mobile. This principle was further underlined by the finding that the succession patterns do change their direction running through the body when the rotational axis (punctum fixum) has been changed (e.g., high bar or rings [hands] vs. floor or trampoline [feet]). The findings improve our understanding of intersegmental neuromuscular coordination patterns to generate intentional movements most efficiently. This could help to develop more specific methods to facilitate such patterns in particular contexts, thus allowing for shorter motor learning procedures of

Kinesthetic illusions attenuate experimental muscle pain, as do muscle and cutaneous stimulation.

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Gay, André; Aimonetti, Jean-Marc; Roll, Jean-Pierre; Ribot-Ciscar, Edith

2015-07-30

In the present study, muscle pain was induced experimentally in healthy subjects by administrating hypertonic saline injections into the tibialis anterior (TA) muscle. We first aimed at comparing the analgesic effects of mechanical vibration applied to either cutaneous or muscle receptors of the TA or to both types simultaneously. Secondly, pain alleviation was compared in subjects in whom muscle tendon vibration evoked kinesthetic illusions of the ankle joint. Muscle tendon vibration, which primarily activated muscle receptors, reduced pain intensity by 30% (p<0.01). In addition, tangential skin vibration reduced pain intensity by 33% (p<0.01), primarily by activating cutaneous receptors. Concurrently stimulating both sensory channels induced stronger analgesic effects (-51%, p<0.01), as shown by the lower levels of electrodermal activity. The strongest analgesic effects of the vibration-induced muscle inputs occurred when illusory movements were perceived (-38%, p=0.01). The results suggest that both cutaneous and muscle sensory feedback reduce muscle pain, most likely via segmental and supraspinal processes. Further clinical trials are needed to investigate these new methods of muscle pain relief. Copyright © 2015 Elsevier B.V. All rights reserved.

Experimental quadriceps muscle pain impairs knee joint control during walking

DEFF Research Database (Denmark)

Henriksen, Marius; Alkjaer, Tine; Lund, Hans

2007-01-01

Pain is a cardinal symptom in musculoskeletal diseases involving the knee joint, and aberrant movement patterns and motor control strategies are often present in these patients. However, the underlying neuromuscular mechanisms linking pain to movement and motor control are unclear. To investigate...... the functional significance of muscle pain on knee joint control during walking, three-dimensional gait analyses were performed before, during, and after experimentally induced muscle pain by means of intramuscular injections of hypertonic saline (5.8%) into vastus medialis (VM) muscle of 20 healthy subjects....... Isotonic saline (0.9%) was used as control. Surface electromyography (EMG) recordings of VM, vastus lateralis (VL), biceps femoris, and semitendinosus muscles were synchronized with the gait analyses. During experimental muscle pain, the loading response phase peak knee extensor moments were attenuated...

Balance and muscle power of children with Charcot-Marie-Tooth.

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Silva, Tais R; Testa, Amanda; Baptista, Cyntia R J A; Marques, Wilson; Mattiello-Sverzut, Ana C

2014-01-01

In certain diseases, functional constraints establish a greater relationship with muscle power than muscle strength. However, in hereditary peripheral polyneuropathies, no such relationship was found in the literature. In children with Charcot-Marie-Tooth (CMT), to identify the impact of muscle strength and range of movement on the static/dynamic balance and standing long jump based on quantitative and functional variables. The study analyzed 19 participants aged between 6 and 16 years, of both genders and with clinical diagnoses of CMT of different subtypes. Anthropometric data, muscle strength of the lower limbs (hand-held dynamometer), ankle and knee range of movement, balance (Pediatric Balance Scale) and standing long jump distance were obtained by standardized procedures. For the statistical analysis, Pearson and Spearman correlation coefficients were used. There was a strong positive correlation between balance and the muscle strength of the right plantar flexors (r=0.61) and dorsiflexors (r=0.59) and a moderate correlation between balance and the muscle strength of inversion (r=0.41) and eversion of the right foot (r=0.44). For the long jump and range of movement, there was a weak positive correlation with right and left plantar flexion (r=0.20 and r=0.12, respectively) and left popliteal angle (r=0.25), and a poor negative correlation with left dorsiflexion (r=-0.15). The data on the patients analyzed suggests that the maintenance of distal muscle strength favors performance during balance tasks, while limitations in the range of movement of the legs seem not to be enough to influence the performance of the horizontal long jump.

Non-voluntary and involuntary euthanasia in The Netherlands: Dutch perspectives.

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Cohen-Almagor, Raphael

2003-01-01

During the summer of 1999, twenty-eight interviews with some of the leading authorities on euthanasia policy were conducted in the Netherlands. They were asked about cases of non-voluntary (when patients are incompetent) and involuntary euthanasia (when patients are competent and made no request to die). This study reports the main findings, showing that most respondents are quite complacent with regard to breaches of the guideline that require the patient's consent as a prerequisite to performance of euthanasia.

Muscle spindle autogenetic inhibition in the extraocular muscles of lamb.

Science.gov (United States)

Pettorossi, V E; Filippi, G M

1981-09-01

The role of extraocular muscle (EOM) proprioceptors on eye motility has been investigated in lambs on "encéphale isolé", by evaluating the tension of EOMs at various lengths and velocities of stretch before and after proprioceptive blocks. The EOM tension, in the absence of proprioceptive input, was higher than in normal conditions. Such an effect occurred at lengthening values greater than 3 mm of stretch from resting muscle length, corresponding to 18 degrees of eye deviation and was dependent on the velocity of the stretch, being more effective at high velocity. The muscle receptors responsible for this effect was determined by comparing the sensitivity to vibratory stimulation of spindles and tendon organs to the amount of inhibition provoked by the same stimulation on an EOM electromyographic activity. The tension inhibition appeared to be correlated to muscle spindle activation. Thus, the presence of muscle spindles can determine a reduction of the tension within the stretched muscles. This result suggests that the EOM length and velocity signals operate moment to moment reduction on the stiffness of the muscle which antagonizes eye displacement, thus facilitating the ocular movements.

The oculomotor system of decapod cephalopods: eye muscles, eye muscle nerves, and the oculomotor neurons in the central nervous system.

Science.gov (United States)

Budelmann, B U; Young, J Z

1993-04-29

Fourteen extraocular eye muscles are described in the decapods Loligo and Sepioteuthis, and thirteen in Sepia; they are supplied by four eye muscle nerves. The main action of most of the muscles is a linear movement of the eyeball, only three muscles produce strong rotations. The arrangement, innervation and action of the decapod eye muscles are compared with those of the seven eye muscles and seven eye muscle nerves in Octopus. The extra muscles in decapods are attached to the anterior and superior faces of the eyes. At least, the anterior muscles, and presumably also the superior muscles, are concerned with convergent eye movements for binocular vision during fixation and capture of prey by the tentacles. The remaining muscles are rather similar in the two cephalopod groups. In decapods, the anterior muscles include conjunctive muscles; these cross the midline and each presumably moves both eyes at the same time during fixation. In the squids Loligo and Sepioteuthis there is an additional superior conjunctive muscle of perhaps similar function. Some of the anterior muscles are associated with a narrow moveable plate, the trochlear cartilage; it is attached to the eyeball by trochlear membranes. Centripetal cobalt fillings showed that all four eye muscle nerves have fibres that originate from somata in the ipsilateral anterior lateral pedal lobe, which is the oculomotor centre. The somata of the individual nerves show different but overlapping distributions. Bundles of small presumably afferent fibres were seen in two of the four nerves. They do not enter the anterior lateral pedal lobe but run to the ventral magnocellular lobe; some afferent fibres enter the brachio-palliovisceral connective and run perhaps as far as the palliovisceral lobe.

Influence of gravity compensation on muscle activity during reach and retrieval in healthy elderly.

NARCIS (Netherlands)

Prange, Grada Berendina; Kallenberg, L.A.C.; Jannink, M.J.A.; Stienen, Arno; van der Kooij, Herman; IJzerman, Maarten Joost; Hermens, Hermanus J.

2007-01-01

INTRODUCTION: Arm support like gravity compensation may improve arm movements during stroke rehabilitation. It is unknown how gravity compensation affects muscle activation patterns during reach and retrieval movements. Since muscle activity during reach is represented by a component varying with

Alleviation of Motor Impairments in Patients with Cerebral Palsy: Acute Effects of Whole-body Vibration on Stretch Reflex Response, Voluntary Muscle Activation and Mobility

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Anne Krause

2017-08-01

Full Text Available IntroductionIndividuals suffering from cerebral palsy (CP often have involuntary, reflex-evoked muscle activity resulting in spastic hyperreflexia. Whole-body vibration (WBV has been demonstrated to reduce reflex activity in healthy subjects, but evidence in CP patients is still limited. Therefore, this study aimed to establish the acute neuromuscular and kinematic effects of WBV in subjects with spastic CP.Methods44 children with spastic CP were tested on neuromuscular activation and kinematics before and immediately after a 1-min bout of WBV (16–25 Hz, 1.5–3 mm. Assessment included (1 recordings of stretch reflex (SR activity of the triceps surae, (2 electromyography (EMG measurements of maximal voluntary muscle activation of lower limb muscles, and (3 neuromuscular activation during active range of motion (aROM. We recorded EMG of m. soleus (SOL, m. gastrocnemius medialis (GM, m. tibialis anterior, m. vastus medialis, m. rectus femoris, and m. biceps femoris. Angular excursion was recorded by goniometry of the ankle and knee joint.ResultsAfter WBV, (1 SOL SRs were decreased (p < 0.01 while (2 maximal voluntary activation (p < 0.05 and (3 angular excursion in the knee joint (p < 0.01 were significantly increased. No changes could be observed for GM SR amplitudes or ankle joint excursion. Neuromuscular coordination expressed by greater agonist–antagonist ratios during aROM was significantly enhanced (p < 0.05.DiscussionThe findings point toward acute neuromuscular and kinematic effects following one bout of WBV. Protocols demonstrate that pathological reflex responses are reduced (spinal level, while the execution of voluntary movement (supraspinal level is improved in regards to kinematic and neuromuscular control. This facilitation of muscle and joint control is probably due to a reduction of spasticity-associated spinal excitability in favor of giving access for greater supraspinal input during voluntary motor

Ictal SPECT in patients with rapid eye movement sleep behaviour disorder.

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Mayer, Geert; Bitterlich, Marion; Kuwert, Torsten; Ritt, Philipp; Stefan, Hermann

2015-05-01

Rapid eye movement sleep behaviour disorder is a rapid eye movement parasomnia clinically characterized by acting out dreams due to disinhibition of muscle tone in rapid eye movement sleep. Up to 80-90% of the patients with rapid eye movement sleep behaviour disorder develop neurodegenerative disorders within 10-15 years after symptom onset. The disorder is reported in 45-60% of all narcoleptic patients. Whether rapid eye movement sleep behaviour disorder is also a predictor for neurodegeneration in narcolepsy is not known. Although the pathophysiology causing the disinhibition of muscle tone in rapid eye movement sleep behaviour disorder has been studied extensively in animals, little is known about the mechanisms in humans. Most of the human data are from imaging or post-mortem studies. Recent studies show altered functional connectivity between substantia nigra and striatum in patients with rapid eye movement sleep behaviour disorder. We were interested to study which regions are activated in rapid eye movement sleep behaviour disorder during actual episodes by performing ictal single photon emission tomography. We studied one patient with idiopathic rapid eye movement sleep behaviour disorder, one with Parkinson's disease and rapid eye movement sleep behaviour disorder, and two patients with narcolepsy and rapid eye movement sleep behaviour disorder. All patients underwent extended video polysomnography. The tracer was injected after at least 10 s of consecutive rapid eye movement sleep and 10 s of disinhibited muscle tone accompanied by movements registered by an experienced sleep technician. Ictal single photon emission tomography displayed the same activation in the bilateral premotor areas, the interhemispheric cleft, the periaqueductal area, the dorsal and ventral pons and the anterior lobe of the cerebellum in all patients. Our study shows that in patients with Parkinson's disease and rapid eye movement sleep behaviour disorder-in contrast to wakefulness

Involuntary Mental Time Travel and Its Effect on Prospective Teachers' Situational Intrinsic Motivations

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Eren, Altay

2010-01-01

Recent cognitive psychological research has argued that involuntary mental time travel is an important individual difference variable that has the potential to affect an individual's motivation. However, this issue has not been empirically investigated in educational settings such as teacher education. Therefore, this study aimed to explore the…

Local Muscle Fatigue and 3D Kinematics of the Cervical Spine in Healthy Subjects.

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Niederer, Daniel; Vogt, Lutz; Pippig, Torsten; Wall, Rudolf; Banzer, Winfried

2016-01-01

The authors aimed to further explore the effects of local muscle fatigue on cervical 3D kinematics and the interrelationship between these kinematic characteristics and local muscle endurance capacity in the unimpaired cervical spine. Twenty healthy subjects (38 ± 10 years; 5 women) performed 2 × 10 maximal cervical flexion-extension movements. Isometric muscle endurance tests (prone/supine lying) were applied between sets to induce local muscle fatigue quantified by Borg scale rates of perceived exertion (RPE) and slope in mean power frequency (MPF; surface electromyography; m. sternocleidomastoideus, m. splenius capitis). Cervical motion characteristics (maximal range of motion [ROM], coefficient of variation of the 10 repetitive movements, mean angular velocity, conjunct movements in transversal and frontal plane) were calculated from raw 3D ultrasonic movement data. Average isometric strength testing duration for flexion and extension correlated to the cervical ROM (r = .49/r = .48; p .05). Although subjects' cervical muscle endurance capacity and motor output seems to be conjugated, no impact of local cervical muscle fatigue on motor function was shown. These findings underline the importance of complementary measures to address muscular performance and kinematic characteristics in outcome assessment and functional rehabilitation of the cervical spine.

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

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.

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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.

Geographic variations in involuntary care and associations with the supply of health and social care: results from a nationwide study.

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Gandré, Coralie; Gervaix, Jeanne; Thillard, Julien; Macé, Jean-Marc; Roelandt, Jean-Luc; Chevreul, Karine

2018-04-06

Involuntary psychiatric care remains controversial. Geographic disparities in its use can challenge the appropriateness of the care provided when they do not result from different health needs of the population. These disparities should be reduced through dedicated health policies. However, their association with the supply of health and social care, which could be targeted by such policies, has been insufficiently studied. Our objectives were therefore to describe geographic variations in involuntary admission rates across France and to identify the characteristics of the supply of care which were associated with these variations. Involuntary admission rate per 100,000 adult inhabitants was calculated in French psychiatric sectors' catchment areas using 2012 data from the national psychiatric discharge database. Its variations were first described numerically and graphically. Several factors potentially associated with these variations were then considered in a negative binomial regression with an offset term accounting for the size of catchment areas. They included characteristics of the supply of care (public and private care, health and social care, hospital and community-based care, specialised and non-specialised care) as well as adjustment factors related to epidemiological characteristics of the population of each sector's catchment area and its level of urbanization. Such variables were extracted from complementary administrative databases. Supply characteristics associated with geographic variations were identified using a significance level of 0.05. Significant variations in involuntary admission rates were observed between psychiatric sectors' catchment areas with a coefficient of variation close to 80%. These variations were associated with some characteristics of the supply of health and social care in the sectors' catchment areas. Notably, an increase in the availability of community-based private psychiatrists and the capacity of housing

A Phenomenological Model and Validation of Shortening Induced Force Depression during Muscle Contractions

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McGowan, C.P.; Neptune, R.R.; Herzog, W.

2009-01-01

History dependent effects on muscle force development following active changes in length have been measured in a number of experimental studies. However, few muscle models have included these properties or examined their impact on force and power output in dynamic cyclic movements. The goal of this study was to develop and validate a modified Hill-type muscle model that includes shortening induced force depression and assess its influence on locomotor performance. The magnitude of force depression was defined by empirical relationships based on muscle mechanical work. To validate the model, simulations incorporating force depression were developed to emulate single muscle in situ and whole muscle group leg extension experiments. There was excellent agreement between simulation and experimental values, with in situ force patterns closely matching the experimental data (average RMS error pedaling with and without force depression were generated. Force depression decreased maximum crank power by 20% – 40%, depending on the relationship between force depression and muscle work used. These results indicate that force depression has the potential to substantially influence muscle power output in dynamic cyclic movements. However, to fully understand the impact of this phenomenon on human movement, more research is needed to characterize the relationship between force depression and mechanical work in large muscles with different morphologies. PMID:19879585

Assessment of muscle fatigue using electromygraphm sensing

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Helmi, Muhammad Hazimin Bin; Ping, Chew Sue; Ishak, Nur Elliza Binti; Saad, Mohd Alimi Bin Mohd; Mokhtar, Anis Shahida Niza Binti

2017-08-01

Muscle fatigue is condition of muscle decline in ability after undergoing any physical activity. Observation of the muscle condition of an athlete during training is crucial to prevent or minimize injury and able to achieve optimum performance in actual competition. The aim of this project is to develop a muscle monitoring system to detect muscle fatigue in swimming athlete. This device is capable to measure muscle stress level of the swimmer and at the same time provide indication of muscle fatigue level to trainer. Electromyography signal was recorded from the muscle movement while practicing the front crawl stroke repetitively. The time domain data was processed to frequency spectra in order to study the effect of muscle fatigue. The results show that the recorded EMG signal is able to sense muscle fatigue.

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.

The architectural design of the gluteal muscle group: implications for movement and rehabilitation.

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Ward, Samuel R; Winters, Taylor M; Blemker, Silvia S

2010-02-01

The organization of fibers within a muscle (architecture) defines the performance capacity of that muscle. In the current commentary, basic architectural terms are reviewed in the context of the major hip muscles and then specific illustrative examples relevant to lower extremity rehabilitation are presented. These data demonstrate the architectural and functional specialization of the hip muscles, and highlight the importance of muscle physiology and joint mechanics when evaluating and treating musculoskeletal disorders.

A Maximum Muscle Strength Prediction Formula Using Theoretical Grade 3 Muscle Strength Value in Daniels et al.’s Manual Muscle Test, in Consideration of Age: An Investigation of Hip and Knee Joint Flexion and Extension

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Hideyuki Usa

2017-01-01

Full Text Available This study attempted to develop a formula for predicting maximum muscle strength value for young, middle-aged, and elderly adults using theoretical Grade 3 muscle strength value (moment fair: Mf—the static muscular moment to support a limb segment against gravity—from the manual muscle test by Daniels et al. A total of 130 healthy Japanese individuals divided by age group performed isometric muscle contractions at maximum effort for various movements of hip joint flexion and extension and knee joint flexion and extension, and the accompanying resisting force was measured and maximum muscle strength value (moment max, Mm was calculated. Body weight and limb segment length (thigh and lower leg length were measured, and Mf was calculated using anthropometric measures and theoretical calculation. There was a linear correlation between Mf and Mm in each of the four movement types in all groups, excepting knee flexion in elderly. However, the formula for predicting maximum muscle strength was not sufficiently compatible in middle-aged and elderly adults, suggesting that the formula obtained in this study is applicable in young adults only.

Analysis and control of a parallel lower limb based on pneumatic artificial muscles

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Feilong Jiang

2016-12-01

Full Text Available Most robots that are actuated by antagonistic pneumatic artificial muscles are controlled by various control algorithms that cannot adequately imitate the actual muscle distribution of human limbs. Other robots in which the distribution of pneumatic artificial muscle is similar to that of human limbs can only analyze the position of the robot using perceptual data instead of rational knowledge. In order to better imitate the movement of a human limb, the article proposes a humanoid lower limb in the form of a parallel mechanism where muscle is unevenly distributed. Next, the kinematic and dynamic movements of bionic hip joint are analyzed, where the joint movement is controlled by an observer-based fuzzy adaptive control algorithm as a whole rather than each individual pneumatic artificial muscle and parameters that are optimized by a neural network. Finally, experimental results are provided to confirm the effectiveness of the proposed method. We also document the role of muscle in trajectory tracking for the piriformis and musculi obturator internus in isobaric processes.

Association of ethnicity with involuntary childlessness and perceived reasons for infertility: baseline data from the Study of Women's Health Across the Nation (SWAN).

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Karmon, Anatte; Hailpern, Susan M; Neal-Perry, Genevieve; Green, Robin R; Santoro, Nanette; Polotsky, Alex J

2011-11-01

To evaluate whether ethnicity is associated with involuntary childlessness and perceived reasons for difficulties in becoming pregnant. Cross-sectional analysis of baseline data from a longitudinal cohort. Multiethnic, community-based observational study of US women. Women in midlife (3,149), aged 42-52 years. None. Involuntary childlessness and perceived etiology of infertility. One hundred thirty-three subjects (4.2%) were involuntarily childless, defined by a reported history of infertility and nulliparity. Ethnicity was significantly associated with self-reported involuntary childlessness. After controlling for economic and other risk factors, African American (odds ratio [OR] 0.30; 95% confidence interval [CI] 0.15-0.59) and Chinese women (OR 0.36; 95% CI 0.14-0.90) were less likely to suffer from involuntary childlessness compared with non-Hispanic white women. In addition, 302 subjects reported a perceived etiology of infertility. An unexpectedly large proportion of these women (24.5%, 74 of 302) reported etiologies not known to cause infertility (i.e., tipped uterus, ligaments for tubes were stretched), with African American women having been most likely to report these etiologies (OR 2.81; 95% CI 1.26-6.28) as the reason for not becoming pregnant. Ethnicity is significantly associated with involuntary childlessness and perceived etiology of infertility. Misattribution of causes of infertility is common and merits further consideration with respect to language or cultural barriers, as well as possible physician misattribution. Copyright © 2011 American Society for Reproductive Medicine. Published by Elsevier Inc. All rights reserved.

Neurophysiological aspects of eye and eyelid movements during blinking in humans

NARCIS (Netherlands)

Bour, L. J.; Aramideh, M.; de Visser, B. W.

2000-01-01

The neural relationships between eyelid movements and eye movements during spontaneous, voluntary, and reflex blinking in a group of healthy subjects were examined. Electromyographic (EMG) recording of the orbicularis oculi (OO) muscles was performed using surface electrodes. Concurrently,

A mini-overview of single muscle fibre mechanics: the effects of age, inactivity and exercise in animals and humans.

