Sample records for submental electromyographic activity
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Berretin-Felix, Giédre; Nary, Hugo; Padovani, Carlos Roberto; Trindade, Alceu Sergio; Machado, Wellington Monteiro
2008-01-01
This study evaluated the effect of implant-supported oral rehabilitation in the mandible on the electromyographic activity during mastication and swallowing in edentulous elderly individuals. Fifteen patients aged more than 60 years were evaluated, being 10 females and 5 males. All patients were edentulous, wore removable complete dentures on both dental arches, and had the mandibular dentures replaced by implant-supported prostheses. All patients were submitted to electromyographic evaluation of the masseter, superior orbicularis oris muscles, and the submental muscles, before surgery and 3, 6 and 18 months postoperatively, using foods of different textures. The results obtained at the different periods were analyzed statistically by Kruskal-Wallis non-parametric test. Statistical analysis showed that only the masseter muscle had a significant loss in electromyographic activity (p<0.001), with a tendency of similar response for the submental muscles. Moreover, there was an increase in the activity of the orbicularis oris muscle during rubber chewing after treatment, yet without statistically significant difference. Mandibular fixed implant-supported prostheses in elderly individuals revealed a decrease in electromyographic amplitude for the masseter muscles during swallowing, which may indicate adaptation to new conditions of stability provided by fixation of the complete denture in the mandibular arch. PMID:19089202
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Giédre Berretin-Felix
2008-04-01
Full Text Available This study evaluated the effect of implant-supported oral rehabilitation in the mandible on the electromyographic activity during mastication and swallowing in edentulous elderly individuals. Fifteen patients aged more than 60 years were evaluated, being 10 females and 5 males. All patients were edentulous, wore removable complete dentures on both dental arches, and had the mandibular dentures replaced by implant-supported prostheses. All patients were submitted to electromyographic evaluation of the masseter, superior orbicularis oris muscles, and the submental muscles, before surgery and 3, 6 and 18 months postoperatively, using foods of different textures. The results obtained at the different periods were analyzed statistically by Kruskal-Wallis non-parametric test. Statistical analysis showed that only the masseter muscle had a significant loss in electromyographic activity (p<0.001, with a tendency of similar response for the submental muscles. Moreover, there was an increase in the activity of the orbicularis oris muscle during rubber chewing after treatment, yet without statistically significant difference. Mandibular fixed implant-supported prostheses in elderly individuals revealed a decrease in electromyographic amplitude for the masseter muscles during swallowing, which may indicate adaptation to new conditions of stability provided by fixation of the complete denture in the mandibular arch.
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Palmer, Phyllis M; McCulloch, Timothy M; Jaffe, Debra; Neel, Amy T
2005-01-01
A sour bolus has been used as a modality in the treatment of oropharyngeal dysphagia based on the hypothesis that this stimulus provides an effective preswallow sensory input that lowers the threshold required to trigger a pharyngeal swallow. The result is a more immediate swallow onset time. Additionally, the sour bolus may invigorate the oral muscles resulting in stronger contractions during the swallow. The purpose of this investigation was to compare the intramuscular electromyographic activity of the mylohyoid, geniohyoid, and anterior belly of the digastric muscles during sour and water boluses with regard to duration, strength, and timing of muscle activation. Muscle duration, swallow onset time, and pattern of muscle activation did not differ for the two bolus types. Muscle activation time was more tightly approximated across the onsets of the three muscles when a sour bolus was used. A sour bolus also resulted in a stronger muscle contraction as evidenced by greater electromyographic activity. These data support the use of a sour bolus as part of a treatment paradigm.
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Submental epidermoid cysts in children.
Zielinski, Rafal; Zakrzewska, Anna
2015-01-01
Epidermoid cysts are lesions, which form as a result of implantation of the epidermis in the layers of the dermis or the mucous membrane. The lesions are rare in adults with 7% occurring in the head and neck area and most often located in the submental region. In children population submental epidermoid cysts are extremely rare. The differential diagnosis of the lesions is necessary as it affects the choice of treatment methods. Among the pathological conditions occurring in that region, salivary retention cyst (ranula), thyroglossal duct cyst, vascular lymphatic malformation (cystic hygroma), median neck cyst, lymphadenopathy, thyroid gland tumor, laryngeal cyst, epidermoid and dermoid cysts, submental abscess, sialolithiasis and salivary gland inflammation should be considered. The authors of the present report demonstrate two cases of submental epidermoid cysts in children. Differential diagnosis in case of suspected submental epidermoid cyst in a child with proposed clinical practice and literature review is provided.
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International Nuclear Information System (INIS)
Hillarp, B.; Rosen, I.; Wickstroem, O.; Malmoe Allmaenna Sjukhus
1991-01-01
Percutaneous submental electrical stimulation during sleep may be a new therapeutic method for patients with obstructive sleep apnea syndrome (OSAS). Electrical stimulation to the submental region during obstructive apnea is reported to break the apnea without arousal and to diminish apneic index, time spent in apnea, and oxygen desaturation. The mode of breaking the apnea by electrical stimulation has not yet been shown. However, genioglossus is supposed to be the muscle responsible for breaking the apnea by forward movement of the tongue. To visualize the effect of submental electrical stimulation, one patient with severe OSAS has been examined with videoradiography. Submental electrical stimulation evoked an immediate complex muscle activity in the tongue, palate, and hyoid bone. This was followed by a forward movement of the tongue which consistently broke obstructive apnea without apparent arousal. Time spent in apnea was diminished but intervals between apnea were not affected. (orig.)
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Submental Intubation in Patients with Complex Maxillofacial Injuries
Cheong, Yuseon; Kang, Seong Sik; Kim, Minsoo; Son, Hee Jeong; Park, Jaewoo; Kim, Jeong-Mo
2016-01-01
Airway management in patients with complex maxillofacial injuries is a challenge to anesthesiologists. Submental intubation is a useful technique that is less invasive than tracheostomy in securing the airways where orotracheal and nasotracheal intubation cannot be performed. This procedure avoids the use of tracheostomy and bypasses its associated morbidities. A flexible and kink-resistant reinforced endotracheal tube with detachable universal connector is commonly used for submental intubation. Herein, we report cases involving submental intubation using a reinforced endotracheal tube with a non-detachable universal connector in patients with complex maxillofacial injuries. PMID:27924286
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Analysis of automated quantification of motor activity in REM sleep behaviour disorder
DEFF Research Database (Denmark)
Frandsen, Rune; Nikolic, Miki; Zoetmulder, Marielle
2015-01-01
Rapid eye movement (REM) sleep behaviour disorder (RBD) is characterized by dream enactment and REM sleep without atonia. Atonia is evaluated on the basis of visual criteria, but there is a need for more objective, quantitative measurements. We aimed to define and optimize a method for establishing...... baseline and all other parameters in automatic quantifying submental motor activity during REM sleep. We analysed the electromyographic activity of the submental muscle in polysomnographs of 29 patients with idiopathic RBD (iRBD), 29 controls and 43 Parkinson's (PD) patients. Six adjustable parameters...... were validated on PD patients. Automatic baseline estimation improved characterization of atonia during REM sleep, as it eliminates inter/intra-observer variability and can be standardized across diagnostic centres. We found an optimized method for quantifying motor activity during REM sleep...
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Accurate Prediction of Submental Lymph Nodes Using Magnetic Resonance Imaging for Lymphedema Surgery
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Mora-Ortiz Asuncion, MD
2018-03-01
Conclusions:. The preoperative MRI is a useful tool for the detection of mean 7.2 submental lymph nodes. Mean 72.2% of submental lymph nodes can be successfully transferred for extremity lymphedema with optimal functional recovery.
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Electromyographic activity of masticatory muscles in elderly women – a pilot study
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Gaszynska E
2017-01-01
Full Text Available Ewelina Gaszynska,1 Karolina Kopacz,2 Magdalena Fronczek-Wojciechowska,2 Gianluca Padula,2 Franciszek Szatko1 1Department of Hygiene and Health Promotion, 2Academic Laboratory of Movement and Human Physical Performance “DynamoLab”, Medical University of Lodz, Lodz, PolandObjectives: To evaluate the effect of age and chosen factors related to aging such as dentition, muscle strength, and nutrition on masticatory muscles electromyographic activity during chewing in healthy elderly women.Background: With longer lifespan there is a need for maintaining optimal quality of life and health in older age. Skeletal muscle strength deteriorates in older age. This deterioration is also observed within masticatory muscles.Methods: A total of 30 women, aged 68–92 years, were included in the study: 10 individuals had natural functional dentition, 10 were missing posterior teeth in the upper and lower jaw reconstructed with removable partial dentures, and 10 were edontoulous, using complete removable dentures. Surface electromyography was performed to evaluate masticatory muscles activity. Afterwards, measurement of masseter thickness with ultrasound imaging was performed, body mass index and body cell mass index were calculated, and isometric handgrip strength was measured.Results: Isometric maximal voluntary contraction decreased in active masseters with increasing age and in active and passive temporalis muscles with increasing age and increasing body mass index. In active masseter, mean electromyographic activity during the sequence (time from the start of chewing till the end when the test food became ready to swallow decreased with increasing age and during the cycle (single bite time decreased with increasing age and increasing body mass index. In active and passive temporalis muscles, mean electromyographic activity during the sequence and the cycle decreased with increasing age, increasing body mass index, and loss of natural dentition
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Xi Chen
2015-09-01
Full Text Available Objective: To explore the feasibility of the submental island flap in the repair of hypopharyngeal defects. Methods: We collected wet specimens of fresh cadaveric heads from the Han Chinese adult population for applied anatomy of the submental island flap, and followed five patients with pyriform sinus carcinoma after reconstruction surgery using submental island flaps. Results: We found that the average length and width of the submental island flaps were (65.20 ± 11.69 mm and (46.70 ± 6.59 mm, respectively. The skin flap in all five patients survived after surgery, and tracheal tubes and gastric tubes were removed 7â36 days after surgery. Patients were followed up for 24â42 months, pharyngeal flaps grew well, and speech and swallowing functions were satisfactory. Conclusion: The submental island flap is a preferred material for the repair of hypopharyngeal defects after hypopharyngeal carcinoma resection, because of good blood supply, easy harvesting, and high survival rate. Keywords: Submental island flap, Submental artery, Submental vein, Hypopharyngeal neoplasms, Reconstructive surgical procedures
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Influence of Exercise Order on Electromyographic Activity During Upper Body Resistance Training
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Soncin Rafael
2014-12-01
Full Text Available The purpose of this study was to investigate the effects of exercise order on electromyographic activity in different muscle groups among youth men with experience in strength training. Three sets of 8 RM were performed of each exercise in two sequences order: (a sequence A: bench press, chest fly, shoulder press, shoulder abduction, close grip bench press and lying triceps extension; (b sequence B: the opposite order. The electromyographic activity was analyzed in the sternocostal head of the pectoralis major, anterior deltoid, and long head triceps brachii, normalized for maximal voluntary isometric contraction. The muscles activity of the sternocostal head of the pectoralis major, anterior deltoid, and long head triceps brachii showed significant interaction between sequence and exercise. The sternocostal head of the pectoralis major showed considerably higher activity in sequence A (100.13 ± 13.56% than sequence B (81.47 ± 13.09% for the chest fly. The anterior deltoid showed significantly higher electromyographic activity in sequence B (86.81 ± 40.43% than sequence A (66.15 ± 22.02% for the chest fly, whereas for the lying triceps extension, the electromyographic activity was significantly higher in sequence A (53.89 ± 27.09% than sequence B (34.32 ± 23.70%. For the long head triceps brachii, only the shoulder press showed differences between sequences (A = 52.43 ± 14.64 vs. B = 38.53 ± 16.26. The present study showed that the exercise order could modify the training results even though there was no alteration in volume and intensity of the exercise. These changes may result in different training adaptations.
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Comparison of electromyographic activity during the bench press and barbell pulloverexercises
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Yuri de Almeida Costa Campos
2014-06-01
Full Text Available The aim of the study was to compare the electromyographic (EMG activity of the following muscles: clavicular portion of pectoralis major, sternal portion of pectoralis major, long portion of triceps brachii, anterior deltoid, posterior deltoid and latissimus dorsi during dynamic contractions between flat horizontal bench press and barbell pulloverexercises. The sample comprised 12 males individuals experienced in resistance training. The volunteers made three visits to the laboratory. The first one consisted of 12 repetitions of the exercises for the electromyographic data collection. The results showed a higher EMG activation of the pectoralis major and anterior deltoid muscles in the flat horizontal bench press in comparison with the barbell pullover. The triceps brachii and latissimus dorsi muscles were more activated in the barbell pullover.
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Fowler, C. J.; Christmas, T. J.; Chapple, C. R.; Parkhouse, H. F.; Kirby, R. S.; Jacobs, H. S.
1988-01-01
A potential association between abnormal electromyographic activity--that is, decelerating bursts and complex repetitive discharges--of the urethral sphincter and difficulty in voiding was examined in 57 women with urinary retention. Abnormal electromyographic activity was found in 33. Ultrasonography of the ovaries in 22 of the 33 women showed that 14 had polycystic ovaries. Of the other eight women, two had had oophorectomies, one had shrunken ovaries and ovarian failure, and one had previo...
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Dynamic factors and electromyographic activity in a sprint start
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M Čoh
2009-07-01
Full Text Available The aim of the study was to establish the major dynamic parameters as well as the EMG activation of muscles in a sprint start as the first derivative of sprint velocity. The subject of the analysis was block velocity, the production of force in the front and rear starting blocks, the block acceleration in the first two steps and the electromyographic activity (EMG of the following muscles: the erector spinae muscle, gluteus maximus muscle, rectus femoris muscle, vastus medialis muscle, vastus lateralis muscle, biceps femoris muscle and gastrocnemius–medialis muscle. One international-class female sprinter participated in the experiment. She performed eight starts in constant laboratory conditions. The 3-D kinematic analysis was made using a system of nine Smart-e 600 cameras operating at a frame rate of 60 Hz. Dynamic parameters were established by means of two separate force platforms to which the starting blocks were fixed. A 16-channel electromyograph was used to analyse electromyographic activity (EMG. It was established that the block velocity depended on the absolute force produced in the front and rear starting blocks and that it was 2.84±0.21 m.s-1. The maximal force on the rear and front blocks was 628±34 N and 1023±30 N, respectively. In view of the total impulse (210±11 Ns the force production/time ratio in the rear and front blocks was 34%:66%. The erector spinae muscle, vastus lateralis muscle and gastrocnemius–medialis muscle generate the efficiency of the start. The block acceleration in the first two steps primarily depends on the activation of the gluteus maximus muscle, rectus femoris muscle, biceps femoris muscle and gastrocnemius–medialis muscle. A sprint start is a complex motor stereotype requiring a high degree of integration of the processes of central movement regulation and an optimal level of biomotor abilities.
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Co, Abigail C; Abad-Casintahan, Maria Flordeliz; Espinoza-Thaebtharm, Agnes
2007-12-01
Excess skin and fatty tissues beneath the jaw lead to a double chin deformity. Localized fat deposits in this area are a cause of discomfort and anguish, leading patients to undergo surgical procedures such as liposuction and dermolipectomy to improve the cosmetic effect. Both procedures require anesthesia and an operating room setting and are quite expensive. Fearful of extensive surgery and its complications, patients and physicians seek less invasive methods. Mesotherapy with phosphatidylcholine and other cocktails have been used to treat localized fat deposits. However, there are few published articles regarding its effectiveness and some are even anecdotal. This study aims to determine the efficacy of phosphatidylcholine alone vs. phosphatidylcholine and organic silicium in submental fat reduction. Twelve patients with submental fat deposit with no coexisting morbidity and with informed consent were included in the study. They were submitted to one to five treatment sessions with an average interval of 2 weeks between each session. The medication administered was injected, either pure phosphatidylcholine or a combination of phosphatidylcholine and organic silicium. Baseline measurements of submental fat using vernier caliper and digital photographs of the patients were taken during each treatment session. The occurrence of adverse effects was likewise noted. Results Among the 12 patients, 11 completed the treatment course, and 1 was excluded from the study because of failure to follow up. Both phosphatidylcholine and a combination of phosphatidylcholine and organic silicium were equally effective in reducing submental fat deposits. There was no significant difference as to the rate and degree of reduction. Significant reduction in the thickness of submental fat was achieved after three treatment sessions. Adverse reactions in both groups were mild and transitory ranging from heavy sensation, localized heat, nodulations, and slight bruising that abated 3 to 5
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J. Brunsó Casellas
2009-08-01
Full Text Available El colgajo submental es un procedimiento eficaz para la reconstrucción en el territorio maxilofacial. Caracterizado por su delgadez, versatilidad, excelente color y textura y mínima morbilidad en la zona donante, su utilización en lesiones malignas es controvertida, por el riesgo de trasladar enfermedad metastásica cervical a la zona receptora. Material y métodos: Se presentan 3 casos clínicos en los que se ha aplicado en pacientes afectos de un carcinoma epidermoide de cabeza y cuello. Describimos las particularidades anatómicas, y se realiza una revisión de la técnica quirúrgica. Resultados: Fueron óptimos en cuanto a cobertura del defecto, estética y función salvo por una necrosis parcial en uno de ellos. En todos los casos la morbilidad en la zona donante fue mínima. Conclusiones: El colgajo submental es una opción a considerar incluso en pacientes oncológicos sobre todo en los que, por edad avanzada o presentar patología asociada no están indicados procedimientos más agresivos.The submental flap is an effective option for the reconstruction in the maxillofacial territory. Characterized by its thinness, versatility, excellent colour and texture and minimum morbidity in the donor zone, its use in malignant injuries is controverted by the risk of transferring cervical metastasic disease to the receiving zone. Material and methods: we present 3 clinical cases in which it has been used in patients affected by an squamous cell carcinoma of head and neck. In addition, the anatomical particularities are described, and a revision of the surgical technique is made. Results: They were optimal in relation to covering of the defect, aesthetics and function except for a partial necrosis in one of them. In all the cases the morbidity in the donor zone was minimum. Conclusions: The submental flap is an option to consider in oncologic patients, mainly in those whom by advanced age or by the existence of comorbidity advice against the use
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Mayer, John M; Verna, Joe L; Manini, Todd M; Mooney, Vert; Graves, James E
2002-11-01
To evaluate the effect of hip position and lumbar posture on the surface electromyographic activity of the trunk extensors during Roman chair exercise. Descriptive, repeated measures. University-based musculoskeletal research laboratory. Twelve healthy volunteers (7 men, 5 women; age range, 18-35y) without a history of low back pain were recruited from a university setting. Not applicable. Surface electromyographic activity was recorded from the lumbar extensor, gluteal, and hamstring musculature during dynamic Roman chair exercise. For each muscle group, electromyographic activity (mV/rep) was compared among exercises with internal hip rotation and external hip rotation and among exercises by using a typical lumbar posture (nonbiphasic) and a posture that accentuated lumbar lordosis (biphasic). For the lumbar extensors, electromyographic activity during exercise was 18% greater with internal hip rotation than external hip rotation (Phamstrings, there was no difference in electromyographic activity between internal and external hip rotation or between biphasic and nonbiphasic postures (P >.05). The level of recruitment of the lumbar extensors can be modified during Roman chair exercise by altering hip position and lumbar posture. Clinicians can use these data to develop progressive exercise protocols for the lumbar extensors with a variety of resistance levels without the need for complex equipment. Copyright 2002 by the American Congress of Rehabilitation Medicine and the American Academy of Physical Medicine and Rehabilitation
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Toxoplasmosis presented as a submental mass: a common disease, uncommon presentation.
Li, Bo; Zou, Jian; Wang, Wei-Ya; Liu, Shi-Xi
2015-01-01
Submental mass secondary to toxoplasmosis is not common in clinical work. A diagnosis of toxoplasmosis is rarely considered by physicians. Here we describe a 50-year-old woman presented with a progressive, painful, submental and left neck swelling for 1 month. After having obtained an insufficient evidence from the fine-needle biopsy, the patient finally received an excisional biopsy which highly indicated the possibility of lymphadenopathy consistent with toxoplasmosis. Diagnosis of toxoplasmosis was finally established by a combination of the pathological criteria, together with the positive serological finding. According to review the clinical presentations, pathological characteristics, diagnostic standard and treatment of this disease, the article aims to remind otolaryngologists who are evaluating a neck mass should be aware of the infectious cause of lymphadenopathy and the possibility of toxoplasmosis.
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Guo, S-X; Li, B-Y; Zhang, Y; Zhou, L-J; Liu, L; Widmalm, S-E; Wang, M-Q
2017-08-01
Mandibular functions are associated with electromyographic activity of the jaw muscles and also the sternocleidomastoid muscle (SCM). The precise spatiotemporal relation of SCM and masticatory muscles activities during chewing is worthy of investigation. To analyse the sequential recruitment of SCM and masseter activities during chewing as indicated by the spatiotemporal locations of their activity peaks. Jaw movements and bilateral surface electromyographic activity of SCM and masseter were recorded during gum chewing in 20 healthy subjects. The timing order was decided by comparing the length of time from the time when the opening started to the time when the surface electromyographic activity reached its peak value. Spatial order was analysed by locating the peak electromyographic activity onto a standard chewing cycle which was created based on 15 unilateral chewing cycles. Paired t-test, one-way ANOVA and Student-Newman-Keuls post-test were used for comparisons. Although the Time to Peak for the balancing side SCM appeared shorter than for the other three tested muscles, most often it did not reach a level of significance. However, the location of the balancing side SCM's peak activity was further from the terminal chewing position (TCP) than the working side SCM and bilateral masseters (P < 0·05). The balancing side SCM activity reached its peak significantly further away from TCP than the other three tested muscles during chewing. Further studies with spatiotemporal variables included should be helpful to understand the roles of the head, neck and jaw muscles in orofacial and cervical dysfunctional problems. © 2017 John Wiley & Sons Ltd.
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Malti Agrawal
2010-01-01
Conclusion: There were no significant operative or postoperative complications. Postoperative submental scarring was acceptable [6] . We conclude that midline submental intubation is a simple and useful technique with low morbidity. It can be chosen in selected cases of maxillofacial trauma and is an excellent substitute to tracheostomy where postoperative mechanical ventilation is not required.
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Boerboom, AL; Hof, AL; Halbertsma, JPK; van Raaij, JJAM; Schenk, W; Diercks, RL; van Horn, [No Value; van Horn, J.R.
Anterior cruciate ligament (ACL) deficiency may cause functional instability of the knee (noncopers), while other patients compensate and perform at the same level as before injury (copers). This pilot study investigated whether there is a compensatory electromyographic (EMG) activity of the
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Raquel, Gilsane; Namba, Eli Luis; Bonotto, Daniel; Ribeiro Rosa, Edvaldo Antônio; Trevilatto, Paula Cristina; Naval Machado, Maria Ângela; Vianna-Lara, Michelle Santos; Azevedo-Alanis, Luciana Reis
2017-01-01
To analyze and compare the electromyographic activity of the temporal (anterior portion) and masseter muscles among Karate-Dō athletes before and after training, with and without the use of a mouthguard. Twenty athletes (14 males and 6 females) with a mean age of 23.7 ± 7.5 years participated. They had surface electromyography recordings taken of their bilateral temporal and masseter muscles before and after training under the following conditions: no mouthguard, with a ready-made mouthguard, and with a custom-made mouthguard. Activity was examined at mandibular rest, while clenching, and at maximum voluntary contraction. The data were normalized using the mean maximum voluntary contraction. The right (p = 0.005) and left (p = 0.015) temporal muscles showed significantly lower electromyographic activity with a custom-made mouthguard compared with no mouthguard after training while clenching. The electromyographic activity of the temporal and masseter muscles did not show significant differences when tested at mandibular rest and while clenching before or after training with a custom-made mouthguard (p > 0.05). The use of a custom-made mouthguard preserved participants' electromyographic profiles before and after training; thus, they allow for stable muscle activity during the training of Karate-Dō athletes. Copyright © 2016 Elsevier Ltd. All rights reserved.
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Arumugam, Ashokan; Milosavljevic, Stephan; Woodley, Stephanie; Sole, Gisela
2015-06-01
There is some evidence that hamstring function can be influenced by interventions focusing on the pelvis via an anatomic and neurophysiologic link between these two segments. Previous research demonstrated increased electromyographic activity from injured hamstrings during transition from bipedal to unipedal stance (BUS). The aim of this study was to investigate the effects of a pelvic compression belt (PCB) on electromyographic activity of selected muscles during BUS in sportsmen with and without hamstring injury. Electromyographic amplitudes (normalised to maximum voluntary isometric contraction [MVIC]) of the hamstrings, gluteus maximus, gluteus medius and lumbar multifidus were obtained during BUS from 20 hamstring-injured participants (both sides) and 30 healthy participants (one side, randomly selected). There was an increase in biceps femoris (by 1.23 ± 2.87 %MVIC; p = 0.027) and gluteus maximus (by 0.63 ± 1.13 %MVIC; p = 0.023) electromyographic activity for the hamstring-injured side but no significant differences other than a decrease in multifidus activity (by 1.36 ± 2.92 %MVIC; p = 0.023) were evident for healthy participants while wearing the PCB. However, the effect sizes for these findings were small. Wearing the PCB did not significantly change electromyographic activity of other muscles in either participant group (p > 0.050). Moreover, the magnitude of change induced by the PCB was not significantly different between groups (p > 0.050) for the investigated muscles. Thus, application of a PCB to decrease electromyographic activity of injured hamstrings during BUS is likely to have little effect. Similar research is warranted in participants with acute hamstring injury. Copyright © 2014 Elsevier Ltd. All rights reserved.
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Celhay, Isabel; Cordova, Rosa; Miralles, Rodolfo; Meza, Francisco; Erices, Pia; Barrientos, Camilo; Valenzuela, Saúl
2015-04-01
To compare electromyographic (EMG) activity in young-adult subjects with different breathing types. This study included 50 healthy male subjects with complete natural dentition, and no history of orofacial pain or craniomandibular-cervical-spinal disorders. Subjects were classified into two groups: upper costal breathing type, and costo-diaphragmatic breathing. Bipolar surface electrodes were located on sternocleidomastoid, diaphragm, external intercostal, and latissimus dorsi muscles. Electromyographic activity was recorded during the following tasks: (1) normal quiet breathing; (2) speaking the word 'Mississippi'; (3) swallowing saliva; and (4) forced deep breathing. Sternocleidomastoid and latissimus dorsi EMG activity was not significantly different between breathing types, whereas diaphragm and external intercostal EMG activity was significantly higher in the upper costal than costo-diaphragmatic breathing type in all tasks (P<0·05; Wilcoxon signed rank-sum test). Diaphragm and external intercostal EMG activity suggests that there could be differences in motor unit recruitment strategies depending on the breathing type.
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Comparison of electromyographic activity during the bench press and barbell pulloverexercises
Campos, Yuri de Almeida Costa; Silva, Sandro Fernandes da
2014-01-01
The aim of the study was to compare the electromyographic (EMG) activity of the following muscles: clavicular portion of pectoralis major, sternal portion of pectoralis major, long portion of triceps brachii, anterior deltoid, posterior deltoid and latissimus dorsi during dynamic contractions between flat horizontal bench press and barbell pulloverexercises. The sample comprised 12 males individuals experienced in resistance training. The volunteers made three visits to the laboratory. The fi...
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DEFF Research Database (Denmark)
Samani, Afshin; Holtermann, Andreas; Søgaard, Karen
2009-01-01
, with passive (relax) and active (30% maximum voluntary contraction of shoulder elevation) pauses given every 2 min at two different work paces (low/high). Bipolar SEMG from four parts of the trapezius muscle was recorded. The relative rest time was higher for the lower parts compared with the upper......The aim of this laboratory study was to evaluate effects of active and passive pauses and investigate the distribution of the trapezius surface electromyographic (SEMG) activity during computer mouse work. Twelve healthy male subjects performed four sessions of computer work for 10 min in one day...... of the trapezius (pwork with active pause compared with passive one (p
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Mendes, André Augusto M T; de Freitas, Sandra Maria Sbeghen Ferreira; Amorin, César Ferreira; Cabral, Cristina Maria Nunes; Padula, Rosimeire Simprini
2018-02-06
This study aimed to evaluate the effect of one workday on pain and perceived exertion, muscular strength, and electromyographic activity of the erector spinae muscles in welders with and without low back pain. This is an observational cohort study. Twenty-two welders, metallurgical shipbuilding, were equally divided into 2 groups: low back pain and no low back pain. Pain and perceived exertion. Muscular strength by maximal voluntary contractions and electromyographic activity of right and left erector spinae muscles during maximal voluntary contractions and in the 3 welding positions for 2 periods of the workday (in the morning and at the end of the workday). At the end of workday, the pain increased significantly for the low back pain group (t(22) = 2.448; P= 0.023). The perceived exertion also increased significantly for both groups at the end of workday groups (F(1,22) = 8.570, P= 0.000) and periods (F(1,22) = 8.142, P= 0.000). There were no significant differences between groups and workday periods for muscular strength and electromyographic activity during maximal voluntary contractions of the erector spinae. There was no significance difference for electromyographic activity between groups and workday period and in the 3 welding positions. Although the pain and perceived exertion increased at the end of the workday, these results did not interfere in muscular strength and electromyographic activity of right and left erector spinae muscles. Thus, we can conclude that welders with chronic low back pain had a good physical capacity (muscular strength) and that muscle performance was maintained.
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Dayan, Steven H; Humphrey, Shannon; Jones, Derek H; Lizzul, Paul F; Gross, Todd M; Stauffer, Karen; Beddingfield, Frederick C
2016-11-01
In 2015, ATX-101 (deoxycholic acid injection; Kybella in the United States and Belkyra in Canada; Kythera Biopharmaceuticals, Inc., Westlake Village, CA [an affiliate of Allergan plc, Dublin, Ireland]) was approved as a first-in-class injectable drug for improvement in the appearance of moderate to severe convexity or fullness associated with submental fat. ATX-101 has been evaluated in a clinical development program that included 18 Phase 1 to 3 studies supporting the current indication. Since 2007, the toxicity and safety profiles of ATX-101 have been characterized in numerous preclinical studies, its pharmacokinetics, pharmacodynamics, and optimal treatment paradigm have been defined in multiple Phase 1 and 2 studies, and its efficacy and clinical safety have been confirmed in 4 large Phase 3 trials (2 conducted in Europe and 2 in the United States and Canada [REFINE-1 and REFINE-2]). As subcutaneous injection of deoxycholic acid has been shown to cause adipocytolysis, the reduction in submental fat achieved after ATX-101 treatment is expected to be long lasting. This prediction is confirmed by data from long-term follow-up studies of up to 4 years after last treatment with ATX-101, which demonstrate that the treatment response is maintained over time in most subjects. ATX-101 offers a durable, minimally invasive alternative to liposuction and surgery for addressing submental fullness.
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Väätäinen, U; Airaksinen, O; Jaroma, H; Kiviranta, I
1995-01-01
The alterations in thigh muscle properties of chondromalacia patellae patients during isometric and dynamic endurance tests were studied using a variokinetic knee testing system linked to surface EMG. A total of 41 patients (chondromalacia group) with arthroscopically certified chondromalacia of the patella were studied. The control group consisted of 31 healthy adult volunteers with no history of knee pain or trauma. Peak torque values were 21% (p chondromalacia group than in the control group. The decrease in the ratio between integrated EMG (IEMG) and measured force were found in all parts of the quadriceps femoris muscle in patients with chondromalacia of the patella in isometric extension. No change in the normalized IEMG levels of the thigh muscles were found between chondromalacia patients and controls in dynamic endurance test. The severity of the chondromalacia of the patella did not affect the level of electromyographic activation in thigh muscles. The ratio of normalized EMG levels of vastus medialis and vastus lateralis did not differ between the groups. The present study showed that chondromalacia patellae patients have reduced force and electromyographic activation levels of quadriceps femoris muscle. Especially, the explosive strength of the quadriceps femoris muscle is reduced.
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Electromyographic activity of beating and reaching during simulated boardsailing.
Buchanan, M; Cunningham, P; Dyson, R J; Hurrion, P D
1996-04-01
This study examined the responses of six competitive boardsailors (three males, three females) during laboratory-based simulation tasks while the electromyographic activity of up to 13 muscles was recorded. A sailboard, mounted in a steel frame and resting on a waterbed, allowed simulation of roll and pitch movements. Wind force was simulated by attaching the boom to a weight stack with a hydraulically controlled buffered release phase. The progression of the simulation test was controlled by the sailor copying movements on an edited video of each subject boardsailing on the open water. Analysis of individual pumping movements for mean peak percentage of maximal enveloped voluntary contraction (%MEVC) in 'beating' and 'reaching' showed that muscular activity in the arm (flexor carpi ulnaris, extensor carpi radialis and biceps brachii) was greatest (66-94% MEVC), with considerable activity (58-75% MEVC) in the deltoid and trapezius shoulder muscles, but much less activity in the leg muscles (16-40% MEVC). For the combined upper and lower body muscles there was a significant difference (P reflecting the current dynamic nature of the sport.
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Maenhout, A; Van Praet, K; Pizzi, L; Van Herzeele, M; Cools, A
2010-11-01
First, to look for appropriate closed kinetic chain exercises to restore intramuscular imbalance between upper trapezius (UT) and serratus anterior (SA) in overhead athletes. Second, to determine the influence of using diagonal pattern muscle recruitment during knee push up plus (KPP) exercises on scapular electromyographic activity. Single group repeated-measures design. Controlled laboratory study. Thirty-two physically active individuals in good general health who did not have a history of neck and/or shoulder injury or surgery nor participated in high-level overhead sports or performed upper limb strength training for more than 5 h/week. Interventions Subjects performed the standard KPP and six variations. Electromyographic activity of the three trapezius parts and the SA. Four exercises with a low UT/SA can be selected for rehabilitation of intramuscular balance: standard KPP, KPP with homolateral leg extension, KPP with a wobble board and homolateral leg extension and one-handed KPP. The use of a wobble board during KPP exercises and performance on one hand has no influence on SA electromyographic activity. Heterolateral leg extension during KPP stimulates lower trapezius activity, whereas homolateral leg extension stimulates SA activity. In case of intramuscular scapular imbalance, some exercises are preferable over others because of their low UT/SA ratio. The use of a kinetic chain approach during KPP exercises influences scapular muscle activity.
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Directory of Open Access Journals (Sweden)
Denise DalAva Augusto
2008-07-01
Full Text Available http://dx.doi.org/10.5007/1980-0037.2008v10n2p155 The Patellofemoral pain syndrome (PFPS is described as an anterior or retropatellar knee pain in the absence of other associated diseases, and has often been associated with dysfunction of the vastus medialis oblique muscle (VMO. However, several studies have demonstrated the impossibility of selectively activating this muscle with exercises. The aim of the present study was to analyze the immediate effect of neuromuscular electrical stimulation of VMO muscle by means of monitoring the electromyographic activity of the vastus medialis oblique (VMO and vastus lateralis (VL muscles. Eighteen healthy women with a mean age of 23.2 years and mean BMI of 20 Kg/m2 were evaluated. The study protocol included electromyographic analysis of VMO and VL muscles, before and immediately after neuromuscular electrical stimulation of the VMO muscle. During the electromyographic analysis, the volunteers performed maximal voluntary isometric contraction in a 60° knee extension on an isokinetic dynamometer. “Russian current” apparatus was used for electrical stimulation. Results: The data analysis demonstrated a signifi cant increase in VMO activation intensity immediately after it had been electrically stimulated (p=0.0125, whereas VL activation intensity exhibited no signifi cant increase (p=0.924. Moreover, a significant increase in the VMO/VL ratio was also detected (p=0.048. In this study it was observed that electrical stimulation modifiedthe VMO/VL ratio, which suggests electrical stimulation has a benefi cial effect on VMO muscle strength.
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Electromyographic Grasp Recognition for a Five Fingered Robotic Hand
Directory of Open Access Journals (Sweden)
Nayan M. Kakoty
2012-09-01
Full Text Available This paper presents classification of grasp types based on surface electromyographic signals. Classification is through radial basis function kernel support vector machine using sum of wavelet decomposition coefficients of the EMG signals. In a study involving six subjects, we achieved an average recognition rate of 86%. The electromyographic grasp recognition together with a 8-bit microcontroller has been employed to control a fivefingered robotic hand to emulate six grasp types used during 70% daily living activities.
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Electromyographic comparison of concentric and eccentric ...
African Journals Online (AJOL)
The study was conducted to compare the Electromyographic (EMG) activity variation of contractions (concentric and eccentric) during three different abdominal exercises (sit-up) exercises on rectus abdominal (upper and lower rectus). The sit-up exercises were: straight leg sit-up, bent leg sit-up and crunches. The EMG ...
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Erickson, Brandon J; Zaferiou, Antonia; Chalmers, Peter N; Ruby, Deana; Malloy, Phillip; Luchetti, Timothy J; Verma, Nikhil N; Romeo, Anthony A
2017-11-01
Ulnar collateral ligament reconstruction (UCLR) has become a common procedure among baseball players of all levels. There are several graft choices in performing UCLR, one of which is a hamstring (gracilis or semitendinosus) autograft. It is unclear whether the hamstring muscle from a pitcher's drive leg (ipsilateral side of the UCLR) or landing leg (contralateral side of the UCLR) is more active during the pitching motion. We hypothesized that the landing leg semitendinosus will be more electromyographically active than the drive leg. Healthy, elite male pitchers aged 16-21 years were recruited. Sixteen pitchers (average age, 17.6 ± 1.6 years; 67% threw right handed) underwent electromyographic analysis. Pitchers threw 5 fastballs at 100% effort from the wind-up with electromyographic analysis of every pitch. Activation of the semitendinosus and biceps femoris in both legs was compared within pitchers and between pitchers. Hamstring activity was higher in the drive leg than in the landing leg during each phase and in sum, although the difference was significant only during the double support phase (P = .021). On within-pitcher analysis, 10 of 16 pitchers had significantly more sum hamstring activity in the drive leg than in the landing leg, while only 4 of 16 had more activity in the landing leg (P = .043). During the baseball pitch, muscle activity of the semitendinosus was higher in the drive leg than in the landing leg in most pitchers. Surgeons performing UCLR using hamstring autograft should consider harvesting the graft from the pitcher's landing leg to minimize disruption to the athlete's pitching motion. Copyright © 2017 Journal of Shoulder and Elbow Surgery Board of Trustees. Published by Elsevier Inc. All rights reserved.
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A test of the submentalizing hypothesis: Apes' performance in a false belief task inanimate control
Hirata, Satoshi; Call, Josep; Tomasello, Michael
2017-01-01
ABSTRACT Much debate concerns whether any nonhuman animals share with humans the ability to infer others' mental states, such as desires and beliefs. In a recent eye-tracking false-belief task, we showed that great apes correctly anticipated that a human actor would search for a goal object where he had last seen it, even though the apes themselves knew that it was no longer there. In response, Heyes proposed that apes' looking behavior was guided not by social cognitive mechanisms but rather domain-general cueing effects, and suggested the use of inanimate controls to test this alternative submentalizing hypothesis. In the present study, we implemented the suggested inanimate control of our previous false-belief task. Apes attended well to key events but showed markedly fewer anticipatory looks and no significant tendency to look to the correct location. We thus found no evidence that submentalizing was responsible for apes' anticipatory looks in our false-belief task. PMID:28919941
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Automated analysis of prerecorded evoked electromyographic activity from rat muscle.
Basarab-Horwath, I; Dewhurst, D G; Dixon, R; Meehan, A S; Odusanya, S
1989-03-01
An automated microprocessor-based data acquisition and analysis system has been developed specifically to quantify electromyographic (EMG) activity induced by the convulsant agent catechol in the anaesthetized rat. The stimulus and EMG response are recorded on magnetic tape. On playback, the stimulus triggers a digital oscilloscope and, via interface circuitry, a BBC B microcomputer. The myoelectric activity is digitized by the oscilloscope before being transferred under computer control via a RS232 link to the microcomputer. This system overcomes the problems of dealing with signals of variable latency and allows quantification of latency, amplitude, area and frequency of occurrence of specific components within the signal. The captured data can be used to generate either signal or superimposed high resolution graphic reproductions of the original waveforms. Although this system has been designed for a specific application, it could easily be modified to allow analysis of any complex waveform.