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Jee, Hyunseok; Kim, Jong-Hee

2017-09-05

Many basic movements of living organisms are dependent on muscle function. Muscle function allows for the coordination and harmonious integrity of movement that is necessary for various biological processes. Gross and fine motor skills are both regulated at the micro-level (single muscle fibre level), controlled by neuronal regulation, and it is therefore important to understand muscle function at both micro- and macro-levels to understand the overall movement of living organisms. Single muscle mechanics and the cellular environment of muscles fundamentally allow for the harmonious movement of our bodies. Indeed, a clear understanding of the functionality of muscle at the micro-level is indispensable for explaining muscular function at the macro-(whole gross muscle) level. By investigating single muscle fibre mechanics, we can also learn how other factors such Ca2+ kinetics, enzyme activity and contractile proteins can contribute to muscle mechanics at the micro- and macro-levels. Further, we can also describe how aging affects the capacity of skeletal muscle cells, as well as how exercise can prevent aging-based sarcopenia and frailty. The purpose of this review is to introduce and summarise the current knowledge of single muscle fibre mechanics in light of aging and inactivity. We then describe how exercise mitigates negative muscle adaptations that occur under those circumstances. In addition, single muscle fibre mechanics in both animal and human models are discussed.

[Characteristics of opening movement in patients with unilateral mastication].

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Jia, Ling; Wang, Yun; Wang, Mengya

2016-08-01

To analyze characteristics of mandibular movement in patients with unilateral mastication.
 Undergraduate students in oral medicine from Grade 2011 and 2012 in Wannan Medical College were enrolled for this study by cluster sampling method, which include 30 people with unilateral mastication and 30 people with bilateral mastication. The surface electromyogram (sEMG) of masseter muscle and anterovent of digastric muscle were recorded and the trajectory of mandibular incisor point was recorded simultaneously in the maximum opening and closing movement. The results were analyzed by SPSS 19.0 software.
 Average electrical peak of left anterior digastric muscle and right anterior digastric muscle in the unilateral chewing group was lower than that in the bilateral chewing group (P<0.05). The jaw tangent point trajectory was separate in the unilateral chewing group. There were significant differences at the opening type between the 2 groups. The vertical displacement and the sagittal displacement in the unilateral chewing group were significantly lower than those in the bilateral chewing group (P<0.01). There was significant positive correlation between the average peak potential of masseter muscle and displacement on the right side.
 Average electrical peak of left masseter muscle, left anterior digastric muscle, and right anterior digastric muscle decreases in the unilateral chewing group. Jaw tracking in most people deflects to the working side. Opening and closing jaw tracking is separate in 50% unilateral chewing individuals with the decreased opening degree. Unilateral chewing leads to changes in muscle performance accompanied by trajectory anomalies.

Parameter interdependence and succes of skeletal muscle modelling

NARCIS (Netherlands)

Huijing, P.A.J.B.M.

1995-01-01

In muscle and movement modelling it is almost invariably assumed that force actually exerted is determined by several independent factors. This review considers the fact that length force characteristics are not a relatively fixed property of muscle but should be considered the product of a

Fatigue effects on tracking performance and muscle activity

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Huysmans, M.A.; Hoozemans, M.J.M.; van der Beek, A.J.; de Looze, M.P.; van Dieen, J.H.

2008-01-01

It has been suggested that fatigue affects proprioception and consequently movement accuracy, the effects of which may be counteracted by increased muscle activity. To determine the effects of fatigue on tracking performance and muscle activity in the M. extensor carpi radialis (ECR), 11 female

Medical Futility and Involuntary Passive Euthanasia.

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Nair-Collins, Michael

2018-01-01

Conflicts between providers and patients or their families surrounding end-of-life care are both regrettable and extremely challenging, interpersonally and ethically, for all involved. These conflicts often implicate the concept of medical futility. The concept of futility is too often conflated with distinct concepts that are more ethically salient, including the fiduciary responsibility to assess surrogate decision-making, and distributive justice. By distinguishing these concepts from futility, it becomes clear that there are some situations in which forgoing life-sustaining treatment over objection is permissible, and perhaps even obligatory. But the justification lies in the constellation of rights and responsibilities surrounding surrogate decision-making, or in distributive justice, but not futility. Once futility is disambiguated from these other concepts, the practice of withholding or withdrawing life-sustaining treatment over the objection of a valid surrogate or a competent patient, based on the alleged futility of such treatment, is more clearly described as involuntary passive euthanasia.

Involuntary attention with uncertainty: peripheral cues improve perception of masked letters, but may impair perception of low-contrast letters.

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Kerzel, Dirk; Gauch, Angélique; Buetti, Simona

2010-10-01

Improvements of perceptual performance following the presentation of peripheral cues have been ascribed to accelerated accrual of information, enhanced contrast perception, and decision bias. We investigated effects of peripheral cues on the perception of Gabor and letter stimuli. Non-predictive, peripheral cues improved perceptual accuracy when the stimuli were masked. In contrast, peripheral cues degraded perception of low-contrast letters and did not affect the perception of low-contrast Gabors. The results suggest that involuntary attention accelerates accrual of information but are not entirely consistent with the idea that involuntary attention enhances subjective contrast. Rather, peripheral cues may cause crowding with single letter targets of low contrast. Further, we investigated the effect of the amount of uncertainty on involuntary attention. Cueing effects were (initially) larger when there were more possible target locations. In addition, cueing effects were larger when error feedback was absent and observers had no knowledge of results. Despite these strategic factors, location uncertainty was not sufficient to produce cueing effects, showing that location uncertainty paired with non-predictive cues reveals perceptual and not (only) decisional processes.

Dynamic model of the octopus arm. II. Control of reaching movements.

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Yekutieli, Yoram; Sagiv-Zohar, Roni; Hochner, Binyamin; Flash, Tamar

2005-08-01

The dynamic model of the octopus arm described in the first paper of this 2-part series was used here to investigate the neural strategies used for controlling the reaching movements of the octopus arm. These are stereotypical extension movements used to reach toward an object. In the dynamic model, sending a simple propagating neural activation signal to contract all muscles along the arm produced an arm extension with kinematic properties similar to those of natural movements. Control of only 2 parameters fully specified the extension movement: the amplitude of the activation signal (leading to the generation of muscle force) and the activation traveling time (the time the activation wave takes to travel along the arm). We found that the same kinematics could be achieved by applying activation signals with different activation amplitudes all exceeding some minimal level. This suggests that the octopus arm could use minimal amplitudes of activation to generate the minimal muscle forces required for the production of the desired kinematics. Larger-amplitude signals would generate larger forces that increase the arm's stability against perturbations without changing the kinematic characteristics. The robustness of this phenomenon was demonstrated by examining activation signals with either a constant or a bell-shaped velocity profile. Our modeling suggests that the octopus arm biomechanics may allow independent control of kinematics and resistance to perturbation during arm extension movements.

Building Alliances with (In)Voluntary Clients: A Study Focused on Therapists' Observable Behaviors.

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Sotero, Luciana; Cunha, Diana; da Silva, José Tomás; Escudero, Valentín; Relvas, Ana Paula

2017-12-01

This study aimed to compare therapists' observable behaviors to promote alliances with involuntary and voluntary clients during brief family therapy. The therapists' contributions to fostering alliances were rated in sessions 1 and 4 using videotapes of 29 families who were observed in brief therapy. Using the System for Observing Family Therapy Alliances, trained raters searched for specific therapist behaviors that contributed to or detracted from the four alliance dimensions: engagement in the therapeutic process, an emotional connection with the therapist, safety within the therapeutic system, and a shared sense of purpose within the family. The results showed that when working with involuntary clients, therapists presented more behaviors to foster the clients' engagement and to promote a shared sense of purpose within the family. However, in the fourth session, the therapists in both groups contributed to the alliance in similar ways. The results are discussed in terms of (a) the therapists' alliance-building behaviors, (b) the specificities of each client group, and (c) the implications for clinical practice, training, and research. © 2016 Family Process Institute.

Institutional investors' involuntary trading behaviors,commonality in liquidity change and stock price fragility

Institute of Scientific and Technical Information of China (English)

Guojin Chen; Aihuan Xu; Xiangqin Zhao

2013-01-01

Purpose-The aim of this paper is to empirically analyze the source of commonality in liquidity change in China's stock market.Design/methodology/approach-This paper used two-step test method in Coughenour and Saad and empirically tested the relationship between institutional investors' involuntary trading behaviors and commonality in liquidity change in China's stock market.Findings-The results showed that to take the open-end fund as a representative of institutional investors,their involuntary trading behaviors were an important source of commonality in liquidity change in China's stock market.Originality/value-For a long time,the domestic researchers have ignored the study about the source of commonality in liquidity change in China's stock market.But,this study's conclusion expanded the explanation about the source of commonality in liquidity change in China's stock market from a new point of view that the demand-side explanation.Because there is no market-maker trading behaviors in China's stock market,the paper cannot explain the source of commonality in liquidity change in China's stock market from the point of view of the supply-side explanation.

Sliding mode closed-Loop control of FES: controlling the shank movement

NARCIS (Netherlands)

Jezernik, Saso; Wassink, R.G.V.; Keller, Thierry

2004-01-01

Functional electrical stimulation (FES) enables restoration of movement in individuals with spinal cord injury. FES-based devices use electric current pulses to stimulate and excite the intact peripheral nerves. They produce muscle contractions, generate joint torques, and thus, joint movements.

Neural basis for hand muscle synergies in the primate spinal cord.

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Takei, Tomohiko; Confais, Joachim; Tomatsu, Saeka; Oya, Tomomichi; Seki, Kazuhiko

2017-08-08

Grasping is a highly complex movement that requires the coordination of multiple hand joints and muscles. Muscle synergies have been proposed to be the functional building blocks that coordinate such complex motor behaviors, but little is known about how they are implemented in the central nervous system. Here we demonstrate that premotor interneurons (PreM-INs) in the primate cervical spinal cord underlie the spatiotemporal patterns of hand muscle synergies during a voluntary grasping task. Using spike-triggered averaging of hand muscle activity, we found that the muscle fields of PreM-INs were not uniformly distributed across hand muscles but rather distributed as clusters corresponding to muscle synergies. Moreover, although individual PreM-INs have divergent activation patterns, the population activity of PreM-INs reflects the temporal activation of muscle synergies. These findings demonstrate that spinal PreM-INs underlie the muscle coordination required for voluntary hand movements in primates. Given the evolution of neural control of primate hand functions, we suggest that spinal premotor circuits provide the fundamental coordination of multiple joints and muscles upon which more fractionated control is achieved by superimposed, phylogenetically newer, pathways.

Histological study of rat masseter muscle following experimental occlusal alteration.

Science.gov (United States)

Nishide, N; Baba, S; Hori, N; Nishikawa, H

2001-03-01

It has been suggested that occlusal interference results in masticatory muscle dysfunction. In our previous study, occlusal interference reduced the rat masseter energy level during masticatory movements. The purpose of this study was to investigate the histological alterations of rat masseter muscles following experimental occlusal alteration with unilateral bite-raising. A total of eight male adult Wistar rats were equally divided into control and experimental groups. The experimental rats wore bite-raising splints on the unilateral upper molar. However, 4 weeks after the operation, the anterior deep masseter muscles were removed and then stained for succinic acid dehydrogenase (SDH), haematoxylin eosin (HE) and myofibrillar ATPase. Most of the muscle fibres in experimental rats remained intact, although partial histological changes were observed, such as extended connective tissue, appearance of inflammatory cells in the muscle fibres and existence of muscle fibres with central nuclei and central cores. Moreover, the fibre area-fibre frequency histograms of experimental muscle indicated a broad pattern than that of controls. These results indicated that occlusal interference caused histological changes in masseter muscles and that this may be related to the fact that the masseter energy level was reduced during masticatory movements in unilateral bite-raised rats.

Experimental muscle pain produces central modulation of proprioceptive signals arising from jaw muscle spindles.

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Capra, N F; Ro, J Y

2000-05-01

The aim of the present study was to investigate the effects of intramuscular injection with hypertonic saline, a well-established experimental model for muscle pain, on central processing of proprioceptive input from jaw muscle spindle afferents. Fifty-seven cells were recorded from the medial edge of the subnucleus interpolaris (Vi) and the adjacent parvicellular reticular formation from 11 adult cats. These cells were characterized as central units receiving jaw muscle spindle input based on their responses to electrical stimulation of the masseter nerve, muscle palpation and jaw stretch. Forty-five cells, which were successfully tested with 5% hypertonic saline, were categorized as either dynamic-static (DS) (n=25) or static (S) (n=20) neurons based on their responses to different speeds and amplitudes of jaw movement. Seventy-six percent of the cells tested with an ipsilateral injection of hypertonic saline showed a significant modulation of mean firing rates (MFRs) during opening and/or holding phases. The most remarkable saline-induced change was a significant reduction of MFR during the hold phase in S units (100%, 18/18 modulated). Sixty-nine percent of the DS units (11/16 modulated) also showed significant changes in MFRs limited to the hold phase. However, in the DS neurons, the MFRs increased in seven units and decreased in four units. Finally, five DS neurons showed significant changes of MFRs during both opening and holding phases. Injections of isotonic saline into the ipsilateral masseter muscle had little effect, but hypertonic saline injections made into the contralateral masseter muscle produced similar results to ipsilateral injections with hypertonic saline. These results unequivocally demonstrate that intramuscular injection with an algesic substance, sufficient to produce muscle pain, produces significant changes in the proprioceptive properties of the jaw movement-related neurons. Potential mechanisms involved in saline-induced changes in the

Measuring leg movements during sleep using accelerometry: comparison with EMG and piezo-electric scored events.

Science.gov (United States)

Terrill, Philip I; Leong, Matthew; Barton, Katrina; Freakley, Craig; Downey, Carl; Vanniekerk, Mark; Jorgensen, Greg; Douglas, James

2013-01-01

Periodic Limb Movements during Sleep (PLMS) can cause significant disturbance to sleep, resulting in daytime sleepiness and reduced quality of life. In conventional clinical practice, PLMS are measured using overnight electromyogram (EMG) of the tibialis anterior muscle, although historically they have also been measured using piezo-electric gauges placed over the muscle. However, PLMS counts (PLM index) do not correlate well with clinical symptomology. In this study, we propose that because EMG and piezo derived signals measure muscle activation rather than actual movement, they may count events with no appreciable movement of the limb and therefore no contribution to sleep disturbance. The aim of this study is thus to determine the percentage of clinically scored limb movements which are not associated with movement of the great toe measured using accelerometry. 9 participants were studied simultaneously with an overnight diagnostic polysomnogram (including EMG and piezo instrumentation of the right leg) and high temporal resolution accelerometry of the right great toe. Limb movements were scored, and peak acceleration during each scored movement was quantified. Across the participant population, 54.9% (range: 26.7-76.3) and 39.0% (range: 4.8-69.6) of limb movements scored using piezo and EMG instrumentation respectively, were not associated with toe movement measured with accelerometry. If sleep disturbance is the consequence of the limb movements, these results may explain why conventional piezo or EMG derived PLMI is poorly correlated with clinical symptomology.

Voluntary and involuntary emotional memory following an analogue traumatic stressor: the differential effects of communality in men and women.

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Kamboj, Sunjeev K; Oldfield, Lucy; Loewenberger, Alana; Das, Ravi K; Bisby, James; Brewin, Chris R

2014-12-01

Men and women show differences in performance on emotional processing tasks. Sex also interacts with personality traits to affect information processing. Here we examine effects of sex, and two personality traits that are differentially expressed in men and women - instrumentality and communality - on voluntary and involuntary memory for distressing video-footage. On session one, participants (n = 39 men; 40 women) completed the Bem Sex-Role Inventory, which assesses communal and instrumental traits. After viewing film-footage of death/serious injury, participants recorded daily involuntary memories (intrusions) relating to the footage on an online diary for seven days, returning on day eight for a second session to perform a voluntary memory task relating to the film. Communality interacted with sex such that men with higher levels of communality reported more frequent involuntary memories. Alternatively, a communality × sex interaction reflected a tendency for women with high levels of communality to perform more poorly on the voluntary recognition memory task. The study involved healthy volunteers with no history of significant psychological disorder. Future research with clinical populations will help to determine the generalizability of the current findings. Communality has separate effects on voluntary and involuntary emotional memory. We suggest that high levels of communality in men and women may confer vulnerability to the negative effects of stressful events either through the over-encoding of sensory/perceptual-information in men or the reduced encoding of contextualised, verbally-based, voluntarily accessible representations in women. Copyright © 2014 Elsevier Ltd. All rights reserved.

Flexible adaptation to an artificial recurrent connection from muscle to peripheral nerve in man.

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Kato, Kenji; Sasada, Syusaku; Nishimura, Yukio

2016-02-01

Controlling a neuroprosthesis requires learning a novel input-output transformation; however, how subjects incorporate this into limb control remains obscure. To elucidate the underling mechanisms, we investigated the motor adaptation process to a novel artificial recurrent connection (ARC) from a muscle to a peripheral nerve in healthy humans. In this paradigm, the ulnar nerve was electrically stimulated in proportion to the activation of the flexor carpi ulnaris (FCU), which is ulnar-innervated and monosynaptically innervated from Ia afferents of the FCU, defined as the "homonymous muscle," or the palmaris longus (PL), which is not innervated by the ulnar nerve and produces similar movement to the FCU, defined as the "synergist muscle." The ARC boosted the activity of the homonymous muscle and wrist joint movement during a visually guided reaching task. Participants could control muscle activity to utilize the ARC for the volitional control of wrist joint movement and then readapt to the absence of the ARC to either input muscle. Participants reduced homonymous muscle recruitment with practice, regardless of the input muscle. However, the adaptation process in the synergist muscle was dependent on the input muscle. The activity of the synergist muscle decreased when the input was the homonymous muscle, whereas it increased when it was the synergist muscle. This reorganization of the neuromotor map, which was maintained as an aftereffect of the ARC, was observed only when the input was the synergist muscle. These findings demonstrate that the ARC induced reorganization of neuromotor map in a targeted and sustainable manner. Copyright © 2016 the American Physiological Society.

Effects of Kinesio taping on scapular kinematics of overhead athletes following muscle fatigue.

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Zanca, Gisele Garcia; Grüninger, Bruno; Mattiello, Stela Márcia

2016-08-01

Scapular kinematics alterations have been found following muscle fatigue. Considering the importance of the lower trapezius in coordinated scapular movement, this study aimed to investigate the effects of elastic taping (Kinesio taping, KT) for muscle facilitation on scapular kinematics of healthy overhead athletes following muscle fatigue. Twenty-eight athletes were evaluated in a crossover, single-blind, randomized design, in three sessions: control (no taping), KT (KT with tension) and sham (KT without tension). Scapular tridimensional kinematics and EMG of clavicular and acromial portions of upper trapezius, lower trapezius and serratus anterior were evaluated during arm elevation and lowering, before and after a fatigue protocol involving repetitive throwing. Median power frequency decline of serratus anterior was significantly lower in KT session compared to sham, possibly indicating lower muscle fatigue. However, the effects of muscle fatigue on scapular kinematics were not altered by taping conditions. Although significant changes were found in scapular kinematics following muscle fatigue, they were small and not considered relevant. It was concluded that healthy overhead athletes seem to present an adaptive mechanism that avoids the disruption of scapular movement pattern following muscle fatigue. Therefore, these athletes do not benefit from the use of KT to assist scapular movement under the conditions tested. Copyright © 2015 Elsevier Ltd. All rights reserved.

Comparative anatomy of the cheek muscles within the Centromochlinae subfamily (Ostariophysi, Siluriformes, Auchenipteridae).

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Sarmento-Soares, Luisa Maria; Porto, Marcovan

2006-02-01

Glanidium melanopterum Miranda Ribeiro, a typical representative of the subfamily Centromochlinae (Siluriformes: Auchenipteridae), is herein described myologically and compared to other representative species within the group, Glanidium ribeiroi, G. leopardum, Tatia neivai, T. intermedia, T. creutzbergi, Centromochlus heckelii, and C. existimatus. The structure of seven pairs of striated cephalic muscles was compared anatomically: adductor mandibulae, levator arcus palatini, dilatator operculi, adductor arcus palatini, extensor tentaculi, retractor tentaculi, and levator operculi. We observed broad adductor mandibulae muscles in both Glanidium and Tatia, catfishes with depressed heads and smaller eyes. Similarities between muscles were observed: the presence of a large aponeurotic insertion for the levator arcus palatini muscle; an adductor arcus palatini muscle whose origin spread over the orbitosphenoid, pterosphenoid, and parasphenoid; and the extensor tentaculi muscle broadly attached to the autopalatine. There is no retractor tentaculi muscle in either the Glanidium or Tatia species. On the other hand, in Centromochlus, with forms having large eyes and the tallest head, the adductor mandibulae muscles are slim; there is a thin aponeurotic or muscular insertion for the levator arcus palatini muscle; the adductor arcus palatini muscle originates from a single osseous process, forming a keel on the parasphenoid; the extensor tentaculi muscle is loosely attached to the autopalatine, permitting exclusive rotating and sliding movements between this bone and the maxillary. The retractor tentaculi muscle is connected to the maxilla through a single tendon, so that both extensor and retractor tentaculi muscles contribute to a wide array of movements of the maxillary barbels. A discussion on the differences in autopalatine-maxillary movements among the analyzed groups is given. (c) 2005 Wiley-Liss, Inc.

Involuntary and voluntary recall of musical memories: A comparison of temporal accuracy and emotional responses.

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Jakubowski, Kelly; Bashir, Zaariyah; Farrugia, Nicolas; Stewart, Lauren

2018-01-29

Comparisons between involuntarily and voluntarily retrieved autobiographical memories have revealed similarities in encoding and maintenance, with differences in terms of specificity and emotional responses. Our study extended this research area into the domain of musical memory, which afforded a unique opportunity to compare the same memory as accessed both involuntarily and voluntarily. Specifically, we compared instances of involuntary musical imagery (INMI, or "earworms")-the spontaneous mental recall and repetition of a tune-to deliberate recall of the same tune as voluntary musical imagery (VMI) in terms of recall accuracy and emotional responses. Twenty participants completed two 3-day tasks. In an INMI task, participants recorded information about INMI episodes as they occurred; in a VMI task, participants were prompted via text message to deliberately imagine each tune they had previously experienced as INMI. In both tasks, tempi of the imagined tunes were recorded by tapping to the musical beat while wearing an accelerometer and additional information (e.g., tune name, emotion ratings) was logged in a diary. Overall, INMI and VMI tempo measurements for the same tune were strongly correlated. Tempo recall for tunes that have definitive, recorded versions was relatively accurate, and tunes that were retrieved deliberately (VMI) were not recalled more accurately in terms of tempo than spontaneous and involuntary instances of imagined music (INMI). Some evidence that INMI elicited stronger emotional responses than VMI was also revealed. These results demonstrate several parallels to previous literature on involuntary memories and add new insights on the phenomenology of INMI.

Restoration of Central Programmed Movement Pattern by Temporal Electrical Stimulation-Assisted Training in Patients with Spinal Cerebellar Atrophy.

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Huang, Ying-Zu; Chang, Yao-Shun; Hsu, Miao-Ju; Wong, Alice M K; Chang, Ya-Ju

2015-01-01

Disrupted triphasic electromyography (EMG) patterns of agonist and antagonist muscle pairs during fast goal-directed movements have been found in patients with hypermetria. Since peripheral electrical stimulation (ES) and motor training may modulate motor cortical excitability through plasticity mechanisms, we aimed to investigate whether temporal ES-assisted movement training could influence premovement cortical excitability and alleviate hypermetria in patients with spinal cerebellar ataxia (SCA). The EMG of the agonist extensor carpi radialis muscle and antagonist flexor carpi radialis muscle, premovement motor evoked potentials (MEPs) of the flexor carpi radialis muscle, and the constant and variable errors of movements were assessed before and after 4 weeks of ES-assisted fast goal-directed wrist extension training in the training group and of general health education in the control group. After training, the premovement MEPs of the antagonist muscle were facilitated at 50 ms before the onset of movement. In addition, the EMG onset latency of the antagonist muscle shifted earlier and the constant error decreased significantly. In summary, temporal ES-assisted training alleviated hypermetria by restoring antagonist premovement and temporal triphasic EMG patterns in SCA patients. This technique may be applied to treat hypermetria in cerebellar disorders. (This trial is registered with NCT01983670.).

Tissue Selective Androgen Receptor Modulators (SARMs) Increase Pelvic Floor Muscle Mass in Ovariectomized Mice.

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Ponnusamy, Suriyan; Sullivan, Ryan D; Thiyagarajan, Thirumagal; Tillmann, Heather; Getzenberg, Robert H; Narayanan, Ramesh

2017-03-01

Stress urinary incontinence (SUI), a prevalent condition, is represented by an involuntary leakage of urine that results, at least in part, from weakened or damaged pelvic floor muscles and is triggered by physical stress. Current treatment options are limited with no oral therapies available. The pelvic floor is rich in androgen receptor and molecules with anabolic activity including selective androgen receptor modulators (SARMs) may serve as therapeutic options for individuals with SUI. In this study, two SARMs (GTx-024 and GTx-027) were evaluated in a post-menopausal animal model in order to determine their effect on pelvic floor muscles. Female C57BL/6 mice were ovariectomized and their pelvic muscles allowed to regress. The animals were then treated with vehicle or doses of GTx-024 or GTx-027. Animal total body weight, lean body mass, and pelvic floor muscle weights were measured along with the expression of genes associated with muscle catabolism. Treatment with the SARMs resulted in a restoration of the pelvic muscles to the sham-operated weight. Coordinately, the induction of genes associated with muscle catabolism was inhibited. Although a trend was observed towards an increase in total lean body mass in the SARM-treated groups, no significant differences were detected. Treatment of an ovariectomized mouse model with SARMs resulted in an increase in pelvic floor muscles, which may translate to an improvement of symptoms associated with SUI and serves as the basis for evaluating their clinical use. J. Cell. Biochem. 118: 640-646, 2017. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

[Analysis of fatigue associated to periodic limb movement during sleep in former poliomyelitis patients].

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Oliveira, A R; Correa, F I; Correa, J C F; Oliveira, L V F

2012-01-01

Following poliomyelitis, patients may experience sleep disorders stemming from periodic limb movement, leading to fatigue and compromised muscle function the following day. To establish the presence or absence of muscle fatigue in these patients using electromyography and relating the data to polysomnographic findings. An analytical cross-sectional study was carried out involving 19 individuals with motor sequelae in the lower limbs stemming from poliomyelitis. Quantitative tests for the assessment of neurophysiological aspects (knee-jerk/Achilles reflexes and peripheral muscle strength of rectus femoris) and a sleep study (standard, level I polysomnography) were administered. A statistically significant difference was detected (p fatigue associated to sleep disorder. Individuals with sequelae from poliomyelitis exhibit sleep disorders that may lead to muscle fatigue. Periodic limb movement may contribute to this phenomenon.

Degeneration of rapid eye movement sleep circuitry underlies rapid eye movement sleep behavior disorder.

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McKenna, Dillon; Peever, John

2017-05-01

During healthy rapid eye movement sleep, skeletal muscles are actively forced into a state of motor paralysis. However, in rapid eye movement sleep behavior disorder-a relatively common neurological disorder-this natural process is lost. A lack of motor paralysis (atonia) in rapid eye movement sleep behavior disorder allows individuals to actively move, which at times can be excessive and violent. At first glance this may sound harmless, but it is not because rapid eye movement sleep behavior disorder patients frequently injure themselves or the person they sleep with. It is hypothesized that the degeneration or dysfunction of the brain stem circuits that control rapid eye movement sleep paralysis is an underlying cause of rapid eye movement sleep behavior disorder. The link between brain stem degeneration and rapid eye movement sleep behavior disorder stems from the fact that rapid eye movement sleep behavior disorder precedes, in the majority (∼80%) of cases, the development of synucleinopathies such as Parkinson's disease, dementia with Lewy bodies, and multiple system atrophy, which are known to initially cause degeneration in the caudal brain stem structures where rapid eye movement sleep circuits are located. Furthermore, basic science and clinical evidence demonstrate that lesions within the rapid eye movement sleep circuits can induce rapid eye movement sleep-specific motor deficits that are virtually identical to those observed in rapid eye movement sleep behavior disorder. This review examines the evidence that rapid eye movement sleep behavior disorder is caused by synucleinopathic neurodegeneration of the core brain stem circuits that control healthy rapid eye movement sleep and concludes that rapid eye movement sleep behavior disorder is not a separate clinical entity from synucleinopathies but, rather, it is the earliest symptom of these disorders. © 2017 International Parkinson and Movement Disorder Society. © 2017 International Parkinson and

Hemichorea after multiple bee stings.

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An, Jin Young; Kim, Ji Seon; Min, Jin Hong; Han, Kyu Hong; Kang, Jun Ho; Lee, Suk Woo; Kim, Hoon; Park, Jung Soo

2014-02-01

Bee sting is one of the most commonly encountered insect bites in the world. Despite the common occurrence of local and systemic allergic reactions, there are few reports of ischemic stroke after bee stings. To the best our knowledge, there have been no reports on involuntary hyperkinetic movement disorders after multiple bee stings. We report the case of a 50-year-old man who developed involuntary movements of the left leg 24 hours after multiple bee stings, and the cause was confirmed to be a right temporal infarction on a diffusion magnetic resonance imaging scan. Thus, we concluded that the involuntary movement disorder was caused by right temporal infarction that occurred after multiple bee stings.

Association between Thigh Muscle Volume and Leg Muscle Power in Older Women.

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Ulrich Lindemann

Full Text Available The construct of sarcopenia is still discussed with regard to best appropriate measures of muscle volume and muscle function. The aim of this post-hoc analysis of a cross-sectional experimental study was to investigate and describe the hierarchy of the association between thigh muscle volume and measurements of functional performance in older women. Thigh muscle volume of 68 independently living older women (mean age 77.6 years was measured via magnetic resonance imaging. Isometric strength was assessed for leg extension in a movement laboratory in sitting position with the knee flexed at 90° and for hand grip. Maximum and habitual gait speed was measured on an electronic walk way. Leg muscle power was measured during single leg push and during sit-to-stand performance. Thigh muscle volume was associated with sit-to-stand performance power (r = 0.628, leg push power (r = 0.550, isometric quadriceps strength (r = 0.442, hand grip strength (r = 0.367, fast gait speed (r = 0.291, habitual gait speed (r = 0.256, body mass index (r = 0.411 and age (r = -0.392. Muscle power showed the highest association with thigh muscle volume in healthy older women. Sit-to-stand performance power showed an even higher association with thigh muscle volume compared to single leg push power.

Relationship between physical exercise, muscle damage and delayed-onset muscle soreness

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Denis Foschini

2007-03-01

Full Text Available The objective of the present study was to investigate the relationship between physical exercise involving muscle damage and delayed-onset muscle soreness (DOMS. A literature review of national and international periodicals was carried out. Muscle structures (membranes, Z-line, sarcomeres, T tubules and myofi brils can become damaged as a result of an imposed mechanical overload. Of greatest note are exercises requiring strength, particularly when muscular action is eccentric. Damage to skeletal musculature can be analyzed by direct methods (muscle biopsy or magnetic resonance or by indirect methods (maximum voluntary movement, subjective pain perception scales, analysis of enzyme and protein concentrations in blood. Creatine kinase (CK, lactate dehydrogenase (LDH, myosin heavy chain fragments, troponin-I and myoglobin can be used as indirect markers of muscle damage. Both DOMS and muscle damage can be infl uenced by the type of activity, with emphasis on eccentric muscle movements, type of exercise, velocity of the movement, interval period between series, the level of individual fi tness, this last primarily affecting beginners. When myotrauma occurs, muscle damage repair is initiated by leukocytes migrating to the injured area, although, the histamines, prostaglandins, kinins and K+ produced by neutrophils and macrophages stimulate free nerve endings in the muscle, causing the DOMS. Despite this apparent relationship between muscle damage and DOMS, it is not possible toestablish a linear relationship between these two variables, since published data are divergent. RESUMO O objetivo desse estudo foi investigar as relações do exercício físico com o dano muscular e dor muscular de início tardio (DMIT. Para tanto, foi realizada uma revisão de literatura de periódicos nacionais e internacionais. O dano muscular pode ocorrer em estruturas musculares (membranas, linha Z, sarcolema, túbulos T e miofi brilas em função da sobrecarga mec

Involuntary memory chaining versus event cueing: Which is a better indicator of autobiographical memory organisation?

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Mace, John H; Clevinger, Amanda M; Martin, Cody

2010-11-01

Involuntary memory chains are spontaneous recollections of the past that occur in a sequence. Much like semantic memory priming, this memory phenomenon has provided some insights into the nature of associations in autobiographical memory. The event-cueing procedure (a laboratory-based memory sequencing task) has also provided some insights into the nature of autobiographical memory organisation. However, while both of these memory-sequencing phenomena have exhibited the same types of memory associations (conceptual associations and general-event or temporal associations), both have also produced discrepant results with respect to the relative proportions of such associations. This study investigated the possibility that the results from event cueing are artefacts of various memory production responses. Using a number of different approaches we demonstrated that these memory production responses cause overestimates of general-event association. We conclude that for this reason, the data from involuntary memory chains provide a better picture of the organisation of autobiographical memory.

Re-Creation in the Age of Wisdom : Involuntary Job Transition in Women over 50

NARCIS (Netherlands)

Lyon-Dugin, Frances E.

2017-01-01

Re-Creation in the Age of Wisdom: Involuntary Job Transition in Women over 50 Frances Elizabeth Lyon-Dugin A large share of our time with each other is centered around employment or ‘work’, however we define it. A time of transition between jobs, especially when a job is lost through no choice of

Why Am I Remembering This Now? Predicting the Occurrence of Involuntary (Spontaneous) Episodic Memories

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Berntsen, Dorthe; Staugaard, Soren Rislov; Sorensen, Louise Maria Torp

2013-01-01

Involuntary episodic memories are memories of events that come to mind spontaneously, that is, with no preceding retrieval attempts. They are common in daily life and observed in a range of clinical disorders in the form of negative, intrusive recollections or flashbacks. However, little is known about their underlying mechanisms. Here we report a…

Contingent capture of involuntary visual attention interferes with detection of auditory stimuli

OpenAIRE

Kamke, Marc R.; Harris, Jill

2014-01-01

The involuntary capture of attention by salient visual stimuli can be influenced by the behavioral goals of an observer. For example, when searching for a target item, irrelevant items that possess the target-defining characteristic capture attention more strongly than items not possessing that feature. Such contingent capture involves a shift of spatial attention toward the item with the target-defining characteristic. It is not clear, however, if the associated decrements in performance for...

Modulation of jaw muscle spindle afferent activity following intramuscular injections with hypertonic saline.

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Ro, J Y; Capra, N F

2001-05-01

Transient noxious chemical stimulation of small diameter muscle afferents modulates jaw movement-related responses of caudal brainstem neurons. While it is likely that the effect is mediated from the spindle afferents in the mesencephalic nucleus (Vmes) via the caudally projecting Probst's tract, the mechanisms of pain induced modulations of jaw muscle spindle afferents is not known. In the present study, we tested the hypothesis that jaw muscle nociceptors gain access to muscle spindle afferents in the same muscle via central mechanisms and alter their sensitivity. Thirty-five neurons recorded from the Vmes were characterized as muscle spindle afferents based on their responses to passive jaw movements, muscle palpation, and electrical stimulation of the masseter nerve. Each cell was tested by injecting a small volume (250 microl) of either 5% hypertonic and/or isotonic saline into the receptor-bearing muscle. Twenty-nine units were tested with 5% hypertonic saline, of which 79% (23/29) showed significant modulation of mean firing rates (MFRs) during one or more phases of ramp-and-hold movements. Among the muscle spindle primary-like units (n = 12), MFRs of 4 units were facilitated, five reduced, two showed mixed responses and one unchanged. In secondary-like units (n = 17), MFRs of 9 were facilitated, three reduced and five unchanged. Thirteen units were tested with isotonic saline, of which 77% showed no significant changes of MFRs. Further analysis revealed that the hypertonic saline not only affected the overall output of muscle spindle afferents, but also increased the variability of firing and altered the relationship between afferent signal and muscle length. These results demonstrated that activation of muscle nociceptors significantly affects proprioceptive properties of jaw muscle spindles via central neural mechanisms. The changes can have deleterious effects on oral motor function as well as kinesthetic sensibility.

Agonist mediated fetal muscle-type nicotinic acetylcholine receptor desensitization

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The exposure of a developing embryo or fetus to teratogenic alkaloids from plants has the potential to cause developmental defects in livestock due to the inhibition of fetal movement by alkaloids. The mechanism behind the inhibition of fetal movement is the desensitization of fetal muscle-type nico...

The role of involuntary aware memory in the implicit stem and fragment completion tasks: a selective review.

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Kinoshita, S

2001-03-01

In this article I argue that an awareness of the study episode that arises involuntarily during an implicit stem/fragment completion test can under some conditions lead to enhanced repetition priming effects, even though subjects are not engaged in intentional retrieval. I review findings that are consistent with this possibility, which include the effects of depth of processing, and of typography match and new association priming following deep encoding. A theoretical account of involuntary aware memory couched within Moscovitch's (1995b) memory systems framework which suggests that the medial-temporal lobe/hippocampal (MTL/H) complex functions as a memory module is outlined. A putative mechanism is proposed in which involuntary aware memory of a studied item enhances the size of repetition priming effects by guiding its selection in preference to the competitors.

Design and Experimental Investigation of Pneumatic Movement Mechanism Supported by Mechanic Cam and Crank Shaft

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Salih KORUCU

2015-02-01

Full Text Available The pressurized air is applied to many sectors required purity and velocity. One of these sectors is to use of air as impulsive force in the moving mechanisms. In this study, the movement mechanism prototype worked with compressed air was designed and produced forlight vehicle engine as motorbike and ATV (All-Terrain Vehicle. In developed mechanisms, pneumatic artificial muscles were used for a given movement of crankshaft. A cam system was also designed for synchronization pneumatic muscles. In this way, these muscles transmit the synchronous movement to crankshaft. At the end of the study, the developed mechanism was mounted on an ATV vehicle(110 cc/ Cubic Centimeter, engine displacement capacityand its performance was tested using the four different weights (50, 75, 100 and 150 kg, three different pressures (4, 5 and 6 bar and two different hoses (Ø 6 and Ø 8 mm. By considering experimental results and design criteria, power of the movement mechanism was obtained as 886 Watt. With this study, minimization of energy consumption for movement of passenger cars, and using clean and cheap energy as ATV which can be alternative for single or two passenger vehicles.

Influence of experimental occlusal discrepancy on masticatory muscle activity during clenching.

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Baba, K; Ai, M; Mizutani, H; Enosawa, S

1996-01-01

The influence of the experimental occlusal discrepancy on masticatory muscle activity was investigated on 12 subjects. Specially designed occlusal interferences were fabricated and various occlusal states were simulated with their aid. Subjects were asked to carry out eccentric clenching efforts and electromyographic activity of the masseter plus the anterior and posterior temporal muscles was measured. When compared with clenching on the unaltered natural dentition, clenching on the experimental interferences resulted in distinct patterns in the jaw elevator muscles, and the most characteristic change was observed when clenching effort was exerted on the experimental non-working side interference. Electromyographic activity in the anterior and posterior temporal muscles was decreased on the working side and increased on the non-working side and originally unilateral activity pattern with clear dominance on the working side was altered to a bilateral pattern, while that of the masseter muscles remained uninfluenced. Resultant bilateral activity in the anterior and posterior temporal muscles is thought to cause a superior movement of the working side condyle and an inferior movement of the non-working side condyle.

Effects of External Loads on Human Head Movement Control Systems

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Nam, M. H.; Choi, O. M.

1984-01-01

The central and reflexive control strategies underlying movements were elucidated by studying the effects of external loads on human head movement control systems. Some experimental results are presented on dynamic changes weigh the addition of aviation helmet (SPH4) and lead weights (6 kg). Intended time-optimal movements, their dynamics and electromyographic activity of neck muscles in normal movements, and also in movements made with external weights applied to the head were measured. It was observed that, when the external loads were added, the subject went through complex adapting processes and the head movement trajectory and its derivatives reached steady conditions only after transient adapting period. The steady adapted state was reached after 15 to 20 seconds (i.e., 5 to 6 movements).

Dance Movement: Effects on Elderly Self-Concept.

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Berryman-Miller, Sherrill

1988-01-01

An investigation into the effects of dance/movement programs on self-concept in older retired adults indicated that participants had higher, more positive self-esteem than nonparticipants and also had a heightened awareness of joint and muscle usage and body habits. (CB)

Kinetic magnetic resonance imaging of orbital blowout fracture with restricted ocular movement

International Nuclear Information System (INIS)

Totsuka, Nobuyoshi; Koide, Ryouhei; Inatomi, Makoto; Fukado, Yoshinao; Hisamatsu, Katsuji.

1992-01-01

We analyzed the mechanism of gaze limitation in blowout fracture in 19 patients by means of kinetic magnetic resonance imaging (MRI). We could identify herniation of fat tissue and rectus muscles with connective tissue septa in 11 eyes. Depressed rectus muscles were surrounded by fat tissue. In no instance was the rectus muscle actually incarcerated. Entrapped connective tissue septa seemed to prevent movement of affected rectus muscle. We occasionally observed incarcerated connective tissue septa to restrict motility of the optic nerve. (author)

Effects of balance training by knee joint motions on muscle activity in adult men with functional ankle instability.

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Nam, Seung-Min; Kim, Won-Bok; Yun, Chang-Kyo

2016-05-01

[Purpose] This study examined the effects of balance training by applying knee joint movements on muscle activity in male adults with functional ankle instability. [Subjects and Methods] 28 adults with functional ankle instability, divided randomly into an experimental group, which performed balance training by applying knee joint movements for 20 minutes and ankle joint exercises for 10 minutes, and a control group, which performed ankle joint exercise for 30 minutes. Exercises were completed three times a week for 8 weeks. Electromyographic values of the tibialis anterior, peroneus longus, peroneus brevis, and the lateral gastrocnemius muscles were obtained to compare and analyze muscle activity before and after the experiments in each group. [Results] The experimental group had significant increases in muscle activity in the tibialis anterior, peroneus longus, and lateral gastrocnemius muscles, while muscle activity in the peroneus brevis increased without significance. The control group had significant increases in muscle activity in the tibialis anterior and peroneus longus, while muscle activity in the peroneus brevis and lateral gastrocnemius muscles increased without significance. [Conclusion] In conclusion, balance training by applying knee joint movements can be recommended as a treatment method for patients with functional ankle instability.

Muscle synergies during bench press are reliable across days.

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Kristiansen, Mathias; Samani, Afshin; Madeleine, Pascal; Hansen, Ernst Albin

2016-10-01

Muscle synergies have been investigated during different types of human movement using nonnegative matrix factorization. However, there are not any reports available on the reliability of the method. To evaluate between-day reliability, 21 subjects performed bench press, in two test sessions separated by approximately 7days. The movement consisted of 3 sets of 8 repetitions at 60% of the three repetition maximum in bench press. Muscle synergies were extracted from electromyography data of 13 muscles, using nonnegative matrix factorization. To evaluate between-day reliability, we performed a cross-correlation analysis and a cross-validation analysis, in which the synergy components extracted in the first test session were recomputed, using the fixed synergy components from the second test session. Two muscle synergies accounted for >90% of the total variance, and reflected the concentric and eccentric phase, respectively. The cross-correlation values were strong to very strong (r-values between 0.58 and 0.89), while the cross-validation values ranged from substantial to almost perfect (ICC3, 1 values between 0.70 and 0.95). The present findings revealed that the same general structure of the muscle synergies was present across days and the extraction of muscle synergies is thus deemed reliable. Copyright © 2016 Elsevier Ltd. All rights reserved.

Why does society accept a higher risk for alcohol than for other voluntary or involuntary risks?

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Rehm, Jürgen; Lachenmeier, Dirk W; Room, Robin

2014-10-21

Societies tend to accept much higher risks for voluntary behaviours, those based on individual decisions (for example, to smoke, to consume alcohol, or to ski), than for involuntary exposure such as exposure to risks in soil, drinking water or air. In high-income societies, an acceptable risk to those voluntarily engaging in a risky behaviour seems to be about one death in 1,000 on a lifetime basis. However, drinking more than 20 g pure alcohol per day over an adult lifetime exceeds a threshold of one in 100 deaths, based on a calculation from World Health Organization data of the odds in six European countries of dying from alcohol-attributable causes at different levels of drinking. The voluntary mortality risk of alcohol consumption exceeds the risks of other lifestyle risk factors. In addition, evidence shows that the involuntary risks resulting from customary alcohol consumption far exceed the acceptable threshold for other involuntary risks (such as those established by the World Health Organization or national environmental agencies), and would be judged as not acceptable. Alcohol's exceptional status reflects vagaries of history, which have so far resulted in alcohol being exempted from key food legislation (no labelling of ingredients and nutritional information) and from international conventions governing all other psychoactive substances (both legal and illegal). This is along with special treatment of alcohol in the public health field, in part reflecting overestimation of its beneficial effect on ischaemic disease when consumed in moderation. A much higher mortality risk from alcohol than from other risk factors is currently accepted by high income countries.