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Chang, Chia-Wei; Lee, Wei-Ju; Liao, Yi-Chu; Chang, Ming-Hong
2013-11-01
We investigate electrodiagnostic markers to determine which parameters are the best predictors of spontaneous electromyographic (EMG) activity in carpal tunnel syndrome (CTS). We enrolled 229 patients with clinically proven and nerve conduction study (NCS)-proven CTS, as well as 100 normal control subjects. All subjects were evaluated using electrodiagnostic techniques, including median distal sensory latencies (DSLs), sensory nerve action potentials (SNAPs), distal motor latencies (DMLs), compound muscle action potentials (CMAPs), forearm median nerve conduction velocities (FMCVs) and wrist-palm motor conduction velocities (W-P MCVs). All CTS patients underwent EMG examination of the abductor pollicis brevis (APB) muscle, and the presence or absence of spontaneous EMG activities was recorded. Normal limits were determined by calculating the means ± 2 standard deviations from the control data. Associations between parameters from the NCS and EMG findings were investigated. In patients with clinically diagnosed CTS, abnormal median CMAP amplitudes were the best predictors of spontaneous activity during EMG examination (p95% (positive predictive rate >95%). If the median CMAP amplitude was higher than the normal limit (>4.9 mV), the rate of no spontaneous EMG activity was >94% (negative predictive rate >94%). An abnormal SNAP amplitude was the second best predictor of spontaneous EMG activity (p<0.001; OR 4.13; 95% CI 2.16-7.90), and an abnormal FMCV was the third best predictor (p=0.01; OR 2.10; 95% CI 1.20-3.67). No other nerve conduction parameters had significant power to predict spontaneous activity upon EMG examination. The CMAP amplitudes of the APB are the most powerful predictors of the occurrence of spontaneous EMG activity. Low CMAP amplitudes are strongly associated with spontaneous activity, whereas high CMAP amplitude are less associated with spontaneous activity, implying that needle EMG examination should be recommended for the detection of
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Electromyographic activity and 6RM strength in bench press on stable and unstable surfaces.
Saeterbakken, Atle H; Fimland, Marius S
2013-04-01
The purpose of the study was to compare 6-repetition maximum (6RM) loads and muscle activity in bench press on 3 surfaces, namely, stable bench, balance cushion, and Swiss ball. Sixteen healthy, resistance-trained men (age 22.5 ± 2.0 years, stature 1.82 ± 6.6 m, and body mass 82.0 ± 7.8 kg) volunteered for 3 habituation/strength testing sessions and 1 experimental session. In randomized order on the 3 surfaces, 6RM strength and electromyographic activity of pectoralis major, deltoid anterior, biceps brachii, triceps brachii, rectus abdominis, oblique external and erector spinae were assessed. Relative to stable bench, the 6RM strength was approximately 93% for balance cushion (p ≤ 0.001) and approximately 92% for Swiss ball (p = 0.008); the pectoralis major electromyographic (EMG) activity was approximately 90% using the balance cushion (p = 0.080) and approximately 81% using Swiss ball (p = 0.006); the triceps EMG was approximately 79% using the balance cushion (p = 0.028) and approximately 69% using the Swiss ball (p = 0.002). Relative to balance cushion, the EMG activity in pectoralis, triceps, and erector spinae using Swiss ball was approximately 89% (p = 0.016), approximately 88% (p = 0.014) and approximately 80% (p = 0.020), respectively. In rectus abdominis, the EMG activity relative to Swiss ball was approximately 69% using stable bench (p = 0.042) and approximately 65% using the balance cushion (p = 0.046). Similar EMG activities between stable and unstable surfaces were observed for deltoid anterior, biceps brachii, and oblique external. In conclusion, stable bench press had greater 6RM strength and triceps and pectoralis EMG activity compared with the unstable surfaces. These findings have implications for athletic training and rehabilitation, because they demonstrate an inferior effect of unstable surfaces on muscle activation of prime movers and strength in bench press. If an unstable surface in bench press is desirable, a balance cushion should
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Directory of Open Access Journals (Sweden)
Syczewska Małgorzata
2017-10-01
Full Text Available Study aim: Improvement of the upper extremities’ performance is one of the key aims in the rehabilitation process. In order to achieve high effectiveness of this process the amount of functional improvement achieved by a patient during the therapy needs to be assessed. The aim of this study was to obtain electromyographic (EMG activity profiles of the upper extremity muscles during execution of simple tasks in healthy subjects. Additionally the ranges of wrist, elbow and shoulder joints were measured and reported during performed trials. The second aim was to determine whether the movement execution and ranges of movements and muscular activity depend on age. Material and methods: Twenty-eight healthy adults, age range 21 to 65 years old, participated in the study. Surface electrodes were placed bilaterally on 7 upper extremity muscles. To obtain information about the beginning and end of the movement task and ranges of upper extremity joints, 13 markers were placed on the elbows and wrists of both upper extremities. The movements of the segments were calculated (distal vs proximal in five simple functional tasks (each task involved only one joint, performed while sitting. Kinematic data were collected by the VICON 460 system, and electromyographic data with the Motion Lab EMG system. Results: Charts of timing of EMG activity of the upper extremity muscles together with ranges of upper extremity joint motion were obtained. Conclusion: The results show that the number of muscles activated and the time (or percentage of the task during which they are active depend on the type of the task and age. These data can be used as a reference in evaluation of functional deficits of patients.
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Electromyographic permutation entropy quantifies diaphragmatic denervation and reinnervation.
Directory of Open Access Journals (Sweden)
Christopher Kramer
Full Text Available Spontaneous reinnervation after diaphragmatic paralysis due to trauma, surgery, tumors and spinal cord injuries is frequently observed. A possible explanation could be collateral reinnervation, since the diaphragm is commonly double-innervated by the (accessory phrenic nerve. Permutation entropy (PeEn, a complexity measure for time series, may reflect a functional state of neuromuscular transmission by quantifying the complexity of interactions across neural and muscular networks. In an established rat model, electromyographic signals of the diaphragm after phrenicotomy were analyzed using PeEn quantifying denervation and reinnervation. Thirty-three anesthetized rats were unilaterally phrenicotomized. After 1, 3, 9, 27 and 81 days, diaphragmatic electromyographic PeEn was analyzed in vivo from sternal, mid-costal and crural areas of both hemidiaphragms. After euthanasia of the animals, both hemidiaphragms were dissected for fiber type evaluation. The electromyographic incidence of an accessory phrenic nerve was 76%. At day 1 after phrenicotomy, PeEn (normalized values was significantly diminished in the sternal (median: 0.69; interquartile range: 0.66-0.75 and mid-costal area (0.68; 0.66-0.72 compared to the non-denervated side (0.84; 0.78-0.90 at threshold p<0.05. In the crural area, innervated by the accessory phrenic nerve, PeEn remained unchanged (0.79; 0.72-0.86. During reinnervation over 81 days, PeEn normalized in the mid-costal area (0.84; 0.77-0.86, whereas it remained reduced in the sternal area (0.77; 0.70-0.81. Fiber type grouping, a histological sign for reinnervation, was found in the mid-costal area in 20% after 27 days and in 80% after 81 days. Collateral reinnervation can restore diaphragm activity after phrenicotomy. Electromyographic PeEn represents a new, distinctive assessment characterizing intramuscular function following denervation and reinnervation.
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Erdag, Deniz
2017-01-01
The aim of this study was to investigate the possible kinematic and muscular activity changes with maximal loading during squat maneuver. Fourteen healthy male individuals, who were experienced at performing squats, participated in this study. Each subject performed squats with 80%, 90%, and 100% of the previously established 1 repetition maximum (1RM). Electromyographic (EMG) activities were measured for the vastus lateralis, vastus medialis, rectus femoris, semitendinosus, biceps femoris, gluteus maximus, and erector spinae by using an 8-channel dual-mode portable EMG and physiological signal data acquisition system (Myomonitor IV, Delsys Inc., Boston, MA, USA). Kinematical data were analyzed by using saSuite 2D kinematical analysis program. Data were analyzed with repeated measures analysis of variance (p squat may not be necessary for focusing on knee extensor improvement and may increase the lumbar injury risk. PMID:28546738
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Oshikawa, Tomoki; Morimoto, Yasuhiro; Kaneoka, Koji
2018-03-01
[Purpose] To compare the lumbar lordosis angle and electromyographic activities of the trunk and lower-limb muscles in the hip neutral position and external rotation during back squats. [Subjects and Methods] Ten healthy males without severe low back pain or lower-limb injury participated in this study. The lumbar lordosis angle and electromyographic activities were measured using three-dimensional motion-capture systems and surface electrodes during four back squats: parallel back squats in the hip neutral position and external rotation and full back squats in the hip neutral position and external rotation. A paired t-test was used to compare parallel and full back squats measurements in the hip neutral position and external rotation, respectively. [Results] During parallel back squats, the average lumbar lordosis angle was significantly larger in hip external rotation than in the hip neutral position. During full back squats, lumbar erector spinae and multifidus activities were significantly lower in hip external rotation than in the hip neutral position, whereas gluteus maximus activity was significantly higher in hip external rotation than in the hip neutral position. [Conclusion] The back squat in hip external rotation induced improvement of lumbar kyphosis, an increasing of the gluteus maximus activity and a decrease of both lumbar erector spinae and multifidus activities.
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International Nuclear Information System (INIS)
Jha, Naresh; Seikaly, Hadi; Harris, Jeff; Williams, David; Liu, Richard; McGaw, Timothy; Hofmann, Henry; Robinson, Don; Hanson, John; Barnaby, Pam
2003-01-01
Background and purpose: Xerostomia is a significant morbidity of radiation treatment in the management of head and neck cancers. We hypothesized that the surgical transfer of one submandibular salivary gland to the submental space, where it can be shielded from radiation treatment (XRT), would prevent xerostomia. Materials and methods: We conducted a prospective Phase II clinical trial and the patients were followed clinically with salivary flow studies and the University of Washington Quality of Life questionnaire. Results: We report the results on 76 evaluable patients. The salivary gland transfer was done in 60 patients. Nine patients (of 60) did not have postoperative XRT and in eight patients (of 60) the transferred gland was not shielded from XRT due to proximity of disease. The median follow up is 14 months. Of the 43 patients with the salivary gland transfer and post-operative XRT with protection of the transferred gland, 81% have none or minimal xerostomia, and 19% developed moderate to severe xerostomia. Three patients (6.9%) developed local recurrence, five patients (11.6%) developed distant metastases and five patients (11.6%) have died. There were no complications attributed to the surgical procedure. Conclusion: Surgical transfer of a submandibular salivary gland to the submental space preserves its function and prevents the development of radiation induced xerostomia
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Electromyographic Comparison of Squats Using Constant or Variable Resistance.
Andersen, Vidar; Steiro Fimland, Marius; Knutson Kolnes, Maria; Jensen, Susanne; Laume, Martine; Hole Saeterbakken, Atle
2016-12-01
Andersen, V, Fimland, MS, Kolnes, MK, Jensen, S, Laume, M and Saeterbakken, AH. Electromyographic comparison of squats using constant or variable resistance. J Strength Cond Res 30(12): 3456-3463, 2016-The aim of the study was to compare the electromyographic (EMG) activity of vastus lateralis, vastus medialis, rectus femoris, and biceps femoris when performing the squat with constant resistance or variable resistance with 2 or 4 elastic bands, respectively, contributing with a mean of 39 and 73% of the total loads. Nineteen resistance-trained women performed 6 repetition maximum using 3 different experimental conditions: free weights (FW), free weights + 2 elastic bands (FW + 2EB), and free weights + 4 elastic bands (FW + 4EB). During analyses, each repetition was divided into 6 phases: upper (more extended knee), middle, and lower phase of the descending and ascending movements. Increased activation in the upper parts of the movement was observed for both variable resistance conditions compared with constant resistance (9-51%, p squat using free weights in combination with elastic bands seems to be preferable compared with free weights alone and more so with a high contribution from variable resistance to the total load.
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Spall, Peter; Ribeiro, Daniel Cury; Sole, Gisela
2016-09-01
To compare electromyographic activity in patients with symptomatic rotator cuff tears with healthy controls or to those with asymptomatic cuff tears. TYPE: Systematic review and meta-analysis. PubMed, Scopus, Ovid Medline, and Web of Science were searched from inception to August 1, 2014, and a search update was performed on June 8, 2015. Case-control studies or intervention studies that had baseline comparisons for symptomatic versus healthy shoulders or those with asymptomatic rotator cuff tear were searched. Methodological quality was assessed with a modified Critical Appraisal Skills Programme score and meta-analyses were performed when 2 or more studies explored the same outcome measures. Nine studies were included, with the quality ranging from 1 to 3 (maximum 6). Electromyographic outcomes included amplitudes and ratios thereof, activity duration, and median frequency of shoulder girdle muscles during isometric contractions (4 studies) and functional tasks (5 studies). Longer activity duration was found for upper trapezius during glenohumeral movements, and greater fatigability of anterior and middle deltoids during isometric hand gripping for patients with rotator cuff tears compared to controls. The meta-analysis (3 studies) showed that patients with rotator cuff tears had lower activation ratios for latissimus dorsi during isometric abduction contraction compared to controls (P muscle activity differences between the rotator cuff tear group and controls is thus limited. Copyright © 2016. Published by Elsevier Inc.
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Directory of Open Access Journals (Sweden)
Vanessa S. Pereira
2014-10-01
Full Text Available Background: The proper evaluation of the pelvic floor muscles (PFM is essential for choosing the correct treatment. Currently, there is no gold standard for the assessment of female PFM function. Objective: To determine the correlation between vaginal palpation, vaginal squeeze pressure, and electromyographic and ultrasonographic variables of the female PFM. Method: This cross-sectional study evaluated 80 women between 18 and 35 years of age who were nulliparous and had no pelvic floor dysfunction. PFM function was assessed based on digital palpation, vaginal squeeze pressure, electromyographic activity, bilateral diameter of the bulbocavernosus muscles and the amount of bladder neck movement during voluntary PFM contraction using transperineal bi-dimensional ultrasound. The Pearson correlation was used for statistical analysis (p<0.05. Results: There was a strong positive correlation between PFM function and PFM contraction pressure (0.90. In addition, there was a moderate positive correlation between these two variables and PFM electromyographic activity (0.59 and 0.63, respectively and movement of the bladder neck in relation to the pubic symphysis (0.51 and 0.60, respectively. Conclusions: This study showed that there was a correlation between vaginal palpation, vaginal squeeze pressure, and electromyographic and ultrasonographic variables of the PFM in nulliparous women. The strong correlation between digital palpation and PFM contraction pressure indicated that perineometry could easily be replaced by PFM digital palpation in the absence of equipment.
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Electromyographical Comparison of a Traditional, Suspension Device, and Towel Pull-Up
Directory of Open Access Journals (Sweden)
Snarr Ronald L.
2017-08-01
Full Text Available Strengthening muscles of the back may have various implications for improving functions of daily living, aiding in the transfer of power in throwing, and assist in injury prevention of the shoulder complex. While several versions of the pull-up exist, there is currently no literature comparing their differences. The purpose of this investigation was to compare the electromyographical activity of the latissimus dorsi, posterior deltoid, middle trapezius, and biceps brachii while performing three variations of the pull-up. Resistance-trained men and women (n =15, age = 24.87 ± 6.52 years participated in this study by performing traditional pull-ups, suspension device pull-ups, and towel pull-ups in a randomized fashion. Each pull-up was performed for three repetitions with a 1.5 bi-acromial grip-width for each participant. Normalized (%MVC electromyographical values were recorded for each muscle group during each pull-up variation. No significant differences existed within the latissimus dorsi, biceps brachii or posterior deltoid between any of the exercises. For the middle trapezius, towel pull-ups provided significantly lower muscle activity than the traditional pull-up, while no differences between suspension pull-ups and the other variations occurred. In conclusion, only one muscular difference existed between the exercise variations and all versions examined provided electromyographical values, determined by current literature, to invoke a sufficient stimulus to promote increases in muscle strength and hypertrophy. Although further research is needed, practitioners can be confident when programming any of the movement variations examined when attempting to elicit adaptations of muscular strength and hypertrophy.
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Cheung, J.; Halbertsma, J.P.; Veldhuizen, A.G.; Sluiter, W.J.; Maurits, N.M.; Cool, J.C.; van Horn, J.R.
The paraspinal muscles have been implicated as a major causative factor in the progression of idiopathic scoliosis. Therefore, the objectives of this preliminary study were to measure the electromyographic activity (EMG) of the paraspinal muscles to determine its relationship to progression of the
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Directory of Open Access Journals (Sweden)
Hamideh Khodaveisi
2016-01-01
Full Text Available Objective: In recent years, it has been focused much attention on gait analysis. Factors such as speed, age and gender affect gait parameters. The purpose of the present study was to compare the electromyographic activity pattern of knee two-joint muscles between younger and older subjects in different gait speeds. Matterials & Methods: The method of current study was analytical cross-sectional method in which 15 healthy young men and 15 old men, were selected conveniently. Electromyographic activity of rectus femoris, biceps femoris, semitendinus and gastrocenemius were recorded during walking with preferred (100%, slow (80% and fast (120% speeds in a 10 meter walkway. Normalized RMSs of muscles were compared using RM-ANOVA and Tokey’s tests by SPSS 18 software. Results: According to results, RMSs of rectus femoris in midstance (P<0.01 and gastrocenemius in loading response (P=0.02 phases in all walking speeds were higher in older subjects than in younger ones, and it increased with speed in both age groups (P<0.01. Biceps femoris RMS in terminal stance at 80% speed, was lower in older subjects than in younger ones (P=0.01 and it increased with walking speed (P=0.01. Semitendinus activity in loading and midstance phases at 120% speed was higher in older subjects than in younger ones (P<0.01, and it increased with speed in both age groups in swing phase (P<0.05. Conclusion: According to the results, older subjects have more muscle co-contraction around knee at high speed in midstance phase than younger subjects. These age-related changes in muscle activity, leads to increase in joint stiffness and stability during single support, and probably play a role in reducing push off power at faster speeds.
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Directory of Open Access Journals (Sweden)
Hasan U. Yavuz
2017-01-01
Full Text Available The aim of this study was to investigate the possible kinematic and muscular activity changes with maximal loading during squat maneuver. Fourteen healthy male individuals, who were experienced at performing squats, participated in this study. Each subject performed squats with 80%, 90%, and 100% of the previously established 1 repetition maximum (1RM. Electromyographic (EMG activities were measured for the vastus lateralis, vastus medialis, rectus femoris, semitendinosus, biceps femoris, gluteus maximus, and erector spinae by using an 8-channel dual-mode portable EMG and physiological signal data acquisition system (Myomonitor IV, Delsys Inc., Boston, MA, USA. Kinematical data were analyzed by using saSuite 2D kinematical analysis program. Data were analyzed with repeated measures analysis of variance (p<0.05. Overall muscle activities increased with increasing loads, but significant increases were seen only for vastus medialis and gluteus maximus during 90% and 100% of 1RM compared to 80% while there was no significant difference between 90% and 100% for any muscle. The movement pattern in the hip joint changed with an increase in forward lean during maximal loading. Results may suggest that maximal loading during squat may not be necessary for focusing on knee extensor improvement and may increase the lumbar injury risk.
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Electromyographic study of rotator cuff muscle activity during full and empty can tests
Directory of Open Access Journals (Sweden)
Yoshihiro Kai
2015-01-01
Full Text Available The empty can (EC and full can (FC tests are used as diagnostic tools for patients with rotator cuff disease. However, recently concerns have been raised that these tests do not selectively activate the muscle. Therefore, the purpose of this study was to evaluate the rotator cuff muscle activation levels during the EC and FC tests in various positions using electromyography. Twelve healthy, right-handed men without shoulder complaints (mean age: 26.1 years, range: 23–35 years were included. The tests were performed isometrically with the shoulder elevated at 45° and 90° in the sagittal, scapular, and coronal planes, either in the thumb-up (FC test or thumb-down (EC test positions. During these positions, the electromyographic signal was recorded simultaneously from the four shoulder muscles using a combination of surface and intramuscular fine-wire electrodes. The average activation of the supraspinatus and subscapularis was greater during the EC test than during the FC test and in the scapular and coronal planes than in the sagittal plane at 90°. For the infraspinatus, there were no significant differences in any positions between the two tests. Thus, the rotator cuff muscles are influenced by arm position and the elevation plane during the EC and FC tests.
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Kaegi, Sibille; Schwab, Martin E; Dietz, Volker; Fouad, Karim
2002-07-01
This investigation was designed to study the spontaneous functional recovery of adult rats with incomplete spinal cord injury (SCI) at thoracic level during a time course of 2 weeks. Daily testing sessions included open field locomotor examination and electromyographic (EMG) recordings from a knee extensor (vastus lateralis, VL) and an ankle flexor muscle (tibialis anterior, TA) in the hindlimbs of treadmill walking rats. The BBB score (a locomotor score named after Basso et al., 1995, J. Neurotrauma, 12, 1-21) and various measures from EMG recordings were analysed (i.e. step cycle duration, rhythmicity of limb movements, flexor and extensor burst duration, EMG amplitude, root-mean-square, activity overlap between flexor and extensor muscles and hindlimb coupling). Directly after SCI, a marked drop in locomotor ability occurred in all rats with subsequent partial recovery over 14 days. The recovery was most pronounced during the first week. Significant changes were noted in the recovery of almost all analysed EMG measures. Within the 14 days of recovery, many of these measures approached control levels. Persistent abnormalities included a prolonged flexor burst and increased activity overlap between flexor and extensor muscles. Activity overlap between flexor and extensor muscles might be directly caused by altered descending input or by maladaptation of central pattern generating networks and/or sensory feedback.
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Directory of Open Access Journals (Sweden)
Ossowski Zbigniew
2016-06-01
Full Text Available Introduction. Osteoporosis and osteopenia are related to changes in the quantity and quality of skeletal muscle and contribute to a decreased level of muscle strength. The purpose of this study was to evaluate the impact of Nordic walking training on muscle strength and the electromyographic (EMG activity of the lower body in women with low bone mass. Material and methods. The participants of the study were 27 women with low bone mass. The sample was randomly divided into two groups: a control group and an experimental group. Women from the experimental group participated in 12 weeks of regular Nordic walking training. Functional strength was assessed with a 30-second chair stand test. The EMG activities of the gluteus maximus (GMax, rectus femoris (RF, biceps femoris (BF, soleus (SOL, and lumbar (LB muscles were measured using a surface electromyogram. Results. Nordic walking training induced a significant increase in the functional strength (p = 0.006 of the lower body and activity of GMax (p = 0.013 and a decrease in body mass (p = 0.006 in women with reduced bone mass. There was no statistically significant increase in the EMG activities of the RF, BF, SOL, or LB muscles. The study did not indicate any significant changes in functional muscle strength, the EMG activity of the lower body, or anthropometry in women from the control group. Conclusions. Nordic walking training induces positive changes in lower body strength and the electromyographic activity of the gluteus maximus as well as a decrease in body mass in women with low bone mass.
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DEFF Research Database (Denmark)
Henriksen, Marius; Alkjaer, T; Simonsen, Erik Bruun
2009-01-01
. Isotonic saline (0.9%) was used as control. MAIN OUTCOME MEASUREMENTS: Three-dimensional movement analyses were performed and inverse dynamics were used to calculate joint kinematics and kinetics for ankle, knee and hip joints. Electromyographic (EMG) signals of the hamstrings and quadriceps muscles were...
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Muscle force output and electromyographic activity in squats with various unstable surfaces.
Saeterbakken, Atle H; Fimland, Marius S
2013-01-01
The purpose of the study was to compare force output and muscle activity of leg and trunk muscles in isometric squats executed on stable surface (i.e., floor), power board, BOSU ball, and balance cone. Fifteen healthy men (23.3 ± 2.7 years, mass: 80.5 ± 8.5 kg, height: 1.81 ± 0.09 m) volunteered. The force output and electromyographic (EMG) activities of the rectus femoris, vastus medialis, vastus lateralis, biceps femoris, soleus, rectus abdominis, oblique external, and erector spinae were assessed. The order of the surfaces was randomized. One familiarization session was executed before the experimental test. Compared with stable surface (749 ± 222 N), the force output using power board was similar (-7%, p = 0.320) but lower for BOSU ball (-19%, p = 0.003) and balance cone (-24%, p ≤ 0.001). The force output using BOSU ball and balance cone was approximately 13% (p = 0.037) and approximately 18% (p = 0.001) less than the power board. There were similar EMG activities between the surfaces in all muscles except for rectus femoris, in which stable squat provided greater EMG activity than did the other exercises (p = 0.004-0.030). Lower EMG activity was observed in the rectus femoris using balance cone compared with the BOSU ball (p = 0.030). In conclusion, increasing the instability of the surface during maximum effort isometric squats usually maintains the muscle activity of lower-limb and superficial trunk muscles although the force output is reduced. This suggests that unstable surfaces in the squat may be beneficial in rehabilitation and as a part of periodized training programs, because similar muscle activity can be achieved with reduced loads.
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Ascher, B; Hoffmann, K; Walker, P; Lippert, S; Wollina, U; Havlickova, B
2014-12-01
Unwanted submental fat (SMF) may result in an unattractive chin profile and dissatisfaction with appearance. An approved and rigorously tested non-surgical method for SMF reduction is lacking. To evaluate the efficacy and safety of ATX-101 for the pharmacological reduction of unwanted SMF in a phase III randomized, double-blind, placebo-controlled study. Patients (n = 360) with moderate or severe SMF were randomized to receive ATX-101 1 or 2 mg/cm(2) or placebo injected into their SMF for up to four treatments ~28 days apart, with a 12-week follow-up. Coprimary efficacy endpoints were the proportions of treatment responders, defined as a ≥1-point reduction in SMF on the Clinician-Reported Submental Fat Rating Scale (CR-SMFRS), and those satisfied with their appearance in association with their face and chin after treatment on the Subject Self-Rating Scale (SSRS score ≥4). Secondary efficacy endpoints included a ≥1-point improvement in SMF on the Patient-Reported Submental Fat Rating Scale (PR-SMFRS) and changes in the Patient-Reported Submental Fat Impact Scale (PR-SMFIS). Additional patient-reported outcomes and changes in the Skin Laxity Rating Scale were recorded. Adverse events (AEs) and laboratory test results were monitored. Compared with placebo, a greater proportion of patients treated with ATX-101 1 and 2 mg/cm(2) showed a ≥1-point improvement in CR-SMFRS (58.3% and 62.3%, respectively, vs. 34.5% with placebo; P < 0.001) and patient satisfaction (SSRS score ≥4) with the appearance of their face and chin (68.3% and 64.8%, respectively, vs. 29.3%; P < 0.001). Patient-reported secondary efficacy endpoints showed significant improvements in SMF severity (PR-SMFRS; P = 0.009 for ATX-101 1 mg/cm(2) , P < 0.001 for ATX-101 2 mg/cm(2) vs. placebo) and emotions and perceived self-image (PR-SMFIS; P < 0.001). No overall worsening of skin laxity was observed. AEs were mostly transient, mild to moderate in intensity and localized to the treatment area. ATX
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Nairn, Brian C; Sutherland, Chad A; Drake, Janessa D M
2015-11-01
Instability training devices with the bench press exercise are becoming increasingly popular. Typically, the instability device is placed at the trunk/upper body (e.g., lying on a Swiss ball); however, a recent product called the Attitube has been developed, which places the location of instability at the hands by users lifting a water-filled tube. Therefore, the purpose of this study was to analyze the effects of different instability devices (location of instability) on kinematic and electromyographical patterns during the bench press exercise. Ten healthy males were recruited and performed 1 set of 3 repetitions for 3 different bench press conditions: Olympic bar on a stable bench (BENCH), Olympic bar on a stability ball (BALL), and Attitube on a stable bench (TUBE). The eccentric and concentric phases were analyzed in 10% intervals while electromyography was recorded from 24 electrode sites, and motion capture was used to track elbow flexion angle and 3-dimensional movement trajectories and vertical velocity of the Bar/Attitube. The prime movers tended to show a reduction in muscle activity during the TUBE trials; however, pectoralis major initially showed increased activation during the eccentric phase of the TUBE condition. The trunk muscle activations were greatest during the TUBE and smallest during the BAR. In addition, the TUBE showed decreased range of elbow flexion and increased medial-lateral movement of the Attitube itself. The results further support the notion that instability devices may be more beneficial for trunk muscles rather than prime movers.
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Directory of Open Access Journals (Sweden)
Michele Caroline dos Santos
2017-08-01
Full Text Available Abstract Introduction Military police activity individuals performing operational activity remain 12 hours using mandatory safety equipment. This work aimed to verify the electromyographic response in operational military police officers before and after a cycle of two working days. Methods Forty-four male individuals were evaluated, with an average age of 34.59 ± 8.05. The used protocol consisted in the evaluation of paravertebral muscles and rectus abdominis muscles in a maximum isometric voluntary contraction test (MVC during trunk extension movements, starting from the sitting position. Moreover, the Roland-Morris functional evaluation questionnaire and the Corlett and Manenica diagram for painful areas were used. An electromyograph with 16 pre-set channels was used. Signals were processed in time (EMGME and spectral (EMGMF domains, using the MatLab® program. The Shapiro-Wilk test and Wilcoxon Signed Ranks Test were applied. Statistical analyses were performed through the SPSS v21.0 software and Microsoft Office Excel 2010, considering p < 0.05 as significance level. Results Results showed statistical differences in the post-working day for time analysis, an EMGME decrease in the right rectus abdominis muscle (p = 0.016 and in the age-stratified sample, with individuals over 31 years old (p = 0.016; in the spectral analysis, EMGMF reduction in the right iliocostalis (p = 0.027 and right and left side in the stratified sample, in individuals over 31 years old and with more than 10 years of service. Conclusion The used protocol highlighted a decrease in the amplitude of the electromyographic signal, as well as possible muscle fatigue on the right side where officers usually carry their weapons.
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Directory of Open Access Journals (Sweden)
Jamilson Simões Brasileiro
2008-04-01
Full Text Available The Patellofemoral pain syndrome (PFPS is described as an anterior or retropatellar knee pain in the absence of other associated diseases, and has often been associated with dysfunction of the vastus medialis oblique muscle (VMO. However, several studies have demonstrated the impossibility of selectively activating this muscle with exercises. The aim of the present study was to analyze the immediate effect of neuromuscular electrical stimulation of VMO muscle by means of monitoring the electromyographic activity of the vastus medialis oblique (VMO and vastus lateralis (VL muscles. Eighteen healthy women with a mean age of 23.2 years and mean BMI of 20 Kg/m2 were evaluated. The study protocol included electromyographic analysis of VMO and VL muscles, before and immediately after neuromuscular electrical stimulation of the VMO muscle. During the electromyographic analysis, the volunteers performed maximal voluntary isometric contraction in a 60° knee extension on an isokinetic dynamometer. “Russian current” apparatus was used for electrical stimulation. Results: The data analysis demonstrated a signifi cant increase in VMO activation intensity immediately after it had been electrically stimulated (p=0.0125, whereas VL activation intensity exhibited no signifi cant increase (p=0.924. Moreover, a significant increase in the VMO/VL ratio was also detected (p=0.048. In this study it was observed that electrical stimulation modifiedthe VMO/VL ratio, which suggests electrical stimulation has a benefi cial effect on VMO muscle strength. Resumo A Síndrome da dor patelofemoral (SDPF é descrita como dor anterior ou retro-patelar do joelho na ausência de outras patologias associadas, sendo freqüentemente associada à disfunção do Vasto Medial Oblíquo (VMO. Entretanto, diversos estudos têm demonstrado a impossibilidade de ativar seletivamente este músculo através de exercícios. O objetivo do presente estudo foi analisar o efeito imediato da
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Wang, Mei-Qing; He, Jian-Jun; Wang, Kelun; Svensson, Peter
2009-01-01
To test whether changes in occlusal support differentially modulate masseter and anterior temporalis muscle electromyographic (EMG) activity during controlled maximal voluntary clenching. Forty-seven healthy subjects (32 M and 15 F, 22.9+/-1.3 years) were recruited. Cotton-rolls were used to modify the occlusal contact relations and were positioned on the right, left, or both sides, and either in the molar or premolar regions, i.e. six different occlusal combinations. Surface EMG activity was recorded bilaterally from the masseter and anterior temporalis area and normalized with respect to maximal voluntary clenching in the intercuspal position. Analysis of variance and the paired t-test were used to test the data. Normalized EMG activity was influenced by changes in cotton-roll modified occlusal support, and there were differences between muscles (pocclusal support was moved from the molar to the premolar region. When occlusal support was moved from bilateral to unilateral contacts, EMG activity in the balancing-side anterior temporalis muscle and in bilateral masseter muscles decreased. Unilateral clenching on the molars, but not on the premolars, was associated with lower EMG activity in the balancing-side masseter and always associated with lower EMG activity in the balancing-side anterior temporalis compared to the working side (pocclusal support, which may have implications for stability of the mandible during intense clenching.
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Zhu, Yong; Hollis, James H
2015-01-01
To characterize changes in chewing behaviors associated with healthy aging, 10 young and 10 older fully dentate healthy participants were enrolled in this study. They chewed carrot samples that differed in hardness until their normal swallowing threshold. Their chewing behaviors were assessed using an electromyographic recording device. Adjusting for gender and body mass index, older adults had a higher number of chewing cycles (p = 0.020), a longer chewing duration (p chewing rate (p = 0.002), a greater maximal electromyographic voltage (p = 0.003) and a greater muscle activity (p = 0.002) before they could comfortably swallow the food bolus. A statistically significant main effect of food hardness on the number of chewing cycles, chewing duration, chewing rate and muscle activity was also observed (p < 0.001 for all). These results suggest that reduced mastication efficiency is associated with healthy aging in fully dentate adults. This ingestive behavior may contribute to aging-related reduction in appetite in older adults.
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Ertl, Peter; Kruse, Annika; Tilp, Markus
2016-10-01
The aim of the current paper was to systematically review the relevant existing electromyographic threshold concepts within the literature. The electronic databases MEDLINE and SCOPUS were screened for papers published between January 1980 and April 2015 including the keywords: neuromuscular fatigue threshold, anaerobic threshold, electromyographic threshold, muscular fatigue, aerobic-anaerobictransition, ventilatory threshold, exercise testing, and cycle-ergometer. 32 articles were assessed with regard to their electromyographic methodologies, description of results, statistical analysis and test protocols. Only one article was of very good quality. 21 were of good quality and two articles were of very low quality. The review process revealed that: (i) there is consistent evidence of one or two non-linear increases of EMG that might reflect the additional recruitment of motor units (MU) or different fiber types during fatiguing cycle ergometer exercise, (ii) most studies reported no statistically significant difference between electromyographic and metabolic thresholds, (iii) one minute protocols with increments between 10 and 25W appear most appropriate to detect muscular threshold, (iv) threshold detection from the vastus medialis, vastus lateralis, and rectus femoris is recommended, and (v) there is a great variety in study protocols, measurement techniques, and data processing. Therefore, we recommend further research and standardization in the detection of EMGTs. Copyright © 2016 Elsevier Ltd. All rights reserved.
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Directory of Open Access Journals (Sweden)
Hodgson David
2008-01-01
Full Text Available Abstract Background It has been proposed that high-heeled shoes may contribute to the development and progression of knee pain. However, surprisingly little research has been carried out on how shoe heel height affects muscle activity around the knee joint. The purpose of this study was to investigate the effect of differing heel height on the electromyographic (EMG activity in vastus medialis (VM and vastus lateralis (VL during a sit to stand activity. This was an exploratory study to inform future research. Methods A repeated measures design was used. Twenty five healthy females carried out a standardised sit to stand activity under 4 conditions; barefoot, and with heel wedges of 1, 3, and 5 cm in height. EMG activity was recorded from VM and VL during the activity. Data were analysed using 1 × 4 repeated measures ANOVA. Results Average rectified EMG activity differed with heel height in both VM (F2.2, 51.7 = 5.24, p 3, 72 = 5.32, p 3, 72 = 0.61, p = 0.609. Conclusion We found that as heel height increased, there was an increase in EMG activity in both VM and VL, but no change in the relative EMG intensity of VM and VL as measured by the VM: VL ratio. This showed that no VM: VL imbalance was elicited. This study provides information that will inform future research on how heel height affects muscle activity around the knee joint.
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Electromyographic investigation of unstable patella before and after its realignment operation
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D D Baksi
2011-01-01
Full Text Available Background: Patellar dislocations are either due to superolateral contracture of the soft tissue or imbalance of the power between the vastus medialis (VM and the vastus lateralis (VL. The imbalance of muscle power as an etiology of patellar dislocation has not been studied. Hence, we studied the recurrent, habitual and permanent dislocations of the patella with an electromyogram (EMG of the vastus medialis, vastus lateralis, and pes anserinus, before and after realignment operations, to document the muscle imbalance and effectiveness of the realignment operation. Materials and Methods: An electromyographic investigation was carried out on the vastus medialis and vastus lateralis in nine recurrent, 20 habitual, and 13 permanent dislocations of the patella, before and after their realignment operations. Pes anserinus transposition, which acted as a medial stabilizer of the patella, was also investigated with an EMG study, to understand its role on patellar stability at 0, 30, 60, 90, 120, 150, and full flexion of the knee. The age of the patients varied from nine to 30 (mean 15 years. There were 24 males and 18 females. Twenty-six patellar dislocations were on the right and 16 were on the left side. Results: Electromyographic pictures reveal subnormal activity of the vastus medialis in all types of dislocations and similar activities of the vastus lateralis in permanent and habitual dislocations recorded pre operatively, which recovered to almost normal values postoperatively, at the mean one-year follow-up. Pes anserinus, which was used for medial stabilization of the patella after its realignment, maintained normal EMG activity before and after the operation. Conclusion: This study is significant for understanding the imbalance of muscle activities in patients with an unstable patella, which can be rectified without recurrence after pes anserinus transposition.
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Xu, L; Fan, S; Cai, B; Fang, Z; Jiang, X
2017-05-01
This study aimed to investigate whether the fatigue induced by sustained motor task in the jaw elevator muscles differed between healthy subjects and patients with temporomandibular disorder (TMD). Fifteen patients with TMD and thirteen age- and sex-matched healthy controls performed a fatigue test consisting of sustained clenching contractions at 30% maximal voluntary clenching intensity until test failure (the criterion for terminating the fatigue test was when the biting force decreased by 10% or more from the target force consecutively for >3 s). The pre- and post-maximal bite forces (MBFs) were measured. Surface electromyographic signals were recorded from the superficial masseter muscles and anterior temporal muscles bilaterally, and the median frequency at the beginning, middle and end of the fatigue test was calculated. The duration of the fatigue test was also quantified. Both pre- and post-MBFs were lower in patients with TMD than in controls (P fatigue test in TMD patients was significantly shorter than that of the controls (P fatigued, but the electromyographic activation process during the fatigue test is similar between healthy subjects and patients with TMD. However, the mechanisms involved in this process remain unclear, and further research is warranted. © 2017 John Wiley & Sons Ltd.
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Silvestre, Rony; Fuentes, Jorge; da Costa, Bruno R.; Gadotti, Inae C.; Warren, Sharon; Major, Paul W.; Thie, Norman M.R.; Magee, David J.
2011-01-01
Background Most patients with temporomandibular disorders (TMD) have been shown to have cervical spine dysfunction. However, this cervical dysfunction has been evaluated only qualitatively through a general clinical examination of the cervical spine. Purpose The purpose of this study was to determine whether patients with TMD had increased activity of the superficial cervical muscles when performing the craniocervical flexion test (CCFT) compared with a control group of individuals who were healthy. Design A cross-sectional study was conducted. Methods One hundred fifty individuals participated in this study: 47 were healthy, 54 had myogenous TMD, and 49 had mixed TMD. All participants performed the CCFT. Data for electromyographic activity of the sternocleidomastoid (SCM) and anterior scalene (AS) muscles were collected during the CCFT for all participants. A 3-way mixed-design analysis of variance for repeated measures was used to evaluate the differences in EMG activity for selected muscles while performing the CCFT under 5 incremental levels. Effect size values were calculated to evaluate the clinical relevance of the results. Results Although there were no statistically significant differences in electromyographic activity in the SCM or AS muscles during the CCFT in patients with mixed and myogenous TMD compared with the control group, those with TMD tended to have increased activity of the superficial cervical muscles. Limitations The results obtained in this research are applicable for the group of individuals who participated in this study under the protocols used. They could potentially be applied to people with TMD having characteristics similar to those of the participants of this study. Conclusion This information may give clinicians insight into the importance of evaluation and possible treatment of the deep neck flexors in patients with TMD. However, future research should test the effectiveness of this type of program through a randomized controlled
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Deschamps, P. K. H.; Coppes, L.; Kenemans, J. L.; Schutter, D. J. L. G.; Matthys, W.
2015-01-01
This study aimed to examine facial mimicry in 6-7 year old children with autism spectrum disorder (ASD) and to explore whether facial mimicry was related to the severity of impairment in social responsiveness. Facial electromyographic activity in response to angry, fearful, sad and happy facial expressions was recorded in twenty 6-7 year old…
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Hill, Aron T; Briggs, Belinda A; Seneviratne, Udaya
2014-06-01
To investigate the usefulness of adjunctive electromyographic (EMG) polygraphy in the diagnosis of clinical events captured during long-term video-EEG monitoring. A total of 40 patients (21 women, 19 men) aged between 19 and 72 years (mean 43) investigated using video-EEG monitoring were studied. Electromyographic activity was simultaneously recorded with EEG in four patients selected on clinical grounds. In these patients, surface EMG electrodes were placed over muscles suspected to be activated during a typical clinical event. Of the 40 patients investigated, 24 (60%) were given a diagnosis, whereas 16 (40%) remained undiagnosed. All four patients receiving adjunctive EMG polygraphy obtained a diagnosis, with three of these diagnoses being exclusively reliant on the EMG recordings. Specifically, one patient was diagnosed with propriospinal myoclonus, another patient was diagnosed with facio-mandibular myoclonus, and a third patient was found to have bruxism and periodic leg movements of sleep. The information obtained from surface EMG recordings aided the diagnosis of clinical events captured during video-EEG monitoring in 7.5% of the total cohort. This study suggests that EEG-EMG polygraphy may be used as a technique of improving the diagnostic yield of video-EEG monitoring in selected cases.
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Directory of Open Access Journals (Sweden)
O. G. Oseni
2015-01-01
Full Text Available Lip reconstruction following resection for tumour or following extensive trauma may pose a challenge. This is more so when the resection is total and a complete lip has to be constructed. We present a case of lip reconstruction following a total resection of the upper lip. The procedure used in this case was a combination of bilateral nasolabial flaps with a submental flap and buccal mucosal graft lining. We believe that this provides an alternative method of total upper lip reconstruction with minimal disruption of the facial aesthesis.
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Ferrario, V F; Sforza, C; Serrao, G; Colombo, A; Schmitz, J H
1999-07-01
In 13 healthy subjects (eight men and five women, mean age, 22 years), an aluminum intercuspal interference (height, 0.25 mm) was placed on the maxillary right first premolar to study its effect on the contractile symmetry of the right and left masseter and anterior temporalis muscles when measured through a Percentage Overlapping Coefficient (POC), derived from surface electromyographic recordings of maximum voluntary teeth clenching. Additionally, and to estimate the potential of the experimental intercuspal interference to induce lateral displacement of the mandible, a Torque Coefficient (TC) was derived from surface electromyographic recordings. The conclusion was that the experimental occlusal interference gave rise to asymmetric contractile activity in the studied mandibular elevator muscles as well as a potential to displace the mandible in a lateral direction.
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Processing Electromyographic Signals to Recognize Words
Jorgensen, C. C.; Lee, D. D.
2009-01-01
A recently invented speech-recognition method applies to words that are articulated by means of the tongue and throat muscles but are otherwise not voiced or, at most, are spoken sotto voce. This method could satisfy a need for speech recognition under circumstances in which normal audible speech is difficult, poses a hazard, is disturbing to listeners, or compromises privacy. The method could also be used to augment traditional speech recognition by providing an additional source of information about articulator activity. The method can be characterized as intermediate between (1) conventional speech recognition through processing of voice sounds and (2) a method, not yet developed, of processing electroencephalographic signals to extract unspoken words directly from thoughts. This method involves computational processing of digitized electromyographic (EMG) signals from muscle innervation acquired by surface electrodes under a subject's chin near the tongue and on the side of the subject s throat near the larynx. After preprocessing, digitization, and feature extraction, EMG signals are processed by a neural-network pattern classifier, implemented in software, that performs the bulk of the recognition task as described.
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Dmytrenko, Maryna I; Kuroiedowa, Vira D
2016-01-01
electromyographic indices were developed for complex analysis of functional condition of orbicularis oris. to study electromyographic indices of orbicularis oris in patients with dental crowding in permanent occlusion. thirty four patients with malocclusion and a severe degree of severity of dental crowding (15 males, 19 females, aged 16-29 years) who underwent orthodontic examination. The treatment group was divided into three: Group Ia comprised 11 subjects with mandibular crowding (mean age 19,27 ± 1,08 years); group Ib, 10 patients with maxillary dental crowding (mean age 20,10 ± 1,60 years) and group Ic, 13 subjects with both maxillary and mandibular crowding (mean age 20,15 ± 1,45 years). The control group consisted of 10 patients with malocclusions but without dental crowding (mean age 20,70 ± 1,32 years). The findings were compared with similar indices in subjects with normal occlusion (mean age 21,3 ± 1,25 years). The index of orbicularis oris activity (ACTIV,%) was determined for each patient. A Student's t-test was used to analyze statistical difference between different groups. patients having crowding of maxillary teeth showed greater activity of muscles of the upper lip during maximum voluntary clenching (АCTІV= -0,99±7,44%). Activity of the muscles of the lower lip in patients with crowding of mandibular teeth (АСTІV=20,52±4,22%) and crowding of maxillary and mandibular teeth (АСTІV=17,93±4,33%) is prevailing. аctivity of the orbicularis oris in patients with malocclusion, complicated by dental crowding depend on clinical localization of crowding.
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Evoked Electromyographically Controlled Electrical Stimulation
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Mitsuhiro Hayashibe
2016-07-01
Full Text Available Time-variant muscle responses under electrical stimulation (ES are often problematic for all the applications of neuroprosthetic muscle control. This situation limits the range of ES usage in relevant areas, mainly due to muscle fatigue and also to changes in stimulation electrode contact conditions, especially in transcutaneous ES. Surface electrodes are still the most widely used in noninvasive applications.Electrical field variations caused by changes in the stimulation contact condition markedly affect the resulting total muscle activation levels. Fatigue phenomena under functional electrical stimulation (FES are also well known source of time-varying characteristics coming from muscle response under ES. Therefore it is essential to monitor the actual muscle state and assess the expected muscle response by ES so as to improve the current ES system in favour of adaptive muscle-response-aware FES control. To deal with this issue, we have been studying a novel control technique using evoked electromyography (eEMG signals to compensate for these muscle time-variances under ES for stable neuroprosthetic muscle control. In this perspective article, I overview the background of this topic and highlight important points to be aware of when using ES to induce the desired muscle activation regardless of the time-variance. I also demonstrate how to deal with the common critical problem of ES to move toward robust neuroprosthetic muscle control with the Evoked Electromyographically Controlled Electrical Stimulation paradigm.
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Park, Kyue-nam; Kwon, Oh-yun; Ha, Sung-min; Kim, Su-jung; Choi, Hyun-jung; Weon, Jong-hyuck
2012-12-01
Neck pain is common in violin students during a musical performance. The purpose of this study was to compare electromyographic (EMG) activity in superficial neck muscles with neck motion when playing the violin as well as neck range of motion (ROM) at rest, between violin students with and without neck pain. Nine violin students with neck pain and nine age- and gender-matched subjects without neck pain were recruited. Muscle activity of the bilateral upper trapezius, sternocleidomastoid, and superficial cervical extensor muscles was measured using surface EMG. Kinematic data on neck motion while playing and active neck ROM were also measured using a three-dimensional motion analysis system. Independent t-tests were used to compare EMG activity with kinematic data between groups. These analyses revealed that while playing, both the angle of left lateral bending and leftward rotation of the cervical spine were significantly greater in the neck pain group than among those without neck pain. Similarly, EMG activity of the left upper trapezius, both cervical extensors, and both sternocleidomastoid muscles were significantly greater in the neck pain group. The active ROM of left axial rotation was significantly lower in the neck pain group. These results suggest that an asymmetric playing posture and the associated increased muscle activity as well as decreased neck axial rotation may contribute to neck pain in violin students.
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Lauer, Susanne K; Hillman, Robert B; Li, Li; Hosgood, Giselle L
2009-05-01
To evaluate the effect of treadmill incline on muscle activity and joint range of motion (ROM) in hind limbs of dogs. 8 purpose-bred healthy adult hounds. Activities of the hamstring (semimembranosus, semitendinosus, and biceps femoris muscles), gluteal (superficial, middle, and deep gluteal muscles), and quadriceps (femoris, vastus lateralis, vastus intermedius, and vastus medialis muscles) muscle groups and hip and stifle joint ROM were measured with surface electrogoniometric and myographic sensors in hounds walking on a treadmill at 0.54 m/s at inclines of 5%, 0%, and -5% in random order. Mean electromyographic activities and mean ROMs at each inclination were compared for swing and stance phases. Treadmill inclination did not affect duration of the stance and swing phases or the whole stride. When treadmill inclination was increased from -5% to 5%, hip joint ROM increased and the degree of stifle joint extension decreased significantly. In the beginning of the stance phase, activity of the hamstring muscle group was significantly increased when walking at a 5% incline versus a 5% decline. In the end of the stance phase, that activity was significantly increased when walking at a 5% incline versus at a 5% decline or on a flat surface. Activity of the gluteal and quadriceps muscle groups was not affected when treadmill inclination changed. Treadmill inclination affected joint kinematics only slightly. Walking on a treadmill at a 5% incline had more potential to strengthen the hamstring muscle group than walking on a treadmill with a flat or declined surface.
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Lee, Jeong J; You, Joshua Sung H
2017-12-01
To compare the immediate effects of conventional treadmill gait and guidance tubing gait (GTG) on electromyographic neuromuscular imbalance and knee joint kinematics in hemiparetic gait. Case-control study. University medical center. Participants (N=33; 19 men, 14 women) were patients with hemiparetic stroke (n=18 [experimental]; mean age ± SD, 39.2±16.8y) and healthy controls (n=15; mean age ± SD, 26.3±2.6y). The GTG was provided for approximately 30 minutes and involved application of an assistive guidance force using the tubing, specifically to improve knee joint stabilization during midstance and increase knee joint flexion during midswing phase. Clinical tests included the Korean Mini-Mental State Examination, Modified Ashworth Scale, Berg Balance Scale, manual muscle test, and knee joint range of motion and sensory tests. Knee joint muscle electromyographic and kinematic analyses were determined at pretest and posttest. After the intervention, the experimental group showed significantly greater improvements in balanced quadriceps and hamstring electromyographic coactivation and knee joint kinematics relative to the control group (P=.005). The GTG intervention decreased overactive hamstring activity (P=.018) and reciprocally increased quadriceps activity (Pjoint kinematic analysis showed significant changes in the hemiparetic stroke group (P=.004). This study demonstrates the effectiveness of the tubing gait condition to restore knee joint muscle imbalance and kinematics in individuals with hemiparetic stroke who present with an abnormal hyperextension knee gait. Copyright © 2016 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.
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Fuentes, Aler D; Sforza, Chiarella; Miralles, Rodolfo; Ferreira, Cláudia L; Mapelli, Andrea; Lodetti, Gianluigi; Martin, Conchita
2017-05-01
The aim of this study was to investigate whether the presence of a natural mediotrusive contact influences electromyographic (EMG) pattern activity in patients with temporomandibular disorders (TMDs). Bilateral surface EMG activity of the anterior temporalis (AT), masseter (MM), and sternocleidomastoid (SCM) muscles was recorded in 43 subjects during unilateral chewing and tooth grinding. Thirteen patients had TMD and a natural mediotrusive contact (Group 1), 15 had TMD without a natural mediotrusive contact (Group 2), and 15 were healthy subjects without mediotrusive contacts (Group 3). All subjects were examined according to the Research Diagnostic Criteria for TMD (RDC/TMD). All EMG values were standardized as the percentage of EMG activity recorded during maximum isometric contraction on cotton rolls. EMG activity from all muscles measured showed no significant differences between groups during chewing and grinding. Overall, in all groups, the EMG activity during chewing was higher in the working side than the non-working side in AT and MM muscles. During grinding, these differences were only found in masseter muscles (mainly in eccentric grinding). SCM EMG activity did not show significant differences during chewing and grinding tasks. Symmetry, muscular balance, and absence of lateral jaw displacement were common findings in all groups. EMG results suggest that the contribution of a natural mediotrusive occlusal contact to EMG patterns in TMD patients is minor. Therefore, the elimination of this occlusal feature for therapeutic purposes could be not indicated.
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Spaulding, S J; Robinson, K L
1984-04-01
Electromyographic information was obtained from seven right shoulder complex muscles in nine subjects (three normal, three paraplegic, and three quadriplegic) during the occupational therapy activity of bilateral sanding on an incline board, an activity that has been recommended as a treatment modality to strengthen the triceps brachii. Electromyography revealed that the anterior and middle portions of the deltoid were the muscles most responsible for the subjects' arm movements during both resisted and unresisted bilateral sanding . Triceps lateralis and medialis were also active during the up phase, but not as consistently as the deltoid. Pectoralis major and biceps brachii were not extensively active in most subjects. The small size and heterogeneity of the subject sample limits the generalizations of our findings. However, graded resisted bilateral sanding does appear to be an appropriate activity for strengthening the shoulder muscle group, especially the deltoid and triceps brachii, in the tested patient populations.
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Gomes, Cid André Fidelis de Paula; El Hage, Yasmin; Amaral, Ana Paula; Politti, Fabiano; Biasotto-Gonzalez, Daniela Aparecida
2014-01-01
Temporomandibular disorder (TDM) is the most common source of orofacial pain of a non-dental origin. Sleep bruxism is characterized by clenching and/or grinding the teeth during sleep and is involved in the perpetuation of TMD. The aim of the present study was to investigate the effects of massage therapy, conventional occlusal splint therapy and silicone occlusal splint therapy on electromyographic activity in the masseter and anterior temporal muscles and the intensity of signs and symptoms in individuals with severe TMD and sleep bruxism. Sixty individuals with severe TMD and sleep bruxism were randomly distributed into four treatment groups: 1) massage group, 2) conventional occlusal splint group, 3) massage + conventional occlusal splint group and 4) silicone occlusal splint group. Block randomization was employed and sealed opaque envelopes were used to conceal the allocation. Groups 2, 3 and 4 wore an occlusal splint for four weeks. Groups 1 and 3 received three weekly massage sessions for four weeks. All groups were evaluated before and after treatment through electromyographic analysis of the masseter and anterior temporal muscles and the Fonseca Patient History Index. The Wilcoxon test was used to compare the effects of the different treatments and repeated-measures ANOVA was used to determine the intensity of TMD. The inter-group analysis of variance revealed no statistically significant differences in median frequency among the groups prior to treatment. In the intra-group analysis, no statistically significant differences were found between pre-treatment and post-treatment evaluations in any of the groups. Group 3 demonstrated a greater improvement in the intensity of TMD in comparison to the other groups. Massage therapy and the use of an occlusal splint had no significant influence on electromyographic activity of the masseter or anterior temporal muscles. However, the combination of therapies led to a reduction in the intensity of signs and
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Beckmann, Yesim; Gürgör, Nevin; Çakır, Ahmet; Arıcı, Şehnaz; İncesu, Tülay Kurt; Seçil, Yaprak; Ertekin, Cumhur
2015-06-01
Swallowing mechanism and neurogenic dysphagia in MS have been rarely studied by electromyographical (EMG) methods. This study aims to evaluate the presence of subclinical dysphagia in patients with mild multiple sclerosis (MS) using electrophysiological methods. A prospective study of 51 patients with relapsing remitting multiple sclerosis and 18 age-matched healthy adults was investigated. We used electromyography to measure the activity of the submental muscles during swallowing. Electrophysiological recordings of patients were obtained during relapse, after relapse, and at any time in remission period. Clinical dysphagia was found in 12% of MS patients, while electrophysiological swallowing abnormalities were encountered in 33% of patients. Subclinical dysphagia was determined in 35% of patients during an MS relapse, in 20% of patients after a relapse, and in 25% of all 51 patients in the remission period based on EMG findings. Duration of swallowing signal of submental muscles in all MS patients was found to be longer than in normal subjects (p = 0.001). During swallowing of 50 ml of sequential water, the compensatory respiratory cycles occurred more often in MS patients than normal subjects, especially during a relapse (p = 0.005). This is the first study investigating swallowing abnormalities and subclinical dysphagia from the electrophysiological aspect in MS patients with mild disability. The electrophysiological tests described in this study are useful to uncover subclinical dysphagia since they have the advantage of being rapid, easy to apply, non-invasive, and without risk for the patients.
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Potter, P J; Kirby, R L
1991-12-01
The effect of simulated bilateral knee-flexion contractures (KFC) on the electromyographic (EMG) activity of the vastus lateralis was studied by testing 10 normal subjects using surface EMG to test the hypothesis that the activity of the knee extensors would increase as a function of the severity of the contracture. The root mean square of the EMG activity was determined from four 4-s samples taken at 30-s intervals, during 2 min of standing in each of five positions of simulated KFC (0 degree, 10 degrees, 20 degrees, 30 degrees and 40 degrees). A randomly balanced order of conditions was used. KFC were simulated in each subject by means of an adjustable line from the subject's waist to the sole of each foot. An analysis of variance was used to contrast EMG activity, and a significant difference was found between each of the positions (P less than 0.05). The mean (+/- 1 SD) EMG activity, expressed as a percentage of the maximum voluntary contraction, was 0.3% (+/- 0.2) at 0 degree, 7.6% (+/- 5.6) at 10 degrees, 10.9% (+/- 7.6) at 20 degrees, 16.6% (+/- 12.4) at 30 degrees and 24.0% (+/- 14.0) at 40 degrees. A linear relationship was found (r2 = 0.986), expressed by the equation y = 0.62 + 0.56 x, where y represents EMG activity and x represents the extent of simulated KFC (P = 0.0007). The results provide insight into the increased knee extensor activity necessary to stand with KFC and underline the importance of treating this common disorder.
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Rzany, B; Griffiths, T; Walker, P; Lippert, S; McDiarmid, J; Havlickova, B
2014-01-01
Summary Background Unwanted submental fat (SMF) is aesthetically unappealing, but methods of reduction are either invasive or lack evidence for their use. An injectable approach with ATX-101 (deoxycholic acid) is under investigation. Objectives To evaluate the efficacy and safety of ATX-101 for the reduction of unwanted SMF. Methods In this double-blind, placebo-controlled, phase III study, 363 patients with moderate/severe SMF were randomized to receive ATX-101 (1 or 2 mg cm−2) or placebo injections into their SMF at up to four treatment sessions ∽28 days apart, with a 12-week follow-up. The co-primary efficacy endpoints were the proportions of treatment responders [patients with ≥ 1-point improvement in SMF on the 5-point Clinician-Reported Submental Fat Rating Scale (CR-SMFRS)] and patients satisfied with their face and chin appearance on the Subject Self-Rating Scale (SSRS). Secondary endpoints included skin laxity, calliper measurements and patient-reported outcomes. Adverse events were monitored. Results Significantly more ATX-101 recipients met the primary endpoint criteria vs. placebo: on the clinician scale, 59·2% and 65·3% of patients treated with ATX-101 1 and 2 mg cm−2, respectively, were treatment responders vs. 23·0% for placebo (CR-SMFRS;P < 0·001); on the patient scale, 53·3% and 66·1%, respectively, vs. 28·7%, were satisfied with their face/chin appearance (SSRS;P < 0·001). Calliper measurements showed a significant reduction in SMF (P < 0·001), skin laxity was not worsened and patients reported improvements in the severity and psychological impact of SMF with ATX-101 vs. placebo. Most adverse events were transient and associated with the treatment area. Conclusions ATX-101 was effective and well tolerated for nonsurgical SMF reduction. What's already known about this topic? Unwanted submental fat (SMF) is considered aesthetically unappealing. Liposuction and face-lift are effective treatments for SMF reduction but are
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Verikas, Antanas; Vaiciukynas, Evaldas; Gelzinis, Adas; Parker, James; Olsson, M Charlotte
2016-04-23
This study analyzes muscle activity, recorded in an eight-channel electromyographic (EMG) signal stream, during the golf swing using a 7-iron club and exploits information extracted from EMG dynamics to predict the success of the resulting shot. Muscles of the arm and shoulder on both the left and right sides, namely flexor carpi radialis, extensor digitorum communis, rhomboideus and trapezius, are considered for 15 golf players (∼5 shots each). The method using Gaussian filtering is outlined for EMG onset time estimation in each channel and activation sequence profiling. Shots of each player revealed a persistent pattern of muscle activation. Profiles were plotted and insights with respect to player effectiveness were provided. Inspection of EMG dynamics revealed a pair of highest peaks in each channel as the hallmark of golf swing, and a custom application of peak detection for automatic extraction of swing segment was introduced. Various EMG features, encompassing 22 feature sets, were constructed. Feature sets were used individually and also in decision-level fusion for the prediction of shot effectiveness. The prediction of the target attribute, such as club head speed or ball carry distance, was investigated using random forest as the learner in detection and regression tasks. Detection evaluates the personal effectiveness of a shot with respect to the player-specific average, whereas regression estimates the value of target attribute, using EMG features as predictors. Fusion after decision optimization provided the best results: the equal error rate in detection was 24.3% for the speed and 31.7% for the distance; the mean absolute percentage error in regression was 3.2% for the speed and 6.4% for the distance. Proposed EMG feature sets were found to be useful, especially when used in combination. Rankings of feature sets indicated statistics for muscle activity in both the left and right body sides, correlation-based analysis of EMG dynamics and features
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Antanas Verikas
2016-04-01
Full Text Available This study analyzes muscle activity, recorded in an eight-channel electromyographic (EMG signal stream, during the golf swing using a 7-iron club and exploits information extracted from EMG dynamics to predict the success of the resulting shot. Muscles of the arm and shoulder on both the left and right sides, namely flexor carpi radialis, extensor digitorum communis, rhomboideus and trapezius, are considered for 15 golf players (∼5 shots each. The method using Gaussian filtering is outlined for EMG onset time estimation in each channel and activation sequence profiling. Shots of each player revealed a persistent pattern of muscle activation. Profiles were plotted and insights with respect to player effectiveness were provided. Inspection of EMG dynamics revealed a pair of highest peaks in each channel as the hallmark of golf swing, and a custom application of peak detection for automatic extraction of swing segment was introduced. Various EMG features, encompassing 22 feature sets, were constructed. Feature sets were used individually and also in decision-level fusion for the prediction of shot effectiveness. The prediction of the target attribute, such as club head speed or ball carry distance, was investigated using random forest as the learner in detection and regression tasks. Detection evaluates the personal effectiveness of a shot with respect to the player-specific average, whereas regression estimates the value of target attribute, using EMG features as predictors. Fusion after decision optimization provided the best results: the equal error rate in detection was 24.3% for the speed and 31.7% for the distance; the mean absolute percentage error in regression was 3.2% for the speed and 6.4% for the distance. Proposed EMG feature sets were found to be useful, especially when used in combination. Rankings of feature sets indicated statistics for muscle activity in both the left and right body sides, correlation-based analysis of EMG
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Anwer, S; Equebal, A; Nezamuddin, M; Kumar, R; Lenka, P K
2013-09-01
The objective of this trial was to evaluate the effect of gender on strength gains after five week training programme that consisted of isometric exercise coupled with electromyographic biofeedback to the quadriceps muscle. Forty-three (20 men and 23 women) patients with knee osteoarthritis (OA), were placed into two groups based on their gender. Both groups performed isometric exercise coupled with electromyographic biofeedback for five days a week for five weeks. Both groups reported gains in muscle strength after five week training. However, the difference was found to be statistically insignificant between the two groups (P=0.224). The results suggest that gender did not affect gains in muscle strength by isometric exercise coupled with electromyographic biofeedback in patients with knee OA. Copyright © 2013 Elsevier Masson SAS. All rights reserved.
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A cola-induced hypokalemic rhabdomyolysis with electromyographic evaluation: A case report
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Davide Ferrazzoli
2017-02-01
Full Text Available Objective: To report a rare case of hypokalemic rhabdomyolysis induced by the heavy and prolonged ingestion of cola-based beverages, and its uneventful recovery after kalemia normalization. Methods: We report a 38-year-old Caucasian male presented in our emergency room with a recent and progressive weakness of the lower limbs proximal muscles. Results: A dietary history revealed a prolonged ingestion of cola-based beverages. Blood tests showed severe hypokalemia and marked increase in serum creatine phosphokinase. The analysis of cerebrospinal fluid resulted normal. Electromyography was suggestive for a myopathy. The clinical, laboratory and neurophysiological data were evocative for a cola-induced hypokalemic rhabdomyolysis. After kalemia normalization, the improvements of the electromyographic findings paralleled the clinical recovery. Conclusion: Chronic consumption of large amount of cola-based soft drinks may result in severe symptomatic hypokalemia, eventually leading in turn to myopathy. To our knowledge, this is the first description of the electromyographic findings of the cola-induced hypokalemic rhabdomyolysis. An early diagnosis and a prompt treatment appear to be crucial for a benign clinical course.
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A cola-induced hypokalemic rhabdomyolysis with electromyographic evaluation: A case report.
Ferrazzoli, Davide; Sabetta, Annarita; Palamara, Grazia; Caremani, Luca; Capobianco, Marina; Balbi, Pietro; Frazzitta, Giuseppe
2017-01-01
To report a rare case of hypokalemic rhabdomyolysis induced by the heavy and prolonged ingestion of cola-based beverages, and its uneventful recovery after kalemia normalization. We report a 38-year-old Caucasian male presented in our emergency room with a recent and progressive weakness of the lower limbs proximal muscles. A dietary history revealed a prolonged ingestion of cola-based beverages. Blood tests showed severe hypokalemia and marked increase in serum creatine phosphokinase. The analysis of cerebrospinal fluid resulted normal. Electromyography was suggestive for a myopathy. The clinical, laboratory and neurophysiological data were evocative for a cola-induced hypokalemic rhabdomyolysis. After kalemia normalization, the improvements of the electromyographic findings paralleled the clinical recovery. Chronic consumption of large amount of cola-based soft drinks may result in severe symptomatic hypokalemia, eventually leading in turn to myopathy. To our knowledge, this is the first description of the electromyographic findings of the cola-induced hypokalemic rhabdomyolysis. An early diagnosis and a prompt treatment appear to be crucial for a benign clinical course.
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Ashmawy, Tarek Mohy; El Talawy, Dina Bahgat; Shaheen, Nasser Hussein
2014-09-01
To objectively evaluate the effect of mini-implant- supported mandibular overdentures on electromyographic activity (EMG) of the masseter muscle during chewing of hard and soft foods. Twelve completely edentulous patients (4 females and 8 males) with maladaptive experience of wearing mandibular dentures received new maxillary and mandibular dentures. After 3 months of adaptation, four mini dental implants (MDIs) were inserted in the interforaminal region of the mandible, and the new mandibular dentures were connected to the implants immediately with O/ring attachments. The activity of masseter muscle (EMG) and the duration of chewing cycle were measured during chewing hard (carrot) and soft (gum) foods. The measurements were made 3 months after wearing each of the following prostheses: the new conventional dentures; and the MDI-retained mandibular overdentures. The EMG of masseter muscle increased and the DC decreased with MDI-retained mandibular overdentures when compared to conventional dentures. Hard food (carrot) was associated with increased EMG and decreased DC when compared to soft food (gum) for both conventional dentures and MDI-retained mandibular overdentures. Mini-implant-supported mandibular overdentures are associated with increased activity of masseter muscle and decreased duration of chewing cycle for both hard and soft foods when compared to conventional dentures.
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Electromyographic analysis of the vertebral extensor muscles during the Biering-Sorensen Test
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Ligia Moreira de Santana
2014-03-01
Full Text Available The purpose of the study was to analyze the electromyographic signal of the multifidus, longissimus thoracis and the lumbar iliocostalis muscles during the Biering-Sorensen test in subjects without lower back pain. Twenty volunteers performed the test on three separate occasions. An analysis of variance detected a difference between the three test times (p = 0.0026. For the frequency domain, it was observed that there were differences between the multifidus and the lumbar erectors muscles; longissimus and iliocostalis muscles. However, in the time domain analysis, no difference was observed. As the values of the slope coefficients of median frequencies were higher for the multifidus muscle, compared to the longissimus and lumbar iliocostalis muscles, this may indicate a higher tendency toward muscle fatigue. Therefore, considering the applied methodology, the study of electromyographic signals in the frequency domain should be considered as an instrument to assess fatigue of the spinal extensor muscles in clinical situations.
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Vieira e Silva, Carolina A; da Silva, Marco Antônio M Rodrigues; Melchior, Melissa de Oliveira; de Felício, Cláudia Maria; Sforza, Chiarella; Tartaglia, Gianluca M
2012-07-01
The purpose of this study was to apply Functional Anatomy Research Center (FARC) Protocol of TMD treatment, which includes the use of a specific type of mandibular occlusal splint, adjusted based on the electromyographic index, in a group of 15 patients with disc displacement, classified according to the Research Diagnostic Criteria for Temporomandibular Disorders (RDC/TMD) and then analyzing the results compared with the control group. The clinical evaluations were completed both before and after the treatment. Electromyographic (EMG) data was collected and recorded on the day the splint was inserted (visit 1), after one week (visit 2) and after five weeks of treatment (visit 3). The control group consisted of 15 asymptomatic subjects, according to the same diagnostic criteria (RDC/TMD), who were submitted to the same evaluations with the same interval periods as the treatment group. Immediately after splint adjustment, masseter muscle symmetry and total muscular activity were significantly different with than without the splint (p < 0.05), showing an increased neuromuscular coordination. After treatment, significant variations (p < .05) were found in mouth opening and in pain remission. There were no significant differences among the three sessions, either with or without the splint. There were significant differences between the TMD and control groups for all analyzed indices of muscular symmetry, activity and torque, with the exception of total muscular activity. The use of the splint promoted balance of the EMG activities during its use, relieving symptoms. EMG parameters identified neuromuscular imbalance, and allowed an objective analysis of different phases of TMD treatment, differentiating individuals with TMD from the asymptomatic subjects.
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Cheung, J; Veldhuizen, AG; Halberts, JPK; Sluiter, WJ; Van Horn, [No Value
2006-01-01
Study Design. The natural history of patients with idiopathic scoliosis was analyzed radiographically and electromyographically in a prospective longitudinal study. Objectives. To identify changes in geometric variables and the sequence in which these changes occur during curve progression in the
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Smith Toby O
2010-03-01
Full Text Available Abstract Background Subacromial impingement syndrome (SIS is a commonly reported cause of shoulder pain. The purpose of this study was to systematically review the literature to examine whether a difference in electromyographic (EMG activity of the shoulder complex exists between people with SIS and healthy controls. Methods Medline, CINAHL, AMED, EMBASE, and grey literature databases were searched from their inception to November 2008. Inclusion, data extraction and trial quality were assessed in duplicate. Results Nine studies documented in eleven papers, eight comparing EMG intensity and three comparing EMG onset timing, representing 141 people with SIS and 138 controls were included. Between one and five studies investigated each muscle totalling between 20 and 182 participants. The two highest quality studies of five report a significant increase in EMG intensity in upper trapezius during scaption in subjects with SIS. There was evidence from 2 studies of a delayed activation of lower trapezius in patients with SIS. There was otherwise no evidence of a consistent difference in EMG activity between the shoulders of subjects with painful SIS and healthy controls. Conclusions A difference may exist in EMG activity within some muscles, in particular upper and lower trapezius, between people with SIS and healthy controls. These muscles may be targets for clinical interventions aiding rehabilitation for people with SIS. These differences should be investigated in a larger, high quality survey and the effects of therapeutically targeting these muscles in a randomised controlled trial.
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Electromyographic analysis of exercise resulting in symptoms of muscle damage.
McHugh, M P; Connolly, D A; Eston, R G; Gleim, G W
2000-03-01
Surface electromyographic (EMG) signals were recorded from the hamstring muscles during six sets of submaximal isokinetic (2.6 rad x s(-1)) eccentric (11 men, 9 women) or concentric (6 men, 4 women) contractions. The EMG per unit torque increased during eccentric (P exercise. Similarly, the median frequency increased during eccentric (P exercise. The EMG per unit torque was lower for submaximal eccentric than maximum isometric contractions (P unit torque was lower for eccentric than concentric contractions (P exercise resulted in significant isometric strength loss (P exercise, while the most severe pain and muscle tenderness occurred 2 days after eccentric exercise. A lower EMG per unit torque is consistent with the selective recruitment of a small number of motor units during eccentric exercise. A higher median frequency during eccentric contractions may be explained by selective recruitment of fast-twitch motor units. The present results are consistent with the theory that muscle damage results from excessive stress on a small number of active fibres during eccentric contractions.
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On the behavior of surface electromyographic variables during the menstrual cycle
International Nuclear Information System (INIS)
Soares, Fabiano Araujo; Salomoni, Sauro Emerick; De Carvalho, Joao Luiz Azevedo; Nascimento, Francisco Assis de Oliveira; Veneziano, Wilson Henrique; Pires, Kenia Fonseca; Da Rocha, Adson Ferreira
2011-01-01
The goal of this work is to study the behavior of electromyographic variables during the menstrual cycle. Ten female volunteers (24.0 ± 2.8 years of age) performed fatiguing isometric contractions, and electromyographic signals were measured on the biceps brachii in four phases of the menstrual cycle. Adaptations of classical algorithms were used for the estimation of the root mean square (RMS) value, absolute rectified value (ARV), mean frequency (MNF), median frequency (MDF), and conduction velocity (CV). The CV estimator had a higher (p = 0.002) rate of decrease at the end of the follicular phase and at the end of the luteal phase. The MDF (p = 0.002) and MNF (p = 0.004) estimators had a higher rate of decrease at the beginning of the follicular phase and at the end of the luteal phase. No significant differences between phases of the menstrual cycle were detected with the ARV and RMS estimators (p > 0.05). These results suggest that the behavior of the muscles in women presents different characteristics during different phases of the menstrual cycle. In particular, women were more susceptible to fatigue at the end of the luteal phase
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Electromyographic analyses of muscle pre-activation induced by single joint exercise.
Júnior, Valdinar A R; Bottaro, Martim; Pereira, Maria C C; Andrade, Marcelino M; P Júnior, Paulo R W; Carmo, Jake C
2010-01-01
To investigate whether performing a low-intensity, single-joint exercises for knee extensors was an efficient strategy for increasing the number of motor units recruited in the vastus lateralis muscle during a subsequent multi-joint exercises. Nine healthy male participants (23.33+/-3.46 yrs) underwent bouts of exercise in which knee extension and 45 degrees , and leg press exercises were performed in sequence. In the low-intensity bout (R30), 15 unilateral knee extensions were performed, followed by 15 repetitions of the leg presses at 30% and 60% of one maximum repetition load (1-MR), respectively. In the high-intensity bout (R60), the same sequence was performed, but the applied load was 60% of 1-MR for both exercises. A single set of 15 repetitions of the leg press at 60% of 1-MR was performed as a control exercise (CR). The surface electromyographic signals of the vastus lateralis muscle were recorded by means of a linear electrode array. The root mean square (RMS) values were determined for each repetition of the leg press, and linear regressions were calculated from these results. The slopes of the straight lines obtained were then normalized using the linear coefficients of the regression equations and compared using one-way ANOVAs for repeated measures. The slopes observed in the CR were significantly lower than those in the R30 and R60 (precruitment of motor units was more effective when a single-joint exercise preceded the multi-joint exercise. Article registered in the Australian New Zealand Clinical Trials Registry (ANZCTR) under the number ACTRN12609000413224.
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Electromyographical Comparison of Four Common Shoulder Exercises in Unstable and Stable Shoulders
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Aaron Sciascia
2012-01-01
Full Text Available This study examines if electromyographic (EMG amplitude differences exist between patients with shoulder instability and healthy controls performing scaption, prone horizontal abduction, prone external rotation, and push-up plus shoulder rehabilitation exercises. Thirty nine subjects were categorized by a single orthopedic surgeon as having multidirectional instability (n=10, anterior instability (n=9, generalized laxity (n=10, or a healthy shoulder (n=10. Indwelling and surface electrodes were utilized to measure EMG activity (reported as a % of maximum voluntary isometric contraction (MVIC in various shoulder muscles during 4 common shoulder exercises. The exercises studied effectively activated the primary musculature targeted in each exercise equally among all groups. The serratus anterior generated high activity (50–80% MVIC during a push-up plus, while the infraspinatus and teres major generated moderate-to-high activity (30–80% MVIC during both the prone horizontal and prone external rotation exercises. Scaption exercise generated moderate activity (20–50% MVIC in both rotator cuff and scapular musculature. Clinicians should feel confident in prescribing these shoulder-strengthening exercises in patients with shoulder instability as the activation levels are comparable to previous findings regarding EMG amplitudes and should improve the dynamic stabilization capability of both rotator cuff and scapular muscles using exercises designed to address glenohumeral joint instability.
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Sex Comparisons for Relative Peak Torque and Electromyographic Mean Frequency during Fatigue
Stock, Matt S.; Beck, Travis W.; DeFreitas, Jason M.; Ye, Xin
2013-01-01
Purpose: This study compared the relative peak torque and normalized electromyographic (EMG) mean frequency (MNF) responses during fatiguing isokinetic muscle actions for men versus women. Method: Twenty men M[subscript age] ± SD = 22 ± 2 years) and 20 women M[subscript age] ± SD = 22 ± 1 years) performed 50 maximal concentric isokinetic muscle…
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Roberto Censolo
Full Text Available BACKGROUND: A vast body of social and cognitive psychology studies in humans reports evidence that external rewards, typically monetary ones, undermine intrinsic motivation. These findings challenge the standard selfish-rationality assumption at the core of economic reasoning. In the present work we aimed at investigating whether the different modulation of a given monetary reward automatically and unconsciously affects effort and performance of participants involved in a game devoid of visual and verbal interaction and without any perspective-taking activity. METHODOLOGY/PRINCIPAL FINDINGS: Twelve pairs of participants were submitted to a simple motor coordination game while recording the electromyographic activity of First Dorsal Interosseus (FDI, the muscle mainly involved in the task. EMG data show a clear effect of alternative rewards strategies on subjects' motor behavior. Moreover, participants' stock of relevant past social experiences, measured by a specifically designed questionnaire, was significantly correlated with EMG activity, showing that only low social capital subjects responded to monetary incentives consistently with a standard rationality prediction. CONCLUSIONS/SIGNIFICANCE: Our findings show that the effect of extrinsic motivations on performance may arise outside social contexts involving complex cognitive processes due to conscious perspective-taking activity. More importantly, the peculiar performance of low social capital individuals, in agreement with standard economic reasoning, adds to the knowledge of the circumstances that makes the crowding out/in of intrinsic motivation likely to occur. This may help in improving the prediction and accuracy of economic models and reconcile this puzzling effect of external incentives with economic theory.
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Rzany, B; Griffiths, T; Walker, P; Lippert, S; McDiarmid, J; Havlickova, B
2014-02-01
Unwanted submental fat (SMF) is aesthetically unappealing, but methods of reduction are either invasive or lack evidence for their use. An injectable approach with ATX-101 (deoxycholic acid) is under investigation. To evaluate the efficacy and safety of ATX-101 for the reduction of unwanted SMF. In this double-blind, placebo-controlled, phase III study, 363 patients with moderate/severe SMF were randomized to receive ATX-101 (1 or 2 mg cm(-2) ) or placebo injections into their SMF at up to four treatment sessions ~28 days apart, with a 12-week follow-up. The co-primary efficacy endpoints were the proportions of treatment responders [patients with ≥ 1-point improvement in SMF on the 5-point Clinician-Reported Submental Fat Rating Scale (CR-SMFRS)] and patients satisfied with their face and chin appearance on the Subject Self-Rating Scale (SSRS). Secondary endpoints included skin laxity, calliper measurements and patient-reported outcomes. Adverse events were monitored. Significantly more ATX-101 recipients met the primary endpoint criteria vs. placebo: on the clinician scale, 59·2% and 65·3% of patients treated with ATX-101 1 and 2 mg cm(-2) , respectively, were treatment responders vs. 23·0% for placebo (CR-SMFRS; P < 0·001); on the patient scale, 53·3% and 66·1%, respectively, vs. 28·7%, were satisfied with their face/chin appearance (SSRS; P < 0·001). Calliper measurements showed a significant reduction in SMF (P < 0·001), skin laxity was not worsened and patients reported improvements in the severity and psychological impact of SMF with ATX-101 vs. placebo. Most adverse events were transient and associated with the treatment area. ATX-101 was effective and well tolerated for nonsurgical SMF reduction. © 2013 The Authors. British Journal of Dermatology published by John Wiley & Sons Ltd on behalf of British Association of Dermatologists.