Controlled chaos: three-dimensional kinematics, fiber histochemistry, and muscle contractile dynamics of autotomized lizard tails.

Science.gov (United States)

Higham, Timothy E; Lipsett, Kathryn R; Syme, Douglas A; Russell, Anthony P

2013-01-01

The ability to shed an appendage occurs in both vertebrates and invertebrates, often as a tactic to avoid predation. The tails of lizards, unlike most autotomized body parts of animals, exhibit complex and vigorous movements once disconnected from the body. Despite the near ubiquity of autotomy across groups of lizards and the fact that this is an extraordinary event involving the self-severing of the spinal cord, our understanding of why and how tails move as they do following autotomy is sparse. We herein explore the histochemistry and physiology of the tail muscles of the leopard gecko (Eublepharis macularius), a species that exhibits vigorous and variable tail movements following autotomy. To confirm that the previously studied tail movements of this species are generally representative of geckos and therefore suitable for in-depth muscle studies, we quantified the three-dimensional kinematics of autotomized tails in three additional species. The movements of the tails of all species were generally similar and included jumps, flips, and swings. Our preliminary analyses suggest that some species of gecko exhibit short but high-frequency movements, whereas others exhibit larger-amplitude but lower-frequency movements. We then compared the ATPase and oxidative capacity of muscle fibers and contractile dynamics of isolated muscle bundles from original tails, muscle from regenerate tails, and fast fibers from an upper limb muscle (iliofibularis) of the leopard gecko. Histochemical analysis revealed that more than 90% of the fibers in original and regenerate caudal muscles had high ATPase but possessed a superficial layer of fibers with low ATPase and high oxidative capacity. We found that contraction kinetics, isometric force, work, power output, and the oscillation frequency at which maximum power was generated were lowest in the original tail, followed by the regenerate tail and then the fast fibers of the iliofibularis. Muscle from the original tail exhibited

Postural adjustments associated with voluntary contraction of leg muscles in standing man.

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Nardone, A; Schieppati, M

1988-01-01

The postural adjustments associated with a voluntary contraction of the postural muscles themselves have been studied in the legs of normal standing men. We focussed on the following questions. Do postural adjustments precede the focal movement as in the case of movements of the upper limb? Which muscle(s) are involved in the task of stabilizing posture? Can the same postural muscle be activated in postural stabilization and in voluntary movement at the same time, in spite of the opposite changes in activity possibly required by these conditions? Six subjects standing on a dynamometric platform were asked to rise onto the tips their toes by contracting their soleus muscles, or to rock on their heels by contracting their tibialis anterior muscles. The tasks were made in a reaction time (RT) situation or in a self-paced mode, standing either freely or holding onto a stable structure. Surface EMGs of leg and thigh muscles, and the foot-floor reaction forces were recorded. The following results were obtained in the RT mode, standing freely. 1. Rising onto toe tips: a striking silent period in soleus preceded its voluntary activation; during this silent period, a tibialis anterior burst could be observed in three subjects; these anticipatory activities induced a forward sway, as monitored by a change in the force exerted along the x axis of the platform. 2. Rocking on heels: an enhancement in tonic EMG of soleus was observed before tibialis anterior voluntary burst, at a mean latency from the go-signal similar to that of the silent period; this anticipatory activity induced a backward body sway. 3. Choice RT conditions showed that the above anticipatory patterns in muscle activity were pre-programmed, specific for the intended tasks, and closely associated with the focal movement. When both tasks were performed in a self-paced mode, all the above EMG and mechanical features were more pronounced and unfolded in time. If the subjects held onto the frame, the early

Reflections on involuntary treatment in the prevention of fatal anorexia nervosa: A review of five cases

DEFF Research Database (Denmark)

Holm, Janni Schmidt; Brixen, Kim; Andries, Alin

2011-01-01

OBJECTIVE: Involuntary treatment in the prevention of fatal anorexia nervosa (AN) is still controversial. METHOD: Five fatal cases of AN were identified out of 1,160 patients who attended a specialized eating disorder unit between 1994 and 2006. Information on inpatient, ambulatory, and emergency...

SOCIAL CAPITAL IN INVOLUNTARY DISPLACEMENT AND RESETTLEMENT

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Melissa Quetulio-Navarra

2013-07-01

Full Text Available Social capital is often seen as a substitute for lack of other types of capital amongpoor people. Because of the recognized applicability of the social capital conceptand its correlation with the different dimensions of poverty, it has been used inevaluating the adaptation and integration of involuntarily displaced individualsinto their new environment. This paper presents insights based on a review of thefindings of studies that looked into the role of social capital in conflict- anddevelopment-induced displacement contexts. Althoughboth types of displace-ments are involuntary or forced in nature, they differ in terms of the role of socialcapital regarding its main sources, the formation pattern and its determinants.Social capital studies in forced resettlement appear to be relatively small innumber and are heavily concentrated on first worldcountries and conflict- anddevelopment-induced displacements. The conduct of similar studies in developingcountries and in a disaster-induced resettlement context, the third type ofinvoluntary displacement, should generate new and relevant findings regardingthe role of social capital in resettlement communities.

Radiation-induced camptocormia and dropped head syndrome. Review and case report of radiation-induced movement disorders

Energy Technology Data Exchange (ETDEWEB)

Seidel, Clemens; Kuhnt, Thomas; Kortmann, Rolf-Dieter; Hering, Kathrin [Leipzig University, Department of Radiotherapy and Radiation Oncology, Leipzig (Germany)

2015-10-15

In recent years, camptocormia and dropped head syndrome (DHS) have gained attention as particular forms of movement disorders. Camptocormia presents with involuntary forward flexion of the thoracolumbar spine that typically increases during walking or standing and may severely impede walking ability. DHS is characterized by weakness of the neck extensors and a consecutive inability to extend the neck; in severe cases the head is fixed in a ''chin to chest position.'' Many diseases may underlie these conditions, and there have been some reports about radiation-induced camptocormia and DHS. A PubMed search with the keywords ''camptocormia,'' ''dropped head syndrome,'' ''radiation-induced myopathy,'' ''radiation-induced neuropathy,'' and ''radiation-induced movement disorder'' was carried out to better characterize radiation-induced movement disorders and the radiation techniques involved. In addition, the case of a patient developing camptocormia 23 years after radiation therapy of a non-Hodgkin's lymphoma of the abdomen is described. In total, nine case series of radiation-induced DHS (n = 45 patients) and - including our case - three case reports (n = 3 patients) about radiogenic camptocormia were retrieved. Most cases (40/45 patients) occurred less than 15 years after radiotherapy involving extended fields for Hodgkin's disease. The use of wide radiation fields including many spinal segments with paraspinal muscles may lead to radiation-induced movement disorders. If paraspinal muscles and the thoracolumbar spine are involved, the clinical presentation can be that of camptocormia. DHS may result if there is involvement of the cervical spine. To prevent these disorders, sparing of the spine and paraspinal muscles is desirable. (orig.) [German] In den letzten Jahren haben Bewegungsstoerungen von Wirbelsaeule und paraspinaler Muskulatur in

GRIN1 mutations cause encephalopathy with infantile-onset epilepsy, and hyperkinetic and stereotyped movement disorders.

Science.gov (United States)

Ohba, Chihiro; Shiina, Masaaki; Tohyama, Jun; Haginoya, Kazuhiro; Lerman-Sagie, Tally; Okamoto, Nobuhiko; Blumkin, Lubov; Lev, Dorit; Mukaida, Souichi; Nozaki, Fumihito; Uematsu, Mitsugu; Onuma, Akira; Kodera, Hirofumi; Nakashima, Mitsuko; Tsurusaki, Yoshinori; Miyake, Noriko; Tanaka, Fumiaki; Kato, Mitsuhiro; Ogata, Kazuhiro; Saitsu, Hirotomo; Matsumoto, Naomichi

2015-06-01

Recently, de novo mutations in GRIN1 have been identified in patients with nonsyndromic intellectual disability and epileptic encephalopathy. Whole exome sequencing (WES) analysis of patients with genetically unsolved epileptic encephalopathies identified four patients with GRIN1 mutations, allowing us to investigate the phenotypic spectrum of GRIN1 mutations. Eighty-eight patients with unclassified early onset epileptic encephalopathies (EOEEs) with an age of onset stereotypic hand movements were observed in two and three patients, respectively. All the four patients exhibited only nonspecific focal and diffuse epileptiform abnormality, and never showed suppression-burst or hypsarrhythmia during infancy. A de novo mosaic mutation (c.1923G>A) with a mutant allele frequency of 16% (in DNA of blood leukocytes) was detected in one patient. Three mutations were located in the transmembrane domain (3/4, 75%), and one in the extracellular loop near transmembrane helix 1. All the mutations were predicted to impair the function of the NMDA receptor. Clinical features of de novo GRIN1 mutations include infantile involuntary movements, seizures, and hand stereotypies, suggesting that GRIN1 mutations cause encephalopathy resulting in seizures and movement disorders. Wiley Periodicals, Inc. © 2015 International League Against Epilepsy.

Employees’ Involuntary Non-Use of ICT Influenced by Power Differences: A Case Study with the Grounded Theory Approach

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Thale Kvernberg Andersen

2015-07-01

Full Text Available Power differences affect implementation of information and communication technology (ICT in a way that creates differences in ICT use. Involuntary non-use of new ICT at work occurs when employees want to use the new technology, but are unable to due to factors beyond their control. Findings from an in-depth qualitative study show how involuntary non-use of new ICT can be attributed to power differences between occupational groups in the same organization. The findings suggest that experience is a moderating variable and that closeness to formal power holders as well as closeness to the new technology increases the probability for expert control of the ICT-organization processes. These power differences favor ICT experts over ICT novices and result in a high-quality learning environment for the ICT experts characterized by autonomy, inclusion, and adequate work processes and technological solutions. The ICT novices try to navigate in a learning-hostile work environment characterized by marginalization through expert control, isolation, and inadequate work processes and technological solutions. This led to involuntary non-use by the ICT novices, while the experts became more proficient in ICT use. These findings give managers facing a technological organizational change tools to understand important mechanisms for implementing the change in their own organization, and help them take the right actions to integrate new technology and new organization of work.

Kinesthetic perception based on integration of motor imagery and afferent inputs from antagonistic muscles with tendon vibration.

Science.gov (United States)

Shibata, E; Kaneko, F

2013-04-29

The perceptual integration of afferent inputs from two antagonistic muscles, or the perceptual integration of afferent input and motor imagery are related to the generation of a kinesthetic sensation. However, it has not been clarified how, or indeed whether, a kinesthetic perception would be generated by motor imagery if afferent inputs from two antagonistic muscles were simultaneously induced by tendon vibration. The purpose of this study was to investigate how a kinesthetic perception would be generated by motor imagery during co-vibration of the two antagonistic muscles at the same frequency. Healthy subjects participated in this experiment. Illusory movement was evoked by tendon vibration. Next, the subjects imaged wrist flexion movement simultaneously with tendon vibration. Wrist flexor and extensor muscles were vibrated according to 4 patterns such that the difference between the two vibration frequencies was zero. After each trial, the perceived movement sensations were quantified on the basis of the velocity and direction of the ipsilateral hand-tracking movements. When the difference in frequency applied to the wrist flexor and the extensor was 0Hz, no subjects perceived movements without motor imagery. However, during motor imagery, the flexion velocity of the perceived movement was higher than the flexion velocity without motor imagery. This study clarified that the afferent inputs from the muscle spindle interact with motor imagery, to evoke a kinesthetic perception, even when the difference in frequency applied to the wrist flexor and extensor was 0Hz. Furthermore, the kinesthetic perception resulting from integrations of vibration and motor imagery increased depending on the vibration frequency to the two antagonistic muscles. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

Clinical assessment and three-dimensional movement analysis: An integrated approach for upper limb evaluation in children with unilateral cerebral palsy.

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Lisa Mailleux

Full Text Available The clinical application of upper limb (UL three-dimensional movement analysis (3DMA in children with unilateral cerebral palsy (uCP remains challenging, despite its benefits compared to conventional clinical scales. Moreover, knowledge on UL movement pathology and how this relates to clinical parameters remains scarce. Therefore, we investigated UL kinematics across different manual ability classification system (MACS levels and explored the relation between clinical and kinematic parameters in children with uCP.Fifty children (MACS: I = 15, II = 26, III = 9 underwent an UL evaluation of sensorimotor impairments (grip force, muscle strength, muscle tone, two-point discrimination, stereognosis, bimanual performance (Assisting Hand Assessment, AHA, unimanual capacity (Melbourne Assessment 2, MA2 and UL-3DMA during hand-to-head, hand-to-mouth and reach-to-grasp tasks. Global parameters (Arm Profile Score (APS, duration, (timing of maximum velocity, trajectory straightness and joint specific parameters (angles at task endpoint, ROM and Arm Variable Scores (AVS were extracted. The APS and AVS refer respectively to the total amount of movement pathology and movement deviations of wrist, elbow, shoulder, scapula and trunk.Longer movement durations and increased APS were found with higher MACS-levels (p<0.001. Increased APS was also associated with more severe sensorimotor impairments (r = -0.30-(-0.73 and with lower AHA and MA2-scores (r = -0.50-(-0.86. For the joint specific parameters, stronger movement deviations distally were significantly associated with increased muscle weakness (r = -0.32-(-0.74 and muscle tone (r = 0.33-(-0.61; proximal movement deviations correlated only with muscle weakness (r = -0.35-0.59. Regression analysis exposed grip force as the most important predictor for the variability in APS (p<0.002.We found increased movement pathology with increasing MACS-levels and demonstrated the adverse impact of especially muscle weakness

Clinical assessment and three-dimensional movement analysis: An integrated approach for upper limb evaluation in children with unilateral cerebral palsy.

Science.gov (United States)

Mailleux, Lisa; Jaspers, Ellen; Ortibus, Els; Simon-Martinez, Cristina; Desloovere, Kaat; Molenaers, Guy; Klingels, Katrijn; Feys, Hilde

2017-01-01

The clinical application of upper limb (UL) three-dimensional movement analysis (3DMA) in children with unilateral cerebral palsy (uCP) remains challenging, despite its benefits compared to conventional clinical scales. Moreover, knowledge on UL movement pathology and how this relates to clinical parameters remains scarce. Therefore, we investigated UL kinematics across different manual ability classification system (MACS) levels and explored the relation between clinical and kinematic parameters in children with uCP. Fifty children (MACS: I = 15, II = 26, III = 9) underwent an UL evaluation of sensorimotor impairments (grip force, muscle strength, muscle tone, two-point discrimination, stereognosis), bimanual performance (Assisting Hand Assessment, AHA), unimanual capacity (Melbourne Assessment 2, MA2) and UL-3DMA during hand-to-head, hand-to-mouth and reach-to-grasp tasks. Global parameters (Arm Profile Score (APS), duration, (timing of) maximum velocity, trajectory straightness) and joint specific parameters (angles at task endpoint, ROM and Arm Variable Scores (AVS)) were extracted. The APS and AVS refer respectively to the total amount of movement pathology and movement deviations of wrist, elbow, shoulder, scapula and trunk. Longer movement durations and increased APS were found with higher MACS-levels (pMA2-scores (r = -0.50-(-0.86)). For the joint specific parameters, stronger movement deviations distally were significantly associated with increased muscle weakness (r = -0.32-(-0.74)) and muscle tone (r = 0.33-(-0.61)); proximal movement deviations correlated only with muscle weakness (r = -0.35-0.59). Regression analysis exposed grip force as the most important predictor for the variability in APS (p<0.002). We found increased movement pathology with increasing MACS-levels and demonstrated the adverse impact of especially muscle weakness. The lower correlations suggest that 3DMA provides additional information regarding UL motor function, particularly for

Eye movement identification based on accumulated time feature

Science.gov (United States)

Guo, Baobao; Wu, Qiang; Sun, Jiande; Yan, Hua

2017-06-01

Eye movement is a new kind of feature for biometrical recognition, it has many advantages compared with other features such as fingerprint, face, and iris. It is not only a sort of static characteristics, but also a combination of brain activity and muscle behavior, which makes it effective to prevent spoofing attack. In addition, eye movements can be incorporated with faces, iris and other features recorded from the face region into multimode systems. In this paper, we do an exploring study on eye movement identification based on the eye movement datasets provided by Komogortsev et al. in 2011 with different classification methods. The time of saccade and fixation are extracted from the eye movement data as the eye movement features. Furthermore, the performance analysis was conducted on different classification methods such as the BP, RBF, ELMAN and SVM in order to provide a reference to the future research in this field.

Physiological modules for generating discrete and rhythmic movements: action identification by a dynamic recurrent neural network.

Science.gov (United States)

Bengoetxea, Ana; Leurs, Françoise; Hoellinger, Thomas; Cebolla, Ana M; Dan, Bernard; McIntyre, Joseph; Cheron, Guy

2014-01-01

In this study we employed a dynamic recurrent neural network (DRNN) in a novel fashion to reveal characteristics of control modules underlying the generation of muscle activations when drawing figures with the outstretched arm. We asked healthy human subjects to perform four different figure-eight movements in each of two workspaces (frontal plane and sagittal plane). We then trained a DRNN to predict the movement of the wrist from information in the EMG signals from seven different muscles. We trained different instances of the same network on a single movement direction, on all four movement directions in a single movement plane, or on all eight possible movement patterns and looked at the ability of the DRNN to generalize and predict movements for trials that were not included in the training set. Within a single movement plane, a DRNN trained on one movement direction was not able to predict movements of the hand for trials in the other three directions, but a DRNN trained simultaneously on all four movement directions could generalize across movement directions within the same plane. Similarly, the DRNN was able to reproduce the kinematics of the hand for both movement planes, but only if it was trained on examples performed in each one. As we will discuss, these results indicate that there are important dynamical constraints on the mapping of EMG to hand movement that depend on both the time sequence of the movement and on the anatomical constraints of the musculoskeletal system. In a second step, we injected EMG signals constructed from different synergies derived by the PCA in order to identify the mechanical significance of each of these components. From these results, one can surmise that discrete-rhythmic movements may be constructed from three different fundamental modules, one regulating the co-activation of all muscles over the time span of the movement and two others elliciting patterns of reciprocal activation operating in orthogonal directions.

Forma intermediária de síndrome de Foix-Chavany-Marie / síndrome de Worster-Drought associada a movimentos involuntários: aspectos neuropsicológicos e fonoaudiológicos Intermediary form of Foix-Chavany-Marie / Worster-Drought syndromes associated to involuntary movements: neuropsychological and phonoaudiological features

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Marcio Gadelha Vasconcelos

2006-06-01

Full Text Available A síndrome de Foix-Chavany-Marie (SFCM caracteriza-se por apraxia da fala associada à paralisia bilateral da face, palato mole, língua e musculatura da faringe, mas com preservação das funções reflexas e automáticas. Na síndrome de Worster-Drought (SWD, há predomínio da disartria. Descrevemos o caso de uma jovem de 18 anos, que apresenta os achados clínicos e radiológicos compatíveis com a forma intermediária de SFCM/SWD, acompanhados de movimentos involuntários (coréia e distonia, fato de ocorrência rara na descrição destas síndromes.The Foix-Chavany-Marie syndrome (FCMS is characterized by apraxia of speech associated to bilateral central facio-linguo-velo-pharyngeal paralysis, with automatic-voluntary dissociation. In Worster-Drought Syndrome (WDS, dysarthria is remarkable. We report an 18-year-old female, with clinical and radiological findings of intermediary form of FCMS/WDS, and showing involuntary movements, an unusual fact.

Effect of Visual Angle on the Head Movement Caused by Changing Binocular Disparity

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Toru Maekawa

2011-10-01

Full Text Available It has been shown that vertical binocular disparity has no or little effect on the perception of visual direction (Banks et al., 2002. On the other hand, our previous study has reported that a continuous change of vertical disparity causes an involuntary sway of the head (Maekawa et al., 2009. We predict that the difference between those results attributes to the dissociation between the processes for perception and action in the brain. The aim of this study is to investigate in more details the condition that influences the process of disparity information. The present experiment particularly varied the visual angle of stimulus presentation and measured the head movement and body sway caused by changing vertical disparity. Results showed that the head movement was greater as the visual angle of the stimulus was smaller. It has been reported that stimulus of only small visual angle affect depth perception (Erklens et al., 1995. Thus, our result suggests that perception and action produced by vertical disparity are consistent as far as the effect of the stimulus size is concerned.

Assessment of Motor Control during Three-Dimensional Movements Tracking with Position-Varying Gravity Compensation

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Yao Huang

2017-05-01

Full Text Available Active movements are important in the rehabilitation training for patients with neurological motor disorders, while weight of upper limb impedes movements due to muscles weakness. The objective of this study is to develop a position-varying gravity compensation strategy for a cable-based rehabilitation robot. The control strategy can estimate real-time gravity torque according to position feedback. Then, the performance of this control strategy was compared with the other two kinds of gravity compensation strategies (i.e., without compensation and with fixed compensation during movements tracking. Seven healthy subjects were invited to conduct tracking tasks along four different directions (i.e., upward, forward, leftward, and rightward. The performance of movements with different compensation strategies was compared in terms of root mean square error (RMSE between target and actual moving trajectories, normalized jerk score (NJS, mean velocity ratio (MVR of main motion direction, and the activation of six muscles. The results showed that there were significant effects in control strategies in all four directions with the RMSE and NJS values in the following order: without compensation > fixed compensation > position-varying compensation and MVR values in the following order: without compensation < fixed compensation < position-varying compensation (p < 0.05. Comparing with movements without compensation in all four directions, the activation of muscles during movements with position-varying compensation showed significant reductions, except the activations of triceps and in forward and leftward movements, the activations of upper trapezius and middle parts of deltoid in upward movements and the activations of posterior parts of deltoid in all four directions (p < 0.05. Therefore, with position-varying gravity compensation, the upper limb cable-based rehabilitation robotic system might assist subjects to perform movements with higher quality and

Reliability of the Q Force; a mobile instrument for measuring isometric quadriceps muscle strength

NARCIS (Netherlands)

Douma, K W; Regterschot, G R H; Krijnen, W P; Slager, G E C; van der Schans, C P; Zijlstra, W

2016-01-01

BACKGROUND: The ability to generate muscle strength is a pre-requisite for all human movement. Decreased quadriceps muscle strength is frequently observed in older adults and is associated with a decreased performance and activity limitations. To quantify the quadriceps muscle strength and to

Reliability of the Q Force; a mobile instrument for measuring isometric quadriceps muscle strength

NARCIS (Netherlands)

Douma, Rob; Regterschot, G.R.H.; Krijnen, Wim; Slager, Geranda; van der Schans, Cees; Zijlstra, W.