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Bosch, T.; Looze, M.P. de; Kingma, I.; Visser, B.; Dieën, J.H. van
2009-01-01
The purpose of this study was to determine whether objective electromyographical manifestations of muscle fatigue develop in the upper trapezius muscle in two assembly tasks involving contractions of different low-intensity levels (8% and 12% MVC) and whether these indications of fatigue are
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Light, Sharee N.; Moran, Zachary D.; Swander, Lena; Le, Van; Cage, Brandi; Burghy, Cory; Westbrook, Cecilia; Greishar, Larry; Davidson, Richard J.
2016-01-01
The relation between empathy subtypes and prosocial behavior was investigated in a sample of healthy adults. "Empathic concern" and "empathic happiness," defined as negative and positive vicarious emotion (respectively) combined with an other-oriented feeling of “goodwill” (i.e. a thought to do good to others/see others happy), were elicited in 68 adult participants who watched video clips extracted from the television show Extreme Makeover: Home Edition. Prosocial behavior was quantified via performance on a non-monetary altruistic decision-making task involving book selection and donation. Empathic concern and empathic happiness were measured via self-report (immediately following each video clip) and via facial electromyography recorded from corrugator (active during frowning) and zygomatic (active during smiling) facial regions. Facial electromyographic signs of (a) empathic concern (i.e. frowning) during sad video clips, and (b) empathic happiness (i.e. smiling) during happy video clips, predicted increased prosocial behavior in the form of increased goodwill-themed book selection/donation. PMID:25486408
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Branthwaite, Helen; Chockalingam, Nachiappan; Pandyan, Anand; Khatri, Gaurav
2013-08-01
Unstable shoes, which have recently become popular, claim to provide additional physiological and biomechanical advantages to people who wear them. Alterations in postural stability have been shown when using the shoe after training. However, the immediate effect on muscle activity when walking in unstable shoes for the first time has not been investigated. To evaluate muscle activity and temporal parameters of gait when wearing Masai Barefoot Technology shoes(®) for the first time compared to the subject's own regular trainer shoes. A pilot repeated-measures quasi control trial. Electromyographic measurements of lower leg muscles (soleus, medial gastrocnemius, lateral gastrocnemius, tibialis anterior, peroneus longus, rectus femoris, biceps femoris and gluteus medius) were measured in 15 healthy participants using Masai Barefoot Technology shoes and trainer shoes over a 10-m walkway. Muscle activity of the third and sixth steps was used to study the difference in behaviour of the muscles under the two shoe conditions. Temporal parameters were captured with footswitches to highlight heel strike, heel lift and toe off. Paired samples t-test was completed to compare mean muscle activity for Masai Barefoot Technology and trainer shoes. Indicated that the use of Masai Barefoot Technology shoes increased the intensity of the magnitude of muscle activity. While this increase in the activity was not significant across the subjects, there were inter-individual differences in muscle activity. This variance between the participants demonstrates that some subjects do alter muscle behaviour while wearing such shoes. A more rigorous and specific assessment is required when advising patients to purchase the Masai Barefoot Technology shoe. Not all subjects respond positively to using unstable shoes, and the point in time when muscle behaviour can change is variable. Use of Masai Barefoot Technology shoe in patient management should be monitored closely as the individual muscle
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Stokes, M J; Colter, C; Klestov, A; Cooper, R G
1993-08-01
Paraspinal muscle fatigue mechanisms were compared in 14 primary fibromyalgia patients and 14 age and sex matched normal subjects using a standardized 60-s isometric endurance test of the paraspinal muscles, during which surface integrated electromyographic (IEMG) activity was recorded. Fatigue-induced IEMG increases were similar for both groups during the initial 40 s (up to 112 +/- 20% and 111 +/- 6% of initial values in patients and normal subjects respectively). Thereafter, IEMG fell significantly in patients (P BMI, range 19-25 in controls) those with a BMI BMI > 26 (n = 9) showed greater IEMG declines after 40 s than either normal subjects or in the fibromyalgia group as a whole. Paraspinal muscle fatigue mechanisms appear normal in primary fibromyalgia patients. Isometric force maintenance in overweight patients, despite IEMG declines, illustrates the action of intrinsic fatigue resistance mechanisms which were presumably utilized to a greater extent in these patients to cope with the extra load.
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Electromyographic analysis of repeated bouts of eccentric exercise.
McHugh, M P; Connolly, D A; Eston, R G; Gartman, E J; Gleim, G W
2001-03-01
The repeated bout effect refers to the protective effect provided by a single bout of eccentric exercise against muscle damage from a similar subsequent bout. The aim of this study was to determine if the repeated bout was associated with an increase in motor unit activation relative to force production, an increased recruitment of slow-twitch motor units or increased motor unit synchronization. Surface electromyographic (EMG) signals were recorded from the hamstring muscles during two bouts of submaximal isokinetic (2.6 rad x s(-1)) eccentric (11 men, 9 women) or concentric (6 men, 4 women) contractions separated by 2 weeks. The EMG per unit torque and median frequency were analysed. The initial bout of eccentric exercise resulted in strength loss, pain and muscle tenderness, while the repeated eccentric bout resulted in a slight increase in strength, no pain and no muscle tenderness (bout x time effects, P exercise. The EMG per unit torque and median frequency were not different between the initial and repeated bouts of eccentric exercise. The EMG per unit torque and median frequency increased during both bouts of eccentric exercise (P < 0.01) but did not change during either concentric bout. In conclusion, there was no evidence that the repeated bout effect was due to a neural adaptation.
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VASTUS LATERALIS OBLIQUE ACTIVITY DURING GAIT OF SUBJECTS WITH PATELLOFEMORAL PAIN
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Gilmar Moraes Santos
Full Text Available ABSTRACT Introduction: So far, little is known about the behavior of electromyographic activity of vastus lateralis oblique muscle during treadmill gait in subjects with and without patellofemoral pain syndrome. Objective: The purpose of this study was to investigate the electromyographic activity of the patellar stabilizers muscles and the angle of the knee joint flexion in subjects with and without patellofemoral pain syndrome. Method: Fifteen subjects without (21 ± 3 years and 12 with patellofemoral pain syndrome (20 ± 2 years were evaluated. The electromyographic activity and flexion angle of the knee joint were obtained during gait on the treadmill with a 5 degree inclination. Results: The knee flexion angle was significantly lower in the subjects with patellofemoral pain syndrome when compared with the healthy controls. The electromyographic activity of vastus lateralis longus was significantly greater during gait on the treadmill with inclination in subjects with patellofemoral pain syndrome. The results also showed that the electromyographic activity of vastus lateralis oblique and vastus medialis oblique were similar in both groups, regardless of the condition (with/without inclination. Conclusion: We have shown that knee kinematics during gait differs among patients with and without patellofemoral pain syndrome and healthy controls and that a different motor strategy persists even when the pain is no longer present. In addition, the findings suggested that the vastus lateralis oblique has a minor role in patellar stability during gait.
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Vervuert, I; Brüssow, N; Bochnia, M; Cuddeford, D; Coenen, M
2013-06-01
The aims of this study were to monitor electromyographic (EMG) activity of masseter muscle in healthy horses fed (i) different types of roughage and (ii) maize after different hay allocations. Four horses were offered the following three diets ad libitum: hay, haylage or straw/alfalfa chaff (SAC). In a second trial, four horses were fed cracked maize (CM) and hay in three different orders: (i) CM after a 12-h overnight fast; (ii) CM immediately after restricted hay intake (0.6 kg hay/100 kg BW); or 3) CM after hay intake ad libitum. The activity of the masseter muscle was determined by EMG (IED(®) ), and the following were measured: amplitude (muscle action potential = MAP, maximum voltage) and duration of MAP (s). The intake of hay or haylage was associated with intense masseter muscle activity (MAP: hay, 10 ± 1.7 V; haylage, 11 ± 3.3 V; and duration of MAP: hay, 0.31 ± 0.04 s; haylage, 0.30 ± 0.04 s). Similar intense chewing was measured for SAC (MAP 13 ± 3.8 V), although duration of the chewing cycle was relatively short (0.22 ± 0.03 s, diet p haylage or SAC was associated with intensive masseter muscle activity that was likely to stimulate salivary flow rate. In contrast to roughage, concentrates like CM are consumed rapidly with less intensive masseter muscle activity. This situation is associated with a low salivary flow that may have an adverse effect on gastric function. © 2012 Blackwell Verlag GmbH.
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Patrícia Silva de Camargo
2018-02-01
Full Text Available The purpose of this study was to analyze and compare intra and intergroup the immediate effect of the auricular and LR8 systemic acupuncture on the electromyographic activity of the trapezius with the trigger points. This is an experimental clinical trial; 40 people were split in 4 distinct groups (n = 10: GI mustard seed application in the auricular acupoint; GII bilateral needle application in the LR8 acupoint; GIII combination of the techniques; GIV/Control Group mustard seed application in an acupoint not linked to the muscle tension. The EMG was used to assess the muscle contraction for 5 seconds during the resting time and during the isometric contraction time. The EMG signal was first collect without the acupuncture intervention; then both techniques were applied for 5 minutes; and the EMG was collected again right after these applications. The Shapiro-Wilk test was used, the t test was paired with the Wilcoxon test to the intragroup comparison; One-way analysis of variance test for intergroup comparison. There was no statistical difference in the intragroup comparison for the groups. The same happened to the intergroup comparison before and after application. Systemic and auricular acupuncture did not promote immediate changes in the EMG activity of the trapezius muscle in individuals with MTrPs.
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Cox, Daniel J.; And Others
1975-01-01
Adults with chronic tension headaches were assigned to auditory electromyograph (EMG) feedback (N=9), to progressive relaxation (N=9), and to placebo treatment (N=9). Data indicated that biofeedback and verbal relaxation instructions were equally superior to the medicine placebo on all measured variables in the direction of clinical improvement,…
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Çagdas Erdogan
2013-01-01
Full Text Available Here, we report a case of serotonergic toxicity due to combination of essitalopram and isoniazid, which was rarely reported before. Moreover, we observed transient neurogenic denervation potentials in needle electromyography, which disappeared with the treatment of serotonergic toxicity. As to our best knowledge, this is the first case, reporting transient electromyographic changes probably due to serotonergic toxicity.
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Electromyographic control of functional electrical stimulation in selected patients.
Graupe, D; Kohn, K H; Basseas, S; Naccarato, E
1984-07-01
The paper describes initial results of above-lesion electromyographic (EMG) controlled functional electrical stimulation (FES) of paraplegics. Such controlled stimulation is to provide upper-motor-neuron paraplegics (T5 to T12) with self-controlled standing and some walking without braces and with only the help of walkers or crutches. The above-lesion EMG signal employed serves to map the posture of the patient's upper trunk via a computerized mapping of the temporal patterns of that EMG. Such control also has an inherent safety feature in that it prevents the patient from performing a lower-limb movement via FES unless his trunk posture is adequate. Copyright 2013, SLACK Incorporated.
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M.L. Moura
2011-01-01
Full Text Available The purpose of this study was to verify the electromyographic activity of the rectus abdominis and obliquus externus abdominis during abdominal crunch exercise performed with maximum and submaximum loads. Thirteen male and female university students participated in this investigation (18-23 years old. The subjects completed abdominal crunch exercise until exhaustion with 20, 40, 60 and 80% of the maximum load. The root-mean-square (RMS from electromyography activity of the rectus abdominis and obliquus externus muscles from the first and last three repetitions from each workload performed was analyzed. RMS for the last repetitions increased in relation to the first repetitions for the 20% workload, first two repetitions on 40% workload and first repetition on the 80% workload. There was no difference for the 60% workload. Results showed that external load on abdominal crunch exercise might be an alternative to increase intensity while performing abdominal crunch exercise, which on its turn can be a practical tool for subjects that aim to increase abdominal strength level.
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Calamita, Simone Aparecida Penimpedo; Biasotto-Gonzalez, Daniela Aparecida; De Melo, Nivea Cristina; dos Santos, Douglas Meira; de Lassa, Roberta; de Mendonça, Fabiana Sarilho; Oliveira, Claudia Santos; Amorim, César Ferreira; Gonzalez, Tabajara Oliveira; Fumagalli, Marco Antônio; de Gomes, Cid André Fidelis Paula; Politti, Fabiano
2015-03-19
Nonspecific neck pain can cause considerable suffering, possible disability and reductions in quality of life and productivity. The aim of the proposed study is to evaluate the immediate effect of acupuncture on pain, cervical range of motion and electromyographic activity of the upper trapezius muscle in patients with nonspecific neck pain. A total of 12 patients with nonspecific neck pain and 12 healthy subjects will be enrolled in a randomized, single-blind crossover study. Each subject will receive two forms of treatment in random order: a single session of traditional acupuncture (acupoints: triple energizer 5, 'Wai-guan' and large intestine 11, 'Qu-chi') and sham acupuncture. To eliminate carry-over treatment effects, a one-week wash-out period will be respected between sessions. Surface electromyography will be used to determine motor control in the upper trapezius muscle before and after treatment. The outcome measures in the group with neck pain will be a numerical pain rating scale (range: 0 (no pain) to 10 (maximum pain)), documentation of the pain area on a body chart and cervical range of motion. Comparisons before and after acupuncture treatment will demonstrate whether acupoints affect the activity of the upper trapezius muscle, pain and cervical range of motion. The purpose of this randomized clinical trial is to evaluate the immediate effect of acupuncture on pain, cervical range of motion and electromyographic activity of the upper trapezius muscle in patients with nonspecific neck pain. Data will be published after the study is completed. The study will support the practice of evidence-based physical therapy for individuals with nonspecific neck pain. This trial was registered with Clinicaltrials.gov (identifier: NCT0984021 ) on 7 November 2013 ( https://clinicaltrials.gov/ct2/show/NCT01984021 ).
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Neuro-lepra: valor de la electromiografia Neuro-leprosy: electromyographic studies
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Ernesto Herskovits
1971-09-01
Full Text Available Dada la frecuencia con que la lepra afecta al sistema nervioso, consideramos de interés realizar un estudio electromiográfico en zonas corporales clínicamente sanas. Hemos elegido para tal fin 14 enfermos que no tenían lesión sensitivo-motora clínicamente perceptible en el nervio cubital izquierdo. Hemos estudiado tambén un grupo de control de 5 enfermos con lesión evidente del mismo nervio. Se ha comprobado que de los 14 enfermos que aparentemente no tenían lesión del nervio cubital izquierdo, en 12 de ellos surgieron alteraciones electromiográficas que señalan la lesión del nervio, aunque en um grado menor que en el grupo de control. Este hecho nos hace pensar que la agresión que sufre el sistema nervioso periférico es de una extensión mayor que lo hace suponer la clínica, o que las lesiones anatómicas no retrogradan como nos lo sugiere el examen de los pacientes.Considering the frequency of the peripheral nervous system envolvement in leprosy 14 patients without clinical signs indicating impairment of the left ulnar nerve were submitted to electromyographic studies. All were chronic cases in which the disease had an evolution of three years for the most recent one, the longest during thirty one years. All patients were under leprosy treatment: nine had lepromatous leprosy, four had tuberculoid form, one had a dimorfous form. At the same time, as a control group, were studied 5 patients presenting clinical signis of injury of the left ulnar nerve. An electromiograph DISA with 3 channels, a Multistin estimulator and concentric electrodes were employed. In all the 19 cases the espontaneous activity, the type of recruiting reaction and the conduction velocity were analysed. Results were synthetized in Tables 1 and 2. The finding of electromyographic abnormalities in clinically healthy territores of 12/14 patients examined lead to the conclusion that in leprosy the agression to the peripheral nervous system is more extensive than
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Electromyographic assessment of trunk and shoulder muscles during a Pilates pull-up exercise
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Isabel C.N. Sacco
2014-06-01
Full Text Available This study compares surface electromyographic activity of the internal oblique, rectus abdominis, multifidus, iliocostalis, anterior deltoids during the pull-up on a lower and on a higher difficulty level. We assessed nine adults with previous experience in Pilates. The root mean square (RMS values were normalized by maximum isometric contraction for each participant. During the ascent phase, the low spring position showed a significantly higher RMS than the high spring position of 8.9% for deltoid, 17.2% for internal oblique, 22.3% for rectus abdominis, 4.1% for iliocostalis, and 5.6% for multifidus, and in the descent phase, the RMS in the lower spring exceeded significantly the high spring position in 1.6% for the deltoid, 10% for internal oblique, 31.4% for rectus abdominis and 11.4% for iliocostalis. There was no predominance of abdominal muscles over the shoulder muscle in any spring position. The pull-up exercise can be a useful choice for the core and anterior deltoid muscles strengthening.
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Camilla Zamfolini Hallal
2013-03-01
Full Text Available O objetivo deste estudo foi investigar a influência do medo de cair e da dupla tarefa sobre a variabilidade de parâmetros eletromiográficos e cinemáticos da marcha de idosas. Dezessete universitárias (21,47 ± 2,06 anos e dezoito idosas (65,33 ± 3,14 anos, fisicamente ativas, realizaram teste de marcha em três condições: velocidade de preferência; medo de cair; e dupla tarefa. A atividade eletromiográfica dos músculos do membro inferior dominante e o comprimento e tempo de passada foram registrados. Utilizou-se o teste ANOVA Two-Way (pThe main goal of this study was to investigate the influence of fear of fall and dual task on electromyographic and kinematic variability parameters on the gait of older females. Seventeen college students (21,47 ± 2,06 years old and eighteen older female adults, both groups were physically fit and performed the gait test on three different conditions: walking at self-select speed, fear of fall and dual task. Electromyographic activity was measured on muscles of dominant leg and stride time was recorded. ANOVA two-way (p<0.05 was used. Electromyographic and kinematic gait variability were higher in older adult groups. However, for the comparison between gait conditions was only found significant difference for electromyographic variability. In line with this, the higher EMG and kinematic variability in older adults suggest that aging contributes for a higher motor challenge while walking, which may be predispose these individuals a higher risk of fall.
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Ahmed Shafik
2007-06-01
Full Text Available
BACKGROUND: The role of the anterolateral abdominal wall muscles (AAWMs during the vesical filling and evacuation has not been sufficiently addressed in the literature. We have investigated the hypothesis that the AAWMs exhibit the increased electromyographic (EMG activity on the vesical distension and contraction which presumably assists vesical evacuation.
METHODS: The effects of the vesical balloon distension on the vesical pressure (VP, vesical neck (VNP pressures and the AAWMs' EMG activity were studied in 28 healthy volunteers aged 40.7 ± 9.7 years (18 men, 10 women. These effects were tested after the individual anesthetization of the bladder and AAWMs and after saline infiltration.
RESULTS: The VP and the VNP showed a gradual increase upon the incremental vesical balloon distension which started at a distending volume of 120–140 ml. At a mean volume of 364.6 ± 23.8 ml, the VP increased to a mean of 36.6 ± 3.2 cmH2O, the VNP decreased to 18.4 ± 2.4 cmH2O, and the AAWMs EMG registered a significant increase. This effect disappeared in the individual bladder and in the AAWMs' anesthetization. However, it did not disappear in the saline administration.
CONCLUSIONS: The AAWMs appear to contract simultaneously with vesical contraction. This action presumably increases the IAP and it
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Onset Detection in Surface Electromyographic Signals: A Systematic Comparison of Methods
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Claus Flachenecker
2001-06-01
Full Text Available Various methods to determine the onset of the electromyographic activity which occurs in response to a stimulus have been discussed in the literature over the last decade. Due to the stochastic characteristic of the surface electromyogram (SEMG, onset detection is a challenging task, especially in weak SEMG responses. The performance of the onset detection methods were tested, mostly by comparing their automated onset estimations to the manually determined onsets found by well-trained SEMG examiners. But a systematic comparison between methods, which reveals the benefits and the drawbacks of each method compared to the other ones and shows the specific dependence of the detection accuracy on signal parameters, is still lacking. In this paper, several classical threshold-based approaches as well as some statistically optimized algorithms were tested on large samples of simulated SEMG data with well-known signal parameters. Rating between methods is performed by comparing their performance to that of a statistically optimal maximum likelihood estimator which serves as reference method. In addition, performance was evaluated on real SEMG data obtained in a reaction time experiment. Results indicate that detection behavior strongly depends on SEMG parameters, such as onset rise time, signal-to-noise ratio or background activity level. It is shown that some of the threshold-based signal-power-estimation procedures are very sensitive to signal parameters, whereas statistically optimized algorithms are generally more robust.
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Raheleh Dorosti
2017-10-01
Conclusion: It seems that electromyographic activities of some of core muscles in patients with patellofemoral pain syndrome in comparison with healthy subjects are different. However, there was no differences in electromyographic activities in some of the muscles around the knee between patients and healthy subjects.
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Reid, Duncan; McNair, Peter J; Johnson, Shelley; Potts, Geoff; Witvrouw, Erik; Mahieu, Nele
2012-08-01
To compare surface electromyographic (EMG) activity of the gastrocnemius and soleus muscles between persons with and without Achilles tendinopathy (AT) during an eccentric muscle exercise in different knee joint positions. Repeated measures design. Research laboratory. Participants (n = 18) diagnosed with AT and 18 control subjects were recruited. Gastrocnemius and soleus muscle activity was examined by surface (EMG) during extended and flexed knee joint conditions while performing the eccentric training technique. The EMG data were expressed as a percentage of a maximum voluntary contraction (MVC). EMG activity was notably higher (mean difference: 10%, effect size: 0.59) in those subjects with AT. Irrespective of the presence of AT, there was a significant interaction effect between muscle and joint position. The gastrocnemius muscle was significantly more active in the extended knee condition and soleus muscle activity was unchanged across joint positions. The results indicated that the presence of AT influenced calf muscle activity levels during performance of the eccentric exercise. There were differences in muscle activity during the extended and flexed knee conditions. This result does support performing Alfredson, Pietila, Jonsson, and Lorentzon (1998) eccentric exercise in an extended knee position but the specific effects of the knee flexed position on the Achilles tendon during eccentric exercise have yet to be determined, particularly in those with AT. Copyright © 2011 Elsevier Ltd. All rights reserved.
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Amaral, Josária F.; Alvim, Felipe C.; Castro, Eliane A.; Doimo, Leonice A.; Silva, Marcus V.; Novo, José M.
2014-01-01
Background Aging is a multifactorial process that leads to changes in the quantity and quality of skeletal muscle and contributes to decreased levels of muscle strength. Objective This study sought to investigate whether the isometric muscle strength, fat-free mass (FFM) and power of the electromyographic (EMG) signal of the upper and lower limbs of women are similarly affected by aging. Method The sample consisted of 63 women, who were subdivided into three groups (young (YO) n=33, 24.7±3.5 years; middle age (MA) n=15, 58.6±4.2 years; and older adults (OA). n=15, 72.0±4.2 years). Isometric strength was recorded simultaneously with the capture of the electrical activity of the flexor muscles of the fingers and the vastus lateralis during handgrip and knee extension tests, respectively. FFM was assessed using dual-energy X-ray absorptiometry. Results The handgrip strength measurements were similar among groups (p=0.523), whereas the FFM of the upper limbs was lower in group OA compared to group YO (p=0.108). The RMSn values of the hand flexors were similar among groups (p=0.754). However, the strength of the knee extensors, the FFM of the lower limbs and the RMSn values of the vastus lateralis were lower in groups MA (p=0.014, p=0.006 and p=0.013, respectively) and OA (p=0.000, p=0.000 and pisometric muscle strength in MLG and electromyographic activity of the lower limbs are more pronounced with the aging process of the upper limb. PMID:24676705
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Pâmela Maiara Machado
2018-02-01
Full Text Available Abstract AIMS The aim of this study was to verify the influence of Pilates on muscle activation of lumbar multifidus (LM and transversus abdominis/internal oblique muscles (TrA/IO in individuals with nonspecific low back pain. METHODS Twelve individuals of both sexes with non-specific low back pain were evaluated before and after a two-month Pilates program in relation to electromyographic activity of LM and TrA/IO, as well as clinical aspects such as pain, flexibility, muscular endurance, quality of life; and Fear-Avoidance Beliefs Questionnaire (in relation to physical and work-related activities. A statistical analysis was performed using a test for independent samples and significance was established at the level of 0.05. RESULTS After eight weeks of Pilates training, there was an improvement in the clinical parameters of pain, flexibility, muscular endurance and disability. The individuals presented lower LM activation (p=0.025, higher trunk extension strength (p=0.005 and an increase in time from onset to peak muscle activation (p=0.02. CONCLUSION Pilates protocol was effective for clinical improvement and motor behavior in patients with nonspecific low back pain and the parameters assessed showed a large effect size despite the small sample.
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Muscle Activation during Push-Ups with Different Suspension Training Systems
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Joaquin Calatayud, Sebastien Borreani, Juan C. Colado, Fernando F Martín, Michael E. Rogers
2014-09-01
Full Text Available The purpose of this study was to analyze upper extremity and core muscle activation when performing push-ups with different suspension devices. Young fit male university students (n = 29 performed 3 push-ups each with 4 different suspension systems. Push-up speed was controlled using a metronome and testing order was randomized. Average amplitude of the electromyographic root mean square of Triceps Brachii, Upper Trapezius, Anterior Deltoid, Clavicular Pectoralis, Rectus Abdominis, Rectus Femoris, and Lumbar Erector Spinae was recorded. Electromyographic signals were normalized to the maximum voluntary isometric contraction (MVIC. Electromyographic data were analyzed with repeated-measures analysis of variance with a Bonferroni post hoc. Based upon global arithmetic mean of all muscles analyzed, the suspended push-up with a pulley system provided the greatest activity (37.76% of MVIC; p < 0.001. Individually, the suspended push-up with a pulley system also provided the greatest triceps brachii, upper trapezius, rectus femoris and erector lumbar spinae muscle activation. In contrast, more stable conditions seem more appropriate for pectoralis major and anterior deltoid muscles. Independent of the type of design, all suspension systems were especially effective training tools for reaching high levels of rectus abdominis activation.
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Arumugam, Ashokan; Milosavljevic, Stephan; Woodley, Stephanie; Sole, Gisela
2015-06-01
There is evidence that applying a pelvic compression belt (PCB) can decrease hamstring and lumbar muscle electromyographic activity and increase gluteus maximus activity in healthy women during walking. Increased isokinetic eccentric hamstring strength in the terminal range (25 ° - 5 °) of knee extension has been reported with the use of such a belt in sportsmen with and without hamstring injuries. However, it is unknown whether wearing a pelvic belt alters activity of the hamstrings in sportsmen during walking. To examine the effects of wearing a PCB on electromyographic activity of the hamstring and lumbopelvic muscles during walking in sportsmen with and without hamstring injuries. Randomised crossover, cross-sectional study. Thirty uninjured sportsmen (23.53 ± 3.68 years) and 20 sportsmen with hamstring injuries (22.00 ± 1.45 years) sustained within the previous 12 months participated in this study. Electromyographic amplitudes of the hamstrings, gluteus maximus, gluteus medius and lumbar multifidus were monitored during defined phases of walking and normalised to maximum voluntary isometric contraction. Within-group comparisons [PCB vs. no PCB] for the normalised electromyographic amplitudes were performed for each muscle group using paired t tests. Electromyographic change scores [belt - no belt] were calculated and compared between the two groups with independent t tests. No significant change was evident in hamstring activity for either group while walking with the PCB (p > 0.050). However, with the PCB, gluteus medius activity (p ≤ 0.028) increased in both groups, while gluteus maximus activity increased (p = 0.025) and multifidus activity decreased (p hamstrings during walking, resulting in no significant changes within or between the two groups. Future studies investigating effects of the PCB on hamstring activity in participants with acute injury and during a more demanding functional activity such as running are warranted
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Hybrid soft computing systems for electromyographic signals analysis: a review.
Xie, Hong-Bo; Guo, Tianruo; Bai, Siwei; Dokos, Socrates
2014-02-03
Electromyographic (EMG) is a bio-signal collected on human skeletal muscle. Analysis of EMG signals has been widely used to detect human movement intent, control various human-machine interfaces, diagnose neuromuscular diseases, and model neuromusculoskeletal system. With the advances of artificial intelligence and soft computing, many sophisticated techniques have been proposed for such purpose. Hybrid soft computing system (HSCS), the integration of these different techniques, aims to further improve the effectiveness, efficiency, and accuracy of EMG analysis. This paper reviews and compares key combinations of neural network, support vector machine, fuzzy logic, evolutionary computing, and swarm intelligence for EMG analysis. Our suggestions on the possible future development of HSCS in EMG analysis are also given in terms of basic soft computing techniques, further combination of these techniques, and their other applications in EMG analysis.
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Hybrid soft computing systems for electromyographic signals analysis: a review
2014-01-01
Electromyographic (EMG) is a bio-signal collected on human skeletal muscle. Analysis of EMG signals has been widely used to detect human movement intent, control various human-machine interfaces, diagnose neuromuscular diseases, and model neuromusculoskeletal system. With the advances of artificial intelligence and soft computing, many sophisticated techniques have been proposed for such purpose. Hybrid soft computing system (HSCS), the integration of these different techniques, aims to further improve the effectiveness, efficiency, and accuracy of EMG analysis. This paper reviews and compares key combinations of neural network, support vector machine, fuzzy logic, evolutionary computing, and swarm intelligence for EMG analysis. Our suggestions on the possible future development of HSCS in EMG analysis are also given in terms of basic soft computing techniques, further combination of these techniques, and their other applications in EMG analysis. PMID:24490979
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Ko, Ellen Wen-Ching; Teng, Terry Te-Yi; Huang, Chiung Shing; Chen, Yu-Ray
2015-01-01
The study was conducted to evaluate the effect of early physical rehabilitation by comparing the differences of surface electromyographic (sEMG) activity in the masseter and anterior temporalis muscles after surgical correction of skeletal class III malocclusion. The prospective study included 63 patients; the experimental groups contained 31 patients who received early systematic physical rehabilitation; the control group (32 patients) did not receive physiotherapy. The amplitude of sEMG in the masticatory muscles reached 72.6-121.3% and 37.5-64.6% of pre-surgical values in the experimental and control groups respectively at 6 weeks after orthognathic surgery (OGS). At 6 months after OGS, the sEMG reached 135.1-233.4% and 89.6-122.5% of pre-surgical values in the experimental and control groups respectively. Most variables in the sEMG examination indicated that recovery of the masticatory muscles in the experimental group was better than the control group as estimated in the early phase (T1 to T2) and the total phase (T1 to T3); there were no significant differences between the mean recovery percentages in the later phase (T2 to T3). Early physical rehabilitative therapy is helpful for early recovery of muscle activity in masticatory muscles after OGS. After termination of physical therapy, no significant difference in recovery was indicated in patients with or without early physiotherapy. Copyright © 2014 European Association for Cranio-Maxillo-Facial Surgery. Published by Elsevier Ltd. All rights reserved.
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Smirnov, M S; Kiyatkin, E A
2010-01-20
Many important physiological, behavioral and subjective effects of i.v. cocaine (COC) are exceptionally rapid and transient, suggesting a possible involvement of peripheral neural substrates in their triggering. In the present study, we used high-speed electroencephalographic (EEG) and electromyographic (EMG) recordings (4-s resolution) in freely moving rats to characterize the central electrophysiological effects of i.v. COC at low doses within a self-administration range (0.25-1.0 mg/kg). We found that COC induces rapid, strong, and prolonged desynchronization of cortical EEG (decrease in alpha and increase in beta and gamma activity) and activation of the neck EMG that begin within 2-6 s following the start of a 10-s injection; immediate components of both effects were dose-independent. The rapid effects of COC were mimicked by i.v. COC methiodide (COC-MET), a derivative that cannot cross the blood-brain barrier. At equimolar doses (0.33-1.33 mg/kg), COC-MET had equally fast and strong effects on EEG and EMG total powers, decreasing alpha and increasing beta and gamma activities. Rapid EEG desynchronization and EMG activation was also induced by i.v. procaine, a structurally similar, short-acting local anesthetic with virtually no effects on monoamine uptake; at equipotential doses (1.25-5.0 mg/kg), these effects were weaker and shorter in duration than those of COC. Surprisingly, i.v. saline injection delivered during slow-wave sleep (but not during quiet wakefulness) also induced a transient EEG desynchronization but without changes in EMG and motor activity; these effects were significantly weaker and much shorter than those induced by all tested drugs. These data suggest that in awake animals, i.v. COC induces rapid cortical activation and a subsequent motor response via its action on peripheral non-monoamine neural elements, involving neural transmission via visceral sensory pathways. By providing a rapid neural signal and triggering neural activation, such
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Electromyographic evaluation of the upper lip according to the breathing mode: a longitudinal study
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Aldrieli Regina Ambrosio
2009-12-01
Full Text Available The present study aimed at analyzing and comparing longitudinally the EMG (electromyographic activity of the superior orbicularis oris muscle according to the breathing mode. The sample, 38 adolescents with Angle Class II Division 1 malocclusion with predominantly nose (PNB or mouth (PMB breathing, was evaluated at two different periods, with a two-year interval between them. For that purpose, a 16channel electromyography machine was employed, which was properly calibrated in a PC equipped with an analogue-digital converter, with utilization of surface, passive and bipolar electrodes. The RMS data (root mean square were collected at rest and in 12 movements and normalized according to time and amplitude, by the peak value of EMG, in order to allow comparisons between subjects and between periods. Comparison of the muscle function of PNB and PMB subjects at period 1 (P1, period 2 (P2 and the variation between periods (Δ did not reveal statistically significant differences between groups (p < 0.05. However, longitudinal evaluation of the muscle function in PNB and PMB subjects demonstrated different evolutions in the percentage of required EMG for accomplishment of the movements investigated. It was possible to conclude that there are differences in the percentage of electric activity of the upper lip with the growth of the subjects according to the breathing mode.
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Szyszka-Sommerfeld, Liliana; Woźniak, Krzysztof; Matthews-Brzozowska, Teresa; Kawala, Beata; Mikulewicz, Marcin
2017-09-01
The aim of this study was to assess the electrical activity of the superior orbicularis oris muscle in children surgically treated for unilateral complete cleft lip and palate (UCCLP). The sample comprised 45 patients 6.38-12.68 years of age with UCCLP and 40 subjects 6.61-11.71 years of age with no clefts. Electromyographical (EMG) recordings were taken with a DAB-Bluetooth Instrument (Zebris Medical GmbH, Germany) in the rest position and during saliva swallowing, lip protrusion and reciprocal compression of the lips, as well as while producing the phonemes /p/, /b/, and /m/ combined with the vowel /a/. The electrical activity of the upper lip during saliva swallowing and lip compression was significantly greater in the cleft group. Similar resting level activity was observed in both groups. During the production of the /p/, /b/, and /m/ phonemes combined with the vowel /a/ the results showed no significant differences in the EMG activity between children with UCCLP and noncleft subjects. Patients with UCCLP have abnormal upper lip function characterized by increased activity of the superior orbicularis oris muscle during saliva swallowing and lip compression, and this may affect facial morphology. Copyright © 2017 The Author(s). Published by Elsevier Ltd.. All rights reserved.
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Papadakis Stamatios A
2007-09-01
Full Text Available Abstract Background Several studies have been carried out in order to investigate the effect of ankle bracing on ankle joint function and performance. However, no study so far has examined the role of skin-brace interface pressure in neuromuscular control. The aim of this study was to investigate the effect of different skin-ankle brace interface pressures on quiet single limb balance and the electromyographic (EMG activation sequence of four lower limb muscles. Methods Thirty three male physical education students who volunteered to take part in the study were measured under three ankle brace conditions: i without brace, ii with brace and 30 kPa application pressure and iii with brace and 60 kPa application pressure. Single limb balance (anteroposterior and mediolateral parameter was assessed on the dominant lower limb, with open and closed eyes, on a force platform, simultaneously with the EMG recording of four lower lower limb muscles' (gastrocnemius, peroneus longus, rectus femoris and biceps femoris activation onset. Results The results showed that overall balance (total stability parameter was not significantly affected in any of the three ankle brace conditions. However, the anteroposterior centre of pressure excursion and centre of pressure excursion velocity were significantly increased with the application of ankle brace, both with 30 and 60 kPa application pressures. Furthermore, it was found that single limb balance was significantly worse with closed eyes compared to open eyes. EMG measurements showed that the sequence of lower limb activation onset was not affected in any of the three ankle brace application conditions. The results of this study showed that the application of an ankle brace with two different skin-brace interface pressures had no effect on overall single limb balance and the sequence of lower limb muscle activation. Conclusion These findings suggest that peripheral joint receptors are either not adequately
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Clinical and electromyographic criteria for the diagnosis of hereditary myotonic syndromes
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V. P. Fedotov
2012-01-01
Full Text Available Hereditary myotonic syndromes (HMS are a group of genetically heterogeneous diseases of the chlorine and sodium ion channels (channelopathies with evident clinical polymorphism and high prevalence in the population. The differential diagnosis of early‑stage NMS poses a challenge to clinicians to this day. The investigation has attempted to elaborate informative differentiating criteria on the basis of a clinical and electromyographic study of 2 groups of patients with hereditary Thomsen or Becker myotonia (n = 45 and myotonic dystrophy type 1 (n = 39 verified by DNA analysis of the CLCN1 and DMPK genes. Along with the clinical symptoms, there may be the value of M‑response amplitude decrement in rhythmic stimulation of the n. ulnaris and the duration of myotonic discharges at pin electromyography of the m. tibialis anterior.
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Muscle fiber velocity and electromyographic signs of fatigue in fibromyalgia.
Klaver-Król, Ewa G; Rasker, Johannes J; Henriquez, Nizare R; Verheijen, Wilma G; Zwarts, Machiel J
2012-11-01
Fibromyalgia (FM) is a disorder of widespread muscular pain. We investigated possible differences in surface electromyography (sEMG) in clinically unaffected muscle between patients with FM and controls. sEMG was performed on the biceps brachii muscle of 13 women with FM and 14 matched healthy controls during prolonged dynamic exercises, unloaded, and loaded up to 20% of maximum voluntary contraction. The sEMG parameters were: muscle fiber conduction velocity (CV); skewness of motor unit potential (peak) velocities; peak frequency (PF) (number of peaks per second); and average rectified voltage (ARV). There was significantly higher CV in the FM group. Although the FM group performed the tests equally well, their electromyographic fatigue was significantly less expressed compared with controls (in CV, PF, and ARV). In the patients with FM, we clearly showed functional abnormalities of the muscle membrane, which led to high conduction velocity and resistance to fatigue in electromyography. Copyright © 2012 Wiley Periodicals, Inc.
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Martinez-Valdes, Eduardo; Negro, Francesco; Falla, Deborah; De Nunzio, Alessandro Marco; Farina, Dario
2018-04-01
Surface electromyographic (EMG) signal amplitude is typically used to compare the neural drive to muscles. We experimentally investigated this association by studying the motor unit (MU) behavior and action potentials in the vastus medialis (VM) and vastus lateralis (VL) muscles. Eighteen participants performed isometric knee extensions at four target torques [10, 30, 50, and 70% of the maximum torque (MVC)] while high-density EMG signals were recorded from the VM and VL. The absolute EMG amplitude was greater for VM than VL ( P differences in EMG amplitude can be due to both differences in the neural drive and in the size of the MU action potentials, we indirectly inferred the neural drives received by the two muscles by estimating the synaptic inputs received by the corresponding motor neuron pools. For this purpose, we analyzed the increase in discharge rate from recruitment to target torque for motor units matched by recruitment threshold in the two muscles. This analysis indicated that the two muscles received similar levels of neural drive. Nonetheless, the size of the MU action potentials was greater for VM than VL ( P difference explained most of the differences in EMG amplitude between the two muscles (~63% of explained variance). These results indicate that EMG amplitude, even following normalization, does not reflect the neural drive to synergistic muscles. Moreover, absolute EMG amplitude is mainly explained by the size of MU action potentials. NEW & NOTEWORTHY Electromyographic (EMG) amplitude is widely used to compare indirectly the strength of neural drive received by synergistic muscles. However, there are no studies validating this approach with motor unit data. Here, we compared between-muscles differences in surface EMG amplitude and motor unit behavior. The results clarify the limitations of surface EMG to interpret differences in neural drive between muscles.