2016-01-01

Background: The ability to generate muscle strength is a pre-requisite for all human movement. Decreased quadriceps muscle strength is frequently observed in older adults and is associated with a decreased performance and activity limitations. To quantify the quadriceps muscle strength and to

[The investigation of control mechanisms of stepping rhythm in human in the air-stepping conditions during passive and voluntary leg movements].

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Solopova, I A; Selionon, V A; Grishin, A A

2010-01-01

In unloading condition the degree of activation of the central stepping program was investigated during passive leg movements in healthy subjects, as well as the excitability of spinal motoneurons during passive and voluntary stepping movement. Passive stepping movements with characteristics maximally approximated to those during voluntary stepping were accomplished by experimenter. The comparison of the muscle activity bursts during voluntary and imposed movements was made. In addition to that the influence of artificially created loading onto the foot to the leg movement characteristics was analyzed. Spinal motoneuron excitability was estimated by means of evaluation of amplitude modulation of the soleus H-reflex. The changes of H-reflexes under the fixation of knee or hip joints were also studied. In majority of subjects the passive movements were accompanied by bursts of EMG activity of hip muscles (and sometimes of knee muscles), which timing during step cycle was coincided with burst timing of voluntary step cycle. In many cases the bursts of EMG activity during passive movements exceeded activity in homonymous muscles during voluntary stepping. The foot loading imitation exerted essential influence on distal parts of moving extremity during voluntary as well passive movements, that was expressed in the appearance of movements in the ankle joint and accompanied by emergence and increasing of phasic EMG activity of shank muscles. The excitability of motoneurons during passive movements was greater then during voluntary ones. The changes and modulation of H-reflex throughout the step cycle without restriction of joint mobility and during exclusion of hip joint mobility were similar. The knee joint fixation exerted the greater influence. It is supposed that imposed movements activate the same mechanisms of rhythm generation as a supraspinal commands during voluntary movements. In the conditions of passive movements the presynaptic inhibition depend on afferent

Hyperadditive Ventilatory Response Arising from Interaction between the Carotid Chemoreflex and the Muscle Mechanoreflex in Healthy Humans.

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Silva, Talita M; Aranda, Liliane C; Paula-Ribeiro, Marcelle; Oliveira, Diogo M; Medeiros, Wladimir Musetti; Vianna, Lauro C; Nery, Luiz E; Silva, Bruno M

2018-03-22

Physical exercise potentiates the carotid chemoreflex control of ventilation (VE). Hyperadditive neural interactions may partially mediate the potentiation. However, some neural interactions remain incompletely explored. As the potentiation occurs even during low-intensity exercise, we tested the hypothesis that the carotid chemoreflex and the muscle mechanoreflex could interact in a hyperadditive fashion. Fourteen young healthy subjects inhaled, randomly, in separate visits, 12% O 2 to stimulate the carotid chemoreflex, and 21% O 2 as control. A rebreathing circuit maintained isocapnia. During gases administration, subjects either remained at rest (i.e., normoxic and hypoxic rest) or the muscle mechanoreflex was stimulated, via passive knee movement (i.e., normoxic and hypoxic movement). Surface muscle electrical activity did not increase during the passive movement, confirming the absence of active contractions. Hypoxic rest and normoxic movement similarly increased VE [change (mean {plus minus} SEM) = 1.24 {plus minus} 0.72 vs. 0.73 {plus minus} 0.43 L/min, respectively; P = 0.46], but hypoxic rest only increased tidal volume (Vt) and normoxic movement only increased breathing frequency (BF). Hypoxic movement induced greater VE and mean inspiratory flow (Vt/Ti) increase than the sum of hypoxic rest and normoxic movement isolated responses (VE change: hypoxic movement = 3.72 {plus minus} 0.81 vs. sum = 1.96 {plus minus} 0.83 L/min, P = 0.01; Vt/Ti change: hypoxic movement = 0.13 {plus minus} 0.03 vs. sum = 0.06 {plus minus} 0.03 L/s, P = 0.02). Moreover, hypoxic movement increased both Vt and BF. Collectively, the results indicate the carotid chemoreflex and the muscle mechanoreflex interacted mediating a hyperadditive ventilatory response in healthy humans.

A case of atypical adult-onset tic disorder.

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Colosimo, Carlo

2015-04-01

The differential diagnosis of adult tic disorder is complex, and several common and uncommon causes have to be taken into consideration. A 30-year-old man came to our movement disorders clinic with multiple tics which had begun insidiously about 10 years earlier. No family history was reported, but his 65-year-old otherwise healthy father also had very subtle involuntary movements. A diagnosis of atypical Gilles de la Tourette syndrome was made. However, the neurological and psychiatric symptoms of the patient rapidly progressed over the following 2 years, resulting in increasingly severe involuntary movements and profound mood disorder. Further diagnostic tests were performed, and a genetic screening for Huntington disease revealed 45 repeats of the CAG nucleotide in the IT-15 gene. This case underlines the marked phenotypic variability of Huntington disease at presentation, including the presence of involuntary movements different from chorea and possibility of an apparently sporadic disorder.

A Case of Blunt Trauma of the Eyeball Associated With an Inferior Oblique Muscle and an Inferior Rectus Muscle Rupture.

Science.gov (United States)

Nitta, Keisuke; Kashima, Tomoyuki; Miura, Fumihide; Hiroe, Takashi; Akiyama, Hideo; Kishi, Shoji

2016-01-01

Rupture of the extraocular muscle in the absence of significant injury to the eyeball and adnexa is uncommon. The authors report a case of blunt trauma of the eyeball associated with an inferior oblique muscle and an inferior rectus muscle rupture. A 55-year-old man slipped and fell down hitting his eye on an extended windshield wiper blade. Although he had treatment in the emergency room, he complained of diplopia in the primary position 1 day postoperatively. After noticing ruptures of the inferior oblique muscle and an inferior rectus muscle during exploratory surgery, the authors carefully repaired it. Diplopia in the primary position had disappeared within 1 month after the operation and by 6 months postoperatively. The movement of the eye had almost completely recovered.

Coping with Terrorism: Age and Gender Differences in Effortful and Involuntary Responses to September 11th

Science.gov (United States)

Wadsworth, Martha E.; Gudmundsen, Gretchen R.; Raviv, Tali; Ahlkvist, Jarl A.; McIntosh, Daniel N.; Kline, Galena H.; Rea, Jacqueline; Burwell, Rebecca A.

2004-01-01

This study examined age and gender differences and similarities in stress responses to September 11th. Adolescents, young adults, and adults reported using a variety of strategies to cope with the terrorist attacks including acceptance, positive thinking, and emotional expression. In addition, involuntary stress responses such as physiological…

Skeletal muscle glucose uptake during exercise

DEFF Research Database (Denmark)

Rose, Adam John; Richter, Erik

2005-01-01

The increase in skeletal muscle glucose uptake during exercise results from a coordinated increase in rates of glucose delivery (higher capillary perfusion), surface membrane glucose transport, and intracellular substrate flux through glycolysis. The mechanism behind the movement of GLUT4...

Phase-dependent organization of postural adjustments associated with arm movements while walking.

Science.gov (United States)

Nashner, L M; Forssberg, H

1986-06-01

This study examines the interactions between anteroposterior postural responses and the control of walking in human subjects. In the experimental paradigm, subjects walked upon a treadmill, gripping a rigid handle with one hand. Postural responses at different phases of stepping were elicited by rapid arm pulls or pushes against the handle. During arm movements, EMG's recorded the activity of representative arm, ankle, and thigh segment muscles. Strain gauges in the handle measured the force of the arm movement. A Selspot II system measured kinematics of the stepping movements. The duration of support and swing phases were marked by heel and toe switches in the soles of the subjects' shoes. In the first experiment, subjects were instructed to pull on the handle at their own pace. In these trials all subjects preferred to initiate pulls near heel strikes. Next, when instructed to pull as rapidly as possible in response to tone stimuli, reaction times were similar for all phases of the step cycle. Leg muscle responses associated with arm pulls and pushes, referred to as "postural activations," were directionally specific and preceded arm muscle activity. The temporal order and spatial distribution of postural activations in the muscles of the support leg were similar when arm pull movements occurred while the subject was standing in place and after heel strike while walking. Activations began in the ankle and radiated proximally to the thigh and then the arm. Activations of swing leg muscles were also directionally specific and involved flexion and forward or backward thrust of the limb. When arm movements were initiated during transitions from support by one leg to the other, patterns of postural activations were altered. Alterations usually occurred 10-20 ms before hell strikes and involved changes in the timing and sometimes the spatial structure of postural activations. Postural activation patterns are similar during in-place standing and during the support phase

Poverty and involuntary engagement stress responses: examining the link to anxiety and aggression within low-income families.

Science.gov (United States)

Wolff, Brian C; Santiago, Catherine DeCarlo; Wadsworth, Martha E

2009-05-01

Families living with the burdens of poverty-related stress are at risk for developing a range of psychopathology. The present study examines the year-long prospective relationships among poverty-related stress, involuntary engagement stress response (IESR) levels, and anxiety symptoms and aggression in an ethnically diverse sample of 98 families (300 individual family members) living at or below 150% of the US federal poverty line. Hierarchical Linear Modeling (HLM) moderator model analyses provided strong evidence that IESR levels moderated the influence of poverty-related stress on anxiety symptoms and provided mixed evidence for the same interaction effect on aggression. Higher IESR levels, a proxy for physiological stress reactivity, worsened the impact of stress on symptoms. Understanding how poverty-related stress and involuntary stress responses affect psychological functioning has implications for efforts to prevent or reduce psychopathology, particularly anxiety, among individuals and families living in poverty.

[A complex study of the movement biomechanics in patients with post-stroke hemiparesis].

Science.gov (United States)

Skvortsov, D V; Bulatova, M A; Kovrazhkina, E A; Suvorov, A Iu; Ivanova, G E; Skvortsova, V I

2012-01-01

The authors present results of a pilot study on biomechanics of non-cyclic movements of the human consequent verticalization in the ontogenesis of patients with post-stroke hemiparesis (10 patients in the acute stage of cerebral stroke) and 10 healthy volunteers without neurologic and orthopedic pathology. Some movements of therapeutic exercises Balance (a model of ontogenetic kinesitherapy) have been selected for the study. Cinematic parameters have been recorded using a system of motion 3D video analysis, a kinematic model was build in accordance to standard protocols. The skin (native and straightened) electromyogram (EMG) was recorded synchronously with kinematic data using 16-channel electromyography from the following pairs of muscles: mm. sternocleido-mastoideus, trapezius (горизонтальная порция), biceps brachii, triceps brachii, rectus femoris, adductor magnus. Major differences in the EMG picture between patients and controls were: 1) the EMG "monotony" with the involvement of multiple additional muscles in locomotions with the prevalence of the peculiar "tonic" muscle activity (low amplitudes without distinct peaks), stretching along the whole cycle of movement. In controls, EMG demonstrated variability and had mostly "phasic" character with distinct 1 or 2 peaks; 2) the asymmetry of EMG profile in symmetric movements. i.e. when performed simultaneously from the right and from the left sides. The latter feature may be considered as predictive because it was never found in healthy people. It allows to identify objectively weak muscles even in the absence of visible parethis during the routine neurological examination.

Muscle mechanics and neuromuscular control

NARCIS (Netherlands)

Hof, AL

The purpose of this paper is to demonstrate that the properties of the mechanical system, especially muscle elasticity and limb mass, to a large degree determine force output and movement. This makes the control demands of the central nervous system simpler and more robust. In human triceps surae, a

Involuntary outpatient treatment (iot) for severe mental patients: current situation in Spain.

Science.gov (United States)

Cañete-Nicolás, Carlos; Hernández-Viadel, Miguel; Bellido-Rodríguez, Carmen; Lera-Calatayud, Guillem; Asensio-Pascual, Pedro; Pérez-Prieto, Juan F; Calabuig-Crespo, Roman; Leal-Cercós, Carmen

2012-01-01

Involuntary Outpatient Treatment (IOT) expects to improve treatment compliance and, therefore, prevent the impairment of patients with severe mental illness, as well as the risk for them and others. Besides IOT introduction defenders and opponent's states, scientific literature offers contradictory results. Legislative changes have been taken in the vast majority of our neighbouring countries in order to regulate IOT application. There is no legal regulation in Spain; however, OIT application is possible in certain Spanish cities. This article reviews IOT in Spain and surrounding countries.

The role of eccentric regime of leg muscle work in alpine skiing

Directory of Open Access Journals (Sweden)

Ropret Robert

2017-01-01

Full Text Available Alpine skiing is characterized by a great number of leg movements with muscle contractions in eccentric regime. The role of these movements is to absorb gravitation and inertial forces, manage skis more precisely and maintain balance. Recent studies have determined the volume, duration and intenisty of eccentric contractions as well as the basic characteristics of movement amplitudes and velocities. Based on the previous findings the experiments involving eccentric training using a bicycle ergometer confirmed a positive impact that this kind of training has on increasing maximum power, strength, endurance, coordination, injury prevention, metabolic work efficiency, more efficient work with longer muscle length and its role in miming skiers' movements. This paper is an review of the studies so far in the field of kinematics, skiing dynamics and the effect of eccentric training on the development of athletes' performances.

Bilateral experimental neck pain reorganize axioscapular muscle coordination and pain sensitivity.

Science.gov (United States)

Christensen, S W; Hirata, R P; Graven-Nielsen, T

2017-04-01

Neck pain is a large clinical problem where reorganized trunk and axioscapular muscle activities have been hypothesised contributing to pain persistence and pain hypersensitivity. This study investigated the effects of bilateral experimental neck pain on trunk and axioscapular muscle function and pain sensitivity. In 25 healthy volunteers, bilateral experimental neck pain was induced in the splenius capitis muscles by hypertonic saline injections. Isotonic saline was used as control. In sitting, subjects performed slow, fast and slow-resisted unilateral arm movements before, during and after injections. Electromyography (EMG) was recorded from eight shoulder and trunk muscles bilaterally. Pressure pain thresholds (PPTs) were assessed bilaterally at the neck, head and arm. Data were normalized to the before-measures. Compared with control and post measurements, experimental neck pain caused (1) decreased EMG activity of the ipsilateral upper trapezius muscles during all but slow-resisted down movements (p neck pain reorganized axioscapular and trunk muscle activity together with local hyperalgesia and widespread hypoalgesia indicating that acute neck pain immediately affects trunk and axioscapular function which may affect both assessment and treatment. Bilateral clinical neck pain alters axioscapular muscle coordination but only effects of unilateral experimental neck pain has been investigated. Bilateral experimental neck pain causes task-dependent reorganized axioscapular and trunk muscle activity in addition to widespread decrease in pressure pain sensitivity. © 2016 European Pain Federation - EFIC®.

Optogenetic probing of nerve and muscle function after facial nerve lesion in the mouse whisker system

Science.gov (United States)

Bandi, Akhil; Vajtay, Thomas J.; Upadhyay, Aman; Yiantsos, S. Olga; Lee, Christian R.; Margolis, David J.

2018-02-01

Optogenetic modulation of neural circuits has opened new avenues into neuroscience research, allowing the control of cellular activity of genetically specified cell types. Optogenetics is still underdeveloped in the peripheral nervous system, yet there are many applications related to sensorimotor function, pain and nerve injury that would be of great benefit. We recently established a method for non-invasive, transdermal optogenetic stimulation of the facial muscles that control whisker movements in mice (Park et al., 2016, eLife, e14140)1. Here we present results comparing the effects of optogenetic stimulation of whisker movements in mice that express channelrhodopsin-2 (ChR2) selectively in either the facial motor nerve (ChAT-ChR2 mice) or muscle (Emx1-ChR2 or ACTA1-ChR2 mice). We tracked changes in nerve and muscle function before and up to 14 days after nerve transection. Optogenetic 460 nm transdermal stimulation of the distal cut nerve showed that nerve degeneration progresses rapidly over 24 hours. In contrast, the whisker movements evoked by optogenetic muscle stimulation were up-regulated after denervation, including increased maximum protraction amplitude, increased sensitivity to low-intensity stimuli, and more sustained muscle contractions (reduced adaptation). Our results indicate that peripheral optogenetic stimulation is a promising technique for probing the timecourse of functional changes of both nerve and muscle, and holds potential for restoring movement after paralysis induced by nerve damage or motoneuron degeneration.

Contribution of pelvic floor muscles to stiffness of the pelvic ring

NARCIS (Netherlands)

Pool-Goudzwaard, A.L.; Hoek van Dijke, G; van Gurp, M; Mulder, P; Snijders, C.J.; Stoeckart, R.

2004-01-01

STUDY DESIGN: A biomechanical study in embalmed specimens, on the relation between applied tension in the pelvic floor muscles, stiffness of the pelvic ring and generation of movement in the sacroiliac joints. OBJECTIVE: To gain insight into the effect of tension in the pelvic floor muscles on

The Acute Effect of Cryotherapy on Muscle Strength and Shoulder Proprioception.

Science.gov (United States)

Torres, Rui; Silva, Filipa; Pedrosa, Vera; Ferreira, João; Lopes, Alexandre

2017-11-01

Cryotherapy, a common intervention used by clinicians, poses several benefits in managing acute injuries. However, cooling muscle tissue can interfere with muscular properties and the sensory-motor system. The aim of this study was to analyze the influence of cryotherapy with a crushed-ice pack on shoulder proprioception concerning joint position sense, force sense, the threshold for detecting passive movement, and maximal force production. A randomized, double-blind controlled trial. 48 healthy women aged 22.6 ± 0.4 y with a mean body mass index of 22.8 ±0.37 kg/m2 and a percentage of body fat of 15.4 ± 1.5%. In the experimental group, a crushed-ice pack was applied to the shoulder for 15 min, whereas participants in the control group applied a sandbag at skin temperature, also for 15 min. An isokinetic dynamometer was used to assess maximal voluntary contraction, force sense, joint position sense, and the threshold for detecting passive movement. Paired sample t tests revealed that maximal voluntary isometric contraction decreased significantly after cryotherapy (P ≤ .001), or approximately 10% of the reduction found in both muscular groups assessed. Shoulder position sense (P < .001) and the threshold for detecting passive movement (P = .01 and P = .01 for lateral and medial shoulder rotator muscles, respectively) also suffered significant impairment. Nevertheless, no significant differences emerged in force sense at 20% and 50% of maximal force reproduction (P = .41 and P = .10 for lateral rotator muscles at 20% and 50%, respectively; and P = .20 and P = .09 for medial rotator muscles at 20% and 50%, respectively). Applying a crushed-ice pack to the shoulder for 15 min negatively affected muscle strength and impaired shoulder proprioception by decreasing joint position sense and the threshold for detecting passive movement.

Different corticospinal control between discrete and rhythmic movement of the ankle

OpenAIRE

Goto, Yumeno; Jono, Yasutomo; Hatanaka, Ryota; Nomura, Yoshifumi; Tani, Keisuke; Chujo, Yuta; Hiraoka, Koichi

2014-01-01

We investigated differences in corticospinal and spinal control between discrete and rhythmic ankle movements. Motor evoked potentials (MEPs) in the tibialis anterior and soleus muscles and soleus H-reflex were elicited in the middle of the plantar flexion phase during discrete ankle movement or in the initial or later cycles of rhythmic ankle movement. The H-reflex was evoked at an intensity eliciting a small M-wave and MEPs were elicited at an intensity of 1.2 times the motor threshold of t...

Involuntary Smoking in Adolescents, Their Awareness of Its Harmfulness, and Attitudes towards Smoking in the Presence of Non-Smokers

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Dorota Kaleta

2017-09-01

Full Text Available The aim of the study was to examine involuntary smoking among young people, their awareness of its harmfulness and the factors associated with attitudes towards smoking in the presence of non-smokers. A cross-sectional study was conducted among 3552 students from a socially disadvantaged rural area in central Poland. Almost 40% of the participants were exposed to involuntary smoking at home and 60% outside of home on a daily or almost daily basis. More than 80% of the students felt that smoking should be banned around children at home, 59% thought it should be banned in vehicles, and 41% in the presence of non-smokers. The majority of the students were aware of the health consequences of active smoking, and 69% understood the threats of passive smoking. Females, never-smokers and current non-smokers, as well as those without smoking parents were more likely to claim that smoking should be banned at home and in vehicles (p < 0.05. Those aware of the fact that smoking was harmful to health, who discussed those issues with their parents and teachers, and who saw school tobacco control policies, were more likely to maintain that passive smoking should be banned (p < 0.05. The study results highlight the need for programs and policies to eliminate involuntary smoking among young people.

Involuntary Smoking in Adolescents, Their Awareness of Its Harmfulness, and Attitudes towards Smoking in the Presence of Non-Smokers.

Science.gov (United States)

Kaleta, Dorota; Polanska, Kinga; Wojtysiak, Piotr; Szatko, Franciszek

2017-09-21

The aim of the study was to examine involuntary smoking among young people, their awareness of its harmfulness and the factors associated with attitudes towards smoking in the presence of non-smokers. A cross-sectional study was conducted among 3552 students from a socially disadvantaged rural area in central Poland. Almost 40% of the participants were exposed to involuntary smoking at home and 60% outside of home on a daily or almost daily basis. More than 80% of the students felt that smoking should be banned around children at home, 59% thought it should be banned in vehicles, and 41% in the presence of non-smokers. The majority of the students were aware of the health consequences of active smoking, and 69% understood the threats of passive smoking. Females, never-smokers and current non-smokers, as well as those without smoking parents were more likely to claim that smoking should be banned at home and in vehicles ( p < 0.05). Those aware of the fact that smoking was harmful to health, who discussed those issues with their parents and teachers, and who saw school tobacco control policies, were more likely to maintain that passive smoking should be banned ( p < 0.05). The study results highlight the need for programs and policies to eliminate involuntary smoking among young people.