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Woodburn James
2009-08-01
Full Text Available Abstract Tibialis posterior has a vital role during gait as the primary dynamic stabiliser of the medial longitudinal arch; however, the muscle and tendon are prone to dysfunction with several conditions. We present an overview of tibialis posterior muscle and tendon anatomy with images from cadaveric work on fresh frozen limbs and a review of current evidence that define normal and abnormal tibialis posterior muscle activation during gait. A video is available that demonstrates ultrasound guided intra-muscular insertion techniques for tibialis posterior electromyography. Current electromyography literature indicates tibialis posterior intensity and timing during walking is variable in healthy adults and has a disease-specific activation profile among different pathologies. Flat-arched foot posture and tibialis posterior tendon dysfunction are associated with greater tibialis posterior muscle activity during stance phase, compared to normal or healthy participants, respectively. Cerebral palsy is associated with four potentially abnormal profiles during the entire gait cycle; however it is unclear how these profiles are defined as these studies lack control groups that characterise electromyographic activity from developmentally normal children. Intervention studies show antipronation taping to significantly decrease tibialis posterior muscle activation during walking compared to barefoot, although this research is based on only four participants. However, other interventions such as foot orthoses and footwear do not appear to systematically effect muscle activation during walking or running, respectively. This review highlights deficits in current evidence and provides suggestions for the future research agenda.
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Muscle Activation during Push-Ups with Different Suspension Training Systems.
Calatayud, Joaquin; Borreani, Sebastien; Colado, Juan C; Martín, Fernando F; Rogers, Michael E; Behm, David G; Andersen, Lars L
2014-09-01
The purpose of this study was to analyze upper extremity and core muscle activation when performing push-ups with different suspension devices. Young fit male university students (n = 29) performed 3 push-ups each with 4 different suspension systems. Push-up speed was controlled using a metronome and testing order was randomized. Average amplitude of the electromyographic root mean square of Triceps Brachii, Upper Trapezius, Anterior Deltoid, Clavicular Pectoralis, Rectus Abdominis, Rectus Femoris, and Lumbar Erector Spinae was recorded. Electromyographic signals were normalized to the maximum voluntary isometric contraction (MVIC). Electromyographic data were analyzed with repeated-measures analysis of variance with a Bonferroni post hoc. Based upon global arithmetic mean of all muscles analyzed, the suspended push-up with a pulley system provided the greatest activity (37.76% of MVIC; p push-up with a pulley system also provided the greatest triceps brachii, upper trapezius, rectus femoris and erector lumbar spinae muscle activation. In contrast, more stable conditions seem more appropriate for pectoralis major and anterior deltoid muscles. Independent of the type of design, all suspension systems were especially effective training tools for reaching high levels of rectus abdominis activation. Key PointsCompared with standard push-ups on the floor, suspended push-ups increase core muscle activation.A one-anchor system with a pulley is the best option to increase TRICEP, TRAPS, LUMB and FEM muscle activity.More stable conditions such as the standard push-up or a parallel band system provide greater increases in DELT and PEC muscle activation.A suspended push-up is an effective method to achieve high muscle activity levels in the ABS.
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Rayegani, S M; Raeissadat, S A; Sedighipour, L; Rezazadeh, I Mohammad; Bahrami, M H; Eliaspour, D; Khosrawi, S
2014-01-01
The aim of the present study was to evaluate the effect of applying electroencephalogram (EEG) biofeedback (neurobiofeedback) or electromyographic (EMG) biofeedback to conventional occupational therapy (OT) on improving hand function in stroke patients. This study was designed as a preliminary clinical trial. Thirty patients with stroke were entered the study. Hand function was evaluated by Jebsen Hand Function Test pre and post intervention. Patients were allocated to 3 intervention cohorts: (1) OT, (2) OT plus EMG-biofeedback therapy, and (3) OT plus neurofeedback therapy. All patients received 10 sessions of conventional OT. Patients in cohorts 2 and 3 also received EMG-biofeedback and neurofeedback therapy, respectively. EMG-biofeedback therapy was performed to strengthen the abductor pollicis brevis (APB) muscle. Neurofeedback training was aimed at enhancing sensorimotor rhythm after mental motor imagery. Hand function was improved significantly in the 3 groups. The spectral power density of the sensorimotor rhythm band in the neurofeedback group increased after mental motor imagery. Maximum and mean contraction values of electrical activities of the APB muscle during voluntary contraction increased significantly after EMG-biofeedback training. Patients in the neurofeedback and EMG-biofeedback groups showed hand improvement similar to conventional OT. Further studies are suggested to assign the best protocol for neurofeedback and EMG-biofeedback therapy.
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Andersen, Vidar; Fimland, Marius S; Mo, Dag-Andrè; Iversen, Vegard M; Vederhus, Torbjørn; Rockland Hellebø, Lars R; Nordaune, Kristina I; Saeterbakken, Atle H
2018-03-01
Andersen, V, Fimland, MS, Mo, D-A, Iversen, VM, Vederhus, T, Rockland Hellebø, LR, Nordaune, KI, and Saeterbakken, AH. Electromyographic comparison of barbell deadlift, hex bar deadlift, and hip thrust exercises: a cross-over study. J Strength Cond Res 32(3): 587-593, 2018-The aim of the study was to compare the muscle activation level of the gluteus maximus, biceps femoris, and erector spinae in the hip thrust, barbell deadlift, and hex bar deadlift; each of which are compound resisted hip extension exercises. After 2 familiarization sessions, 13 resistance-trained men performed a 1 repetition maximum in all 3 exercises in 1 session, in randomized and counterbalanced order. The whole ascending movement (concentric phase), as well as its lower and upper parts (whole movement divided in 2), were analyzed. The hip thrust induced greater activation of the gluteus maximus compared with the hex bar deadlift in the whole (16%, p = 0.025) and the upper part (26%, p = 0.015) of the movement. For the whole movement, the biceps femoris was more activated during barbell deadlift compared with both the hex bar deadlift (28%, p bar deadlift (p = 0.049) compared with hip thrust. Biceps femoris activation in the upper part of the movement was 39% higher for the barbell deadlift compared with the hex bar deadlift (p = 0.001) and 34% higher for the hip thrust compared with the hex bar deadlift (p = 0.002). No differences were displayed for the erector spinae activation (p = 0.312-0.859). In conclusion, the barbell deadlift was clearly superior in activating the biceps femoris compared with the hex bar deadlift and hip thrust, whereas the hip thrust provided the highest gluteus maximus activation.
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Electromyographic Pattern Analysis and Classification for a Robotic Prosthetic Arm
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M. José H. Erazo Macias
2006-01-01
Full Text Available This paper deals with the statistical analysis and pattern classification of electromyographic signals from the biceps of a person with amputation below the humerus. Such signals collected from an amputation simulator are synergistically generated to produce discrete elbow movements. The purpose of this study is to utilise these signals to control an electrically driven prosthetic or orthotic elbow with minimum extra mental effort on the part of the subject. The results show very good separability of classes of movements when a learning pattern classification scheme is used, and a superposition of any composite motion to the three basic primitive motions—humeral rotation in and out, flexion and extension, and pronation and supination. Since no synergy was detected for the wrist movement, different inputs have to be provided for a grip. In addition, the method described is not limited by the location of the electrodes. For amputees with shorter stumps, synergistic signals could be obtained from the shoulder muscles. However, the presentation in this paper is limited to biceps signal classification only.
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Core Muscle Activation in Suspension Training Exercises.
Cugliari, Giovanni; Boccia, Gennaro
2017-02-01
A quantitative observational laboratory study was conducted to characterize and classify core training exercises executed in a suspension modality on the base of muscle activation. In a prospective single-group repeated measures design, seventeen active male participants performed four suspension exercises typically associated with core training (roll-out, bodysaw, pike and knee-tuck). Surface electromyographic signals were recorded from lower and upper parts of rectus abdominis, external oblique, internal oblique, lower and upper parts of erector spinae muscles using concentric bipolar electrodes. The average rectified values of electromyographic signals were normalized with respect to individual maximum voluntary isometric contraction of each muscle. Roll-out exercise showed the highest activation of rectus abdominis and oblique muscles compared to the other exercises. The rectus abdominis and external oblique reached an activation higher than 60% of the maximal voluntary contraction (or very close to that threshold, 55%) in roll-out and bodysaw exercises. Findings from this study allow the selection of suspension core training exercises on the basis of quantitative information about the activation of muscles of interest. Roll-out and bodysaw exercises can be considered as suitable for strength training of rectus abdominis and external oblique muscles.
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ELECTROMYOGRAPHIC STUDY OF A SEQUENCE OF YAU-MAN KUNG FU PALM STRIKES WITH AND WITHOUT IMPACT
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Osmar Pinto Neto
2007-10-01
Full Text Available In martial arts and contact sports, strikes are often trained in two different ways: with and without impacts. This study aims to compare the electromyographical activity (EMG of the triceps brachii (TB, biceps brachii (BB and brachioradialis (BR muscles during strikes with and without impacts. Eight Yau-Man Kung Fu practitioners participated in the experiment. Each participant performed 5 sequences of 5 consecutive KF Yau-Man palm strikes with no impact intercalated with 5 sequences of 5 repetitions targeting a KF training shield. Surface EMG signals were obtained from the TB, BB, and RB for 3.0 seconds using an eight-channel module with a total amplifier gain of 2000 and sampled at 3500 Hz. The EMG analyses were done in the time (rms and frequency (wavelet domains. For the frequency domain, Morlet wavelet power spectra were obtained and an original method was used to quantify statistically significant regions on the power spectra. The results both in the time and frequency domains indicate a higher TB and BR muscle activity for the strikes with impacts. No significant difference was found for the BB in the two different scenarios. In addition, the results show that the wavelet power spectra pattern for the three analysed muscles obtained from the strikes with and without impacts were similar
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Firing patterns of spontaneously active motor units in spinal cord-injured subjects
Zijdewind, Inge; Thomas, Christine K.
Involuntary motor unit activity at low rates is common in hand muscles paralysed by spinal cord injury. Our aim was to describe these patterns of motor unit behaviour in relation to motoneurone and motor unit properties. Intramuscular electromyographic activity (EMG), surface EMG and force were
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DEFF Research Database (Denmark)
Jeppesen, Jesper; Otto, Marit; Frederiksen, Yoon
2018-01-01
OBJECTIVES: Rapid eye movement (REM) sleep behavior disorder (RBD) is defined by dream enactment due to a failure of normal muscle atonia. Visual assessment of this muscle activity is time consuming and rater-dependent. METHODS: An EMG computer algorithm for scoring 'tonic', 'phasic' and 'any......' submental muscle activity during REM sleep was evaluated compared with human visual ratings. Subsequently, 52 subjects were analyzed with the algorithm. Duration and maximal amplitude of muscle activity, and self-awareness of RBD symptoms were assessed. RESULTS: The computer algorithm showed high congruency...... sleep without atonia. CONCLUSIONS: Our proposed algorithm was able to detect and rate REM sleep without atonia allowing identification of RBD. Increased duration and amplitude of muscle activity bouts were characteristics of RBD. Quantification of REM sleep without atonia represents a marker of RBD...
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Influence of experimental occlusal discrepancy on masticatory muscle activity during clenching.
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.
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Electromyographic Study of a Sequence of Yau-Man Kung Fu Palm Strikes with and without Impact.
Neto, Osmar Pinto; Magini, Marcio; Pacheco, Marcos T T
2007-01-01
IN MARTIAL ARTS AND CONTACT SPORTS, STRIKES ARE OFTEN TRAINED IN TWO DIFFERENT WAYS: with and without impacts. This study aims to compare the electromyographical activity (EMG) of the triceps brachii (TB), biceps brachii (BB) and brachioradialis (BR) muscles during strikes with and without impacts. Eight Yau-Man Kung Fu practitioners participated in the experiment. Each participant performed 5 sequences of 5 consecutive KF Yau-Man palm strikes with no impact intercalated with 5 sequences of 5 repetitions targeting a KF training shield. Surface EMG signals were obtained from the TB, BB, and RB for 3.0 seconds using an eight-channel module with a total amplifier gain of 2000 and sampled at 3500 Hz. The EMG analyses were done in the time (rms) and frequency (wavelet) domains. For the frequency domain, Morlet wavelet power spectra were obtained and an original method was used to quantify statistically significant regions on the power spectra. The results both in the time and frequency domains indicate a higher TB and BR muscle activity for the strikes with impacts. No significant difference was found for the BB in the two different scenarios. In addition, the results show that the wavelet power spectra pattern for the three analysed muscles obtained from the strikes with and without impacts were similar. Key pointsEMG analysis of a sequence of Kung Fu strikes demonstrates higher Triceps Brachii and Brachioradialis muscle activity for strikes with impact than strikes without impact.An original reliable method for quantifying EMG wavelet transform results is presented.EMG wavelet power spectra describe muscle roles during a Kung Fu sequence of strikes.
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PASTERNAK-JÚNIOR, Braulio; de SOUSA NETO, Manoel Damião; DIONÍSIO, Valdeci Carlos; PÉCORA, Jesus Djalma; SILVA, Ricardo Gariba
2012-01-01
Objective This study assessed the muscular activity during root canal preparation through kinematics, kinetics, and electromyography (EMG). Material and Methods The operators prepared one canal with RaCe rotary instruments and another with Flexo-files. The kinematics of the major joints was reconstructed using an optoelectronic system and electromyographic responses of the flexor carpi radialis, extensor carpi radialis, brachioradialis, biceps brachii, triceps brachii, middle deltoid, and upper trapezius were recorded. The joint torques of the shoulder, elbow and wrist were calculated using inverse dynamics. In the kinematic analysis, angular movements of the wrist and elbow were classified as low risk factors for work-related musculoskeletal disorders. With respect to the shoulder, the classification was medium-risk. Results There was no significant difference revealed by the kinetic reports. The EMG results showed that for the middle deltoid and upper trapezius the rotary instrumentation elicited higher values. The flexor carpi radialis and extensor carpi radialis, as well as the brachioradialis showed a higher value with the manual method. Conclusion The muscular recruitment for accomplishment of articular movements for root canal preparation with either the rotary or manual techniques is distinct. Nevertheless, the rotary instrument presented less difficulty in the generation of the joint torque in each articulation, thus, presenting a greater uniformity of joint torques. PMID:22437679
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Kruluc, P; Nemec, Alenka
2006-03-01
Clinically, the use of detomidine and butorphanol is suitable for sedation and deepening of analgosedation. The aim of our study was to establish the influence of detomidine used alone and a butorphanol-detomidine combination on brain activity and to evaluate and compare brain responses (using electroencephalography, EEG) by recording SEF90 (spectral edge frequency 90%), individual brain wave fractions (beta, alpha, theta and delta) and electromyographic (EMG) changes in the left temporal muscle in standing horses. Ten clinically healthy cold-blooded horses were divided into two groups of five animals each. Group I received detomidine and Group II received detomidine followed by butorphanol 10 min later. SEF90, individual brain wave fractions and EMG were recorded with a pEEG (processed EEG) monitor using computerised processed electroencephalography and electromyography. The present study found that detomidine alone and the detomidine-butorphanol combination significantly reduced SEF90 and EMG, and they caused changes in individual brain wave fractions during sedation and particularly during analgosedation. The EMG results showed that the detomidine-butorphanol combination provided greater and longer muscle relaxation. Our EEG and EMG results confirmed that the detomidine-butorphanol combination is safer and more appropriate for painless and non-painless procedures on standing horses compared to detomidine alone.
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Indira Nayra Paz Santos
Full Text Available Introduction Muscle activity in the aquatic environment was investigated using electromyographic analyses. The physical properties of water and the resistance used may influence the response of the muscle during exercise. The objective of this study was to evaluate the electrical activity in water and on the floor during flexion and knee extension exercises with and without load and aimed at understanding the muscular response while performing resistance exercises in water. Methods The sample consisted of 14 volunteers between 18 and 35 years old who were subjected to active exercises involving knee flexion and extension with and without load on the floor and in water. Electromyography was performed during the movement. Results A significant increase was found in the electrical activity of the rectus femoris muscle during exercises on the floor. The biceps femoris muscle showed increased electromyographic activity when resistance was used. A significant increase was found in the electrical activity of the rectus femoris muscle compared with exercises with and without load and the moment of rest in immersion. The electrical activity of the rectus and biceps femoris muscles was reduced in exercises with load and without load in a therapy pool compared with on the floor. Conclusion There was a reduction of the electromyographic activity in the aquatic environment compared with that on the ground, which could be attributed to the effects from hot water. Therefore, it is believed that resistance exercises can be performed early in a therapy pool, which will facilitate the prevention and treatment of musculoskeletal disorders.
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Cervico-mandibular muscle activity in females with chronic cervical pain
T. Lang; R. Parker; T. Burgess
2013-01-01
Pathophysiological mechanisms behind pain in chroniccervical musculoskeletal conditions (MSC) in office workers remainunclear. Chronic cervical pain has established links with temporomandibular(TM) disorders. Yet there is no current published evidence to reportwhether individuals with cervical dysfunction exhibit altered masseterand cervical extensor (CE) muscle activity. Objective: To explore CE andmasseter surface electromyographic (sEMG) activity and teeth clenchinghabits in females with c...
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Electromyographic Findings in Overt Hypothyroidism and Subclinical Hypothyroidism
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Emel Oğuz Akarsu
2013-12-01
Full Text Available OBJECTIVE: Hypothyroidism may cause neurologic signs and symptoms as its effects neuromuscular system like many other systems. Subclinical hypothyroidism is the most common thyroid dysfuntion, it may cause neuromuscular signs and symptoms. In this retrospective study, it is aimed to compare neuromuscular symptoms and electromyographic (EMG manifestations between hypothyroid patients and control group with normal thyroid function and without a disease causing polyneuropathy. METHODS: 31 overt hypothyroidic, 139 subclinic hypothyroidic patients and 50 individuals with normal thyroid function, without a disease causing polyneuropathy, as control group whom made EMG for another reason were included to the study. Neuromuscular symptoms, neurological examination and electrophysiological findings was obtained from the patient records. RESULTS: In our study, we observed frequent neuromuscular complaints such as fatigue, morning stiffness, cramp, general pain and paresthesia in favor of both for overt and subclinic hypothyroidism. Carpal Tunnel Syndrom(CTS, was statistically higher in overt hypothyroidism group than control group. CTS was also observed higher in subclinic hypothyroidism group when compared with control group but it didn't reach to statistical significance. We did not detect polyneuropathy in any group. Motor nerve velocity and compound muscle action potential amplitudes were found to be statistically significant difference between hypothyroid ve control group. CONCLUSION: Since motor fibres' and neuromuscular area's being affected in hypothyroidism, which we interpret to happen due to basal metabolism's slowing down, can show a significant recovery after thyroid replacement therapy. We consider that, in further studies, comparison of electrophysiological findings after treatment with the findings of pre -treatment is necessary
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Nakagawa, Theresa H; Muniz, Thiago B; Baldon, Rodrigo M; Maciel, Carlos D; Amorim, César F; Serrão, Fábio V
2011-01-01
Proximal factors have been proposed to influence the biomechanics of the patellofemoral joint. A delayed or diminished gluteus medius (GM) activation, before the foot contact on the ground during functional activities could lead to excessive femur adduction and internal rotation and be associated with anterior knee pain (AKP). There are few studies on this topic and the results were inconclusive, therefore, it is necessary to investigate the GM preactivation pattern during functional activities. To compare the GM electromyographic (EMG) preactivation pattern during walking, descending stairs and in single leg jump task in women with and without AKP. Nine women clinically diagnosed with AKP and ten control subjects with no history of knee injury participated in this study. We evaluated GM EMG linear envelope before the foot contact on the ground during walking and GM onset time and EMG linear envelope during descending stairs as well as in a single leg vertical jump. Mann-Whitney U tests were used to determine the between-group differences in GM EMG preactivation pattern. No between-group differences were observed in GM linear envelope during walking (P=0.41), GM onset time and linear envelope during descending stairs (P=0.17 and P=0.15) and single leg jump (P=0.81 and P=0.33). Women with AKP did not demonstrated altered GM preactivation pattern during functional weight bearing activities. Our results did not support the hypothesis that poor GM preactivation pattern could be associated with AKP.
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Lavender, Steven A; Nagavarapu, Shasank; Allread, W Gary
2017-01-01
Many retail distribution centers (DCs) manually load and unload boxes into or out of trailers and shipping containers. This study investigated whether an articulating belt conveyor with a height adjustable platform, positioned at the end of an extendable conveyor, significantly reduces shoulder and back muscle loading and the spine kinematics associated with these tasks. Electromyographic and kinematic data were collected from eight volunteer employees as trailers at a shoe DC were unloaded and from nine volunteer employees as trailers at an apparel DC were loaded. Participants in this repeated measures study handled boxes with a conventional powered extendable conveyor system and with the articulating belt conveyor positioned at the end of the extendable conveyor. Bilaterally the normalized activation levels of the erector spinae and anterior deltoid muscles were reduced when loading and unloading boxes with the articulating belt conveyor. Spine movement speeds were also reduced with the articulating conveyor. Copyright © 2016 Elsevier Ltd. All rights reserved.
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Jin, Huijun; Patil, Pavan Manohar
2015-01-01
No consensus exists to date regarding the best method of controlling the airway for oral or craniomaxillofacial surgery when orotracheal and nasotracheal intubations are unsuccessful or contraindicated. The most commonly used method of tracheostomy has been associated with a high degree of morbidity. Therefore, the present study was conducted to determine the indications, safety, efficacy, time required, drawbacks, complications, and costs of the midline submental intubation (SMI) approach in elective oral and craniomaxillofacial surgical procedures. A retrospective case series study was used to evaluate the surgical, financial, and photographic records of all patients who had undergone oral or craniomaxillofacial operations at Sharda University School of Dental Sciences, Greater Noida, from April 2006 to March 2014. The indications, drawbacks, time required for the procedure, ability to provide a secure airway, intra- and postoperative complications, and additional costs associated with SMI were analyzed. Of the 2,823 patients treated, the present study included 120 patients (97 men and 23 women, aged 19 to 60 years). The average time required for SMI was 10 ± 2 minutes. No episode of intraoperative oxygen desaturation was noted. One intraoperative complication, an injury to the ventral surface of the tongue, was encountered. Two patients developed infection at the skin incision site. No significant additional cost was incurred with the use of SMI. SMI has been successfully used in elective oral and craniomaxillofacial surgical procedures for which oral and nasal intubations were either not indicated or not possible. The advantages include a quick procedure, insignificant complications, the ability to provide a stable airway, and no added costs, making SMI a quick, safe, efficient, and cost-effective alternative in such cases. Copyright © 2015 American Association of Oral and Maxillofacial Surgeons. Published by Elsevier Inc. All rights reserved.
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Lencioni, Tiziana; Piscosquito, Giuseppe; Rabuffetti, Marco; Sipio, Enrica Di; Diverio, Manuela; Moroni, Isabella; Padua, Luca; Pagliano, Emanuela; Schenone, Angelo; Pareyson, Davide; Ferrarin, Maurizio
2018-05-01
Charcot-Marie-Tooth (CMT) is a slowly progressive disease characterized by muscular weakness and wasting with a length-dependent pattern. Mildly affected CMT subjects showed slight alteration of walking compared to healthy subjects (HS). To investigate the biomechanics of step negotiation, a task that requires greater muscle strength and balance control compared to level walking, in CMT subjects without primary locomotor deficits (foot drop and push off deficit) during walking. We collected data (kinematic, kinetic, and surface electromyographic) during walking on level ground and step negotiation, from 98 CMT subjects with mild-to-moderate impairment. Twenty-one CMT subjects (CMT-NLW, normal-like-walkers) were selected for analysis, as they showed values of normalized ROM during swing and produced work at push-off at ankle joint comparable to those of 31 HS. Step negotiation tasks consisted in climbing and descending a two-step stair. Only the first step provided the ground reaction force data. To assess muscle activity, each EMG profile was integrated over 100% of task duration and the activation percentage was computed in four phases that constitute the step negotiation tasks. In both tasks, CMT-NLW showed distal muscle hypoactivation. In addition, during step-ascending CMT-NLW subjects had relevant lower activities of vastus medialis and rectus femoris than HS in weight-acceptance, and, on the opposite, a greater activation as compared to HS in forward-continuance. During step-descending, CMT-NLW showed a reduced activity of tibialis anterior during controlled-lowering phase. Step negotiation revealed adaptive motor strategies related to muscle weakness due to disease in CMT subjects without any clinically apparent locomotor deficit during level walking. In addition, this study provided results useful for tailored rehabilitation of CMT patients. Copyright © 2018 Elsevier B.V. All rights reserved.
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Diaphragm electromyographic activity following unilateral midcervical contusion injury in rats
Sieck, Gary C.
2016-01-01
Contusion-type injuries to the spinal cord are characterized by tissue loss and disruption of spinal pathways. Midcervical spinal cord injuries impair the function of respiratory muscles and may contribute to significant respiratory complications. This study systematically assessed the impact of a 100-kDy unilateral C4 contusion injury on diaphragm muscle activity across a range of motor behaviors in rats. Chronic diaphragm electromyography (EMG) was recorded before injury and at 1 and 7 days postinjury (DPI). Histological analyses assessed the extent of perineuronal net formation, white-matter sparing, and phrenic motoneuron loss. At 7 DPI, ∼45% of phrenic motoneurons were lost ipsilaterally. Relative diaphragm root mean square (RMS) EMG activity increased bilaterally across a range of motor behaviors by 7 DPI. The increase in diaphragm RMS EMG activity was associated with an increase in neural drive (RMS value at 75 ms after the onset of diaphragm activity) and was more pronounced during higher force, nonventilatory motor behaviors. Animals in the contusion group displayed a transient decrease in respiratory rate and an increase in burst duration at 1 DPI. By 7 days, following midcervical contusion, there was significant perineuronal net formation and white-matter loss that spanned 1 mm around the injury epicenter. Taken together, these findings are consistent with increased recruitment of remaining motor units, including more fatigable, high-threshold motor units, during higher force, nonventilatory behaviors. Changes in diaphragm EMG activity following midcervical contusion injury reflect complex adaptations in neuromotor control that may increase the risk of motor-unit fatigue and compromise the ability to sustain higher force diaphragm efforts. NEW & NOTEWORTHY The present study shows that unilateral contusion injury at C4 results in substantial loss of phrenic motoneurons but increased diaphragm muscle activity across a range of ventilatory and higher
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Mondésert, Blandine; Andrade, Jason G; Khairy, Paul; Guerra, Peter G; Dyrda, Katia; Macle, Laurent; Rivard, Léna; Thibault, Bernard; Talajic, Mario; Roy, Denis; Dubuc, Marc; Shohoudi, Azadeh
2014-08-01
Phrenic nerve palsy remains the most frequent complication associated with cryoballoon-based pulmonary vein (PV) isolation. We sought to characterize our experience using a novel monitoring technique for the prevention of phrenic nerve palsy. Two hundred consecutive cryoballoon-based PV isolation procedures between October 2010 and October 2013 were studied. In addition to standard abdominal palpation during right phrenic nerve pacing from the superior vena cava, all patients underwent diaphragmatic electromyographic monitoring using surface electrodes. Cryoablation was terminated on any perceived reduction in diaphragmatic motion or a 30% decrease in the compound motor action potential (CMAP). During right-sided ablation, a ≥30% reduction in CMAP amplitude occurred in 49 patients (24.5%). Diaphragmatic motion decreased in 30 of 49 patients and was preceded by a 30% reduction in CMAP amplitude in all. In 82% of cases, this reduction in CMAP amplitude occurred during right superior PV isolation. The baseline CMAP amplitude was 946.5±609.2 mV and decreased by 13.8±13.8% at the end of application. This decrease was more marked in the 33 PVs with a reduction in diaphragmatic motion than in those without (40.9±15.3% versus 11.3±10.5%; Pphrenic nerve palsy persisted beyond the end of the procedure, with all cases recovering within 6 months. Despite the shortened application all veins were isolated. At repeat procedure the right-sided PVs reconnected less frequently than the left-sided PVs in those with phrenic nerve palsy. Electromyographic phrenic nerve monitoring using the surface CMAP is reliable, easy to perform, and offers an early warning to impending phrenic nerve injury. © 2014 American Heart Association, Inc.
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Chalmers, Peter N; Cvetanovich, Gregory L; Kupfer, Noam; Wimmer, Markus A; Verma, Nikhil N; Cole, Brian J; Romeo, Anthony A; Nicholson, Gregory P
2016-02-01
While Jobe's test is widely used, it does not isolate supraspinatus activity. Our purpose was to examine the electromyographic (EMG) activity within the supraspinatus and deltoid with resisted abduction to determine the shoulder position that best isolates the activity of the supraspinatus. We performed EMG analysis of the supraspinatus, anterior head of the deltoid, and middle head of the deltoid in 10 normal volunteers. We measured EMG activity during resisted shoulder abduction in the scapular plane to both manual resistance and a standardized load in varying degrees of abduction and rotation. To determine which position best isolates supraspinatus activity, the ratio of supraspinatus to deltoid activity (S:D) was calculated for each position. Results were analyzed with a repeated-measures analysis of variance with Bonferroni correction. The posterior deltoid was excluded as it serves mostly to extend and externally rotate. Our study confirmed Jobe's findings of maximal supraspinatus activity at 90° of abduction. However, decreasing abduction significantly increased S:D for both resisted manual testing and testing against a standardized load (P = .002 and .001, respectively). The greatest S:D ratio (4.6 ± 3.4 for standardized load testing) was seen at the "champagne toast" position, i.e., 30° of abduction, mild external rotation, 30° of flexion, and 90° of elbow flexion. The smallest ratio (0.8 ± 0.6) was seen at Jobe's position. Testing of abduction strength in the champagne toast position, i.e., 30° of abduction, mild external rotation, and 30° of flexion, better isolates the activity of the supraspinatus from the deltoid than Jobe's "empty can" position. Copyright © 2016 Journal of Shoulder and Elbow Surgery Board of Trustees. Published by Elsevier Inc. All rights reserved.
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Directory of Open Access Journals (Sweden)
Braulio Pasternak-Júnior
2012-02-01
Full Text Available OBJECTIVE: This study assessed the muscular activity during root canal preparation through kinematics, kinetics, and electromyography (EMG. MATERIAL AND METHODS: The operators prepared one canal with RaCe rotary instruments and another with Flexo-files. The kinematics of the major joints was reconstructed using an optoelectronic system and electromyographic responses of the flexor carpi radialis, extensor carpi radialis, brachioradialis, biceps brachii, triceps brachii, middle deltoid, and upper trapezius were recorded. The joint torques of the shoulder, elbow and wrist were calculated using inverse dynamics. In the kinematic analysis, angular movements of the wrist and elbow were classified as low risk factors for work-related musculoskeletal disorders. With respect to the shoulder, the classification was medium-risk. RESULTS: There was no significant difference revealed by the kinetic reports. The EMG results showed that for the middle deltoid and upper trapezius the rotary instrumentation elicited higher values. The flexor carpi radialis and extensor carpi radialis, as well as the brachioradialis showed a higher value with the manual method. CONCLUSION: The muscular recruitment for accomplishment of articular movements for root canal preparation with either the rotary or manual techniques is distinct. Nevertheless, the rotary instrument presented less difficulty in the generation of the joint torque in each articulation, thus, presenting a greater uniformity of joint torques.
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Schepens, Tom; Cammu, Guy; Saldien, Vera; De Neve, Nikolaas; Jorens, Philippe G; Foubert, Luc; Vercauteren, Marcel
2015-01-01
The use of neuromuscular blocking agents has been associated with severe postoperative respiratory morbidity. Complications can be attributed to inadequate reversal, and reversal agents may themselves have adverse effects. To compare the electromyographic activity of the diaphragm (EMGdi) during recovery from neuromuscular blockade using neostigmine and sugammadex. The hypothesis was that there would be better neuromuscular coupling of the diaphragm when sugammadex was used. A randomised, controlled, parallel-group, single-centre, double-blinded study. District general hospital in Belgium. Twelve healthy male volunteers. Individuals were anaesthetised with propofol and remifentanil. After rocuronium 0.6 mg kg, a transoesophageal electromyography (EMG) recorder was inserted. For reversal of neuromuscular blockade, volunteers received sugammadex 2 mg kg (n = 6) or neostigmine 70 μg kg (n = 6). EMGdi, airway pressure and flow were continuously measured during weaning from the ventilator until tracheal extubation. Arterial blood gas samples were obtained for PaO2 and PaCO2 analysis at the first spontaneous breathing attempt and after tracheal extubation. During weaning, 560 breaths were retained for analysis. The median (95% CI) peak EMGdi was 1.1 (0.9 to 1.5) μV in the neostigmine group and 1.6 (1.3 to 1.9) μV in the sugammadex group (P sugammadex group (P = 0.008). The median (95% CI) tidal volume was 287 (256 to 335) ml after neostigmine and 359 (313 to 398) ml after sugammadex (P = 0.013). The median (95% CI) PaO2 immediately after extubation was 30.5 (22.8 to 37.1) kPa after sugammadex vs. 20.7 (12.9 to 27.5) kPa after neostigmine (P = 0.03). EMGdi, tidal volume and PaO2 following tracheal extubation were increased after sugammadex compared with neostigmine, reflecting diaphragm-driven inspiration after sugammadex administration. Sugammadex may free more diaphragmatic acetylcholine receptors than neostigmine, which has an
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Tecco, Simona; Tetè, Stefano; D'Attilio, Michele; Perillo, Letizia; Festa, Felice
2008-12-01
The aim of this study was to investigate the surface electromyographic (sEMG) activity of neck, trunk, and masticatory muscles in subjects with temporomandibular joint (TMJ) internal derangement treated with anterior mandibular repositioning splints. sEMG activities of the muscles in 34 adult subjects (22 females and 12 males; mean age 30.4 years) with TMJ internal derangement were compared with a control group of 34 untreated adults (20 females and 14 males; mean age 31.8 years). sEMG activities of seven muscles (anterior and posterior temporalis, masseter, posterior cervicals, sternocleidomastoid, and upper and lower trapezius) were studied bilaterally, with the mandible in the rest position and during maximal voluntary clenching (MVC), at the beginning of therapy (T0) and after 10 weeks of treatment (T1). Paired and Student's t-tests were undertaken to determine differences between the T0 and T1 data and in sEMG activity between the study and control groups. At T0, paired masseter, sternocleidomastoid, and cervical muscles, in addition to the left anterior temporal and right lower trapezius, showed significantly greater sEMG activity (P = 0.0001; P = 0.0001; for left cervical, P = 0.03; for right cervical, P = 0.0001; P = 0.006 and P = 0.007 muscles, respectively) compared with the control group. This decreased over the remaining study period, such that after treatment, sEMG activity revealed no statistically significant difference when compared with the control group. During MVC at T0, paired masseter and anterior and posterior temporalis muscles showed significantly lower sEMG activity (P = 0.03; P = 0.005 and P = 0.04, respectively) compared with the control group. In contrast, at T1 sEMG activity significantly increased (P = 0.02; P = 0.004 and P = 0.04, respectively), but no difference was observed in relation to the control group. Splint therapy in subjects with internal disk derangement seems to affect sEMG activity of the masticatory, neck, and trunk
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Directory of Open Access Journals (Sweden)
Farhad Reza-zadeh
2012-07-01
Full Text Available Objective: This study was designed to compare vastus medialis oblique (VMO: vastus lateralis longus (VLL electromyographic intensity ratio during squat with hip adduction in athletes with and without patellofemoral pain syndrome (PFPS. Materials & Methods: In this non-experimental and case-control study, 16 male athletes with PFPS were selected purposefully and 16 healthy male athletes aged 18-30 years from national teams (Volleyball, Handball and Taekwondo were matched based on variables such as weight, height, age, dominancy. All subjects selected based on inclusion and exclusion criteria. EMG activity of VMO and VLL muscles was recorded by surface electrodes with Telemetric EMG System at 15, 30 and 45 degrees of squat and VMO: VLL ratio was calculated. One way ANOVA was used to compare these muscles ratio between two groups. Results: The ratio of VMO: VLL in both groups with and without PFPS in almost all angles were lower than one. However, healthy athletes had lower ratios. Also, there were no significant differences in VMO: VLL ratio at various angles. Conclusion: It seems that sports activities prevent VMO weakening in athletes. However, VMO: VLL ratio in athletes with and without patellofemoral pain does not influence by this syndrome.
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Hensbergen, E; Kernell, D
This article concerns the spontaneous motor behavior of cat hindlimb muscles and muscle regions using 24-h electromyographic (EMG) recordings. Previously, we found marked differences in average daily "duty time" (i.e., the percentage of total sampling time filled with EMG activity) between different
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Clément, Julien; Hagemeister, Nicola; Aissaoui, Rachid; de Guise, Jacques A
2014-01-01
Numerous studies have described 3D kinematics, 3D kinetics and electromyography (EMG) of the lower limbs during quasi-static or dynamic squatting activities. One study compared these two squatting conditions but only at low speed on healthy subjects, and provided no information on kinetics and EMG of the lower limbs. The purpose of the present study was to contrast simultaneous recordings of 3D kinematics, 3D kinetics and EMG of the lower limbs during quasi-stat ic and fast-dynamic squats in healthy and pathological subjects. Ten subjects were recruited: five healthy and five osteoarthritis subjects. A motion-capture system, force plate, and surface electrodes respectively recorded 3D kinematics, 3D kinetics and EMG of the lower limbs. Each subject performed a quasi-static squat and several fast-dynamic squats from 0° to 70° of knee flexion. The two squatting conditions were compared for positions where quasi-static and fast-dynamic knee flexion-extension angles were similar. Mean differences between quasi-static and fast-dynamic squats were 1.5° for rotations, 1.9 mm for translations, 2.1% of subjects' body weight for ground reaction forces, 6.6 Nm for torques, 11.2 mm for center of pressure, and 6.3% of maximum fast-dynamic electromyographic activities for EMG. Some significant differences (psquats were small. 69.5% of compared data were equivalent. In conclusion, this study showed that quasi-static and fast-dynamic squatting activities are comparable in terms of 3D kinematics, 3D kinetics and EMG, although some reservations still remain. Copyright © 2014 Elsevier B.V. All rights reserved.
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Borreani, Sebastien; Colado, Juan Carlos; Furio, Josep; Martin, Fernando; Tella, Víctor
2014-05-01
Little research has been reported on the effects of using different devices with resistance exercises in a water environment. This study compared muscular activation of lower extremity and core muscles during leg adduction performed at maximum velocity with drag and floating devices of different sizes. A total of 24 young men (mean age 23.20 ± 1.18 years) performed 3 repetitions of leg adduction at maximum velocity using 4 different devices (ie, large/small and drag/floating). The maximum amplitude of the electromyographic root mean square of the adductor longus, rectus abdominis, external oblique on the dominant side, external oblique on the nondominant side, and erector lumbar spinae were recorded. Electromyographic signals were normalized to the maximum voluntary isometric contraction (MVIC). Unexpectedly, no significant (P > 0.05) differences were found in the neuromuscular responses among the different devices used; the average activation of agonist muscle adequate for neuromuscular conditioning was 40.95% of MVIC. In addition, external oblique activation is greater on the contralateral side to stabilize the body (average, 151.74%; P < 0.05). Therefore, if maximum muscle activation is required, the kind of device is not relevant. Thus, the choice should be based on economic factors.
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From electromyographic activity to frequency modulation in zebra finch song.
Döppler, Juan F; Bush, Alan; Goller, Franz; Mindlin, Gabriel B
2018-02-01
Behavior emerges from the interaction between the nervous system and peripheral devices. In the case of birdsong production, a delicate and fast control of several muscles is required to control the configuration of the syrinx (the avian vocal organ) and the respiratory system. In particular, the syringealis ventralis muscle is involved in the control of the tension of the vibrating labia and thus affects the frequency modulation of the sound. Nevertheless, the translation of the instructions (which are electrical in nature) into acoustical features is complex and involves nonlinear, dynamical processes. In this work, we present a model of the dynamics of the syringealis ventralis muscle and the labia, which allows calculating the frequency of the generated sound, using as input the electrical activity recorded in the muscle. In addition, the model provides a framework to interpret inter-syllabic activity and hints at the importance of the biomechanical dynamics in determining behavior.
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Directory of Open Access Journals (Sweden)
Aditi Nanda
2011-01-01
Full Text Available Background: To investigate the effect of restoration of lost vertical by centric stabilizing splint on electromyographic (EMG activity of masseter and anterior temporalis muscles bilaterally in patients with generalized attrition of teeth. Materials and Methods: EMG activity of anterior temporalis and masseter muscle was recorded bilaterally for 10 patients whose vertical was restored with centric stabilizing splint. The recording was done at postural rest position and in maximum voluntary clenching for each subject before the start of treatment, immediately after placement of splint and at subsequent recall visits, with splint and without the splint. Results: The EMG activity at postural rest position (PRP and maximum voluntary clench (MVC decreased till 1 month for both the muscles. In the third month, an increase in muscle activity toward normalization was noted at PRP, both with and without splint. At MVC in the third month, the muscle activity without splint decreased significantly as compared to pretreatment values for anterior temporalis and masseter, while with the splint an increase was seen beyond the pretreatment values. Conclusion: A definite response of anterior temporalis and masseter muscle was observed over a period of 3 months. This is suggestive that the reversible increase in vertical prior to irreversible intervention must be carried out for a minimum of 3 months to achieve neuromuscular deprogramming. This allows the muscle to get adapted to the new postural position and attain stability in occlusion following splint therapy.