Interstitial muscle lactate, pyruvate and potassium dynamics in the trapezius muscle during repetitive low-force arm movements, measured with microdialysis

DEFF Research Database (Denmark)

Rosendal, L; Blangsted, A K; Kristiansen, J

2004-01-01

Local muscle metabolic responses to repetitive low-force contractions and to intense static contractions were studied by microdialysis in humans.......Local muscle metabolic responses to repetitive low-force contractions and to intense static contractions were studied by microdialysis in humans....

Artificial muscle: the human chimera is the future.

Science.gov (United States)

Tozzi, P

2011-12-14

Severe heart failure and cerebral stroke are broadly associated with the impairment of muscular function that conventional treatments struggle to restore. New technologies enable the construction of "smart" materials that could be of great help in treating diseases where the main problem is muscle weakness. These materials "behave" similarly to biological systems, because the material directly converts energy, for example electrical energy into movement. The extension and contraction occur silently like in natural muscles. The real challenge is to transfer this amazing technology into devices that restore or replace the mechanical function of failing muscle. Cardiac assist devices based on artificial muscle technology could envelope a weak heart and temporarily improve its systolic function, or, if placed on top of the atrium, restore the atrial kick in chronic atrial fibrillation. Artificial sphincters could be used to treat urinary incontinence after prostatectomy or faecal incontinence associated with stomas. Artificial muscles can restore the ability of patients with facial paralysis due to stroke or nerve injury to blink. Smart materials could be used to construct an artificial oesophagus including peristaltic movement and lower oesophageal sphincter function to replace the diseased oesophagus thereby avoiding the need for laparotomy to mobilise stomach or intestine. In conclusion, in the near future, smart devices will integrate with the human body to fill functional gaps due to organ failure, and so create a human chimera.

Spatiotemporal characteristics of muscle patterns for ball catching

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Mattia eD'Andola

2013-08-01

Full Text Available What sources of information and what control strategies the CNS uses to perform movements that require accurate sensorimotor coordination, such as catching a flying ball, is still debated. Here we analyzed the EMG waveforms recorded from 16 shoulder and elbow muscles in six subjects during catching of balls projected frontally from a distance of 6 m and arriving at two different heights and with three different flight times (550, 650, 750 ms. We found that a large fraction of the variation in the muscle patterns was captured by two time-varying muscle synergies, coordinated recruitment of groups of muscles with specific activation waveforms, modulated in amplitude and shifted in time according to the ball’s arrival height and flight duration. One synergy was recruited with a short and fixed delay from launch time. Remarkably, a second synergy was recruited at a fixed time before impact, suggesting that it is timed according to an accurate time-to-contact estimation. These results suggest that the control of interceptive movements relies on a combination of reactive and predictive processes through the intermittent recruitment of time-varying muscle synergies. Knowledge of the dynamic effect of gravity and drag on the ball may be then implicitly incorporated in a direct mapping of visual information into a small number of synergy recruitment parameters.

Development of artificial muscles based on electroactive ionomeric polymer-metal composites.

Science.gov (United States)

Hirano, Laos A; Escote, Márcia T; Martins-Filho, Luiz S; Mantovani, Gerson L; Scuracchio, Carlos H

2011-05-01

This work contextualizes the research of materials that can be applied as artificial muscles. The main motivation of this research is the importance of the development of mechatronic systems for the replacement of traditional devices of actuation and motion based on rotational electrical motors by other devices that reproduce biological muscle movements. Electroactive polymers (EAPs) are materials that respond to electric stimuli with shape and/or dimension changes, and accomplish movements that are smooth enough to mimic biological muscles. Among EAPs, the ionomeric polymer-metal composites (IPMCs) are an interesting alternative to biomimetic devices due to large displacements when submitted to low applied voltage. This article presents a brief review of IPMCs, a sample preparation procedure, and some electromechanical experimental results. We also discuss the applicability of this technology in medical devices and as artificial muscles. © 2011, Copyright the Authors. Artificial Organs © 2011, International Center for Artificial Organs and Transplantation and Wiley Periodicals, Inc.

Petri net-based prediction of therapeutic targets that recover abnormally phosphorylated proteins in muscle atrophy.

Science.gov (United States)

Jung, Jinmyung; Kwon, Mijin; Bae, Sunghwa; Yim, Soorin; Lee, Doheon

2018-03-05

Muscle atrophy, an involuntary loss of muscle mass, is involved in various diseases and sometimes leads to mortality. However, therapeutics for muscle atrophy thus far have had limited effects. Here, we present a new approach for therapeutic target prediction using Petri net simulation of the status of phosphorylation, with a reasonable assumption that the recovery of abnormally phosphorylated proteins can be a treatment for muscle atrophy. The Petri net model was employed to simulate phosphorylation status in three states, i.e. reference, atrophic and each gene-inhibited state based on the myocyte-specific phosphorylation network. Here, we newly devised a phosphorylation specific Petri net that involves two types of transitions (phosphorylation or de-phosphorylation) and two types of places (activation with or without phosphorylation). Before predicting therapeutic targets, the simulation results in reference and atrophic states were validated by Western blotting experiments detecting five marker proteins, i.e. RELA, SMAD2, SMAD3, FOXO1 and FOXO3. Finally, we determined 37 potential therapeutic targets whose inhibition recovers the phosphorylation status from an atrophic state as indicated by the five validated marker proteins. In the evaluation, we confirmed that the 37 potential targets were enriched for muscle atrophy-related terms such as actin and muscle contraction processes, and they were also significantly overlapping with the genes associated with muscle atrophy reported in the Comparative Toxicogenomics Database (p-value net. We generated a list of the potential therapeutic targets whose inhibition recovers abnormally phosphorylated proteins in an atrophic state. They were evaluated by various approaches, such as Western blotting, GO terms, literature, known muscle atrophy-related genes and shortest path analysis. We expect the new proposed strategy to provide an understanding of phosphorylation status in muscle atrophy and to provide assistance towards

Strength and power of knee extensor muscles

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Knežević Olivera

2011-01-01

Full Text Available In the studies of human neuromuscular function, the function of leg muscles has been most often measured, particularly the function of the knee extensors. Therefore, this review will be focused on knee extensors, methods for assessment of its function, the interdependence of strength and power, relations that describe these two abilities and the influence of various factors on their production (resistance training, stretching, movement tasks, age, etc.. Given that it consists of four separate muscles, the variability of their anatomical characteristics affects their participation in strength and power production, depending on the type of movement and motion that is performed. Since KE is active in a variety of activities it must be able to generate great strength in a large and diverse range of muscle lengths and high shortening velocities, in respect to different patterns of strength production, and thus different generation capacities within the muscle (Blazevich et al., 2006. It has been speculated that KE exerts its Pmax at workloads close to subject's own body weight or lower (Rahmani et al., 2001, which is very close to the maximum dynamic output hypothesis (MDI of Jaric and Markovic (2009. Changes under the influence of resistance training or biological age are variously manifested in muscle's morphological, physiological and neural characteristics, and thus in strength and power. Understanding the issues related to strength and power as abilities of great importance for daily activities, is also important for sports and rehabilitation. Performances improvement in sports in which leg muscles strength and power are crucial, as well as recovery after the injuries, are largely dependent on the research results regarding KE function. Also, the appropriate strength balance between knee flexors and extensors is important for the knee joint stability, so that the presence of imbalance between these two muscle groups might be a risk factor for

Illusory movement perception improves motor control for prosthetic hands

Science.gov (United States)

Marasco, Paul D.; Hebert, Jacqueline S.; Sensinger, Jon W.; Shell, Courtney E.; Schofield, Jonathon S.; Thumser, Zachary C.; Nataraj, Raviraj; Beckler, Dylan T.; Dawson, Michael R.; Blustein, Dan H.; Gill, Satinder; Mensh, Brett D.; Granja-Vazquez, Rafael; Newcomb, Madeline D.; Carey, Jason P.; Orzell, Beth M.

2018-01-01

To effortlessly complete an intentional movement, the brain needs feedback from the body regarding the movement’s progress. This largely non-conscious kinesthetic sense helps the brain to learn relationships between motor commands and outcomes to correct movement errors. Prosthetic systems for restoring function have predominantly focused on controlling motorized joint movement. Without the kinesthetic sense, however, these devices do not become intuitively controllable. Here we report a method for endowing human amputees with a kinesthetic perception of dexterous robotic hands. Vibrating the muscles used for prosthetic control via a neural-machine interface produced the illusory perception of complex grip movements. Within minutes, three amputees integrated this kinesthetic feedback and improved movement control. Combining intent, kinesthesia, and vision instilled participants with a sense of agency over the robotic movements. This feedback approach for closed-loop control opens a pathway to seamless integration of minds and machines. PMID:29540617

Clinical identification of the simple sleep-related movement disorders.

Science.gov (United States)

Walters, Arthur S

2007-04-01

Simple sleep-related movement disorders must be distinguished from daytime movement disorders that persist during sleep, sleep-related epilepsy, and parasomnias, which are generally characterized by activity that appears to be simultaneously complex, goal-directed, and purposeful but is outside the conscious awareness of the patient and, therefore, inappropriate. Once it is determined that the patient has a simple sleep-related movement disorder, the part of the body affected by the movement and the age of the patient give clues as to which sleep-related movement disorder is present. In some cases, all-night polysomnography with accompanying video may be necessary to make the diagnosis. Hypnic jerks (ie, sleep starts), bruxism, rhythmic movement disorder (ie, head banging/body rocking), and nocturnal leg cramps are discussed in addition to less well-appreciated disorders such as benign sleep myoclonus of infancy, excessive fragmentary myoclonus, and hypnagogic foot tremor/alternating leg muscle activation.

A neuro-mechanical model of a single leg joint highlighting the basic physiological role of fast and slow muscle fibres of an insect muscle system.

Directory of Open Access Journals (Sweden)

Tibor Istvan Toth

Full Text Available In legged animals, the muscle system has a dual function: to produce forces and torques necessary to move the limbs in a systematic way, and to maintain the body in a static position. These two functions are performed by the contribution of specialized motor units, i.e. motoneurons driving sets of specialized muscle fibres. With reference to their overall contraction and metabolic properties they are called fast and slow muscle fibres and can be found ubiquitously in skeletal muscles. Both fibre types are active during stepping, but only the slow ones maintain the posture of the body. From these findings, the general hypothesis on a functional segregation between both fibre types and their neuronal control has arisen. Earlier muscle models did not fully take this aspect into account. They either focused on certain aspects of muscular function or were developed to describe specific behaviours only. By contrast, our neuro-mechanical model is more general as it allows functionally to differentiate between static and dynamic aspects of movement control. It does so by including both muscle fibre types and separate motoneuron drives. Our model helps to gain a deeper insight into how the nervous system might combine neuronal control of locomotion and posture. It predicts that (1 positioning the leg at a specific retraction angle in steady state is most likely due to the extent of recruitment of slow muscle fibres and not to the force developed in the individual fibres of the antagonistic muscles; (2 the fast muscle fibres of antagonistic muscles contract alternately during stepping, while co-contraction of the slow muscle fibres takes place during steady state; (3 there are several possible ways of transition between movement and steady state of the leg achieved by varying the time course of recruitment of the fibres in the participating muscles.

Restricted Mandibular Movement Attributed to Ossification of Mandibular Depressors and Medial Pterygoid Muscles in Patients With Fibrodysplasia Ossificans Progressiva: A Report of 3 Cases.

Science.gov (United States)

Okuno, Tetsuko; Suzuki, Hitoshi; Inoue, Akio; Kusukawa, Jingo

2017-09-01

Fibrodysplasia ossificans progressiva (FOP) is an extremely rare genetic condition characterized by congenital malformation and progressive heterotopic ossification (HO) caused by a recurrent single nucleotide substitution at position 617 in the ACVR1 gene. As the condition progresses, HO leads to joint ankylosis, breathing difficulties, and mouth-opening restriction, and it can shorten the patient's lifespan. This report describes 3 cases of FOP confirmed by genetic testing in patients with restricted mouth opening. Each patient presented a different onset and degree of jaw movement restriction. The anatomic ossification site of the mandibular joint was examined in each patient using reconstructed computed tomographic (CT) images and 3-dimensional reconstructed CT (3D-CT) images. A 29-year-old woman complained of jaw movement restriction since 13 years of age. 3D-CT image of the mandibular joint showed an osseous bridge, formed by the mandibular depressors that open the mouth, between the hyoid bone and the mentum of the mandible. A 39-year-old man presented with jaw movement restriction that developed at 3 years of age after a mouth injury. 3D-CT image of the jaw showed ankylosis of the jaw from ossification of the mandibular depressors that was worse than in patient 1. CT images showed no HO findings of the masticatory muscles. To the authors' knowledge, these are the first 2 case descriptions of the anatomic site of ankylosis involving HO of the mandibular depressors in the jaw resulting from FOP. In contrast, a 62-year-old bedridden woman with an interincisal distance longer than 10 mm (onset, 39 years of age) had no HO of the mandibular depressors and slight HO of the medial pterygoid muscle on the right and left sides. These findings suggest that restricted mouth opening varies according to the presence or absence of HO of the mandibular depressors. Copyright © 2017. Published by Elsevier Inc.

Factors associated with bruxism in children with developmental disabilities.

Science.gov (United States)

Souza, Valeska Aparecida Fernandes; Abreu, Mauro Henrique Nogueira Guimarães; Resende, Vera Lúcia Silva; Castilho, Lia Silva

2015-01-01

The aim of the present study was to investigate factors associated with bruxism in children aged from 1 to 13 years with developmental disabilities. A total of 389 dental records were examined. The bruxism analyzed was determined based on parental reports. The following variables were also analyzed: gender, age, International Code of Diseases (ICD), mouth breathing, history of gastroesophageal reflux, use of psychotropic drugs, gingival status, reports of xerostomia, hyperkinesis, pacifier use, thumb sucking and involuntary movements. For the purposes of analysis, the individuals were categorized as being with and without bruxism. Variables with a p-value bruxism than males. Individuals with gastroesophageal reflux had a 2.28-fold (95%CI: 1.03 to 5.02) greater chance of exhibiting bruxism. Individuals with reported involuntary movements had a 2.24-fold (95%CI: 1.19 to 4.24) greater chance of exhibiting bruxism than those without such movements. Exhibiting involuntary movements, the male gender and gastroesophageal reflux are factors associated with bruxism in children with developmental disabilities.

The number and choice of muscles impact the results of muscle synergy analyses

Directory of Open Access Journals (Sweden)

Katherine Muterspaugh Steele

2013-08-01

Full Text Available One theory for how humans control movement is that muscles are activated in weighted groups or synergies. Studies have shown that electromyography (EMG from a variety of tasks can be described by a low-dimensional space thought to reflect synergies. These studies use algorithms, such as nonnegative matrix factorization, to identify synergies from EMG. Due to experimental constraints, EMG can rarely be taken from all muscles involved in a task. However, it is unclear if the choice of muscles included in the analysis impacts estimated synergies. The aim of our study was to evaluate the impact of the number and choice of muscles on synergy analyses. We used a musculoskeletal model to calculate muscle activations required to perform an isometric upper-extremity task. Synergies calculated from the activations from the musculoskeletal model were similar to a prior experimental study. To evaluate the impact of the number of muscles included in the analysis, we randomly selected subsets of between 5 and 29 muscles and compared the similarity of the synergies calculated from each subset to a master set of synergies calculated from all muscles. We determined that the structure of synergies is dependent upon the number and choice of muscles included in the analysis. When five muscles were included in the analysis, the similarity of the synergies to the master set was only 0.57 ± 0.54; however, the similarity improved to over 0.8 with more than ten muscles. We identified two methods, selecting dominant muscles from the master set or selecting muscles with the largest maximum isometric force, which significantly improved similarity to the master set and can help guide future experimental design. Analyses that included a small subset of muscles also over-estimated the variance accounted for (VAF by the synergies compared to an analysis with all muscles. Thus, researchers should use caution using VAF to evaluate synergies when EMG is measured from a small

Analysis of Small Muscle Movement Effects on EEG Signals

Science.gov (United States)

2016-12-22

different conditions are recorded in this experiment. These conditions are the resting state, left finger keyboard press, right finger keyboard...51 4.3.2. Right and Left Finger Keyboard Press Conditions ..................................... 57 4.4. Detection of Hand...solving Gamma 30 Hz and higher Blending of multiple brain functions ; Muscle related artifacts 2.2. EEG Artifacts EEG recordings are intended to

Restoring cortical control of functional movement in a human with quadriplegia.

Science.gov (United States)

Bouton, Chad E; Shaikhouni, Ammar; Annetta, Nicholas V; Bockbrader, Marcia A; Friedenberg, David A; Nielson, Dylan M; Sharma, Gaurav; Sederberg, Per B; Glenn, Bradley C; Mysiw, W Jerry; Morgan, Austin G; Deogaonkar, Milind; Rezai, Ali R

2016-05-12

Millions of people worldwide suffer from diseases that lead to paralysis through disruption of signal pathways between the brain and the muscles. Neuroprosthetic devices are designed to restore lost function and could be used to form an electronic 'neural bypass' to circumvent disconnected pathways in the nervous system. It has previously been shown that intracortically recorded signals can be decoded to extract information related to motion, allowing non-human primates and paralysed humans to control computers and robotic arms through imagined movements. In non-human primates, these types of signal have also been used to drive activation of chemically paralysed arm muscles. Here we show that intracortically recorded signals can be linked in real-time to muscle activation to restore movement in a paralysed human. We used a chronically implanted intracortical microelectrode array to record multiunit activity from the motor cortex in a study participant with quadriplegia from cervical spinal cord injury. We applied machine-learning algorithms to decode the neuronal activity and control activation of the participant's forearm muscles through a custom-built high-resolution neuromuscular electrical stimulation system. The system provided isolated finger movements and the participant achieved continuous cortical control of six different wrist and hand motions. Furthermore, he was able to use the system to complete functional tasks relevant to daily living. Clinical assessment showed that, when using the system, his motor impairment improved from the fifth to the sixth cervical (C5-C6) to the seventh cervical to first thoracic (C7-T1) level unilaterally, conferring on him the critical abilities to grasp, manipulate, and release objects. This is the first demonstration to our knowledge of successful control of muscle activation using intracortically recorded signals in a paralysed human. These results have significant implications in advancing neuroprosthetic technology

A novel computational framework for deducing muscle synergies from experimental joint moments

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Anantharaman eGopalakrishnan

2014-12-01

Full Text Available Prior experimental studies have hypothesized the existence of a ‘muscle synergy’ based control scheme for producing limb movements and locomotion in vertebrates. Such synergies have been suggested to consist of fixed muscle grouping schemes with the co-activation of all muscles in a synergy resulting in limb movement. Quantitative representations of these groupings (termed muscle weightings and their control signals (termed synergy controls have traditionally been derived by the factorization of experimentally measured EMG. This study presents a novel approach for deducing these weightings and controls from inverse dynamic joint moments that are computed from an alternative set of experimental measurements – movement kinematics and kinetics. This technique was applied to joint moments for healthy human walking at 0.7 and 1.7 m/s, and two sets of ‘simulated’ synergies were computed based on two different criteria (1 synergies were required to minimize errors between experimental and simulated joint moments in a musculoskeletal model (pure-synergy solution (2 along with minimizing joint moment errors, synergies also minimized muscle activation levels (optimal-synergy solution. On comparing the two solutions, it was observed that the introduction of optimality requirements (optimal-synergy to a control strategy solely aimed at reproducing the joint moments (pure-synergy did not necessitate major changes in the muscle grouping within synergies or the temporal profiles of synergy control signals. Synergies from both the simulated solutions exhibited many similarities to EMG derived synergies from a previously published study, thus implying that the analysis of the two different types of experimental data reveals similar, underlying synergy structures.

Muscle Synergies Control during Hand-Reaching Tasks in Multiple Directions Post-stroke

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Sharon Israely

2018-02-01

Full Text Available Purpose: A muscle synergies model was suggested to represent a simplifying motor control mechanism by the brainstem and spinal cord. The aim of the study was to investigate the feasibility of such control mechanisms in the rehabilitation of post-stroke individuals during the execution of hand-reaching movements in multiple directions, compared to non-stroke individuals.Methods: Twelve non-stroke and 13 post-stroke individuals participated in the study. Muscle synergies were extracted from EMG data that was recorded during hand reaching tasks, using the NMF algorithm. The optimal number of synergies was evaluated in both groups using the Variance Accounted For (VAF and the Mean Squared Error (MSE. A cross validation procedure was carried out to define a representative set of synergies. The similarity index and the K-means algorithm were applied to validate the existence of such a set of synergies, but also to compare the modulation properties of synergies for different movement directions between groups. The similarity index and hierarchical cluster analysis were also applied to compare between group synergies.Results: Four synergies were chosen to optimally capture the variances in the EMG data, with mean VAF of 0.917 ± 0.034 and 0.883 ± 0.046 of the data variances, with respective MSE of 0.007 and 0.016, in the control and study groups, respectively. The representative set of synergies was set to be extracted from movement to the center of the reaching space. Two synergies had different muscle activation balance between groups. Seven and 17 clusters partitioned the muscle synergies of the control and study groups. The control group exhibited a gradual change in the activation in the amplitude in the time domain (modulation of synergies, as reflected by the similarity index, whereas the study group exhibited consistently significant differences between all movement directions and the representative set of synergies. The study findings support

Congenital Mirror Movements Due to RAD51: Cosegregation with a Nonsense Mutation in a Norwegian Pedigree and Review of the Literature

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Oriane Trouillard

2016-11-01

Full Text Available Background: Autosomal dominant congenital mirror movements (CMM is a neurodevelopmental disorder characterized by early onset involuntary movements of one side of the body that mirror intentional movements on the contralateral side; these persist throughout life in the absence of other neurological symptoms. The main culprit genes responsible for this condition are RAD51 and DCC. This condition has only been reported in a few families, and the molecular mechanisms linking RAD51 mutations and mirror movements (MM are poorly understood. Methods: We collected demographic, clinical, and genetic data of a new family with CMM due to a truncating mutation of RAD51. We reviewed the literature to identify all reported patients with CMM due to RAD51 mutations. Results: We identified a heterozygous nonsense mutation c.760C>T (p.Arg254∗ in eight subjects: four with obvious and disabling MM, and four with a mild phenotype. Including our new family, we identified 32 patients from 6 families with CMM linked to RAD51 variants. Discussion: Our findings further support the involvement of RAD51 in CMM pathogenesis. Possible molecular mechanisms involved in CMM pathogenesis are discussed.

Individual, interpersonal, and social-structural correlates of involuntary sex exchange among female sex workers in two Mexico-U.S. border cities.