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Trunk muscle activation. The effects of torso flexion, moment direction, and moment magnitude.
Lavender, S; Trafimow, J; Andersson, G B; Mayer, R S; Chen, I H
1994-04-01
This study was performed to quantify the electromyographic trunk muscle activities in response to variations in moment magnitude and direction while in forward-flexed postures. Recordings were made over eight trunk muscles in 19 subjects who maintained forward-flexed postures of 30 degrees and 60 degrees. In each of the two flexed postures, external moments of 20 Nm and 40 Nm were applied via a chest harness. The moment directions were varied in seven 30 degrees increments to a subject's right side, such that the direction of the applied load ranged from the upper body's anterior midsagittal plane (0 degree) to the posterior midsagittal plane (180 degrees). Statistical analyses yielded significant moment magnitude by moment-direction interaction effects for the EMG output from six of the eight muscles. Trunk flexion by moment-direction interactions were observed in the responses from three muscles. In general, the primary muscle supporting the torso and the applied load was the contralateral (left) erector spinae. The level of electromyographic activity in the anterior muscles was quite low, even with the posterior moment directions.
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Comparison of methods for removing electromagnetic noise from electromyographic signals.
Defreitas, Jason M; Beck, Travis W; Stock, Matt S
2012-02-01
The purpose of this investigation was to compare three different methods of removing noise from monopolar electromyographic (EMG) signals: (a) electrical shielding with a Faraday cage, (b) denoising with a digital notch-filter and (c) applying a bipolar differentiation with another monopolar EMG signal. Ten men and ten women (mean age = 24.0 years) performed isometric muscle actions of the leg extensors at 10-100% of their maximal voluntary contraction on two separate occasions. One trial was performed inside a Faraday tent (a flexible Faraday cage made from conductive material), and the other was performed outside the Faraday tent. The EMG signals collected outside the Faraday tent were analyzed three separate ways: as a raw signal, as a bipolar signal, and as a signal digitally notch filtered to remove 60 Hz noise and its harmonics. The signal-to-noise ratios were greatest after notch-filtering (range: 3.0-33.8), and lowest for the bipolar arrangement (1.6-10.2). Linear slope coefficients for the EMG amplitude versus force relationship were also used to compare the methods of noise removal. The results showed that a bipolar arrangement had a significantly lower linear slope coefficient when compared to the three other conditions (raw, notch and tent). These results suggested that an appropriately filtered monopolar EMG signal can be useful in situations that require a large pick-up area. Furthermore, although it is helpful, a Faraday tent (or cage) is not required to achieve an appropriate signal-to-noise ratio, as long as the correct filters are applied.
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Comparison of methods for removing electromagnetic noise from electromyographic signals
International Nuclear Information System (INIS)
DeFreitas, Jason M; Beck, Travis W; Stock, Matt S
2012-01-01
The purpose of this investigation was to compare three different methods of removing noise from monopolar electromyographic (EMG) signals: (a) electrical shielding with a Faraday cage, (b) denoising with a digital notch-filter and (c) applying a bipolar differentiation with another monopolar EMG signal. Ten men and ten women (mean age = 24.0 years) performed isometric muscle actions of the leg extensors at 10–100% of their maximal voluntary contraction on two separate occasions. One trial was performed inside a Faraday tent (a flexible Faraday cage made from conductive material), and the other was performed outside the Faraday tent. The EMG signals collected outside the Faraday tent were analyzed three separate ways: as a raw signal, as a bipolar signal, and as a signal digitally notch filtered to remove 60 Hz noise and its harmonics. The signal-to-noise ratios were greatest after notch-filtering (range: 3.0–33.8), and lowest for the bipolar arrangement (1.6–10.2). Linear slope coefficients for the EMG amplitude versus force relationship were also used to compare the methods of noise removal. The results showed that a bipolar arrangement had a significantly lower linear slope coefficient when compared to the three other conditions (raw, notch and tent). These results suggested that an appropriately filtered monopolar EMG signal can be useful in situations that require a large pick-up area. Furthermore, although it is helpful, a Faraday tent (or cage) is not required to achieve an appropriate signal-to-noise ratio, as long as the correct filters are applied. (paper)
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Pinto, Stephanie Santana; Liedtke, Giane Veiga; Alberton, Cristine Lima; da Silva, Eduardo Marczwski; Cadore, Eduardo Lusa; Kruel, Luiz Fernando Martins
2010-11-01
This study was designed to compare surface electromyographic (sEMG) signal and force production during maximal voluntary isometric contractions (MVCs) in water and on dry land. The reproducibility of sEMG and isometric force measurements between water and dry land environments was also assessed. Nine women performed MVC for elbow flexion and extension, hip flexion, and extension against identical fixed resistance in both environments. The sEMG signal from biceps brachii, triceps brachii, rectus femoris, and biceps femoris was recorded with waterproof adhesives placed over each electrode. The sEMG and force production showed no significant difference between water and dry land, except for HEX (p = 0.035). In addition, intraclass correlation coefficient values were significant and ranged from moderate to high (0.66-0.96) for sEMG and force production between environments. These results showed that the environment did not influence the sEMG and force in MVC.
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DEFF Research Database (Denmark)
Larsen, C M; Juul-Kristensen, B; Olsen, H B
2014-01-01
Neuromuscular control of the scapular muscles is important in the etiology of shoulder pain. Electromyographical (EMG) biofeedback in healthy people has been shown to support a selective activation of the lower compartment of the trapezius muscle, specifically. The aim of the present paper was to...
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Otter, A.R. den; Geurts, A.C.H.; Mulder, T.; Duysens, J.E.J.
2006-01-01
OBJECTIVE: To establish whether functional recovery of gait in patients with post-stroke hemiparesis coincides with changes in the temporal patterning of lower extremity muscle activity and coactivity during treadmill walking. METHODS: Electromyographic (EMG) data from both legs, maximum walking
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Den Otter, AR; Mulder, T; Duysens, J
Objective: To establish whether functional recovery of gait in patients with post-stroke hemiparesis coincides with changes in the temporal patterning of lower extremity muscle activity and coactivity during treadmill walking. Methods: Electromyographic (EMG) data from both legs, maximum walking
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Reduced Electromyographic Fatigue Threshold after Performing a Cognitive Fatiguing Task.
Ferris, Justine R; Tomlinson, Mary A; Ward, Tayler N; Pepin, Marie E; Malek, Moh H
2018-02-22
Cognitive fatigue tasks performed prior to exercise may reduce exercise capacity. The electromyographic fatigue threshold (EMGFT) is the highest exercise intensity that can be maintained without significant increase in the EMG amplitude versus time relationship. To date, no studies have examined the effect of cognitive fatigue on the estimation of the EMGFT. The purpose of this study, therefore, was to determine whether or not cognitive fatigue prior to performing exercise reduces the estimated EMGFT. Eight healthy college-aged men were recruited from a university student population and visited the laboratory on multiple occasions. In a randomized order, subjects performed either the cognitive fatigue task (AX Continuous Performance Test; AX-CPT) for 60 min on one visit (experimental condition) or watched a video on trains for 60 min on the other visit (control condition). After each condition, subjects performed the incremental single-leg knee-extensor ergometry test while the EMG amplitude was recorded from the rectus femoris muscle and heart rate was monitored throughout. Thereafter, the EMGFT was calculated for each participant for each visit and compared using paired samples t-test. For exercise outcomes, there were no significant mean differences for maximal power output between the two conditions (control: 51 ± 5 vs. fatigue: 50 ± 3 W), but a significant decrease in EMGFT between the two conditions (control: 31 ± 3 vs. fatigue: 24 ± 2 W; p = 0.013). Moreover, maximal heart rate was significantly different between the two conditions (control: 151 ± 5 vs. fatigue: 132 ± 6; p = 0.027). These results suggest that performing the cognitive fatiguing task reduces the EMGFT with a corresponding reduction in maximal heart rate response.
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Borreani, Sebastien; Calatayud, Joaquin; Colado, Juan C; Tella, Victor; Moya-Nájera, Diego; Martin, Fernando; Rogers, Michael E
2015-08-01
To analyze shoulder muscle activation when performing push-ups under different stability conditions and heights. Comparative study by repeated measures. Valencia University laboratory. 29 healthy males participated. Subjects performed 3 push-ups each with their hands at 2 different heights (10 vs. 65 cm) under stable conditions and using a suspension device. Push-up speed was controlled and the testing order was randomized. The average amplitudes of the electromyographic root mean square of the long head of the triceps brachii (TRICEP), upper trapezius (TRAPS), anterior deltoid (DELT) and clavicular pectoralis (PEC) were recorded. The electromyographic signals were normalized to the maximum voluntary isometric contraction (MVIC). Suspended push-ups at 10 cm resulted in greater activation in the TRICEP (17.14 ± 1.31 %MVIC vs. 37.03 ± 1.80 %MVIC) and TRAPS (5.83 ± 0.58 %MVIC vs. 14.69 ± 1.91 %MVIC) than those performed on the floor. For DELT and PEC similar or higher activation was found performing the push-ups on the floor, respectively. Height determines different muscle activation patterns. Stable push-ups elicit similar PEC and higher DELT muscle activation, being greater at 10 cm; whereas suspended push-ups elicit greater TRAPS and TRICEP muscle activation, being greater at 65 cm. Copyright © 2014 Elsevier Ltd. All rights reserved.
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Fryer, Gary; Bird, Michael; Robbins, Barry; Johnson, Jane C
2017-07-01
This single group, randomized, cross-over study explored whether manual therapy alters motor tone of deep thoracic back muscles by examining resting electromyographic activity (EMG) after 2 types of manual therapy and a sham control intervention. Twenty-two participants with thoracic spinal pain (15 females, 7 males, mean age 28.1 ± 6.4 years) had dual fine-wire, intramuscular electrodes inserted into deep transversospinalis muscles at a thoracic level where tissues appeared abnormal to palpation (AbP) and at 2 sites above and below normal and non-tender to palpation (NT). A surface electrode was on the contralateral paraspinal mass at the level of AbP. EMG signals were recorded for resting prone, two 3-s free neck extension efforts, two 3-s resisted maximal voluntary isometric contractions (MVIC), and resting prone before the intervention. Randomized spinal manipulation, counterstrain, or sham manipulation was delivered and EMG re-measured. Participants returned 1 and 2 weeks later for the remaining 2 treatments. Reductions in resting EMG followed counterstrain in AbP (median decrease 3.3%, P = 0.01) and NT sites (median decrease 1.0%, P = 0.05) and for the surface electrode site (median decrease 2.0%, P = 0.009). Reduction in EMG following counterstrain during free neck extension was found for the surface electrode site (median decrease 2.7%, P < 0.01). Spinal manipulation produced no change in EMG, whereas counterstrain technique produced small significant reductions in paraspinal muscle activity during prone resting and free neck extension conditions. The clinical relevance of these changes is unclear. Copyright © 2017 Elsevier Ltd. All rights reserved.
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Ptaszkowski, Kuba; Paprocka-Borowicz, Małgorzata; Słupska, Lucyna; Bartnicki, Janusz; Dymarek, Robert; Rosińczuk, Joanna; Heimrath, Jerzy; Dembowski, Janusz; Zdrojowy, Romuald
2015-01-01
Muscles such as adductor magnus (AM), gluteus maximus (GM), rectus abdominis (RA), and abdominal external and internal oblique muscles are considered to play an important role in the treatment of stress urinary incontinence (SUI), and the relationship between contraction of these muscles and pelvic floor muscles (PFM) has been established in previous studies. Synergistic muscle activation intensifies a woman's ability to contract the PFM. In some cases, even for continent women, it is not possible to fully contract their PFM without involving the synergistic muscles. The primary aim of this study was to assess the surface electromyographic activity of synergistic muscles to PFM (SPFM) during resting and functional PFM activation in postmenopausal women with and without SUI. This study was a preliminary, prospective, cross-sectional observational study and included volunteers and patients who visited the Department and Clinic of Urology, University Hospital in Wroclaw, Poland. Forty-two patients participated in the study and were screened for eligibility criteria. Thirty participants satisfied the criteria and were categorized into two groups: women with SUI (n=16) and continent women (n=14). The bioelectrical activity of PFM and SPFM (AM, RA, GM) was recorded with a surface electromyographic instrument in a standing position during resting and functional PFM activity. Bioelectrical activity of RA was significantly higher in the incontinent group than in the continent group. These results concern the RA activity during resting and functional PFM activity. The results for other muscles showed no significant difference in bioelectrical activity between groups. In women with SUI, during the isolated activation of PFM, an increased synergistic activity of RA muscle was observed; however, this activity was not observed in asymptomatic women. This may indicate the important accessory contribution of these muscles in the mechanism of continence.
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Directory of Open Access Journals (Sweden)
FSM Alves
2009-04-01
Full Text Available OBJETIVO: Identificar e comparar o padrão eletromiográfico (EMG dos principais músculos do membro inferior com apoio bilateral durante o agachamento padrão e declinado. MÉTODOS: Foram recrutados oito sujeitos (três homens e cinco mulheres, todos destros, atletas de final de semana e saudáveis (médias: 20,57 anos; 69,5±15kg; 1,73±0,15m. Foram registrados os sinais eletromiográficos dos músculos vasto medial oblíquo (VMO, vasto lateral (VL, bíceps femoral (BF, sóleo (SO, tibial anterior (TA e eretor espinhal (EE durante a fase ascendente (70º-0º e descendente (0º-70º dos agachamentos padrão (plano horizontal e declinado (a 25º. A integral da atividade EMG de cada músculo foi calculada no intervalo de 300 milisegundos (ms antes do início e do final do movimento. A média de cada músculo para cada sujeito foi analisada pelo teste de análise de variância para medidas repetidas (ANOVA para verificar o efeito da tarefa de agachar. RESULTADOS:A análise qualitativa revelou que o padrão de atividade muscular durante os agachamentos padrão e declinado foram similares, e a análise quantitativa não revelou diferenças na atividade EMG. CONCLUSÃO: Os resultados demonstram que a atividade EMG dos músculos estudados foi similar entre as tarefas propostas.OBJECTIVE: To identify and compare the electromyographic (EMG pattern of the main muscles of the lower limbs with bilateral support during standard and declined squats. METHODS:Eight healthy subjects were recruited (three men and five women, all right-handed and weekend athletes (means: 20.57 years; 69.5±15kg; 1.73±0.15m. Electromyographic (EMG signals from the vastus medialis obliquus (VMO, vastus lateralis (VL, biceps femoris (BF, soleus (SO, tibialis anterior (TA and erector spinae (ES muscles were recorded during the ascending (70º-0º and descending (0º-70º phases of the standard squat (horizontal plane and declined squat (at 25º. The integral of the EMG activity for
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Eid, Mohamed Ahmed Mahmoud; Aly, Sobhy M; El-Shamy, Shamekh M
2016-12-01
To investigate the effects of electromyographic (EMG) biofeedback training on pain, quadriceps strength, and functional ability in juvenile rheumatoid arthritis (JRA). This is a randomized controlled study; 36 children (11 boys and 25 girls) with polyarticular JRA, with ages ranging from 8 to 13 years, were selected and assigned randomly, using computer-generated random numbers, into 2 groups. The control group (n = 18) received the conventional physical therapy program, whereas the study group (n = 18) received the same program as the control group in addition to EMG biofeedback-guided isometric exercises for 3 days a week for 12 weeks. Pain, peak torque of quadriceps strength, and functional ability were evaluated before, after 6 weeks, and at the end of 12 weeks of the treatment program. By 6 weeks, significant differences were observed in the study group (P biofeedback may be a useful intervention modality to reduce pain, improve quadriceps strength, and functional performance in JRA.
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Yoon, Byung-Nam; Choi, Seong Hye; Rha, Joung-Ho; Kang, Sa-Yoon; Lee, Kwang-Woo; Sung, Jung-Joon
2014-09-01
Flail arm syndrome (FAS), an atypical presentation of amyotrophic lateral sclerosis (ALS), is characterized by progressive, predominantly proximal, weakness of upper limbs, without involvement of the lower limb, bulbar, or respiratory muscles. When encountering a patient who presents with this symptomatic profile, possible diagnoses include upper limb onset ALS (UL-ALS), and FAS. The lack of information regarding FAS may make differential diagnosis between FAS and UL-ALS difficult in clinical settings. The aim of this study was to compare clinical and electromyographic findings from patients diagnosed with FAS with those from patients diagnosed with UL-ALS. To accomplish this, 18 patients with FAS and 56 patients with UL-ALS were examined. Significant differences were observed between the 2 groups pertaining to the rate of fasciculation, patterns of predominantly affected muscles, and the Medical Research Council scale of the weakest muscle. The presence of upper motor neuron signs and lower motor neuron involvement evidenced through electromyography showed no significant between-group differences.
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Shridharani, Sachin M
2017-07-01
Deoxycholic acid (DCA) is approved for improvement in the appearance of moderate to severe convexity or fullness associated with submental fat. To assess early treatment experience with DCA injection in a clinical practice setting. In this single-center, prospective, single-arm, observational study, 100 consecutive patients seeking to decrease submental fullness received subcutaneous DCA (2 mg/cm) injections in the submental area (maximum of 6 sessions at ≥1 month intervals). Treatment response was assessed 1 and 5 to 7 weeks posttreatment using the clinician-reported submental fat rating scale (CR-SMFRS) and retrospective independent photograph review by 2 physicians. Overall, 100 patients had 152 treatment sessions (58, 33, 8, and 1 patients had 1, 2, 3, and 4 sessions, respectively). CR-SMFRS score improved by ≥1 point from baseline in 88 (88%) patients; of these, 46, 33, 8, and 1 patients had 1, 2, 3, and 4 sessions, respectively. Local edema, numbness, and tenderness were reported for a mean (SD) of 7.7 (5.3), 28.5 (11.4), and 3.5 (3.5) days, respectively. Two patients experienced marginal mandibular nerve paresis. Deoxycholic acid injection, a minimally invasive procedure for neck contouring, was effective and generally well tolerated in the private practice setting.
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Directory of Open Access Journals (Sweden)
CCA Bandeira
2009-02-01
Full Text Available OBJETIVO: Avaliar o efeito da isquemia induzida sobre os parâmetros do sinal eletromiográfico e a força do grupo muscular extensor do punho (GMEP em mulheres saudáveis. MÉTODOS: Participaram 13 voluntárias, destras, sedentárias, com idade de 23,38±2,32 anos e índice de massa corporal (IMC de 20,68±1,87kg/m². Para determinar a força do GMEP, foram realizadas 3 contrações isométricas voluntárias máximas (CIVM, utilizando-se uma célula de carga por 15 segundos, com intervalos de 2 minutos entre cada contração, sendo todo procedimento repetido por 3 dias não consecutivos. A isquemia foi realizada por 5 minutos, utilizando um esfigmomanômetro posicionado no braço dominante e inflado até a ausência do fluxo sanguíneo, confirmada pelo ultrassom Doppler. Para coleta do sinal eletromiográfico do GMEP, utilizou-se o equipamento EMG1000 (Lynx® com eletrodo de superfície diferencial (Lynx®. Foram coletadas 3 CIVM por 15 segundos, com intervalo de 30 segundos entre elas, nas situações de pré-isquemia; isquemia; pós-isquemia imediata (pós-1 e pós-isquemia tardia (pós-2 - após 10 minutos do início da isquemia. Para análise dos parâmetros do sinal eletromiográfico, root mean square (RMS, e frequência mediana do espectro de potência do sinal foi utilizado o software MATLAB 6.5.1. Para análise estatística, foram utilizados os testes de Friedman e ANOVA two-way. RESULTADOS: A isquemia promoveu redução significativa (pOBJECTIVE: To analyze the effect of induced ischemia on the parameters of electromyographic signals and the strength of the wrist extensor muscle group (WEMG in healthy women. METHODS: Thirteen right-handed sedentary subjects aged 23.38±2.32 years old, with body mass index (BMI of 20.68±1.87kg/m², took part. To determine WEMG strength, three maximal voluntary isometric contractions (MVIC were performed using a load cell for 15 seconds, with 2 minutes intervals between contractions. The entire
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DEFF Research Database (Denmark)
Frisk, Rasmus F.; Jensen, Peter; Kirk, Henrik
2017-01-01
applied unload perturbations at the ankle, thereby removing sensory feedback naturally activated during push-off. Reduction of electromyographic (EMG) activity in the soleus muscle caused by unloads was compared and related to kinematics and ankle joint stiffness measurements. Similar measures were...... feedback to ongoing soleus muscle activation during push-off than uninjured individuals. Increased passive stiffness around the ankle joint is likely to diminishn sensory feedback during gait, and/or sensory feedback is less integrated with central motor commands in the activation of spinal motor neurons...
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Al-Omiri, Mahmoud K
2018-03-01
Whether masticatory efficiency and electromyographic activity are influenced by type of artificial teeth and food is unclear. The purpose of this clinical study was to evaluate the influence of extension base removable partial dentures (RPDs) with different cusp angles: anatomic (33 degrees), semianatomic (20 degrees), and nonanatomic (0 degrees) teeth on masticatory efficiency and muscle activity during the mastication of test foods with different textures. Twelve participants with RPDs were selected to perform masticatory efficiency and electromyographic tests. Surface electromyograms (EMGs) were used to record the activities of the masseter and temporalis muscles during the mastication of different types of test foods. The maximal voltage and duration were measured on the integrated EMG signal in each muscle during food mastication, and the mean reading of both sides was then recorded. Analysis of variance and the Tukey post hoc test were used to perform statistical analyses (α=.05). The masticatory efficiency of RPDs with nonanatomic teeth was significantly inferior to that of RPDs with anatomic and semianatomic teeth (P.05). Also, muscle activity (according to EMG) with RPDs with NA teeth was significantly higher than that with anatomic and semianatomic teeth (P<.05). RPDs with NA teeth were associated with higher EMG muscle activity and reduced masticatory efficiency than anatomic or semianatomic teeth. Copyright © 2017 Editorial Council for the Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights reserved.
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Raphael, K G; Janal, M N; Sirois, D A; Dubrovsky, B; Wigren, P E; Klausner, J J; Krieger, A C; Lavigne, G J
2013-12-01
Despite theoretical speculation and strong clinical belief, recent research using laboratory polysomnographic (PSG) recording has provided new evidence that frequency of sleep bruxism (SB) masseter muscle events, including grinding or clenching of the teeth during sleep, is not increased for women with chronic myofascial temporomandibular disorder (TMD). The current case-control study compares a large sample of women suffering from chronic myofascial TMD (n = 124) with a demographically matched control group without TMD (n = 46) on sleep background electromyography (EMG) during a laboratory PSG study. Background EMG activity was measured as EMG root mean square (RMS) from the right masseter muscle after lights out. Sleep background EMG activity was defined as EMG RMS remaining after activity attributable to SB, other orofacial activity, other oromotor activity and movement artefacts were removed. Results indicated that median background EMG during these non-SB event periods was significantly higher (P cases exceeding control activity. Moreover, for TMD cases, background EMG was positively associated and SB event-related EMG was negatively associated with pain intensity ratings (0-10 numerical scale) on post-sleep waking. These data provide the foundation for a new focus on small, but persistent, elevations in sleep EMG activity over the course of the night as a mechanism of pain induction or maintenance. © 2013 John Wiley & Sons Ltd.
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Thierry Lelard
2017-06-01
Full Text Available During gait initiation, postural adjustments are needed to deal with balance and movement. With aging, gait initiation changes and reflects functional degradation of frailty individuals. However, physical activities have demonstrated beneficial effects of daily motor tasks. The aim of our study was to compare center of pressure (COP displacement and ankle muscle co-activation during gait initiation in two physically active groups: a group of walkers (n = 12; mean age ± SD 72.6 ± 3.2 years and a yoga group (n = 11; 71.5 ± 3.8 years. COP trajectory and electromyography of leg muscles were recorded simultaneously during five successive trials of gait initiation. Our main finding was that yoga practitioners had slower COP displacements (p < 0.01 and lower leg muscles % of coactivation (p < 0.01 in comparison with walkers. These parameters which characterized gait initiation control were correlated (r = 0.76; p < 0.01. Our results emphasize that lengthy ankle muscle co-activation and COP path in gait initiation differentiate yoga practitioners among physically active subjects.
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Directory of Open Access Journals (Sweden)
João Carlos Comel
Full Text Available Introduction The proper use of the position of the arm and wrist while typing may reduce muscle overload and prevent musculoskeletal disorders.Objective To evaluate the electromyographic activity of upper trapezius and wrist extensor muscles during two typewriting conditions.Materials and methods : Six healthy females (Xage = 42 years,SD= 10, (Xheight = 1.65m, SD = 0.05 and (Xweight = 71kg, SD = 16 participated in this study. The task was performed with a newly developed arm support and without the support. A perceived exertion scale was used with all subjects. An ANOVA with repeated measures was used to verify differences in perceived exertion and root mean square (RMS.Results There were no statistically significant differences for the RMS between the typewriting tasks. The condition without arm support presented a significantly greater mean velocity and amount of words typed (P= 0.02; P= 0.03 and there was a significant difference in perceived exertion during the condition without arm support (P= 0.03. Electromyographic activity did not present differences.Conclusion The muscle electrical activity was not altered regardless the arm support and occurred the improvement of the perceived exertion after 10 minutes of typing without support. Long-term studies are needed.
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DEFF Research Database (Denmark)
Samani, Afshin; Holtermann, Andreas; Søgaard, Karen
2009-01-01
) and active (30% maximum voluntary contraction of shoulder elevation) pauses given every 40s over 2 days, before, immediately and 24h after eccentric exercise. Surface EMG signals were recorded from four parts of the trapezius during computer work. FINDINGS: EMG amplitude during computer work decreased......BACKGROUND: The aim of this laboratory study was to investigate the effects of eccentric exercises on the trapezius muscle spatial electromyographic (EMG) activity during computer work with active and passive pauses. METHODS: Twelve healthy male subjects performed computer work with passive (relax...... immediately after exercise (Pwork with active pauses compared with passive ones (P
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International Nuclear Information System (INIS)
Camic, Clayton L; Kovacs, Attila J; Hill, Ethan C; Calantoni, Austin M; Yemm, Allison J; Enquist, Evan A; VanDusseldorp, Trisha A
2014-01-01
The purposes of the present study were two fold: (1) to determine if the model used for estimating the physical working capacity at the fatigue threshold (PWC FT ) from electromyographic (EMG) amplitude data during incremental cycle ergometry could be applied to treadmill running to derive a new neuromuscular fatigue threshold for running, and (2) to compare the running velocities associated with the PWC FT , ventilatory threshold (VT), and respiratory compensation point (RCP). Fifteen college-aged subjects (21.5 ± 1.3 y, 68.7 ± 10.5 kg, 175.9 ± 6.7 cm) performed an incremental treadmill test to exhaustion with bipolar surface EMG signals recorded from the vastus lateralis. There were significant (p < 0.05) mean differences in running velocities between the VT (11.3 ± 1.3 km h −1 ) and PWC FT (14.0 ± 2.3 km h −1 ), VT and RCP (14.0 ± 1.8 km h −1 ), but not the PWC FT and RCP. The findings of the present study indicated that the PWC FT model could be applied to a single continuous, incremental treadmill test to estimate the maximal running velocity that can be maintained prior to the onset of neuromuscular fatigue. In addition, these findings suggested that the PWC FT , like the RCP, may be used to differentiate the heavy from severe domains of exercise intensity. (paper)
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Directory of Open Access Journals (Sweden)
Luciana Vitaliano Voi Trawitzki
2009-01-01
Full Text Available OBJETIVO: investigar a preferência mastigatória e o comportamento dos músculos mastigatórios, em crianças de 6 a 9 anos, com mordida cruzada posterior. MÉTODOS: 30 crianças foram selecionadas num serviço de Ortodontia de uma universidade pública. Após a concordância na participação no trabalho, foi realizada entrevista com a criança e seu responsável, para investigação de disfunção temporomandibular; análise da preferência mastigatória, por meio de registros em vídeo e avaliação eletromiográfica (EMG dos músculos masseter e temporal anterior, durante a mastigação solicitada, direita e esquerda, de uma goma de marcar. RESULTADOS: houve diferença significante na atividade EMG dos músculos masseter e temporal anterior entre os lados de trabalho e balanceio, porém não houve diferença estatística quando foram comparadas as atividades EMG entre os lados de mordida cruzada e não cruzada, tampouco entre os lados de preferência e não preferência mastigatória. CONCLUSÃO: na amostra estudada não se verificou assimetria funcional muscular estabelecida.PURPOSE: to investigate the masticatory preference and the behavior of masticatory muscles, in children between6 to 9-year old, with posterior crossbite. METHODS: 30 children were selected from the Orthodontical service of a public university. After consenting to take part in the study, there was an interview with the children and the parent, in order to investigate temporomandibular disorders; masticatory was analyzed through video recording and electromyographic (EMG evaluation of the masseter and anterior temporal, during the solicited mastication, on right and left, using chewing gum. RESULTS: there was a significant difference in the EMG activity of the masseter and temporal between work and balance sides, however there was no statistical differences in the comparison between crossbite side and no crossbite side, but neither between preference side and non the
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International Nuclear Information System (INIS)
Chen, Xinpu; Zhu, Xiangyang; Zhang, Dingguo
2009-01-01
Myoelectrical pattern classification is a crucial part in multi-functional prosthesis control. This paper investigates a discriminant Fourier-derived cepstrum (DFC) and feature-level post-processing (FLPP) to discriminate hand and wrist motions using the surface electromyographic signal. The Fourier-derived cepstrum takes advantage of the Fourier magnitude or sub-band power energy of signals directly and provides flexible use of spectral information changing with different motions. Appropriate cepstral coefficients are selected by a proposed separability criterion to construct DFC features. For the post-processing, FLPP which combines features from several analysis windows is used to improve the feature performance further. In this work, two classifiers (a linear discriminant classifier and quadratic discriminant classifier) without hyper-parameter optimization are employed to simplify the training procedure and avoid the possible bias of feature evaluation. Experimental results of the 11-motion problem show that the proposed DFC feature outperforms traditional features such as time-domain statistics and autoregressive-derived cepstrum in terms of the classification accuracy, and it is a promising method for the multi-functionality and high-accuracy control of myoelectric prostheses
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Foot posture influences the electromyographic activity of selected lower limb muscles during gait
Directory of Open Access Journals (Sweden)
Menz Hylton B
2009-11-01
Full Text Available Abstract Background Some studies have found that flat-arched foot posture is related to altered lower limb muscle function compared to normal- or high-arched feet. However, the results from these studies were based on highly selected populations such as those with rheumatoid arthritis. Therefore, the objective of this study was to compare lower limb muscle function of normal and flat-arched feet in people without pain or disease. Methods Sixty adults aged 18 to 47 years were recruited to this study. Of these, 30 had normal-arched feet (15 male and 15 female and 30 had flat-arched feet (15 male and 15 female. Foot posture was classified using two clinical measurements (the arch index and navicular height and four skeletal alignment measurements from weightbearing foot x-rays. Intramuscular fine-wire electrodes were inserted into tibialis posterior and peroneus longus under ultrasound guidance, and surface EMG activity was recorded from tibialis anterior and medial gastrocnemius while participants walked barefoot at their self-selected comfortable walking speed. Time of peak amplitude, peak and root mean square (RMS amplitude were assessed from stance phase EMG data. Independent samples t-tests were performed to assess for significant differences between the normal- and flat-arched foot posture groups. Results During contact phase, the flat-arched group exhibited increased activity of tibialis anterior (peak amplitude; 65 versus 46% of maximum voluntary isometric contraction and decreased activity of peroneus longus (peak amplitude; 24 versus 37% of maximum voluntary isometric contraction. During midstance/propulsion, the flat-arched group exhibited increased activity of tibialis posterior (peak amplitude; 86 versus 60% of maximum voluntary isometric contraction and decreased activity of peroneus longus (RMS amplitude; 25 versus 39% of maximum voluntary isometric contraction. Effect sizes for these significant findings ranged from 0.48 to 1
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ATX-101 (Deoxycholic Acid Injection) Treatment in Men: Insights From Our Clinical Experience.
Shridharani, Sachin M; Behr, Kathleen L
2017-11-01
Excess submental fat (SMF), also called a double chin, is an area of concern for men that can be addressed clinically. ATX-101 (deoxycholic acid injection; Kybella in the United States and Belkyra in Canada, Australia, and various European countries) is the first injectable approved for reduction of SMF. To share the authors' clinical experience using ATX-101 in men with submental fullness and offer insights regarding how this treatment may be presented to men as an option to improve their submental profile. Retrospective review of the authors' medical records for male patients treated with ATX-101. To allow for fewer ATX-101 treatments, it is recommended that a large surface area be treated at the first session. The positive changes and outcomes achieved with ATX-101 build confidence between the physician and patient, which often leads to male patients seeking other aesthetic treatments to improve their overall appearance. ATX-101 treatment is often an effective introduction to aesthetic medicine for men.
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Tang, Yi; Lin, Xiang; Lin, Xiao-Juan; Zheng, Wei; Zheng, Zhi-Kai; Lin, Zhao-Min; Chen, Jian-Hao
2017-09-01
To study the therapeutic effect of neuromuscular electrical stimulation and electromyographic biofeedback (EMG-biofeedback) therapy in improving swallowing function of Alzheimer's disease patients with dysphagia.A series of 103 Alzheimer's disease patients with dysphagia were divided into 2 groups, among which the control group (n = 50) received swallowing function training and the treatment group (n = 53) received neuromuscular electrical stimulation plus EMG-biofeedback therapy. The mini-mental state scale score was performed in all patients along the treatment period. Twelve weeks after the treatment, the swallowing function was assessed by the water swallow test. The nutritional status was evaluated by Mini Nutritional Assessment (MNA) as well as the levels of hemoglobin and serum albumin. The frequency and course of aspiration pneumonia were also recorded.No significant difference on mini-mental state scale score was noted between 2 groups. More improvement of swallowing function, better nutritional status, and less frequency and shorter course of aspiration pneumonia were presented in treatment group when compared with the control group.Neuromuscular electrical stimulation and EMG-biofeedback treatment can improve swallowing function in patients with Alzheimer's disease and significantly reduce the incidence of adverse outcomes. Thus, they should be promoted in clinical practice.
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Directory of Open Access Journals (Sweden)
Gerold R. Ebenbichler
2017-05-01
Full Text Available Purpose: To investigate the differences in neural control of back muscles activated during the eccentric vs. the concentric portions of a cyclic, submaximal, fatiguing trunk extension exercise via the analysis of amplitude and time-frequency parameters derived from surface electromyographic (SEMG data.Methods: Using back dynamometers, 87 healthy volunteers performed three maximum voluntary isometric trunk extensions (MVC's, an isometric trunk extension at 80% MVC, and 25 cyclic, dynamic trunk extensions at 50% MVC. Dynamic testing was performed with the trunk angular displacement ranging from 0° to 40° and the trunk angular velocity set at 20°/s. SEMG data was recorded bilaterally from the iliocostalis lumborum at L1, the longissimus dorsi at L2, and the multifidus muscles at L5. The initial value and slope of the root mean square (RMS-SEMG and the instantaneous median frequency (IMDF-SEMG estimates derived from the SEMG recorded during each exercise cycle were used to investigate the differences in MU control marking the eccentric vs. the concentric portions of the exercise.Results: During the concentric portions of the exercise, the initial RMS-SEMG values were almost twice those observed during the eccentric portions of the exercise. The RMS-SEMG values generally increased during the concentric portions of the exercise while they mostly remained unchanged during the eccentric portions of the exercise with significant differences between contraction types. Neither the initial IMDF-SEMG values nor the time-course of the IMDF-SEMG values significantly differed between the eccentric and the concentric portions of the exercise.Conclusions: The comparison of the investigated SEMG parameters revealed distinct neural control strategies during the eccentric vs. the concentric portions of the cyclic exercise. We explain these differences by relying upon the principles of orderly recruitment and common drive governing motor unit behavior.
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Sotiropoulos, Konstantinos; Smilios, Ilias; Christou, Marios; Barzouka, Karolina; Spaias, Angelos; Douda, Helen; Tokmakidis, Savvas P
2010-01-01
The purpose of this study was to determine the effects of a specific warm-up using half-squats at low and moderate intensity on vertical jump performance and electromyographic activity of the thigh muscles. The subjects were 26 men who were divided into a low intensity group (LIG; n = 13) and a moderate intensity group (MIG; n = 13). The LIG performed a specific warm-up protocol that included the explosive execution of half-squats with loads 25 and 35% of the one repetition maximum (1RM) and the MIG with loads 45 and 65% of the 1RM. The two groups performed a countermovement jump (CMJ) before and three minutes after the specific warm-up protocols. During the concentric phase of the CMJ a linear encoder connected to an A/D converter interfaced to a PC with a software for data acquisition and analysis allowed the calculation of average mechanical power. The electromyographic (EMG) activity of the vastus lateralis (VL), vastus medialis (VM) and rectus femoris (RF) were recorded during the concentric phase of the jumps. The average quadriceps (Qc) activity (mean value of the VL, VM and RF) was also calculated. A two way ANOVA (protocols X time) with repeated measures on the second factor was used to analyze the data. Following the specific warm-up procedure both groups improved (p ≤ 0.05) CMJ performance and mechanical power by 3.5% and 6.3%, respectively, with no differences observed between the two groups. EMG activity of the Qc and VL increased (p ≤ 0.05) for both groups by 5.9% and 8.5%, respectively. It is concluded that the use of a specific warm-up that includes half-squats, performed explosively with low to moderate intensity, improves CMJ performance. This may be due to increased muscle activation as evaluated by the surface EMG. Key pointsThe inclusion of two sets of explosively performed half squats with low to moderate loads in the warm up procedure elicited an acute performance en-hancement.The performance was enhanced regardless of the load used in
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Integration of active pauses and pattern of muscular activity during computer work.
St-Onge, Nancy; Samani, Afshin; Madeleine, Pascal
2017-09-01
Submaximal isometric muscle contractions have been reported to increase variability of muscle activation during computer work; however, other types of active contractions may be more beneficial. Our objective was to determine which type of active pause vs. rest is more efficient in changing muscle activity pattern during a computer task. Asymptomatic regular computer users performed a standardised 20-min computer task four times, integrating a different type of pause: sub-maximal isometric contraction, dynamic contraction, postural exercise and rest. Surface electromyographic (SEMG) activity was recorded bilaterally from five neck/shoulder muscles. Root-mean-square decreased with isometric pauses in the cervical paraspinals, upper trapezius and middle trapezius, whereas it increased with rest. Variability in the pattern of muscular activity was not affected by any type of pause. Overall, no detrimental effects on the level of SEMG during active pauses were found suggesting that they could be implemented without a cost on activation level or variability. Practitioner Summary: We aimed to determine which type of active pause vs. rest is best in changing muscle activity pattern during a computer task. Asymptomatic computer users performed a standardised computer task integrating different types of pauses. Muscle activation decreased with isometric pauses in neck/shoulder muscles, suggesting their implementation during computer work.
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DEFF Research Database (Denmark)
Samani, Afshin; Holtermann, Andreas; Søgaard, Karen
2009-01-01
The aim of this laboratory study was to investigate acute effects of experimental muscle pain on spatial electromyographic (EMG) activity of the trapezius muscle during computer work with active and passive pauses. Twelve healthy male subjects performed four sessions of computer work for 2 min...... in one day, with passive (relax) and active (30% maximum voluntary contraction of shoulder elevation) pauses given every 40 s without and with presence of experimental pain. Surface EMG signals were recorded from four parts of the trapezius. The centroid of exposure variation analysis along the time axis...... was lower during computer work with active pauses when compared with passive one in all muscle parts (P
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The influence of experimentally induced pain on shoulder muscle activity
DEFF Research Database (Denmark)
Diederichsen, L.P.; Winther, A.; Dyhre-Poulsen, P.
2009-01-01
muscles. EMG was recorded before pain, during pain and after pain had subsided and pain intensity was continuously scored on a visual analog scale (VAS). During abduction, experimentally induced pain in the supraspinatus muscle caused a significant decrease in activity of the anterior deltoid, upper......-105A degrees) at a speed of approximately 120A degrees/s, controlled by a metronome. During abduction, electromyographic (EMG) activity was recorded by intramuscular wire electrodes inserted in two deeply located shoulder muscles and by surface-electrodes over six superficially located shoulder...... trapezius and the infraspinatus and an increase in activity of lower trapezius and latissimus dorsi muscles. Following subacromial injection a significantly increased muscle activity was seen in the lower trapezius, the serratus anterior and the latissimus dorsi muscles. In conclusion, this study shows...
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Smith, Cory M; Housh, Terry J; Herda, Trent J; Zuniga, Jorge M; Ryan, Eric D; Camic, Clayton L; Bergstrom, Haley C; Smith, Doug B; Weir, Joseph P; Cramer, Joel T; Hill, Ethan C; Cochrane, Kristen C; Jenkins, Nathaniel D M; Schmidt, Richard J; Johnson, Glen O
2015-08-01
The purposes of the present study were to examine the effects of electrode placements over, proximal, and distal to the innervation zone (IZ) on electromyographic (EMG) amplitude (RMS) and frequency (MPF) responses during: (1) a maximal voluntary isometric contraction (MVIC), and; (2) a sustained, submaximal isometric muscle action. A linear array was used to record EMG signals from the vastus lateralis over the IZ, 30mm proximal, and 30mm distal to the IZ during an MVIC and a sustained isometric muscle action of the leg extensors at 50% MVIC. During the MVIC, lower EMG RMS (p>0.05) and greater EMG MPF (ptime relationships over, proximal, and distal to the IZ occurred. Thus, the results of the present study indicated that during an MVIC, EMG RMS and MPF values recorded over the IZ are not comparable to those away from the IZ. However, the rates of fatigue-induced changes in EMG RMS and MPF during sustained, submaximal isometric muscle actions of the leg extensors were the same regardless of the electrode placement locations relative to the IZ. Copyright © 2015 Elsevier Ltd. All rights reserved.
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Latash, M L; Goodman, S R
1994-01-01
The purpose of this work has been to develop a model of electromyographic (EMG) patterns during single-joint movements based on a version of the equilibrium-point hypothesis, a method for experimental reconstruction of the joint compliant characteristics, the dual-strategy hypothesis, and a kinematic model of movement trajectory. EMG patterns are considered emergent properties of hypothetical control patterns that are equally affected by the control signals and peripheral feedback reflecting actual movement trajectory. A computer model generated the EMG patterns based on simulated movement kinematics and hypothetical control signals derived from the reconstructed joint compliant characteristics. The model predictions have been compared to published recordings of movement kinematics and EMG patterns in a variety of movement conditions, including movements over different distances, at different speeds, against different-known inertial loads, and in conditions of possible unexpected decrease in the inertial load. Changes in task parameters within the model led to simulated EMG patterns qualitatively similar to the experimentally recorded EMG patterns. The model's predictive power compares it favourably to the existing models of the EMG patterns. Copyright © 1994. Published by Elsevier Ltd.
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Kauffman, I B; Ridenour, M
1977-12-01
Acquisition of bipedal locomotor skill in human infants was studied electromyographically with regard to the deprivation or enrichment behavior resulting from the frequent and regular use of an infant walker. Subjects were six sets of male, fraternal twins. One randomly selected sibling from each set underwent a training program, commencing at the age of 300 days, spending a total of 2 hr. per day in a walker. Siblings not included in this group were subjected to no special training. EMG recordings were taken of all subjects at specified intervals in order to establish a model of the typical motor pattern at various stages of skill development. These data were then contrasted with EMG data similarly obtained from the walker-trained subjects. Use of an infant walker modified the mechanics of the infant's locomotion in a number of important ways. It was shown that use of the walker enables an infant to commit substantial mechanical errors yet succeed in bipedal locomotion. Inasmuch as the mechanics of walker-assisted and non-assisted bipedal locomotion are dissimilar in so many important ways, positive transfer from walker-training appears questionable.
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Mimicking muscle activity with electrical stimulation
Johnson, Lise A.; Fuglevand, Andrew J.
2011-02-01
Functional electrical stimulation is a rehabilitation technology that can restore some degree of motor function in individuals who have sustained a spinal cord injury or stroke. One way to identify the spatio-temporal patterns of muscle stimulation needed to elicit complex upper limb movements is to use electromyographic (EMG) activity recorded from able-bodied subjects as a template for electrical stimulation. However, this requires a transfer function to convert the recorded (or predicted) EMG signals into an appropriate pattern of electrical stimulation. Here we develop a generalized transfer function that maps EMG activity into a stimulation pattern that modulates muscle output by varying both the pulse frequency and the pulse amplitude. We show that the stimulation patterns produced by this transfer function mimic the active state measured by EMG insofar as they reproduce with good fidelity the complex patterns of joint torque and joint displacement.
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The corset platysma repair: a technique revisited.
Jacob, Carolyn I; Kaminer, Michael S
2002-03-01
Platysma banding along with excess submental adipose tissue and sagging skin can lead to an aged appearance. Several methods for improving neck and submental contours exist, including neck liposuction, bilateral platysma plication, midline platysma plication with transection of distal fibers, necklift with skin excision, and botulinum toxin injection for platysma relaxation. With the current interest in minimally invasive procedures, surgeons and patients are searching for techniques that produce maximal improvement with minimal intervention. To present a modified technique for maximizing neck contouring, discuss possible complications of the procedure, and describe appropriate candidates for the corset platysmaplasty. We performed a retrospective analysis of 10 consecutive patients who underwent neck liposuction with concomitant corset platysmaplasty at our institution. All 10 patients achieved good to excellent submental and jawline contouring, determined by both physician and patient assessment, with no visible platysma banding at 6 months follow-up. No major complications were noted. Use of corset platysmaplasty is a safe and effective method for neck rejuvenation. This variation of platysmaplasty can be used in conjunction with neck liposuction to maximize jawline and neck contour enhancement.
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DEFF Research Database (Denmark)
Bakke, M; Thomsen, C E; Vilmann, A
1996-01-01
min at maximum (median endurance time 7.1 min). For dynamic activity, the same individuals chewed gum unilaterally until exhaustion or 40 min at maximum (all endured 40 min) with a cycle time of 725 ms, an average load of 9.3% of maximal electromyographic activity (maxEMG) and a peak mean voltage...... analogue scales (VAS) revealed the concomitant occurrence of pain (static 11.9 VAS%; dynamic 5.9 VAS%), and discomfort (static 8.1 VAS%; dynamic 5.9 VAS%), and both sensations decreased to pre-exercise values after 20-min recovery. Systolic blood pressure increased significantly, more during static (12...
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Secondary Neck Lift and the Importance of Midline Platysmaplasty: Review of 101 Cases.
Narasimhan, Kailash; Ramanadham, Smita; O'Reilly, Eamon; Rohrich, Rod J
2016-04-01
The authors believe that open access to the submental region, platysmaplasty, and wide skin undermining provide the most long-lasting results in neck rejuvenation, and sought to evaluate this hypothesis by reviewing their neck-lift patients. The authors performed a retrospective chart review of their experience with neck-lift procedures and patients who underwent a secondary procedure. Patient age, sex, initial technique, visible neck deformities, and reasons for revision were assessed. Photographs were used to assess the features of persistent or recurrent neck-lift deformity and techniques to correct them. Of 1089 neck lifts reviewed, 101 patients underwent secondary or revision procedures (approximately 10 percent of total). The average patient age was 57.4 years, 95 percent were women, and secondary procedures were performed 10.3 years after the first procedure. Seventy percent of the revisions were of the authors' own primary neck lifts, and all of these after 10 years. The most common aesthetic deformities--recurrent platysmal bands (87 percent), persistent/recurrent jowling (48 percent), fat malposition/irregularities (10 percent), and vertical band deformity (8 percent)--were most often corrected with open platysmaplasty and medial or lateral plication and skin redraping. All patients had their submental region opened in the secondary procedure. All secondary operations were performed at least 10 years after primary surgery. The authors believe their technique of open submental neck access and platysmal approximation in patients with medial bands provides long-lasting results. The authors use precise preoperative evaluation, recontouring of neck fat irregularities, opening of the submental region with platysmaplasty, drains, and strict hemostasis. Therapeutic, IV.
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Kao, Huei Chu; Lin, Chiuhsiang Joe; Lee, Yung Hui; Chen, Su Huang
2015-01-01
The purpose of this study was to explore the effects of direction of exertion (DOE) (pushing, pulling), path (walking in a straight line, turning left, walking uphill), and load placement (LP) (the 18 blocks were indicated by X, Y and Z axis; there were 3 levels on the X axis, 2 levels on the Y axis, and 3 levels on the Z axis) on muscle activity and ratings of perceived exertion in nursing cart pushing and pulling tasks. Ten participants who were female students and not experienced nurses were recruited to participate in the experiment. Each participant performed 108 experimental trials in the study, consisting of 2 directions of exertion (push and pull), 3 paths, and 18 load placements (indicated by X, Y and Z axes). A 23kg load was placed into one load placement. The dependent variables were electromyographic (EMG) data of four muscles collected bilaterally as follows: Left (L) and right (R) trapezius (TR), flexor digitorum superficialis (FDS), extensor digitorum (ED), and erector spinae (ES) and subjective ratings of perceived exertion (RPE). Split-split-plot ANOVA was conducted to analyze significant differences between DOE, path, and LP in the EMG and RPE data. Pulling cart tasks produced a significantly higher activation of the muscles (RTR:54.4%, LTR:50.3%, LFDS:57.0%, LED:63.4%, RES:40.7%, LES:36.7%) than pushing cart tasks (RTR:42.4%, LTR:35.1%, LFDS:32.3%, LED:55.1%, RES:33.3%, LES:32.1%). A significantly greater perceived exertion was found in pulling cart tasks than pushing cart tasks. Significantly higher activation of all muscles and perceived exertion were observed for walking uphill than walking in a straight line and turning left. Significantly lower muscle activity of all muscles and subject ratings were observed for the central position on the X axis, the bottom position on the Y axis, and the posterior position on the Z axis. These findings suggest that nursing staff should adopt forward pushing when moving a nursing cart, instead of backward
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Directory of Open Access Journals (Sweden)
Adriana Rahal
2007-06-01
Full Text Available OBJETIVO: verificar a atividade elétrica do músculo masseter em pessoas com paralisia facial periférica de longa duração. MÉTODOS: participaram deste estudo seis sujeitos de ambos os sexos, com paralisia facial há pelo menos doze meses, sem queixas mastigatórias e sem disfunção temporomandibular e com pelo menos seis dentes em cada hemiarcada. Todos preencheram um questionário de anamnese e em seguida foram submetidos à eletromiografia de superfície dos masseteres de ambos os lados. As provas eletromiográficas foram: posição habitual com lábios fechados, apertamento dentário, mastigação habitual e unilateral à direita e à esquerda com uva passa. RESULTADOS: em todas as provas eletromiográficas não foram observadas diferenças significantes (p=0,05 entre os lados com e sem paralisia facial. CONCLUSÃO: observou-se com o presente estudo que a força do músculo masseter não sofre influência da paralisia facial de longa duração.PURPOSE: to check the masseter electrical activity in long lasting facial paralysis patients. METHODS: six subjects, with facial paralysis for over a period of twelve months, males and females, took part in this study. Patients should not show any masticatory complaints or have any diagnoses of temporo-mandibular joint dysfunction, having at least six teeth in each half dental ridge. All subjects filled out a questionnaire regarding oral habits and were assessed by surface electromyography of the masseter muscle of both sides. Electromyographic records were taken with lips closed at rest, teeth tightness, besides usual mastication, and unilateral mastication on both sides with raisins. RESULTS: in all electromyographic tests there were no statistically significant differences (p=0.05 between both sides, with and without facial paralysis. CONCLUSION: it was observed that the strength of the masseter muscle is not under the influence of long lasting facial paralysis.
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Understanding the Active Straight Leg Raise (ASLR): An electromyographic study in healthy subjects
Hu, H.; Meijer, O.G.; Bruijn, S.M.; Strijers, R.L.M.; Nanayakkara, P.W.B.; van Royen, B.J.; Wu, W; Xia, C.; van Dieen, J.H.
2012-01-01
The Active Straight Leg Raise (ASLR) is an important test in diagnosing pelvic girdle pain (PGP). It is difficult to understand what happens normally during the ASLR, let alone why it would be impaired in PGP. In the present study, healthy subjects performed the ASLR under normal conditions, with
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Trunk muscle activity increases with unstable squat movements.
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).
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Herda, Trent J; Zuniga, Jorge M; Ryan, Eric D; Camic, Clayton L; Bergstrom, Haley C; Smith, Doug B; Weir, Joseph P; Cramer, Joel T; Housh, Terry J
2015-06-01
This study examined the effects of electromyographic (EMG) recording methods and innervation zone (IZ) on the mean power frequency (MPF)-torque relationships. Nine subjects performed isometric ramp muscle actions of the leg extensors from 5% to 100% of maximal voluntary contraction with an eight channel linear electrode array over the IZ of the vastus lateralis. The slopes were calculated from the log-transformed monopolar and bipolar EMG MPF-torque relationships for each channel and subject and 95% confidence intervals (CI) were constructed around the slopes for each relationship and the composite of the slopes. Twenty-two to 55% of the subjects exhibited 95% CIs that did not include a slope of zero for the monopolar EMG MPF-torque relationships while 25-75% of the subjects exhibited 95% CIs that did not include a slope of zero for the bipolar EMG MPF-torque relationships. The composite of the slopes from the EMG MPF-torque relationships were not significantly different from zero for any method or channel, however, the method and IZ location slightly influenced the number of significant slopes on a subject-by-subject basis. The log-transform model indicated that EMG MPF-torque patterns were nonlinear regardless of recording method or distance from the IZ. Copyright © 2015 Elsevier Ltd. All rights reserved.
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International Nuclear Information System (INIS)
Herda, Trent J; Weir, Joseph P; Zuniga, Jorge M; Ryan, Eric D; Camic, Clayton L.; Bergstrom, Haley C; Cramer, Joel T; Housh, Terry J; Smith, Doug B
2013-01-01
The present study applied a log-transformation model to compare the electromyographic (EMG) amplitude versus torque relationships from monopolar EMG signals up to 35 mm proximal and distal from the innervation zone (IZ). Seven men (age = 23 ± 2 year; mass = 82 ± 10 kg) and two women (age = 21 ± 1 year; mass = 62 ± 8 kg) performed isometric ramp contractions of the right leg extensors with an eight-channel linear electrode array positioned over the vastus lateralis with the IZ located between channels 4 and 5. Linear regression models were fit to the log-transformed monopolar EMG RMS –torque relationships with the b terms (slope) and the a terms (Y-intercept) calculated for each channel and subject. The b terms for channels 4, 5, and 6 were higher (P ≤ 0.05) than the more distal channels 7 and 8 (P < 0.05). In contrast, there were no differences (P > 0.05) among the a terms of the eight channels. Thus, the shapes of the monopolar EMG RMS –torque relationships were altered as a function of distance between the IZ and recording area, which may be helpful for clinicians and researchers who infer changes in motor control strategies based on the shapes of the EMG RMS –torque relationships. (paper)
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The effects of athletics training on isometric strength and EMG activity in adolescent athletes
NIKOLAOS AGGELOUSIS; NIKOLAOS MANTZOURANIS; THEOPHILOS PILIANIDIS; GEORGIOS DASTERIDIS
2012-01-01
The aim of this study was to evaluate the effect of two different training programs on electromyographic activity (EMG), isometric strength and quadriceps hypertrophy in track and field athletes. 27 male adolescents athletes were divided in three (3) groups of nine (9), the Neuromuscular Group (NeuroGr), the Hypertrophy Group (HyperGr) and the Control Group (ControlG). The participants in both NeuroGr and HyperGr trained 3 times per week for 8 weeks while the athletes’of ControlGr did not tak...
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Muscular activity during dynamic squats in patients with ACL reconstruction.
Ceaglio, Sebastian; Alberto, Federico; Catalfamo, Paola Andrea; Braidot, Ariel Andres
2010-01-01
One of the most frequent injuries in subjects who practice sport is the rupture of the anterior cruciate ligament (ACL). Appropriate reconstruction and rehabilitation are key issues in full recovery of patients and their return to previous activities. This paper presents a new method to estimate muscle strength during a dynamic exercise from kinematic and electromyographic (EMG) data. Recovery of patients with ACL rupture and reconstruction was evaluated 4 and 6 months after surgery by assessing the differences in knee extensor and flexor muscle activity between the unimpaired and injured limbs. The results show that squat EMGs from the extensor muscles of the knee from the injured and unimpaired limb could help assess rehabilitation outputs in patients who had undergone an ACL reconstructive surgery.
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Activation of respiratory muscles during respiratory muscle training.
Walterspacher, Stephan; Pietsch, Fabian; Walker, David Johannes; Röcker, Kai; Kabitz, Hans-Joachim
2018-01-01
It is unknown which respiratory muscles are mainly activated by respiratory muscle training. This study evaluated Inspiratory Pressure Threshold Loading (IPTL), Inspiratory Flow Resistive Loading (IFRL) and Voluntary Isocapnic Hyperpnea (VIH) with regard to electromyographic (EMG) activation of the sternocleidomastoid muscle (SCM), parasternal muscles (PARA) and the diaphragm (DIA) in randomized order. Surface EMG were analyzed at the end of each training session and normalized using the peak EMG recorded during maximum inspiratory maneuvers (Sniff nasal pressure: SnPna, maximal inspiratory mouth occlusion pressure: PImax). 41 healthy participants were included. Maximal activation was achieved for SCM by SnPna; the PImax activated predominantly PARA and DIA. Activations of SCM and PARA were higher in IPTL and VIH than for IFRL (p<0.05). DIA was higher applying IPTL compared to IFRL or VIH (p<0.05). IPTL, IFRL and VIH differ in activation of inspiratory respiratory muscles. Whereas all methods mainly stimulate accessory respiratory muscles, diaphragm activation was predominant in IPTL. Copyright © 2017 Elsevier B.V. All rights reserved.
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The effect of surface electrical stimulation on vocal fold position.
Humbert, Ianessa A; Poletto, Christopher J; Saxon, Keith G; Kearney, Pamela R; Ludlow, Christy L
2008-01-01
Closure of the true and false vocal folds is a normal part of airway protection during swallowing. Individuals with reduced or delayed true vocal fold closure can be at risk for aspiration and may benefit from intervention to ameliorate the problem. Surface electrical stimulation is currently used during therapy for dysphagia, despite limited knowledge of its physiological effects. Prospective single effects study. The immediate physiological effect of surface stimulation on true vocal fold angle was examined at rest in 27 healthy adults using 10 different electrode placements on the submental and neck regions. Fiberoptic nasolaryngoscopic recordings during passive inspiration were used to measure change in true vocal fold angle with stimulation. Vocal fold angles changed only to a small extent during two electrode placements (P vocal fold abduction was 2.4 degrees; while horizontal placements of electrodes in the submental region produced a mean adduction of 2.8 degrees (P = .03). Surface electrical stimulation to the submental and neck regions does not produce immediate true vocal fold adduction adequate for airway protection during swallowing, and one position may produce a slight increase in true vocal fold opening.
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Davarian, Sanaz; Maroufi, Nader; Ebrahimi, Esmaeil; Parnianpour, Mohammad; Farahmand, Farzam
2014-01-01
It is suggested that activation of the transverse abdominis muscle has a stabilizing effect on the lumbar spine by raising intra-abdominal pressure without added disc compression. However, its feedforward activity has remained a controversial issue. In addition, research regarding bilateral activation of trunk muscles during a unilateral arm movement is limited. The aim of this study was to evaluate bilateral anticipatory activity of trunk muscles during unilateral arm flexion. Eighteen healthy subjects (aged 25 ± 3.96 years) participated in this study and performed 10 trials of rapid arm flexion in response to a visual stimulus. The electromyographic activity of the right anterior deltoid (AD) and bilateral trunk muscles including the transverse abdominis/internal oblique (TA/IO), superficial lumbar multifidus (SLM) and lumbar erector spine (LES) was recorded. The onset latency and anticipatory activity of the recorded trunk muscles were calculated. The first muscle activated in anticipation of the right arm flexion was the left TA/IO. The right TA/IO activated significantly later than all other trunk muscles (P 0.05). Healthy subjects showed no bilateral anticipatory co-activation of TA/IO in unilateral arm elevation. Further investigations are required to delineate normal muscle activation pattern in healthy subjects prior to prescribing bilateral activation training of transverse abdominis for subjects with chronic low back pain.
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Lehecka, B J; Edwards, Michael; Haverkamp, Ryan; Martin, Lani; Porter, Kambry; Thach, Kailey; Sack, Richard J; Hakansson, Nils A
2017-08-01
Gluteal strength plays a role in injury prevention, normal gait patterns, eliminating pain, and enhancing athletic performance. Research shows high gluteal muscle activity during a single-leg bridge compared to other gluteal strengthening exercises; however, prior studies have primarily measured muscle activity with the active lower extremity starting in 90 ° of knee flexion with an extended contralateral knee. This standard position has caused reports of hamstring cramping, which may impede optimal gluteal strengthening. The purpose of this study was to determine which modified position for the single-leg bridge is best for preferentially activating the gluteus maximus and medius. Cross-Sectional. Twenty-eight healthy males and females aged 18-30 years were tested in five different, randomized single-leg bridge positions. Electromyography (EMG) electrodes were placed on subjects' gluteus maximus, gluteus medius, rectus femoris, and biceps femoris of their bridge leg (i.e., dominant or kicking leg), as well as the rectus femoris of their contralateral leg. Subjects performed a maximal voluntary isometric contraction (MVIC) for each tested muscle prior to performing five different bridge positions in randomized order. All bridge EMG data were normalized to the corresponding muscle MVIC data. A modified bridge position with the knee of the bridge leg flexed to 135 ° versus the traditional 90 ° of knee flexion demonstrated preferential activation of the gluteus maximus and gluteus medius compared to the traditional single-leg bridge. Hamstring activation significantly decreased (p bridge by flexing the active knee to 135 ° instead of 90 ° minimizes hamstring activity while maintaining high levels of gluteal activation, effectively building a bridge better suited for preferential gluteal activation. 3.
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DEFF Research Database (Denmark)
Bakke, Merete; Michler, L
1991-01-01
values, particularly in subjects with muscular affection, but maximal activity increased significantly when biting on the splint. Maximal voluntary contraction was positively correlated to molar contact and negatively to anterior face height, mandibular inclination, vertical jaw relation and gonial angle......Activity in temporalis and masseter muscles, and traits of facial morphology and occlusal stability were studied in 22 patients (19 women, 3 men; 15-45 yr of age) with anterior open bite and symptoms and signs of craniomandibular disorders. Facial morphology was assessed by profile radiographs......, occlusal stability by tooth contacts, and craniomandibular function by clinical and radiological examination. Electromyographic activity was recorded by surface electrodes after primary treatment with a reflex-releasing, stabilizing splint. Maximal voluntary contraction was reduced compared to reference...
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Effect of Fatigue Upon Performance and Electromyographic Activity in 6-RM Bench Press.
van den Tillaar, Roland; Saeterbakken, Atle
2014-03-27
The aim of this study was to examine the effect of fatigue during one set of 6-RM bench pressing upon the muscle patterning and performance. Fourteen resistance-trained males (age 22.5±2.0 years, stature 1.82±0.07 m, body mass 82.0±7.8 kg) conducted a 6-RM bench press protocol. Barbell kinematics and EMG activity of pectoralis major, deltoid anterior, biceps brachii, triceps brachii, rectus abdominis, oblique external and erector spinae were measured in each repetition during the 6-RM bench press. Total lifting time increased and the velocity in the ascending movement decreased (p≤0.001). However, the kinematics in the descending phase deferred: the time decreased and velocity increased during the 6-RM (p≤0.001). Generally, muscles increased their EMG amplitude during the six repetitions in the ascending movement, while only three of the seven measured muscles showed an increase over the six repetitions in the descending part in 6-RM bench pressing. It was concluded that the bench pressing performance decreased (lower barbell velocities and longer lifting times) with increasing fatigue in the 6-RM execution. Furthermore EMG increased in the prime movers and the trunk stabilizers (abdominal and spine), while the antagonist muscle (biceps) activity was not affected by fatigue during the lifting phase in a single set of 6-RM bench pressing.
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Effect of Fatigue Upon Performance and Electromyographic Activity in 6-RM Bench Press
van den Tillaar, Roland; Saeterbakken, Atle
2014-01-01
The aim of this study was to examine the effect of fatigue during one set of 6-RM bench pressing upon the muscle patterning and performance. Fourteen resistance-trained males (age 22.5±2.0 years, stature 1.82±0.07 m, body mass 82.0±7.8 kg) conducted a 6-RM bench press protocol. Barbell kinematics and EMG activity of pectoralis major, deltoid anterior, biceps brachii, triceps brachii, rectus abdominis, oblique external and erector spinae were measured in each repetition during the 6-RM bench p...
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Rice, Hannah; Fallowfield, Joanne; Allsopp, Adrian; Dixon, Sharon
2017-05-01
The high stress fracture occurrence in military populations has been associated with frequent load carriage activities. This study aimed to assess the influence of load carriage and of completing a load carriage training activity on gait characteristics. Thirty-two Royal Marine recruits completed a 12.8-km load carriage activity as part of their military training. Data were collected during walking in military boots, pre and post-activity, with and without the additional load (35.5 kg). Ground contact time, lower limb sagittal plane kinematics and kinetics, and electromyographic variables were obtained for each condition. When carrying load, there was increased ground contact time, increased joint flexion and joint moments, and increased plantar flexor and knee extensor muscle activity. Post-activity, there were no changes to kinematic variables, knee extensor moments were reduced, and there was evidence of plantar flexor muscle fatigue. The observed gait changes may be associated with stress fracture development. Practitioner Summary: This study identified gait changes due to load carriage and after a military load carriage training activity. Such activities are associated with lower limb stress fractures. A pre-post study design was used. Gait mechanics changed to a greater extent when carrying load, than after completion of the activity when assessed without load.
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Directory of Open Access Journals (Sweden)
Penha-Silva Nilson
2010-06-01
Full Text Available Abstract Background The main problem of tremor is the damage caused to the quality of the life of patients, especially those at more advanced ages. There is not a consensus yet about the origins of this disorder, but it can be examined in the correlations between the biological signs of aging and the tremor characteristics. Methods This work sought correlations between the osmotic fragility of erythrocytes and features extracted from electromyographic (EMG activity resulting from physiological tremor in healthy patients (N = 44 at different ages (24-87 years. The osmotic fragility was spectrophotometrically evaluated by the dependence of hemolysis, provided by the absorbance in 540 nm (A54o, on the concentration of NaCl. The data were adjusted to curves of sigmoidal regression and characterized by the half transition point (H50, amplitude of lysis transition (dx and values of A540 in the curve regions that characterize the presence of lysed (A1 and preserved erythrocytes (A2. The approximate entropy was estimated from EMG signals detected from the extensor carpi ulnaris muscle during the movement of the hand of subjects holding up a laser pen towards an Archimedes spiral, fixed in a whiteboard. The evaluations were carried out with the laser pen at rest, at the center of the spiral, and in movement from the center to the outside and from outside to the center. The correlations among the parameters of osmotic fragility, tremor and age were tested. Results Negative correlations with age were found for A1 and dx. With the hand at rest, a positive correlation with H50 was found for the approximate entropy. Negative correlations with H50 were found for the entropy with the hand in movement, as from the center to the outside or from the outside to the center of the spiral. Conclusion In healthy individuals, the increase in the erythrocyte osmotic fragility was associated with a decrease in the approximate entropy for rest tremor and with an increase
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Mahaki, M; Mi'mar, R; Mahaki, B
2015-10-01
Anterior cruciate ligament (ACL) injury continues to be an important medical issue for athletes participating in sports. Vertical and posterior ground reaction forces have received considerable attention for their potential influence on ACL injuries. The purpose of this study was to examine the relationship between electromyographic activity of lower extremity muscles and the peak vertical and posterior ground reaction forces during single leg drop landing. Thirteen physical education male students participated in this correlation study. Electromyographic activities of gluteus medius, biceps femoris, medial gastrocnemius, soleus as well as anterior tibialis muscles along with ground reaction forces were measured. Participants performed single-leg landing from a 0.3 m height on to a force platform. Landing was divided into two phases: 100 ms preceding ground contact and 100 ms proceeding ground contact. Pearson correlation test was used to determine the relationships between these muscles activity and peak vertical and posterior ground reaction forces. The results of the study indicated that the activity of soleus and tibialis anterior in pre-landing phase were positively correlated with peak vertical ground reaction force ([P≤0.04], [P≤0.008], respectively). However, no significant correlation was found between the activities of other muscles in pre-landing phase and peak vertical as well as peak posterior ground reaction forces. Also, no significant correlation was found between the activities of muscles in post-landing phase and peak vertical as well as peak posterior ground reaction forces. Soleus loading shifts the proximal tibia posterior at the knee joint and tibialis anterior prevent hyperporonation of the ankle, a mechanisms of ACL injury. Hence, neuromuscular training promoting preparatory muscle activity in these muscles may reduce the incidence of ACL injuries.
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Ries, Lilian Gerdi Kittel; Alves, Marcelo Correa; Bérzin, Fausto
2008-01-01
The aim of this study was to analyze the symmetry of the electromyographic (EMG) activity of the temporalis, masseter, and sternocleidomastoid (SCM) muscles in volunteers divided into a control group and a temporomandibular disorder (TMD) group. The surface EMG recordings were made during mandibular rest position, maximal intercuspal position, and during the chewing cycle. Normalized EMG waves of paired muscles were compared by computing a percentage overlapping coefficient (POC). The difference between the groups and between the static and dynamic clenching tests was analyzed through repeated measures, ANOVA. Symmetry of the temporalis, masseter, and SCM muscles activity was smaller in the TMD group compared to the control group. The mandibular postures were also significantly different among themselves. The asymmetric activation of jaw and neck muscles was interpreted as a compensatory strategy to achieve stability for the mandibular and cervical systems during masticatory function.
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DEFF Research Database (Denmark)
Jakobsen, Markus Due; Sundstrup, Emil; Andersen, Christoffer H
2012-01-01
muscle during 10-RM knee-extensions performed with elastic tubing and an isotonic strength training machine. METHODS: 7 women and 9 men aged 28-67 years (mean age 44 and 41 years, respectively) participated. Electromyographic (EMG) activity was recorded in 10 muscles during the concentric and eccentric......BACKGROUND/PURPOSE: While elastic resistance training, targeting the upper body is effective for strength training, the effect of elastic resistance training on lower body muscle activity remains questionable. The purpose of this study was to evaluate the EMG-angle relationship of the quadriceps...... tubing induces similar high (>70% nEMG) quadriceps muscle activity during the concentric contraction phase, but slightly lower during the eccentric contraction phase, as knee extensions performed using an isotonic training machine. During the concentric contraction phase the two different conditions...
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DEFF Research Database (Denmark)
Jakobsen, Markus Due; Sundstrup, Emil; Andersen, Christoffer H
2012-01-01
tubing induces similar high (>70% nEMG) quadriceps muscle activity during the concentric contraction phase, but slightly lower during the eccentric contraction phase, as knee extensions performed using an isotonic training machine. During the concentric contraction phase the two different conditions......BACKGROUND/PURPOSE: While elastic resistance training, targeting the upper body is effective for strength training, the effect of elastic resistance training on lower body muscle activity remains questionable. The purpose of this study was to evaluate the EMG-angle relationship of the quadriceps...... muscle during 10-RM knee-extensions performed with elastic tubing and an isotonic strength training machine. METHODS: 7 women and 9 men aged 28-67 years (mean age 44 and 41 years, respectively) participated. Electromyographic (EMG) activity was recorded in 10 muscles during the concentric and eccentric...
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DEFF Research Database (Denmark)
Vedsted, Pernille; Søgaard, Karen; Blangsted, Anne Katrine
2011-01-01
trapezius (TRA) can reduce bilateral TRA activity but not extensor digitorum communis (EDC) activity; (2) biofeedback from EDC can reduce activity in EDC but not in TRA; (3) biofeedback is more effective in no time constraint than in the time constraint working condition. Eleven healthy women performed......Continuous electromyographic (EMG) activity level is considered a risk factor in developing muscle disorders. EMG biofeedback is known to be useful in reducing EMG activity in working muscles during computer work. The purpose was to test the following hypotheses: (1) unilateral biofeedback from...... computer work during two different working conditions (time constraint/no time constraint) while receiving biofeedback. Biofeedback was given from right TRA or EDC through two modes (visual/auditory) by the use of EMG or mechanomyography as biofeedback source. During control sessions (no biofeedback), EMG...
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Comparing trapezius muscle activity in the different planes of shoulder elevation.
Ishigaki, Tomonobu; Ishida, Tomoya; Samukawa, Mina; Saito, Hiroshi; Hirokawa, Motoki; Ezawa, Yuya; Sugawara, Makoto; Tohyama, Harukazu; Yamanaka, Masanori
2015-05-01
[Purpose] The purpose of this study was to compare the upper, middle, and lower trapezius muscles' activity in the different planes of shoulder elevation. [Subjects] Twenty male subjects volunteered for this study. [Methods] Surface electromyographic (EMG) activity for each of the three regions of the trapezius muscles in the three different planes of elevation were collected while the participants maintained 30, 60, and 90 degrees of elevation in each plane. The EMG data were normalized with maximum voluntary isometric contraction (%MVIC), and compared among the planes at each angle of elevation. [Results] There were significantly different muscle activities among the elevation planes at each angle. [Conclusion] This study found that the three regions of the trapezius muscles changed their activity depending on the planes of shoulder elevation. These changes in the trapezius muscles could induce appropriate scapular motion to face the glenoid cavity in the correct directions in different planes of shoulder elevation.
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DEFF Research Database (Denmark)
Spedden, Meaghan Elizabeth; Nielsen, Jens Bo; Geertsen, Svend Sparre
2018-01-01
Aging is accompanied by impaired motor function, but age-related changes in neural networks responsible for generating movement are not well understood. We aimed to investigate the functional oscillatory coupling between activity in the sensorimotor cortex and ankle muscles during static contract......Aging is accompanied by impaired motor function, but age-related changes in neural networks responsible for generating movement are not well understood. We aimed to investigate the functional oscillatory coupling between activity in the sensorimotor cortex and ankle muscles during static...... contraction. Fifteen young (20–26 yr) and fifteen older (65–73 yr) subjects were instructed to match a target force by performing static ankle dorsi- or plantar flexion, while electroencephalographic (EEG) activity was recorded from the cortex and electromyographic (EMG) activity was recorded from dorsi...
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DEFF Research Database (Denmark)
Larsman, P; Thorn, S; Søgaard, K
2009-01-01
The current study investigated the associations between work-related perceived stress and surface electromyographic (sEMG) parameters (muscle activity and muscle rest) during standardized simulated computer work (typing, editing, precision, and Stroop tasks). It was part of the European case......-control study, NEW (Neuromuscular assessment in the Elderly Worker). The present cross-sectional study was based on a questionnaire survey and sEMG measurements among Danish and Swedish female computer users aged 45 or older (n=49). The results show associations between work-related perceived stress...... and trapezius muscle activity and rest during standardized simulated computer work, and provide partial empirical support for the hypothesized pathway of stress induced muscle activity in the association between an adverse psychosocial work environment and musculoskeletal symptoms in the neck and shoulder....
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Outlet obstruction constipation (anismus) managed by biofeedback.
Kawimbe, B M; Papachrysostomou, M; Binnie, N R; Clare, N; Smith, A N
1991-10-01
Fifteen subjects presenting with intractable constipation due to obstructive defecation, mean (SEM) duration 8.8 (1.8) years, had the inappropriate contraction and electromyographic changes in the pelvic floor muscles and external and sphincter typical of this condition. An electromyographically derived index was used to grade its severity. A self applied biofeedback device was used to allow electromyographic recording of the abnormal external anal sphincter. The subjects were encouraged to reduce the abnormal electromyographic activity on straining after instruction and training. The procedure was intended as a relearning process in which the non-relaxing activity of the pelvic floor was gradually suppressed. Biofeedback training was maintained on a domiciliary basis for a mean time of 3.1 weeks and resulted in a significant reduction in the anismus index (mean (SEM) 69.9 (7.8)% before biofeedback, mean 14 (3.9)% after biofeedback, p less than 0.01). There was an associated reduction in the time spent straining at stool and in the difficulty of defecation and an increased frequency of defecation. Defecatory video proctograms in six subjects showed improvements in the anorectal angle during straining and evacuation. The clinical benefit to the patients persisted after a mean follow up of 6.2 months.
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Safar Cherati, Afsaneh; Lotfian, Sara; Jamshidi, Aliashraf; Sanjari, Mohammad Ali; Razi, Mohammad
2016-09-01
The effects of exercise volume on the pattern of muscle activity is one of the most important factors in training management and injury risk reduction. In the lower limb, the quadriceps muscle which plays a determining role in performing the stance and other karate techniques could be injured in intensive exercise and may induce anterior knee pain in athletes. The aim of this study was to determine the relationship between training volume and muscle activity of vastus medialis and vastus lateralis and its association with anterior knee pain in karate elites. Male and female athletes from national junior and cadet karate team (14 to 18 years) were invited to participate in the study at the beginning and the end of the training camps. Studies involved measurement of electromyographic muscle activity of vastus medialis and vastus lateralis in both lower extremities with surface electromyography device and assessment of movement by electrogoniometery. Muscle activity was recorded in three tests of dachi, walking up and walking down stairs. Simultaneously, anterior knee pain was evaluated using visual analogue scale and anterior knee pain scale questionnaire. Eight athletes of a total number of 23 reported increased ratings of pain in their right knees. No differences in muscle activity were observed in tests of Dachi and stairs between the groups with and without pain. Comparing Dachi task pattern at the beginning and end of training camps, there was no significant difference in pattern of biomechanical movement; however, reducing the amount of muscle activity in early and late phases of tasks was observed in electromyographic assessment. The results showed that performing the same task after a six-week training period, less muscle activity was required in all phases in two groups of tasks, including karate-specific movement (dachi) and activities of daily living (up or down stairs).