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Goldenberg, Shira M; Rangel, Gudelia; Staines, Hugo; Vera, Alicia; Lozada, Remedios; Nguyen, Lucie; Silverman, Jay G; Strathdee, Steffanie A

2013-08-15

To investigate individual, interpersonal, and social-structural factors associated with involuntary sex exchange among female sex workers (FSWs) along the Mexico-U.S. border. In 2010 to 2011, 214 FSWs from Tijuana (n = 106) and Ciudad Juarez (n = 108) aged ≥ 18 years who reported lifetime use of heroin, cocaine, crack, or methamphetamine, having a stable partner, and having sold/traded sex in the past month completed quantitative surveys and HIV/sexually transmitted infection testing. Logistic regression was used to identify correlates of involuntary sex exchange among FSWs. Of 214 FSWs, 31 (14.5%) reported involuntary sex exchange These women were younger at sex industry entry [adjusted odds ratio (AOR): 0.84/1-year increase, 95% confidence interval (CI): 0.72 to 0.97] and were significantly more likely to service clients whom they perceived to be HIV/sexually transmitted infection-infected (AOR: 12.41, 95% CI: 3.15 to 48.91). In addition, they were more likely to have clients who used drugs (AOR: 7.88, 95% CI: 1.52 to 41.00), report poor working conditions (AOR: 3.27, 95% CI: 1.03 to 10.31), and report a history of rape (AOR: 4.46, 95% CI: 1.43 to 13.91). Involuntary sex exchange is disproportionate among FSWs who begin to exchange sex at a younger age, and these women experience elevated risk of violence and HIV/STIs related to their clients' behaviors and their working conditions. These data suggest the critical need for evidence-based approaches to preventing sexual exploitation of women and girls and to reducing harm among current sex workers. Multilevel interventions for all females who exchange sex and their clients that target interpersonal and social-structural risks (eg, measures to improve safety and reduce exploitation within the workplace) are needed.

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

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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.

Motor cortical representation of the pelvic floor muscles.

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Schrum, A; Wolff, S; van der Horst, C; Kuhtz-Buschbeck, J P

2011-07-01

Pelvic floor muscle training involves rhythmical voluntary contractions of the external urethral sphincter and ancillary pelvic floor muscles. The representation of these muscles in the motor cortex has not been located precisely and unambiguously. We used functional magnetic resonance imaging to determine brain activity during slow and fast pelvic floor contractions. Cerebral responses were recorded in 17 healthy male volunteers, 21 to 47 years old, with normal bladder control. Functional magnetic resonance imaging was performed during metronome paced slow (0.25 Hertz) and fast (0.7 Hertz) contractions of the pelvic floor that mimicked the interruption of voiding. To study the somatotopy of the cortical representations, flexion-extension movements of the right toes were performed as a control task. Functional magnetic resonance imaging during pelvic floor contractions detected activity of the supplementary motor area in the medial wall and of the midcingulate cortex, insula, posterior parietal cortex, putamen, thalamus, cerebellar vermis and upper ventral pons. There were no significant differences in activation between slow and fast contractions. Toe movements involved significantly stronger activity of the paracentral lobule (ie the medial primary motor cortex) than did the pelvic floor contractions. Otherwise the areas active during pelvic floor and leg muscle contractions overlapped considerably. The motor cortical representation of pelvic floor muscles is located mostly in the supplementary motor area. It extends further ventrally and anteriorly than the representation of distal leg muscles. Copyright © 2011 American Urological Association Education and Research, Inc. Published by Elsevier Inc. All rights reserved.

The neural response properties and cortical organization of a rapidly adapting muscle sensory group response that overlaps with the frequencies that elicit the kinesthetic illusion.

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Marasco, Paul D; Bourbeau, Dennis J; Shell, Courtney E; Granja-Vazquez, Rafael; Ina, Jason G

2017-01-01

Kinesthesia is the sense of limb movement. It is fundamental to efficient motor control, yet its neurophysiological components remain poorly understood. The contributions of primary muscle spindles and cutaneous afferents to the kinesthetic sense have been well studied; however, potential contributions from muscle sensory group responses that are different than the muscle spindles have not been ruled out. Electrophysiological recordings in peripheral nerves and brains of male Sprague Dawley rats with a degloved forelimb preparation provide evidence of a rapidly adapting muscle sensory group response that overlaps with vibratory inputs known to generate illusionary perceptions of limb movement in humans (kinesthetic illusion). This group was characteristically distinct from type Ia muscle spindle fibers, the receptor historically attributed to limb movement sensation, suggesting that type Ia muscle spindle fibers may not be the sole carrier of kinesthetic information. The sensory-neural structure of muscles is complex and there are a number of possible sources for this response group; with Golgi tendon organs being the most likely candidate. The rapidly adapting muscle sensory group response projected to proprioceptive brain regions, the rodent homolog of cortical area 3a and the second somatosensory area (S2), with similar adaption and frequency response profiles between the brain and peripheral nerves. Their representational organization was muscle-specific (myocentric) and magnified for proximal and multi-articulate limb joints. Projection to proprioceptive brain areas, myocentric representational magnification of muscles prone to movement error, overlap with illusionary vibrational input, and resonant frequencies of volitional motor unit contraction suggest that this group response may be involved with limb movement processing.

[A Case of Psychogenic Tremor during Awake Craniotomy].

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Kujirai, Kazumasa; Kamata, Kotoe; Uno, Toshihiro; Hamada, Keiko; Ozaki, Makoto

2016-01-01

A 31-year-old woman with a left frontal and parietal brain tumor underwent awake craniotomy. Propofol/remifentanil general anesthesia was induced. Following craniotomy, anesthetic administrations ceased. The level of consciousness was sufficient and she was not agitated. However, the patient complained of nausea 70 minutes into the awake phase. Considering the adverse effects of antiemetics and the upcoming surgical strategy, we did not give any medications. Nausea disappeared spontaneously while the operation was suspended. When surgical intervention extended to the left caudate nucleus, involuntary movement, classified as a tremor, with 5-6 Hz frequency, abruptly occurred on her left forearm. The patient showed emotional distress. Tremor appeared on her right forearm and subsequently spread to her lower extremities. Intravenous midazolam and fentanyl could not reduce her psychological stress. Since the tremor disturbed microscopic observation, general anesthesia was induced. Consequently, the tremor disappeared and did not recur. Based on the anatomical ground and the medication status, her involuntary movement was diagnosed as psychogenic tremor. Various factors can induce involuntary movements. In fact, intraoperative management of nausea and vomiting takes priority during awake craniotomy, but we should be reminded that some antiemetics potentially induce involuntary movement that could be caused by surgery around basal ganglia.

Rapid eye movement sleep behavior disorder as an outlier detection problem

DEFF Research Database (Denmark)

Kempfner, Jacob; Sørensen, Gertrud Laura; Nikolic, M.

2014-01-01

OBJECTIVE: Idiopathic rapid eye movement (REM) sleep behavior disorder is a strong early marker of Parkinson's disease and is characterized by REM sleep without atonia and/or dream enactment. Because these measures are subject to individual interpretation, there is consequently need...... for quantitative methods to establish objective criteria. This study proposes a semiautomatic algorithm for the early detection of Parkinson's disease. This is achieved by distinguishing between normal REM sleep and REM sleep without atonia by considering muscle activity as an outlier detection problem. METHODS......: Sixteen healthy control subjects, 16 subjects with idiopathic REM sleep behavior disorder, and 16 subjects with periodic limb movement disorder were enrolled. Different combinations of five surface electromyographic channels, including the EOG, were tested. A muscle activity score was automatically...

Increased sternocleidomastoid, but not trapezius, muscle activity in response to increased chewing load.

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Häggman-Henrikson, Birgitta; Nordh, Erik; Eriksson, Per-Olof

2013-10-01

Previous findings, during chewing, that boluses of larger size and harder texture result in larger amplitudes of both mandibular and head-neck movements suggest a relationship between increased chewing load and incremental recruitment of jaw and neck muscles. The present report evaluated jaw (masseter and digastric) and neck [sternocleidomastoid (SCM) and trapezius] muscle activity during the chewing of test foods of different sizes and textures by 10 healthy subjects. Muscle activity was recorded by surface electromyography and simultaneous mandibular and head movements were recorded using an optoelectronic technique. Each subject performed continuous jaw-opening/jaw-closing movements whilst chewing small and large boluses of chewing gum and rubber silicone (Optosil). For jaw opening/jaw closing without a bolus, SCM activity was recorded for jaw opening concomitantly with digastric activity. During chewing, SCM activity was recorded for jaw closing concomitantly with masseter activity. Trapezius activity was present in some, but not all, cycles. For the masseter and SCM muscles, higher activity was seen with larger test foods, suggesting increased demand and recruitment of these muscles in response to an increased chewing load. This result reinforces the previous notion of a close functional connection between the jaw and the neck motor systems in jaw actions and has scientific and clinical significance for studying jaw function and dysfunction. © 2013 Eur J Oral Sci.

Effect of 4-Horizontal Rectus Muscle Tenotomy on Visual Function and Eye Movement Records in Patients with Infantile Nystagmus Syndrome without Abnormal Head Posture and Strabismus: A Prospective Study

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Ahmad Ameri

2013-10-01

Full Text Available Purpose: To evaluate the effect of tenotomy on visual function and eye movement records in patients with infantile nystagmus syndrome (INS without abnormal head posture (AHP and strabismusMethods: A prospective interventional case-series of patients with INS with no AHP or strabismus. Patients underwent 4-horizontal muscle tenotomy. Best corrected visual acuity (BCVA and eye movement recordings were compared pre and postoperatively.Results: Eight patients were recruited in this study with 3 to 15.5 months of follow-up. Patients showed significant improvement in their visual function. Overall nystagmus amplitude and velocity was decreased 30.7% and 19.8%, respectively. Improvements were more marked at right and left gazes. Conclusion: Tenotomy improves both visual function and eye movement records in INS with no strabismus and eccentric null point. The procedure has more effect on lateral gazes with worse waveforms, thus can broaden area with better visual function. We recommend this surgery in patients with INS but no associated AHP or strabismus.

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

Involuntary and voluntary recall of musical memories: a comparison of temporal accuracy and emotional responses.

OpenAIRE

Jakubowski, Kelly; Bashir, Zaariyah; Farrugia, Nicolas; Stewart, Lauren

2018-01-01

Comparisons between involuntarily and voluntarily retrieved autobiographical memories have revealed similarities in encoding and maintenance, with differences in terms of specificity and emotional responses. Our study extended this research area into the domain of musical memory, which afforded a unique opportunity to compare the same memory as accessed both involuntarily and voluntarily. Specifically, we compared instances of involuntary musical imagery (INMI, or “earworms”)—the spontaneous ...

Isolated and combined effects of asymmetric stance and pushing movement on the anticipatory and compensatory postural control.

Science.gov (United States)

Lee, Yun-Ju; Aruin, Alexander S

2014-04-01

To investigate effects of symmetric and asymmetric stance and pushing movement on anticipatory and compensatory postural adjustments (APAs and CPAs). Ten healthy volunteers stood symmetrically (feet parallel) or asymmetrically (one foot forward and the other backward) and pushed a handle with both hands or right or left hand. Bilateral EMG activity of the trunk and leg muscles and center of pressure (COP) displacements in the anterior-posterior (AP) and medial-lateral (ML) directions were recorded and analyzed during the APAs and CPAs. Isolated asymmetry of stance was associated with larger muscle activity of the backward leg while isolated asymmetry of pushing movement induced larger trunk muscle activity on the contralateral side. A combined asymmetry of stance and pushing movement resulted in the increase or decrease of the thigh muscle activity and ML COP displacement depending on whether both asymmetries were induced on the same side of the body or on opposite sides. Both isolated and combined asymmetries affect APAs and CPAs in pushing. Using combined asymmetry of stance and arm movement might be beneficial in performing pushing activity. The outcome of the study provides a basis for studying postural control in individuals with unilateral impairment while performing daily tasks involving pushing. Copyright © 2013 International Federation of Clinical Neurophysiology. Published by Elsevier Ireland Ltd. All rights reserved.

Differential effects of type of keyboard playing task and tempo on surface EMG amplitudes of forearm muscles

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Hyun Ju eChong

2015-09-01

Full Text Available Despite increasing interest in keyboard playing as a strategy for repetitive finger exercises in fine motor skill development and hand rehabilitation, comparative analysis of task-specific finger movements relevant to keyboard playing has been less extensive. This study examined whether there were differences in surface EMG activity levels of forearm muscles associated with different keyboard playing tasks. Results demonstrated higher muscle activity with sequential keyboard playing in a random pattern compared to individuated playing or sequential playing in a successive pattern. Also, the speed of finger movements was found as a factor that affect muscle activity levels, demonstrating that faster tempo elicited significantly greater muscle activity than self-paced tempo. The results inform our understanding of the type of finger movements involved in different types of keyboard playing at different tempi so as to consider the efficacy and fatigue level of keyboard playing as an intervention for amateur pianists or individuals with impaired fine motor skills.

Differential effects of type of keyboard playing task and tempo on surface EMG amplitudes of forearm muscles

Science.gov (United States)

Chong, Hyun Ju; Kim, Soo Ji; Yoo, Ga Eul

2015-01-01

Despite increasing interest in keyboard playing as a strategy for repetitive finger exercises in fine motor skill development and hand rehabilitation, comparative analysis of task-specific finger movements relevant to keyboard playing has been less extensive. This study examined, whether there were differences in surface EMG activity levels of forearm muscles associated with different keyboard playing tasks. Results demonstrated higher muscle activity with sequential keyboard playing in a random pattern compared to individuated playing or sequential playing in a successive pattern. Also, the speed of finger movements was found as a factor that affect muscle activity levels, demonstrating that faster tempo elicited significantly greater muscle activity than self-paced tempo. The results inform our understanding of the type of finger movements involved in different types of keyboard playing at different tempi. This helps to consider the efficacy and fatigue level of keyboard playing tasks when being used as an intervention for amateur pianists or individuals with impaired fine motor skills. PMID:26388798

The development of involuntary and voluntary attention from childhood to adulthood: a combined behavioral and event-related potential study.

Science.gov (United States)

Wetzel, Nicole; Widmann, Andreas; Berti, Stefan; Schröger, Erich

2006-10-01

This study investigated auditory involuntary and voluntary attention in children aged 6-8, 10-12 and young adults. The strength of distracting stimuli (20% and 5% pitch changes) and the amount of allocation of attention were varied. In an auditory distraction paradigm event-related potentials (ERPs) and behavioral data were measured from subjects either performing a sound duration discrimination task or watching a silent video. Pitch changed sounds caused prolonged reaction times and decreased hit rates in all age groups. Larger distractors (20%) caused stronger distraction in children, but not in adults. The amplitudes of mismatch negativity (MMN), P3a, and reorienting negativity (RON) were modulated by age and by voluntary attention. P3a was additionally affected by distractor strength. Maturational changes were also observed in the amplitudes of P1 (decreasing with age) and N1 (increasing with age). P2-modulation by voluntary attention was opposite in young children and adults. Results suggest quantitative and qualitative changes in auditory voluntary and involuntary attention and distraction during development. The processing steps involved in distraction (pre-attentive change detection, attention switch, reorienting) are functional in children aged 6-8 but reveal characteristic differences to those of young adults. In general, distractibility as indicated by behavioral and ERP measures decreases from childhood to adulthood. Behavioral and ERP markers for different processing stages involved in voluntary and involuntary attention reveal characteristic developmental changes from childhood to young adulthood.

Differences between kinematic synergies and muscle synergies during two-digit grasping

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Michele eTagliabue

2015-03-01

Full Text Available The large number of mechanical degrees of freedom of the hand is not fully exploited during actual movements such as grasping. Usually, angular movements in various joints tend to be coupled, and EMG activities in different hand muscles tend to be correlated. The occurrence of covariation in the former was termed kinematic synergies, in the latter muscle synergies. This study addresses two questions: (i Whether kinematic and muscle synergies can simultaneously accommodate for kinematic and kinetic constraints. (ii If so, whether there is an interrelation between kinematic and muscle synergies. We used a reach-grasp-and-pull paradigm and recorded the hand kinematics as well as 8 surface EMGs. Subjects had to either perform a precision grip or side grip and had to modify their grip force in order to displace an object against a low or high load. The analysis was subdivided into three epochs: reach, grasp-and-pull, and static hold. Principal component analysis (PCA, temporal or static was performed separately for all three epochs, in the kinematic and in the EMG domain. PCA revealed that (i Kinematic- and muscle-synergies can simultaneously accommodate kinematic (grip type and kinetic task constraints (load condition. (ii Upcoming grip and load conditions of the grasp are represented in kinematic- and muscle-synergies already during reach. Phase plane plots of the principal muscle-synergy against the principal kinematic synergy revealed (iii that the muscle-synergy is linked (correlated, and in phase advance to the kinematic synergy during reach and during grasp-and-pull. Furthermore (iv, pair-wise correlations of EMGs during hold suggest that muscle-synergies are (in part implemented by coactivation of muscles through common input. Together, these results suggest that kinematic synergies have (at least in part their origin not just in muscular activation, but in synergiestic muscle activation. In short: kinematic synergies may result from muscle

Evaluation of Functional Correlation of Task-Specific Muscle Synergies with Motor Performance in Patients Poststroke

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Si Li

2017-07-01

Full Text Available The central nervous system produces movements by activating specifically programmed muscle synergies that are also altered with injuries in the brain, such as stroke. In this study, we hypothesize that there exists a positive correlation between task-specific muscle synergy and motor functions at joint and task levels in patients following stroke. The purpose here is to define and evaluate neurophysiological metrics based on task-specific muscle synergy for assessing motor functions in patients. A patient group of 10 subjects suffering from stroke and a control group of nine age-matched healthy subjects were recruited to participate in this study. Electromyography (EMG signals and movement kinematics were recorded in patients and control subjects while performing arm reaching tasks. Muscle synergies of individual patients were extracted off-line from EMG records of each patient, and a baseline pattern of muscle synergy was obtained from the pooled EMG data of all nine control subjects. Peak velocities and movement durations of each reaching movement were computed from measured kinematics. Similarity indices of matching components to those of the baseline synergy were defined by synergy vectors and time profiles, respectively, as well as by a combined similarity of vector and time profile. Results showed that pathological synergies of patients were altered from the characteristics of baseline synergy with missing components, or varied vector patterns and time profiles. The kinematic performance measured by peak velocities and movement durations was significantly poorer for the patient group than the control group. In patients, all three similarity indices were found to correlate significantly to the kinematics of movements for the reaching tasks. The correlation to the Fugl-Meyer score of arm was the highest with the vector index, the lowest with the time profile index, and in between with the combined index. These findings illustrate that the

Contingent capture of involuntary visual attention interferes with detection of auditory stimuli.

Science.gov (United States)

Kamke, Marc R; Harris, Jill

2014-01-01

The involuntary capture of attention by salient visual stimuli can be influenced by the behavioral goals of an observer. For example, when searching for a target item, irrelevant items that possess the target-defining characteristic capture attention more strongly than items not possessing that feature. Such contingent capture involves a shift of spatial attention toward the item with the target-defining characteristic. It is not clear, however, if the associated decrements in performance for detecting the target item are entirely due to involuntary orienting of spatial attention. To investigate whether contingent capture also involves a non-spatial interference, adult observers were presented with streams of visual and auditory stimuli and were tasked with simultaneously monitoring for targets in each modality. Visual and auditory targets could be preceded by a lateralized visual distractor that either did, or did not, possess the target-defining feature (a specific color). In agreement with the contingent capture hypothesis, target-colored distractors interfered with visual detection performance (response time and accuracy) more than distractors that did not possess the target color. Importantly, the same pattern of results was obtained for the auditory task: visual target-colored distractors interfered with sound detection. The decrement in auditory performance following a target-colored distractor suggests that contingent capture involves a source of processing interference in addition to that caused by a spatial shift of attention. Specifically, we argue that distractors possessing the target-defining characteristic enter a capacity-limited, serial stage of neural processing, which delays detection of subsequently presented stimuli regardless of the sensory modality.

Contingent capture of involuntary visual attention interferes with detection of auditory stimuli

Directory of Open Access Journals (Sweden)

Marc R. Kamke

2014-06-01

Full Text Available The involuntary capture of attention by salient visual stimuli can be influenced by the behavioral goals of an observer. For example, when searching for a target item, irrelevant items that possess the target-defining characteristic capture attention more strongly than items not possessing that feature. Such contingent capture involves a shift of spatial attention toward the item with the target-defining characteristic. It is not clear, however, if the associated decrements in performance for detecting the target item are entirely due to involuntary orienting of spatial attention. To investigate whether contingent capture also involves a non-spatial interference, adult observers were presented with streams of visual and auditory stimuli and were tasked with simultaneously monitoring for targets in each modality. Visual and auditory targets could be preceded by a lateralized visual distractor that either did, or did not, possess the target-defining feature (a specific color. In agreement with the contingent capture hypothesis, target-colored distractors interfered with visual detection performance (response time and accuracy more than distractors that did not possess the target color. Importantly, the same pattern of results was obtained for the auditory task: visual target-colored distractors interfered with sound detection. The decrement in auditory performance following a target-colored distractor suggests that contingent capture involves a source of processing interference in addition to that caused by a spatial shift of attention. Specifically, we argue that distractors possessing the target-defining characteristic enter a capacity-limited, serial stage of neural processing, which delays detection of subsequently presented stimuli regardless of the sensory modality.

Sound-induced facial synkinesis following facial nerve paralysis.

Science.gov (United States)

Ma, Ming-San; van der Hoeven, Johannes H; Nicolai, Jean-Philippe A; Meek, Marcel F

2009-08-01

Facial synkinesis (or synkinesia) (FS) occurs frequently after paresis or paralysis of the facial nerve and is in most cases due to aberrant regeneration of (branches of) the facial nerve. Patients suffer from inappropriate and involuntary synchronous facial muscle contractions. Here we describe two cases of sound-induced facial synkinesis (SFS) after facial nerve injury. As far as we know, this phenomenon has not been described in the English literature before. Patient A presented with right hemifacial palsy after lesion of the facial nerve due to skull base fracture. He reported involuntary muscle activity at the right corner of the mouth, specifically on hearing ringing keys. Patient B suffered from left hemifacial palsy following otitis media and developed involuntary muscle contraction in the facial musculature specifically on hearing clapping hands or a trumpet sound. Both patients were evaluated by means of video, audio and EMG analysis. Possible mechanisms in the pathophysiology of SFS are postulated and therapeutic options are discussed.

Illusory movement perception improves motor control for prosthetic hands.

Science.gov (United States)

Marasco, Paul D; Hebert, Jacqueline S; Sensinger, Jon W; Shell, Courtney E; Schofield, Jonathon S; Thumser, Zachary C; Nataraj, Raviraj; Beckler, Dylan T; Dawson, Michael R; Blustein, Dan H; Gill, Satinder; Mensh, Brett D; Granja-Vazquez, Rafael; Newcomb, Madeline D; Carey, Jason P; Orzell, Beth M

2018-03-14

To effortlessly complete an intentional movement, the brain needs feedback from the body regarding the movement's progress. This largely nonconscious kinesthetic sense helps the brain to learn relationships between motor commands and outcomes to correct movement errors. Prosthetic systems for restoring function have predominantly focused on controlling motorized joint movement. Without the kinesthetic sense, however, these devices do not become intuitively controllable. We report a method for endowing human amputees with a kinesthetic perception of dexterous robotic hands. Vibrating the muscles used for prosthetic control via a neural-machine interface produced the illusory perception of complex grip movements. Within minutes, three amputees integrated this kinesthetic feedback and improved movement control. Combining intent, kinesthesia, and vision instilled participants with a sense of agency over the robotic movements. This feedback approach for closed-loop control opens a pathway to seamless integration of minds and machines. Copyright © 2018 The Authors, some rights reserved; exclusive licensee American Association for the Advancement of Science. No claim to original U.S. Government Works.

Vibrating makes for better seeing: from the fly's micro eye movements to hyperacute visual sensors

OpenAIRE

Stéphane eViollet

2014-01-01

Active vision means that visual perception not only depends closely on the subject's own movements, but that these movements actually contribute to the visual perceptual processes. Vertebrates' and invertebrates' eye movements are probably part of an active visual process, but their exact role still remains to be determined. In this paper, studies on the retinal micro-movements occurring in the compound eye of the fly are reviewed. Several authors have located and identified the muscles invo...

The neural response properties and cortical organization of a rapidly adapting muscle sensory group response that overlaps with the frequencies that elicit the kinesthetic illusion.

Directory of Open Access Journals (Sweden)

Paul D Marasco

Full Text Available Kinesthesia is the sense of limb movement. It is fundamental to efficient motor control, yet its neurophysiological components remain poorly understood. The contributions of primary muscle spindles and cutaneous afferents to the kinesthetic sense have been well studied; however, potential contributions from muscle sensory group responses that are different than the muscle spindles have not been ruled out. Electrophysiological recordings in peripheral nerves and brains of male Sprague Dawley rats with a degloved forelimb preparation provide evidence of a rapidly adapting muscle sensory group response that overlaps with vibratory inputs known to generate illusionary perceptions of limb movement in humans (kinesthetic illusion. This group was characteristically distinct from type Ia muscle spindle fibers, the receptor historically attributed to limb movement sensation, suggesting that type Ia muscle spindle fibers may not be the sole carrier of kinesthetic information. The sensory-neural structure of muscles is complex and there are a number of possible sources for this response group; with Golgi tendon organs being the most likely candidate. The rapidly adapting muscle sensory group response projected to proprioceptive brain regions, the rodent homolog of cortical area 3a and the second somatosensory area (S2, with similar adaption and frequency response profiles between the brain and peripheral nerves. Their representational organization was muscle-specific (myocentric and magnified for proximal and multi-articulate limb joints. Projection to proprioceptive brain areas, myocentric representational magnification of muscles prone to movement error, overlap with illusionary vibrational input, and resonant frequencies of volitional motor unit contraction suggest that this group response may be involved with limb movement processing.

Ethanol Exposure Causes Muscle Degeneration in Zebrafish

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Elizabeth C. Coffey

2018-03-01

Full Text Available Alcoholic myopathies are characterized by neuromusculoskeletal symptoms such as compromised movement and weakness. Although these symptoms have been attributed to neurological damage, EtOH may also target skeletal muscle. EtOH exposure during zebrafish primary muscle development or adulthood results in smaller muscle fibers. However, the effects of EtOH exposure on skeletal muscle during the growth period that follows primary muscle development are not well understood. We determined the effects of EtOH exposure on muscle during this phase of development. Strikingly, muscle fibers at this stage are acutely sensitive to EtOH treatment: EtOH induces muscle degeneration. The severity of EtOH-induced muscle damage varies but muscle becomes more refractory to EtOH as muscle develops. NF-kB induction in muscle indicates that EtOH triggers a pro-inflammatory response. EtOH-induced muscle damage is p53-independent. Uptake of Evans blue dye shows that EtOH treatment causes sarcolemmal instability before muscle fiber detachment. Dystrophin-null sapje mutant zebrafish also exhibit sarcolemmal instability. We tested whether Trichostatin A (TSA, which reduces muscle degeneration in sapje mutants, would affect EtOH-treated zebrafish. We found that TSA and EtOH are a lethal combination. EtOH does, however, exacerbate muscle degeneration in sapje mutants. EtOH also disrupts adhesion of muscle fibers to their extracellular matrix at the myotendinous junction: some detached muscle fibers retain beta-Dystroglycan indicating failure of muscle end attachments. Overexpression of Paxillin, which reduces muscle degeneration in zebrafish deficient for beta-Dystroglycan, is not sufficient to rescue degeneration. Taken together, our results suggest that EtOH exposure has pleiotropic deleterious effects on skeletal muscle.

Emotional valence and contextual affordances flexibly shape approach-avoidance movements

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Ana Carolina eSaraiva

2013-12-01

Full Text Available Behaviour is influenced by the emotional content – or valence – of stimuli in our environment. Positive stimuli facilitate approach, whereas negative stimuli facilitate defensive actions such as avoidance (flight and attack (fight. Facilitation of approach or avoidance movements may also be influenced by whether it is the self that moves relative to a stimulus (self-reference or the stimulus that moves relative to the self (object-reference, adding flexibility and context-dependence to behaviour. Alternatively, facilitation of approach avoidance movements may happen in a predefined and muscle-specific way, whereby arm flexion is faster to approach positive (e.g. flexing the arm brings a stimulus closer and arm extension faster to avoid negative stimuli (e.g. extending the arm moves the stimulus away. While this allows for relatively fast responses, it may compromise the flexibility offered by contextual influences. Here we asked under which conditions approach-avoidance actions are influenced by contextual factors (i.e. reference-frame. We manipulated the reference-frame in which actions occurred by asking participants to move a symbolic manikin (representing the self towards or away from a positive or negative stimulus, and move a stimulus towards or away from the manikin. We also controlled for the type of movements used to approach or avoid in each reference. We show that the reference-frame influences approach-avoidance actions to emotional stimuli, but additionally we find muscle-specificity for negative stimuli in self-reference contexts. We speculate this muscle-specificity may be a fast and adaptive response to threatening stimuli. Our results confirm that approach-avoidance behaviour is flexible and reference-frame dependent, but can be muscle-specific depending on the context and valence of the stimulus. Reference-frame and stimulus-evaluation are key factors in guiding approach-avoidance behaviour towards emotional stimuli in our

Altered dopaminergic regulation of the dorsal striatum is able to induce tic-like movements in juvenile rats

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Rizzo, Francesca; Boeckers, Tobias; Schulze, Ulrike

2018-01-01

Motor tics are sudden, repetitive, involuntary movements representing the hallmark behaviors of the neurodevelopmental disease Tourette’s syndrome (TS). The primary cause of TS remains unclear. The initial observation that dopaminergic antagonists alleviate tics led to the development of a dopaminergic theory of TS etiology which is supported by post mortem and in vivo studies indicating that non-physiological activation of the striatum could generate tics. The striatum controls movement execution through the balanced activity of dopamine receptor D1 and D2-expressing medium spiny neurons of the direct and indirect pathway, respectively. Different neurotransmitters can activate or repress striatal activity and among them, dopamine plays a major role. In this study we introduced a chronic dopaminergic alteration in juvenile rats, in order to modify the delicate balance between direct and indirect pathway. This manipulation was done in the dorsal striatum, that had been associated with tic-like movements generation in animal models. The results were movements resembling tics, which were categorized and scored according to a newly developed rating scale and were reduced by clonidine and riluzole treatment. Finally, post mortem analyses revealed altered RNA expression of dopaminergic receptors D1 and D2, suggesting an imbalanced dopaminergic regulation of medium spiny neuron activity as being causally related to the observed phenotype. PMID:29698507

Neuromuscular-skeletal origins of predominant patterns of coordination in rhythmic two-joint arm movement.

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de Rugy, Aymar; Riek, Stephan; Carson, Richard G

2006-01-01

The authors tested for predominant patterns of coordination in the combination of rhythmic flexion-extension (FE) and supination- (SP) at the elbow-joint complex. Participants (N=10) spontaneously established in-phase (supination synchronized with flexion) and antiphase (pronation synchronized with flexion) patterns. In addition, the authors used a motorized robot arm to generate involuntary SP movements with different phase relations with respect to voluntary FE. The involuntarily induced in-phase pattern was accentuated and was more consistent than other patterns. The result provides evidence that the predominance of the in-phase pattern originates in the influence of neuromuscular-skeletal constraints rather than in a preference dictated by perceptual-cognitive factors implicated in voluntary control. Neuromuscular-skeletal constraints involved in the predominance of the in-phase and the antiphase patterns are discussed.

Modifying patterns of movement in people with low back pain -does it help? A systematic review

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Laird Robert A

2012-09-01

Full Text Available Abstract Background Physiotherapy for people with low back pain frequently includes assessment and modification of lumbo-pelvic movement. Interventions commonly aim to restore normal movement and thereby reduce pain and improve activity limitation. The objective of this systematic review was to investigate: (i the effect of movement-based interventions on movement patterns (muscle activation, lumbo-pelvic kinematics or postural patterns of people with low back pain (LBP, and (ii the relationship between changes in movement patterns and subsequent changes in pain and activity limitation. Methods MEDLINE, Cochrane Central, EMBASE, AMI, CINAHL, Scopus, AMED, ISI Web of Science were searched from inception until January 2012. Randomised controlled trials or controlled clinical trials of people with LBP were eligible for inclusion. The intervention must have been designed to influence (i muscle activity patterns, (ii lumbo-pelvic kinematic patterns or (iii postural patterns, and included measurement of such deficits before and after treatment, to allow determination of the success of the intervention on the lumbo-pelvic movement. Twelve trials (25% of retrieved studies met the inclusion criteria. Two reviewers independently identified, assessed and extracted data. The PEDro scale was used to assess method quality. Intervention effects were described using standardised differences between group means and 95% confidence intervals. Results The included trials showed inconsistent, mostly small to moderate intervention effects on targeted movement patterns. There was considerable heterogeneity in trial design, intervention type and outcome measures. A relationship between changes to movement patterns and improvements in pain or activity limitation was observed in one of six studies on muscle activation patterns, one of four studies that examined the flexion relaxation response pattern and in two of three studies that assessed lumbo-pelvic kinematics or

Modifying patterns of movement in people with low back pain -does it help? A systematic review.

Science.gov (United States)

Laird, Robert A; Kent, Peter; Keating, Jennifer L

2012-09-07

Physiotherapy for people with low back pain frequently includes assessment and modification of lumbo-pelvic movement. Interventions commonly aim to restore normal movement and thereby reduce pain and improve activity limitation. The objective of this systematic review was to investigate: (i) the effect of movement-based interventions on movement patterns (muscle activation, lumbo-pelvic kinematics or postural patterns) of people with low back pain (LBP), and (ii) the relationship between changes in movement patterns and subsequent changes in pain and activity limitation. MEDLINE, Cochrane Central, EMBASE, AMI, CINAHL, Scopus, AMED, ISI Web of Science were searched from inception until January 2012. Randomised controlled trials or controlled clinical trials of people with LBP were eligible for inclusion. The intervention must have been designed to influence (i) muscle activity patterns, (ii) lumbo-pelvic kinematic patterns or (iii) postural patterns, and included measurement of such deficits before and after treatment, to allow determination of the success of the intervention on the lumbo-pelvic movement. Twelve trials (25% of retrieved studies) met the inclusion criteria. Two reviewers independently identified, assessed and extracted data. The PEDro scale was used to assess method quality. Intervention effects were described using standardised differences between group means and 95% confidence intervals. The included trials showed inconsistent, mostly small to moderate intervention effects on targeted movement patterns. There was considerable heterogeneity in trial design, intervention type and outcome measures. A relationship between changes to movement patterns and improvements in pain or activity limitation was observed in one of six studies on muscle activation patterns, one of four studies that examined the flexion relaxation response pattern and in two of three studies that assessed lumbo-pelvic kinematics or postural characteristics. Movement

Altered pharyngeal muscles in Parkinson disease.

Science.gov (United States)

Mu, Liancai; Sobotka, Stanislaw; Chen, Jingming; Su, Hungxi; Sanders, Ira; Adler, Charles H; Shill, Holly A; Caviness, John N; Samanta, Johan E; Beach, Thomas G

2012-06-01

Dysphagia (impaired swallowing) is common in patients with Parkinson disease (PD) and is related to aspiration pneumonia, the primary cause of death in PD. Therapies that ameliorate the limb motor symptoms of PD are ineffective for dysphagia. This suggests that the pathophysiology of PD dysphagia may differ from that affecting limb muscles, but little is known about potential neuromuscular abnormalities in the swallowing muscles in PD. This study examined the fiber histochemistry of pharyngeal constrictor and cricopharyngeal sphincter muscles in postmortem specimens from 8 subjects with PD and 4 age-matched control subjects. Pharyngeal muscles in subjects with PD exhibited many atrophic fibers, fiber type grouping, and fast-to-slow myosin heavy chain transformation. These alterations indicate that the pharyngeal muscles experienced neural degeneration and regeneration over the course of PD. Notably, subjects with PD with dysphagia had a higher percentage of atrophic myofibers versus with those without dysphagia and controls. The fast-to-slow fiber-type transition is consistent with abnormalities in swallowing, slow movement of food, and increased tone in the cricopharyngeal sphincter in subjects with PD. The alterations in the pharyngeal muscles may play a pathogenic role in the development of dysphagia in subjects with PD.

The role of intrinsic muscle properties for stable hopping-stability is achieved by the force-velocity relation

International Nuclear Information System (INIS)

Haeufle, D F B; Grimmer, S; Seyfarth, A

2010-01-01

A reductionist approach was presented to investigate which level of detail of the physiological muscle is required for stable locomotion. Periodic movements of a simplified one-dimensional hopping model with a Hill-type muscle (one contractile element, neither serial nor parallel elastic elements) were analyzed. Force-length and force-velocity relations of the muscle were varied in three levels of approximation (constant, linear and Hill-shaped nonlinear) resulting in nine different hopping models of different complexity. Stability of these models was evaluated by return map analysis and the performance by the maximum hopping height. The simplest model (constant force-length and constant force-velocity relations) outperformed all others in the maximum hopping height but was unstable. Stable hopping was achieved with linear and Hill-shaped nonlinear characteristic of the force-velocity relation. The characteristics of the force-length relation marginally influenced hopping stability. The results of this approach indicate that the intrinsic properties of the contractile element are responsible for stabilization of periodic movements. This connotes that (a) complex movements like legged locomotion could benefit from stabilizing effects of muscle properties, and (b) technical systems could benefit from the emerging stability when implementing biological characteristics into artificial muscles.

The effect of fear of movement on muscle activation in posttraumatic neck pain disability

NARCIS (Netherlands)

Nederhand, Marcus Johannes; Hermens, Hermanus J.; IJzerman, Maarten Joost; Groothuis-Oudshoorn, Catharina Gerarda Maria; Turk, Dennis C.

Studies using surface electromyography have demonstrated a reorganization of muscle activation patterns of the neck and shoulder muscles in patients with posttraumatic neck pain disability. The neurophysiologically oriented "pain adaptation" model explains this reorganization as a useful adaptation

Movement Strategies among Groups of Chronic Ankle Instability, Coper, and Control.

Science.gov (United States)

Son, S Jun; Kim, Hyunsoo; Seeley, Matthew K; Hopkins, J Ty

2017-08-01

Comprehensive evaluation of movement strategies during functional movement is a difficult undertaking. Because of this challenge, studied movements have been oversimplified. Furthermore, evaluating movement strategies at only a discrete time point(s) provide limited insight into how movement strategies may change or adapt in chronic ankle instability (CAI) patients. This study aimed to identify abnormal movement strategies in individuals with a history of ankle sprain injury during a sports maneuver compared with healthy controls. Sixty-six participants, consisting of 22 CAI patients, 22 ankle sprain copers, and 22 healthy controls, participated in this study. Functional profiles of lower extremity kinematics, kinetics, and EMG activation from initial contact (0% of stance) to toe-off (100% of stance) were collected and analyzed during a jump landing/cutting task using a functional data analysis approach. Compared with copers, CAI patients displayed landing positions of less plantarflexion, less inversion, more knee flexion, more hip flexion, and less hip abduction during the first 25% of stance. However, restricted dorsiflexion angle was observed in both CAI patients and copers relative to controls during the midlanding to mid-side-cutting phase when the ankle and knee reached its peak range of motion (e.g., dorsiflexion and knee flexion). Reduced EMG activation of tibialis anterior, peroneus longus, medial gastrocnemius, and gluteus medius may be due to altered kinematics that reduce muscular demands on the involved muscles. CAI patients displayed altered movement strategies, perhaps in an attempt to avoid perceived positions of risk. Although sagittal joint positions seemed to increase the external torque on the knee and hip extensors, frontal joint positions appeared to reduce the muscular demands on evertor and hip abductor muscles.

Neurophysiologic studies of functional neurologic disorders.

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Hallett, M

2016-01-01

Functional neurologic disorders are largely genuine and represent conversion disorders, where the dysfunction is unconscious, but there are some that are factitious, where the abnormality is feigned and conscious. Malingering, which can have the same manifestations, is similarly feigned, but not considered a genuine disease. There are no good methods for differentiating these three entities at the present time. Physiologic studies of functional weakness and sensory loss reveal normal functioning of primary motor and sensory cortex, but abnormalities of premotor cortex and association cortices. This suggests a top-down influence creating the dysfunction. Studies of functional tremor and myoclonus show that these disorders utilize normal voluntary motor structures to produce the involuntary movements, again suggesting a higher-level abnormality. Agency is abnormal and studies shows that dysfunction of the temporoparietal junction may be a correlate. The limbic system is overactive and might initiate involuntary movements, but the mechanism for this is not known. The limbic system would then be the source of top-down dysfunction. It can be speculated that the involuntary movements are involuntary due to lack of proper feedforward signaling. © 2016 Elsevier B.V. All rights reserved.

The influence of sodium bicarbonate on maximal force and rates of force development in the triceps surae and brachii during fatiguing exercise.

Science.gov (United States)

Siegler, Jason C; Mudie, Kurt; Marshall, Paul

2016-11-01

What is the central question of this study? Does metabolic alkalosis in humans, induced by sodium bicarbonate, affect rates of skeletal muscle fatigue differentially in muscle groups composed predominately of slow- and fast-twitch fibres? What is the main finding and its importance? Sodium bicarbonate exhibited no effect on the fatigue profile observed between triceps surae and brachii muscle groups during and after 2 min of tetanic stimulation. For the first time in exercising humans, we have profiled the effect of sodium bicarbonate on the voluntary and involuntary contractile characteristics of muscle groups representative of predominately slow- and fast-twitch fibres. The effect of metabolic alkalosis on fibre-specific maximal force production and rates of force development (RFD) has been investigated previously in animal models, with evidence suggesting an improved capacity to develop force rapidly in fast- compared with slow-twitch muscle. We have attempted to model in vivo the fatigue profile of voluntary and involuntary maximal force and RFD in the triceps surae and brachii after sodium bicarbonate (NaHCO 3 ) ingestion. In a double-blind, three-way repeated-measures design, participants (n = 10) ingested either 0.3 g kg -1 NaHCO 3 (ALK) or equivalent calcium carbonate (PLA) prior to 2 min of continuous (1 Hz) supramaximal stimulation (300 ms at 40 Hz) of the triceps surae or brachii, with maximal voluntary efforts (maximal voluntary torque) coupled with direct muscle stimulation also measured at baseline, 1 and 2 min. Metabolic alkalosis was achieved in both ALK trials but was not different between muscle groups. Regardless of the conditions, involuntary torque declined nearly 60% in the triceps brachii (P < 0.001) and ∼30% in the triceps surae (P < 0.001). In all trials, there was a significant decline in normalized involuntary RFD (P < 0.05). Maximal voluntary torque declined nearly 28% but was not different between conditions (P < 0

Reliability of the Q Force; a mobile instrument for measuring isometric quadriceps muscle strength

OpenAIRE

Schans, van der, C.P.; Zijlstra, W.; Regterschot, G.R.H.; Krijnen, W.P.; Douma, K.W.; Slager, G.E.C.

2016-01-01

BACKGROUND: The ability to generate muscle strength is a pre-requisite for all human movement. Decreased quadriceps muscle strength is frequently observed in older adults and is associated with a decreased performance and activity limitations. To quantify the quadriceps muscle strength and to monitor changes over time, instruments and procedures with a sufficient reliability are needed. The Q Force is an innovative mobile muscle strength measurement instrument suitable to measure in various d...

[Tardive dyskinesia--diagnosis and treatment].

Science.gov (United States)

Kazamatsuri, H

1993-11-01

Tardive dyskinesia is defined as a syndrome consisting of abnormal, stereotypical involuntary movements usually of choreoathetoid type, principally affected the mouth, face, limbs and trunk, which occurs relatively late in the course of neuroleptic drug treatment and in the etiology of which the drug treatment is a necessary factor. Presently, the prevalence of tardive dyskinesia in the hospitalized patients in psychiatric hospitals in Japan is estimated to be 20-30%. Epidemiology, possible pathophysiology and symptomatology of tardive dyskinesia are briefly described. Differential diagnosis between this syndrome and other involuntary movements such as psychotic mannerism, senile orofacial dyskinesia, rabbit's syndrome, Pisa syndrome or Meige's syndrome is discussed. Several drugs to suppress involuntary movements of tardive dyskinesia are described. However, there appears to be no consistently reliable therapies for patients who develop the tardive dyskinesia. Treatment for this syndrome, other than neuroleptic withdrawal, are still uncertain.

Role of Active Contraction and Tropomodulins in Regulating Actin Filament Length and Sarcomere Structure in Developing Zebrafish Skeletal Muscle.