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Directory of Open Access Journals (Sweden)
Konstantinos Sotiropoulos
2010-06-01
Full Text Available The purpose of this study was to determine the effects of a specific warm-up using half-squats at low and moderate intensity on vertical jump performance and electromyographic activity of the thigh muscles. The subjects were 26 men who were divided into a low intensity group (LIG; n = 13 and a moderate intensity group (MIG; n = 13. The LIG performed a specific warm-up protocol that included the explosive execution of half-squats with loads 25 and 35% of the one repetition maximum (1RM and the MIG with loads 45 and 65% of the 1RM. The two groups performed a countermovement jump (CMJ before and three minutes after the specific warm-up protocols. During the concentric phase of the CMJ a linear encoder connected to an A/D converter interfaced to a PC with a software for data acquisition and analysis allowed the calculation of average mechanical power. The electromyographic (EMG activity of the vastus lateralis (VL, vastus medialis (VM and rectus femoris (RF were recorded during the concentric phase of the jumps. The average quadriceps (Qc activity (mean value of the VL, VM and RF was also calculated. A two way ANOVA (protocols X time with repeated measures on the second factor was used to analyze the data. Following the specific warm-up procedure both groups improved (p < 0.05 CMJ performance and mechanical power by 3.5% and 6.3%, respectively, with no differences observed between the two groups. EMG activity of the Qc and VL increased (p < 0.05 for both groups by 5.9% and 8.5%, respectively. It is concluded that the use of a specific warm-up that includes half-squats, performed explosively with low to moderate intensity, improves CMJ performance. This may be due to increased muscle activation as evaluated by the surface EMG
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Directory of Open Access Journals (Sweden)
Ptaszkowski K
2015-09-01
Full Text Available Kuba Ptaszkowski,1 Małgorzata Paprocka-Borowicz,2 Lucyna Słupska,2 Janusz Bartnicki,1,3 Robert Dymarek,4 Joanna Rosińczuk,4 Jerzy Heimrath,5 Janusz Dembowski,6 Romuald Zdrojowy6 1Department of Obstetrics, 2Department of Clinical Biomechanics and Physiotherapy in Motor System Disorders, Wroclaw Medical University, Wroclaw, Poland; 3Department of Obstetrics and Gynecology, Health Center Bitterfeld/Wolfen gGmbH, Bitterfeld-Wolfen, Germany; 4Department of Nervous System Diseases, 5Department of Gynaecology and Obstetrics, Faculty of Health Science, 6Department and Clinic of Urology, Faculty of Postgraduate Medical Training, Wroclaw Medical University, Wroclaw, Poland Objective: Muscles such as adductor magnus (AM, gluteus maximus (GM, rectus abdominis (RA, and abdominal external and internal oblique muscles are considered to play an important role in the treatment of stress urinary incontinence (SUI, and the relationship between contraction of these muscles and pelvic floor muscles (PFM has been established in previous studies. Synergistic muscle activation intensifies a woman’s ability to contract the PFM. In some cases, even for continent women, it is not possible to fully contract their PFM without involving the synergistic muscles. The primary aim of this study was to assess the surface electromyographic activity of synergistic muscles to PFM (SPFM during resting and functional PFM activation in postmenopausal women with and without SUI.Materials and methods: This study was a preliminary, prospective, cross-sectional observational study and included volunteers and patients who visited the Department and Clinic of Urology, University Hospital in Wroclaw, Poland. Forty-two patients participated in the study and were screened for eligibility criteria. Thirty participants satisfied the criteria and were categorized into two groups: women with SUI (n=16 and continent women (n=14. The bioelectrical activity of PFM and SPFM (AM, RA, GM was
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Gaudet, Sylvain; Tremblay, Jonathan; Begon, Mickael
2018-05-01
The aims of this study were to investigate the differences in peak muscle activity and recruitment patterns during high- and low-velocity, concentric and eccentric, internal and external isokinetic shoulder rotations. Electromyographic activity of the rotator cuff and eight superficial muscles of the shoulder girdle was recorded on 25 healthy adults during isokinetic internal and external shoulder rotation at 60°/s and 240°/s. Peak muscle activity, electromyographic envelopes and peak isokinetic moments were analyzed using three-factor ANOVA and statistical parametric mapping. The subscapularis and serratus anterior showed moderate to high peak activity levels during each conditions, while the middle and posterior deltoids, upper, middle and lower trapezius, infraspinatus and supraspinatus showed higher peak activity levels during external rotations (+36.5% of maximum voluntary activation (MVA)). The pectoralis major and latissimus dorsi were more active during internal rotations (+40% of MVA). Only middle trapezius and pectoralis major electromyographic activity decreased with increasing velocity. Peak muscle activity was similar or lower during eccentric contractions, although the peak isokinetic moment increased by 35% on average. The subscapularis and serratus anterior appear to be important stabilizers of the glenohumeral joint and scapula. Isokinetic eccentric training at high velocities may allow for faster recruitment of the shoulder girdle muscles, which could improve joint stability during shoulder internal and external rotations.
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Directory of Open Access Journals (Sweden)
Manuela Kobelt
2018-04-01
Full Text Available Introduction: The present study assessed whether motor imagery (MI produces electromyographic activation in specific muscles of the upper limb during a hand grasping and arm-lifting task in healthy volunteers, patients after stroke, or with Parkinson's disease. Electromyographic (EMG activation was compared under three conditions: MI, physical execution (PE, and rest. The task is clinically relevant unilateral executed movement using open muscle chains.Methods: In a cross-sectional study EMG activation was measured in four muscles: M. deltoideus pars clavicularis, M. biceps brachii, M. extensor digitorum, M. flexor carpi radialis. MI ability was evaluated with mental rotation, mental chronometry and the Kinaesthetic and Visual Imagery Questionnaire. Cognitive performance was screened with the Mini-Mental State Examination.Results: Twenty-two participants (11 females, age 52.6 ±15.8, age range 21 to 72 were included: ten healthy volunteers, seven patients after stroke (time after stroke onset 16.3 ± 24.8 months, and five patients with Parkinson's disease (disease duration 60.4 ± 24.5 months. Overall Mini-Mental State Examination scores ranged between 27 and 30. An increased EMG activation during MI compared to rest condition was observed in M. deltoideus pars clavicularis and M. biceps brachii across all participants (p-value = 0.001, p = 0.007. Seven participants (two healthy volunteers, three patients after stroke and two patients with Parkinson's disease showed a EMG activation during MI of the hand grasping and arm-lifting task in at least one of the target muscles. No correlation between EMG activation during MI and scores of three MI ability assessments were found.Conclusions: The findings suggest that MI can yield subliminal EMG activation. However, that might vary on individual basis. It remains unclear what parameters contribute to or inhibit an EMG activation during MI. Future investigations should determine factors that influence
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Ochoa-Escudero, Martin; Juliano, Amy F
2016-10-01
Anomalies of the anterior belly of the digastric muscle (DM) are uncommon. We present a case of hypoplasia of the anterior belly of the left DM with hypertrophy of the anterior belly of the contralateral DM. The importance of recognizing this finding is to differentiate hypoplasia of the anterior belly of the DM from denervation atrophy, and not to confuse contralateral hypertrophy with a submental mass or lymphadenopathy. In denervation atrophy of the anterior belly of the DM, associated atrophy of the ipsilateral mylohyoid muscle is present. Hypertrophy of the anterior belly of the contralateral DM can be differentiated from a submental mass or lymphadenopathy by recognizing its isodensity on computed tomography and isointensity on magnetic resonance imaging to other muscles, without abnormal contrast enhancement.
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Alfonsi, E; Merlo, I M; Ponzio, M; Montomoli, C; Tassorelli, C; Biancardi, C; Lozza, A; Martignoni, E
2010-01-01
Botulinum toxin (BTX) injection into the cricopharyngeal (CP) muscle has been proposed for the treatment of neurogenic dysphagia due to CP hyperactivity. The aim was to determine whether an electrophysiological method exploring oropharyngeal swallowing could guide treatment and discriminate responders from non-responders, based on the association of CP dysfunction with other electrophysiological abnormalities of swallowing. Patients with different neurological disorders were examined: Parkinson disease, progressive supranuclear palsy, multiple system atrophy-Parkinson variant, multiple system atrophy cerebellar variant, stroke, multiple sclerosis and ataxia telangiectasia. All patients presented with clinical dysphagia, and with complete absence of CP muscle inhibition during the hypopharyngeal phase of swallowing. Each patient underwent clinical and electrophysiological investigations before and after treatment with BTX into the CP muscle of one side (15 units of Botox). Clinical and electrophysiological procedures were performed in a blind manner by two different investigators. The following electrophysiological measures were analysed: (1) duration of EMG activity of suprahyoid/submental muscles (SHEMG-D); (2) duration of laryngopharyngeal mechanogram (LPM-D); (3) duration of the inhibition of the CP muscle EMG activity (CPEMG-ID); and (4) interval between onset of EMG activity of suprahyoid/submental muscles and onset of laryngopharyngeal mechanogram (I-SHEMG-LPM). Two months after treatment, 50% of patients showed a significant improvement. Patients with prolonged or reduced SHEMG-D values and prolonged I-SHEMG-LPM values did not respond to BTX. Therefore, values for which BTX had no effect (warning values) were identified. This electrophysiological method can recognise swallowing abnormalities which may affect the outcome of the therapeutic approach to dysphagia with BTX treatment.
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Sorbie, Graeme G; Hunter, Henry H; Grace, Fergal M; Gu, Yaodong; Baker, Julien S; Ugbolue, Ukadike Chris
2016-01-01
The study describes the differences in surface electromyography (EMG) activity of two forearm muscles in the lead and trail arm at specific phases of the golf swing using a 7-iron with three different grip sizes among amateur and professional golfers. Fifteen right-handed male golfers performed five golf swings using golf clubs with three different grip sizes. Surface EMG was used to measure muscle activity of the extensor carpi radialis brevis (ECRB) and flexor digitorum superficialis (FDS) on both forearms. There were no significant differences in forearm muscle activity when using the three golf grips within the group of 15 golfers (p > 0.05). When using the undersize grip, club head speed significantly increased (p = 0.044). During the backswing and downswing phases, amateurs produced significantly greater forearm muscle activity with all three grip sizes (p < 0.05). In conclusion, forearm muscle activity is not affected by grip sizes. However, club head speed increases when using undersize grips.
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SEMG activity of jaw-closing muscles during biting with different unilateral occlusal supports.
Wang, M-Q; He, J-J; Zhang, J-H; Wang, K; Svensson, P; Widmalm, S E
2010-09-01
The aim of this study was to test the hypothesis that experimental and reversible changes of occlusion affect the levels of surface electromyographic (SEMG) activity in the anterior temporalis and masseter areas during unilateral maximal voluntary biting (MVB) in centric and eccentric position. Changes were achieved by letting 21 healthy subjects bite with and without a cotton roll between the teeth. The placement alternated between sides and between premolar and molar areas. The SEMG activity level was lower when biting in eccentric position without than with a cotton roll between teeth (P 0.05). In the anterior temporalis area, the balancing side SEMG activity was lower in eccentric than in centric but only in molar-supported biting (P = 0.026). These results support that the masseter and anterior temporalis muscles have different roles in keeping the mandible in balance during unilateral supported MVB. Changes in occlusal stability achieved by biting with versus without a cotton roll were found to affect the SEMG activity levels.
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Cuevas, Maria-José; Cacho, Alberto; Alarcón, Jose-Antonio; Martín, Conchita
2013-05-01
A longitudinal study was performed to evaluate the jaw muscle activity and mandibular kinematics after Teuscher activator treatment and at 2 years after orthodontic treatment completion. Twenty-seven children with Class II division 1 malocclusion were evaluated before treatment (T0; mean: 11.6 years), after functional treatment (T1; mean: 12.8 years), and 2 years after orthodontic treatment (T2; mean: 18 years). Bilateral surface electromyographic activities of the anterior temporalis, posterior temporalis, masseter, and suprahyoid muscle areas were analyzed at rest and during clenching, swallowing, and mastication. Kinematic recordings of the mandibular maximum opening, lateral shift, right and left lateral excursions, and protrusion were evaluated. Compared to T0, the left masseter activity during clenching was decreased at T1 but increased at T2, similar to the other evaluated muscles. The suprahyoid activity during swallowing was increased at T1 but decreased at T2. The masseter activity during mastication was increased at T1 and further increased at T2. The left and right lateral excursions and protrusion did not show significant changes throughout the experiment. Teuscher activator and subsequent fixed orthodontic treatment improved jaw muscle function; however, a long period was needed to attain complete neuromuscular adaptation.
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DEFF Research Database (Denmark)
Madeleine, Pascal; Vedsted, Pernille; Blangsted, Anne Katrine
2006-01-01
The purpose of this laboratory study was to investigate the effects of surface electromyography (EMG)- and mechanomyography (MMG)-based audio and visual biofeedback during computer work. Standardized computer work was performed for 3 min with/without time constraint and biofeedback in a randomize...... alternative to EMG in ergonomics. A lowering of the trapezius muscle activity may contribute to diminish the risk of work related musculoskeletal disorders development.......The purpose of this laboratory study was to investigate the effects of surface electromyography (EMG)- and mechanomyography (MMG)-based audio and visual biofeedback during computer work. Standardized computer work was performed for 3 min with/without time constraint and biofeedback in a randomized......) values as well as the work performance in terms of number of completed graph/mouse clicks/errors, the rating of perceived exertion (RPE) and the usefulness of the biofeedback were assessed. The duration of muscle activity above the threshold was significantly lower with MMG compared with EMG as source...
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Directory of Open Access Journals (Sweden)
Martinez-Fong Daniel
2011-03-01
Full Text Available Abstract Background Odontogenic necrotizing fasciitis of the neck is a fulminant infection of odontogenic origin that quickly spreads along the fascial planes and results in necrosis of the affected tissues. It is usually polymicrobial, occurs frequently in immunocompromised patients, and has a high mortality rate. Case presentation A 69-year old Mexican male had a pain in the maxillar right-canine region and a swelling of the submental and submandibular regions. Our examination revealed local pain, tachycardia, hyperthermia (39°C, and the swelling of bilateral submental and submandibular regions, which also were erythematous, hyperthermic, crepitant, and with a positive Godet sign. Mobility and third-degree caries were seen in the right mandibular canine. Bacteriological cultures isolated streptococcus pyogenes and staphylococcus aureus. The histopathological diagnosis was odontogenic necrotizing fasciitis of the submental and submandibular regions. The initial treatment was surgical debridement and the administration of antibiotics. After cultures were negative, the surgical wound was treated with a growth factor-enriched autologous plasma eight times every third day until complete healing occurred. Conclusions The treatment with a growth factor-enriched autologous plasma caused a rapid healing of an extensive surgical wound in a patient with odontogenic necrotizing fasciitis. The benefits were rapid tissue regeneration, an aesthetic and a functional scar, and the avoidance of further surgery and possible complications.
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Todd, Michael M; Hindman, Bradley J; King, Brian J
2014-08-01
December 2012), and there have been no cases of NMB-related reintubations in the PACU during the last 2 years. Implementation of universal electromyographic-based quantitative neuromuscular blockade monitoring required a sustained process of education along with repeated PACU surveys and feedback to providers. Nevertheless, this effort resulted in a significant reduction in the incidence of incompletely reversed patients in the PACU.
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Lu, Pei-Hsuan; Yang, Chih-Hsun; Chang, Ya-Ching
2017-11-01
Previous studies of microfocused ultrasound with visualization (MFU-V) on facial and neck laxity were largely based on masked physician assessments, histological analysis, and safety profile. More quantitative studies are needed. To evaluate the 800 treatment lines of MFU-V on skin tightening effect of face and neck in Asians using 2 quantitative analysis systems at 0, 90, and 180 days after treatment. Total 25 subjects were recruited in this prospective study. Subjects were treated with MFU-V to the face and neck using 2 different transducers: 4 MHz, 4.5-mm focal depth and 7 MHz, 3.0-mm focal depth with total 800 lines. The subjects were evaluated by skin complexion analysis and 3-dimensional imaging system at 0, 90, and 180 days. Mean brow height lift and submental lift were calculated. All 25 subjects completed treatment and received the follow-up examinations at 90 and 180 days. Two of the 25 subjects were male. Mean patient age was 53.3 years (range: 39.8-61.1 years). Wrinkles, texture, and pores were 3 variables relevant to analysis of skin laxity. Only mean wrinkles score reduction at 90 days was statistically significant (p = .0222). There was a mean 0.47 mm brow lift at 90 days (p = .0165), but there was a 0.12 mm decrease in brow height compared to baseline at 180 days (p = .6494). At 90 days, a mean 26.44 mm submental lift was noted (p = .0217). And at 180 days, a mean 13.76 mm submental lift was noted (p = .243). This study showed that the most prominent change after the 800-line MFU-V treatments in Asians was the significant submental lift at 90 days. Other noninvasive or minimally invasive treatment modalities can be considered to combine with MFU-V for the optimal treatment response. Additional MFU-V treatments can be considered 3 months after the first treatment.
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Directory of Open Access Journals (Sweden)
Antonio Tadeu de Souza Faleiros
2009-06-01
Full Text Available There is substantial controversy in literature about human dermatomes. We studied L4, L5, and S1 inferior limb dermatomes by comparing clinical signs and symptoms with conduction studies, electromyographical data, neurosurgical findings, and imaging data from computerized tomography (CT or magnetic resonance imaging (MRI. After analyzing 60 patients, we concluded that L4 is probably located in the medial aspect of the leg, L5 in the lateral aspect of the leg and foot dorsus, and S1 in the posterior aspect of the backside, tight, leg and plantar foot skin. This is the first time that these human dermatomes have been evaluated by combined analysis of clinical, electromyographical, neurosurgical, and imaging data.Há controvérsia na literatura sobre os dermátomos humanos. Estudamos dermátomos do membro inferior comparando sinais e sintomas com estudos eletromiográficos, de imagem e achados cirúrgicos. Analisando 60 pacientes, concluímos que o dermátomo L4 provavelmente está localizado na região medial da perna, o dermátomo L5 na região lateral da perna e dorso do pé, e o dermátomo S1 na nádega, região posterior da coxa e da perna e na região plantar. Este é o primeiro estudo que os dermátomos do membro inferior foram analisados através de dados clínicos, eletromiográficos, imagem e achados cirúrgicos.
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The defence technique in Tai Chi Push Hands: a case study.
Chen, Hui-Chuan; Cheng, Kuang-You B; Liu, Yu-Jen; Chiu, Hung-Ta; Cheng, Kuang-Yu
2010-12-01
Developed from traditional Chinese martial arts, Tai Chi exercise includes different forms and interactive Push Hands but biomechanical analyses have focused on the former only. To analyse the techniques of Push Hands, an experienced master was asked to defend pushing by four opponents. Movements were videotaped and digitized using a motion analysis system. Surface electrodes were used to record the electromyographic activity of ten muscle groups. Two force plates were used to measure the ground reaction force on each foot. Inexperienced individuals performed the same procedure to serve as the control group. The results indicate that the master adopted a postural adjustment to maintain balance. A clear shift of body weight from the front to the rear foot and mediolateral displacement of the centre of gravity was observed. Low electromyographic activity was observed in the upper body muscle groups, while high electromyographic activity was observed in the right rectus femoris and very high activity in the left rectus femoris during the defence. All inexperienced participants lost their balance in resisting pushing. It is concluded that the Tai Chi defensive technique includes a subtle postural adjustment that slightly changes the pushing force direction, and allows the rear leg to resist the incoming force.
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Deoxycholic acid injection is used to improve the appearance and profile of moderate to severe submental fat ('double chin'; fatty tissue located under the chin). Deoxycholic acid injection is in a class of medications called ...
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Directory of Open Access Journals (Sweden)
Roberta L. A. Batista
2011-10-01
Full Text Available BACKGROUND: Maintaining continence is among the functions of the pelvic floor muscles (PFM and their dysfunction can cause urinary incontinence (UI, which is a common occurrence during pregnancy and the puerperal period. Pelvic floor muscle training (PFMT, therefore, is important during pregnancy, although most women perform the muscle contractions unsatisfactorily. OBJECTIVES: This study is an exploratory analysis of the results of three electromyographic (EMG activity biofeedback sessions in pregnant women. METHODS: The study sample included 19 nulliparous women with low risk pregnancies. The participants performed three sessions of EMG biofeedback consisting of slow and fast contractions. The average value of the normalized amplitudes of surface electromyography was used to evaluate the results. The linear regression model with mixed effects was used for statistical analysis, with the EMG data normalized by maximum voluntary contraction (MVC. RESULTS: A steady increase in EMG amplitude was observed during each contraction and by the end of the biofeedback sessions, although this difference was only significant when comparing the first tonic contraction of each session (p=0.03. CONCLUSIONS: The results indicate that three sessions of training with biofeedback improved PFM EMG activity during the second trimester in women with low-risk pregnancies. The effectiveness of this protocol should be further investigated in randomized controlled trials.CONTEXTUALIZAÇÃO: Dentre as funções dos músculos do assoalho pélvico (MAPs, pode-se citar a manutenção da continência, sendo que sua disfunção pode causar a incontinência urinária (IU, muito frequente no período gestacional e no puerpério. Diante disso, se faz importante o treinamento dos músculos do assoalho pélvico (TMAP durante o período gestacional, entretanto grande parte das mulheres realiza a contração dessa musculatura de maneira insatisfatória. OBJETIVOS: Realizar uma an
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McDiarmid, James; Ruiz, Jesus Benito; Lee, Daniel; Lippert, Susanne; Hartisch, Claudia; Havlickova, Blanka
2014-10-01
The injectable adipocytolytic drug ATX-101 is the first nonsurgical treatment for the reduction of submental fat (SMF) to undergo comprehensive clinical evaluation. This study aimed to confirm the efficacy and safety of ATX-101 for SMF reduction through a post hoc pooled analysis of two large phase 3 studies. Patients with unwanted SMF were randomized to receive 1 or 2 mg/cm(2) of ATX-101 or a placebo injected into their SMF during a maximum of four treatment sessions spaced approximately 28 days apart, with a 12-week follow-up period. The proportions of patients with reductions in SMF of one point or more on the Clinician-Reported SMF Rating Scale (CR-SMFRS) and the proportions of patients satisfied with the appearance of their face and chin [Subject Self-Rating Scale (SSRS) score ≥4] were reported overall and in subgroups. Other efficacy measures included improvements in the Patient-Reported SMF Rating Scale (PR-SMFRS), calliper measurements of SMF thickness, and assessment of skin laxity [Skin Laxity Rating Scale (SLRS)]. Adverse events and laboratory test results were recorded. Significantly greater proportions of the patients had improvements in clinician-reported measures (≥1-point improvement in CR-SMFRS: 58.8 and 63.8 % of the patients who received ATX-101 1 and 2 mg/cm(2), respectively, and 28.6 % of the placebo recipients; p < 0.001 for both ATX-101 doses vs. placebo) and patient-reported measures (≥1-point improvement in PR-SMFRS: 60.0 and 63.1 % of the patients who received ATX-101 1 and 2 mg/cm(2), respectively, vs. 34.3 % of the placebo recipients; p < 0.001 for both), analyzed alone or in combination, with ATX-101 versus placebo. These improvements correlated moderately with patient satisfaction regarding face and chin appearance (SSRS score ≥4: 60.8 and 65.4 % of the patients who received ATX-101 1 and 2 mg/cm(2), respectively, vs. 29.0 % of the placebo recipients; p < 0.001 for both). In this study, ATX-101 was effective irrespective of
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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.
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DEFF Research Database (Denmark)
Zoetmulder, Marielle; Nikolic, Miki; Biernat, Heidi B
2016-01-01
STUDY OBJECTIVES: Rapid eye movement (REM) sleep behavior disorder (RBD) is a parasomnia characterized by impaired motor inhibition during REM sleep, and dream-enacting behavior. RBD is especially associated with α-synucleinopathies, such as Parkinson disease (PD). Follow-up studies have shown......-FP-CIT uptake in the putamen. In PD patients, EMG-activity was correlated to anti-Parkinson medication. CONCLUSIONS: Our results support the hypothesis that increased EMG-activity during REM sleep is at least partly linked to the nigrostriatal dopamine system in iRBD, and with dopamine function in PD....... the relation between this system and electromyographic (EMG) activity during sleep. The objective of this study was to investigate the relationship between the nigrostriatal dopamine system and muscle activity during sleep in iRBD and PD. METHODS: 10 iRBD patients, 10 PD patients with PD, 10 PD patients...
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DEFF Research Database (Denmark)
Zoetmulder, Marielle; Nikolic, Miki; Biernat, Heidi
2016-01-01
STUDY OBJECTIVES: Rapid eye movement (REM) sleep behavior disorder (RBD) is a parasomnia characterized by impaired motor inhibition during REM sleep, and dream-enacting behavior. RBD is especially associated with α-synucleinopathies, such as Parkinson disease (PD). Follow-up studies have shown...... in the putamen. In PD patients, EMG-activity was correlated to anti-Parkinson medication. CONCLUSIONS: Our results support the hypothesis that increased EMG-activity during REM sleep is at least partly linked to the nigrostriatal dopamine system in iRBD, and with dopamine function in PD....... the relation between this system and electromyographic (EMG) activity during sleep. The objective of this study was to investigate the relationship between the nigrostriatal dopamine system and muscle activity during sleep in iRBD and PD. METHODS: 10 iRBD patients, 10 PD patients with PD, 10 PD patients...
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Mordified Submental Endotracheal Intubation Technique in ...
African Journals Online (AJOL)
over a two-year period. Each patient required maxillomandibular fixation following trauma.Acommon feature in these patients was depressed fracture of the frontonasal bone which could not permit nasal intubation. These patients were reluctant to have tracheostomy if there was an alternative option of securing their airway.
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Directory of Open Access Journals (Sweden)
Yagesh eBhambhani
2014-06-01
Full Text Available This study examined the electromyographic, cerebral and muscle hemodynamic responses during intermittent isometric contractions of biceps brachii at 20%, 40% and 60% of maximal voluntary contraction (MVC. Eleven volunteers completed two minutes of intermittent isometric contractions (12/min at an elbow angle of 90° interspersed with three minutes rest between intensities in systematic order. Surface electromyography (EMG was recorded from the right biceps brachii and near infrared spectroscopy (NIRS was used to simultaneously measure left prefrontal and right biceps brachii oxyhemoglobin (HbO2, deoxyhemoglobin (HHb and total hemoglobin (Hbtot. Transcranial Doppler ultrasound was used to measure middle cerebral artery velocity (MCAv bilaterally. Finger photoplethysmography was used to record beat-to-beat blood pressure and heart rate. EMG increased with force output from 20% to 60% MVC (P0.05. MCAv increased from rest to exercise but was not different among intensities (P>0.05. Force output correlated with the root mean square EMG and changes in muscle HbO2 (P0.05 at all three intensities. Force output declined by 8% from the 1st to the 24th contraction only at 60% MVC and was accompanied by systematic increases in RMS, cerebral HbO2 and Hbtot with a levelling off in muscle HbO2 and Hbtot. These changes were independent of alterations in mean arterial pressure. Since cerebral blood flow and oxygenation were elevated at 60% MVC, we attribute the development of fatigue to reduced muscle oxygen availability rather than impaired central n
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Ervilha, Ulysses Fernandes; Mochizuki, Luis; Figueira, Aylton; Hamill, Joseph
2017-09-01
This study aimed to investigate the activation of lower limb muscles during barefoot and shod running with forefoot or rearfoot footfall patterns. Nine habitually shod runners were asked to run straight for 20 m at self-selected speed. Ground reaction forces and thigh and shank muscle surface electromyographic (EMG) were recorded. EMG outcomes (EMG intensity [iEMG], latency between muscle activation and ground reaction force, latency between muscle pairs and co-activation index between muscle pairs) were compared across condition (shod and barefoot), running cycle epochs (pre-strike, strike, propulsion) and footfall (rearfoot and forefoot) by ANOVA. Condition affected iEMG at pre-strike epoch. Forefoot and rearfoot strike patterns induced different EMG activation time patterns affecting co-activation index for pairs of thigh and shank muscles. All these timing changes suggest that wearing shoes or not is less important for muscle activation than the way runners strike the foot on the ground. In conclusion, the guidance for changing external forces applied on lower limbs should be pointed to the question of rearfoot or forefoot footfall patterns.
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Chen, Yumiao; Yang, Zhongliang
2017-01-01
Recently, several researchers have considered the problem of reconstruction of handwriting and other meaningful arm and hand movements from surface electromyography (sEMG). Although much progress has been made, several practical limitations may still affect the clinical applicability of sEMG-based techniques. In this paper, a novel three-step hybrid model of coordinate state transition, sEMG feature extraction and gene expression programming (GEP) prediction is proposed for reconstructing drawing traces of 12 basic one-stroke shapes from multichannel surface electromyography. Using a specially designed coordinate data acquisition system, we recorded the coordinate data of drawing traces collected in accordance with the time series while 7-channel EMG signals were recorded. As a widely-used time domain feature, Root Mean Square (RMS) was extracted with the analysis window. The preliminary reconstruction models can be established by GEP. Then, the original drawing traces can be approximated by a constructed prediction model. Applying the three-step hybrid model, we were able to convert seven channels of EMG activity recorded from the arm muscles into smooth reconstructions of drawing traces. The hybrid model can yield a mean accuracy of 74% in within-group design (one set of prediction models for all shapes) and 86% in between-group design (one separate set of prediction models for each shape), averaged for the reconstructed x and y coordinates. It can be concluded that it is feasible for the proposed three-step hybrid model to improve the reconstruction ability of drawing traces from sEMG.
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Dieën, J.H. van; Westebring van der; Putten, E.P.; Kingma, I.; Looze, M.P. de
2009-01-01
This study was designed to determine whether trunk extensor fatigue occurs during low-level activity and whether this is associated with a drop in muscle tissue oxygenation. Electromyography (EMG) feedback was used to impose constant activity in a part of the trunk extensor muscles. We hypothesized
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Directory of Open Access Journals (Sweden)
Maria do Socorro Brasileiro-Santos
2012-09-01
electromyography for the sternocleidomastoid muscles showed no statistically significant difference between the two groups. The percentage of electromyographs of the scalene muscles and the sternocleidomastoid muscles was higher in the asthma group than in the controls. CONCLUSIONS: the baseline electromyographs for scalene muscles is heightened in children with asthma. The electromyographic activity of the sternocleidomastoid muscles for the baseline was similar in both groups. The electromyographs for the sternocleidomastoid and scalene muscles on the generation of intrathoracic pressure, during the PImax maneuver give higher values among children with asthma.
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Bilateral neuromuscular and force differences during a plyometric task.
Ball, Nick B; Scurr, Joanna C
2009-08-01
The purpose of this article is to compare the bilateral neuromuscular and force contribution during a plyometric bounce drop jump task and to assess the affects of nonsimultaneous foot placement. Sixteen male participants performed bounce drop jumps from a height of 0.4 m. Mean peak electromyography activity of the soleus, medial, and lateral gastrocnemius of both legs was recorded from each phase of the drop jump and normalized to a reference dynamic muscle action. Resultant ground reaction force, ground contact time, and duration of the drop jumps were recorded from each leg. Multivariate analysis of variance was used to compare bilateral electromyographic activity, resultant peak ground reaction force, and contact duration. Pearson's correlations (r) ascertained relationships between normalized electromyographic activity and contact time. Significant differences were shown between left and right triceps surae normalized electromyography during precontact and contact40ms (p 0.01). Significant differences were found between normalized soleus electromyography and both gastrocnemii for both legs during precontact (p 0.01). Weak relationships were found between normalized electromyographic activity and nonsimultaneous foot contact (r < 0.2). This study showed differences between left and right triceps surae in neuromuscular strategies engaged in the early stages of a drop jump task. Differences in contact time initiation were present; however, they are not significant enough to cause neuromuscular differences in the plantar flexor muscles.
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DEFF Research Database (Denmark)
Falla, Deborah Lorraine; Andersen, Helle; Danneskiold-Samsøe, Bente
2010-01-01
The study compared the distribution of electromyographic (EMG) signal amplitude in the upper trapezius muscle in 10 women with fibromyalgia and in 10 healthy women before and after experimentally-induced muscle pain. Surface EMG signals were recorded over the right upper trapezius muscle with a 10...
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DEFF Research Database (Denmark)
Sundstrup, Emil; Jakobsen, Markus D; Andersen, Christoffer H
2012-01-01
. Electromyographic (EMG) amplitude and median power frequency (MPF) of specific shoulder and neck muscles was analysed and the Borg CR10 scale was used to rate perceived loading immediately after each set of exercise. During the failure set normalized EMG was significantly lower during the first repetition...
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Directory of Open Access Journals (Sweden)
A.C. Cardozo
2004-07-01
Full Text Available The aim of the present study was to assess the spectral behavior of the erector spinae muscle during isometric contractions performed before and after a dynamic manual load-lifting test carried out by the trunk in order to determine the capacity of muscle to perform this task. Nine healthy female students participated in the experiment. Their average age, height, and body mass (± SD were 20 ± 1 years, 1.6 ± 0.03 m, and 53 ± 4 kg, respectively. The development of muscle fatigue was assessed by spectral analysis (median frequency and root mean square with time. The test consisted of repeated bending movements from the trunk, starting from a 45º angle of flexion, with the application of approximately 15, 25 and 50% of maximum individual load, to the stand up position. The protocol used proved to be more reliable with loads exceeding 50% of the maximum for the identification of muscle fatigue by electromyography as a function of time. Most of the volunteers showed an increase in root mean square versus time on both the right (N = 7 and the left (N = 6 side, indicating a tendency to become fatigued. With respect to the changes in median frequency of the electromyographic signal, the loads used in this study had no significant effect on either the right or the left side of the erector spinae muscle at this frequency, suggesting that a higher amount and percentage of loads would produce more substantial results in the study of isotonic contractions.
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KOOLE, P; DEJONGH, HJ; BOERING, G
Electromyographic activity was synchronously recorded by surface and intramuscular electrodes in the same muscle. The activity of the left masseter, left temporalis, and both bellies of the anterior digastric muscle was studied by this double registration technique. In rest position no
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Pitfalls of nonstandardized photography in facial plastic surgery patients.
Sommer, Doron D; Mendelsohn, Martyn
2004-07-01
The authors tested the hypothesis that certain maneuvers (neck flexion/extension and head protrusion/retrusion) alter the appearance of the submental area, jawline, and melolabial groove. They used a questionnaire survey of 20 naïve judges who assessed a standardized photograph album of three subjects. The subjects' faces (frontal and lateral views) were photographed in neutral, neck flexion/extension, and head protrusion/retrusion positions. High Kendall coefficients of correlation were observed in 10 of 12 questions evaluating an improvement in jawline definition with neck extension or head protrusion, as well as in 11 of 12 questions assessing decreased submental soft tissue. All questions relating to the melolabial groove had a correlation coefficient of less than 0.70. Small changes in patient positioning during photodocumentation for facial plastic surgical procedures can cause dramatic changes in the appearance of certain parameters. Standardizing patient positioning for preoperative and postoperative photographs is imperative.
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Youdas, James W; Adams, Kady E; Bertucci, John E; Brooks, Koel J; Nelson, Meghan M; Hollman, John H
2014-02-01
No published studies have compared muscle activation levels simultaneously for the gluteus maximus and medius muscles of stance and moving limbs during standing hip-joint strengthening while using elastic-tubing resistance. To quantify activation levels bilaterally of the gluteus maximus and medius during resisted lower-extremity standing exercises using elastic tubing for the cross-over, reverse cross-over, front-pull, and back-pull exercise conditions. Repeated measures. Laboratory. 26 active and healthy people, 13 men (25 ± 3 y) and 13 women (24 ± 1 y). Subjects completed 3 consecutive repetitions of lower-extremity exercises in random order. Surface electromyographic (EMG) signals were normalized to peak activity in the maximum voluntary isometric contraction (MVIC) trial and expressed as a percentage. Magnitudes of EMG recruitment were analyzed with a 2 × 4 repeated-measures ANOVA for each muscle (α = .05). For the gluteus maximus an interaction between exercise and limb factor was significant (F3,75 = 21.5; P tubing.
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Advanced biofeedback from surface electromyography signals using fuzzy system
DEFF Research Database (Denmark)
Samani, Afshin; Holtermann, Andreas; Søgaard, Karen
2010-01-01
The aims of this study were to develop a fuzzy inference-based biofeedback system and investigate its effects when inducing active (shoulder elevation) and passive (relax) pauses on the trapezius muscle electromyographic (EMG) activity during computer work. Surface EMG signals were recorded from...
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Kalytczak, Marcelo Martins; Lucareli, Paulo Roberto Garcia; Dos Reis, Amir Curcio; Bley, André Serra; Biasotto-Gonzalez, Daniela Aparecida; Correa, João Carlos Ferrari; Politti, Fabiano
2018-04-07
This study aimed to compare the concentric and eccentric activity and the temporal order of peak activity of the hip and knee muscles between women with patellofemoral pain (PFP) and healthy women during the single leg triple hop test (SLTHT). Electromyographic (EMG) and Kinematic data were collected from 14 healthy women (CG) and 14 women diagnosed with PFP (PFG) during a single session of the single leg triple hop test. Integral surface electromyography (iEMG) data of the hip and knee muscles in eccentric and concentric phases and the length of time that each muscle needed to reach the maximal peak of muscle activity were calculated. The iEMG in the eccentric phase was significantly higher (p < 0.05) than the concentric phase, for the gluteus maximus and gluteus medius muscles (CG and PFG) and for the vastus lateralis muscle (PFG). The vastus lateralis muscle was the first muscle to reach the highest peak of activity in the PFG, and the third to reach this peak in the CG. In the present study, the activity of the vastus lateralis muscle during the eccentric phase of the jump was greater than concentric phase, as a temporal anticipation of its peak in activity among women with PFP. Copyright © 2018 Elsevier B.V. All rights reserved.
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DEFF Research Database (Denmark)
Søgaard, Karen; Blangsted, Anne Katrine; Nielsen, Pernille Kofoed
2012-01-01
The aim of this randomized controlled trial was to assess changes in myalgic trapezius activation, muscle oxygenation, and pain intensity during repetitive and stressful work tasks in response to 10 weeks of training. In total, 39 women with a clinical diagnosis of trapezius myalgia were randomly...... levels of pain. SST lowered the relative EMG amplitude by 36%, and decreased pain during resting and working conditions by 52 and 38%, respectively, without affecting trapezius oxygenation. In conclusion, GFT performed as leg-bicycling decreased pain development during repetitive work tasks, possibly due...... assigned to: (1) general fitness training performed as leg-bicycling (GFT); (2) specific strength training of the neck/shoulder muscles (SST) or (3) reference intervention without physical exercise. Electromyographic activity (EMG), tissue oxygenation (near infrared spectroscopy), and pain intensity were...
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Directory of Open Access Journals (Sweden)
Delaine Rodrigues
2004-12-01
Full Text Available Temporomandibular disorders (TMD are characterized by several signs and symptoms, such as pain and changes in the electrical activity of masticatory muscles. Considering that transcutaneous electrical nerve stimulation (TENS is a resource indicated to promote analgesia, the objective of this study was to evaluate the effect of TENS on pain and electromyographic (EMG activity of the jaw elevator muscles in TMD patients. This study evaluated 35 female volunteers: 19 TMD patients (mean age = 23.04 ± 3.5 and 16 normal subjects (mean age = 23.3 ± 3.0. Transcutaneous electrical nerve stimulation (conventional mode, 150 Hz was applied once to each group for 45 minutes. Surface electromyography (gain of 100 times and 1 kHz sampling frequency and the visual analogue scale (VAS were applied before and immediately after TENS application. Both VAS data and root mean square (RMS values were analyzed using Student's t-test. The TMD group, compared to the control group, showed higher EMG activity of the jaw elevator muscles at rest. No difference was observed between the groups regarding maximum voluntary clenching (MVC. In TMD patients, TENS reduced both pain and EMG activity of the anterior portion of the temporal muscle, increasing the activity of the masseter muscles during MVC. It is possible to conclude that a single TENS application is effective in pain reduction. However, it does not act homogeneously on the features of the electric activity of the muscles evaluated.A desordem temporomandibular (DTM é caracterizada por diversos sinais e sintomas, como dor e alteração do sinal eletromiográfico dos músculos da mastigação. Considerando que a estimulação elétrica nervosa transcutânea (TENS é um recurso indicado para promover analgesia, o objetivo deste trabalho foi avaliar o efeito da TENS na dor e na atividade eletromiográfica (EMG dos músculos elevadores da mandíbula em indivíduos com DTM. Foram selecionados 35 voluntários do sexo
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Wolburg, Thomas; Rapp, Walter; Rieger, Jochen; Horstmann, Thomas
2016-01-01
To test the hypotheses that less stable therapy devices require greater muscle activity and that lower leg muscles will have greater increases in muscle activity with less stable therapy devices than upper leg muscles. Cross-sectional laboratory study. Laboratory setting. Twenty-five healthy subjects. Electromyographic activity of four lower (gastrocnemius medialis, soleus, tibialis anterior, peroneus longus) and four upper leg muscles (vastus medialis and lateralis, biceps femoris, semitendinosus) during unipedal quiet barefoot stance on the dominant leg on a flat rigid surface and on five therapy devices with varying stability properties. Muscle activity during unipedal stance differed significantly between therapy devices (P < 0.001). The order from lowest to highest relative muscle activity matched the order from most to least stable therapy device. There was no significant interaction between muscle location (lower versus upper leg) and therapy device (P = 0.985). Magnitudes of additional relative muscle activity for the respective therapy devices differed substantially among lower extremity muscles. The therapy devices offer a progressive increase in training intensity, and thus may be useful for incremental training programs in physiotherapeutic practice and sports training programs. Copyright © 2015 Elsevier Ltd. All rights reserved.
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Higashihara, Ayako; Nagano, Yasuharu; Ono, Takashi; Fukubayashi, Toru
2018-06-01
This study aimed to investigate activation characteristics of the biceps femoris long head (BFlh) and semitendinosus (ST) muscles during the acceleration and maximum-speed phases of sprinting. Lower-extremity kinematics and electromyographic (EMG) activities of the BFlh and ST muscles were examined during the acceleration sprint and maximum-speed sprint in 13 male sprinters during an overground sprinting. Differences in hamstring activation during each divided phases and in the hip and knee joint angles and torques at each time point of the sprinting gait cycle were determined between two sprints. During the early stance of the acceleration sprint, the hip extension torque was significantly greater than during the maximum-speed sprint, and the relative EMG activation of the BFlh muscle was significantly higher than that of the ST muscle. During the late stance and terminal mid-swing of maximum-speed sprint, the knee was more extended and a higher knee flexion moment was observed compared to the acceleration sprint, and the ST muscle showed higher activation than that of the BFlh. These results indicate that the functional demands of the medial and lateral hamstring muscles differ between two different sprint performances.
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An electromyographic analysis of two handwriting grasp patterns.
de Almeida, Pedro Henrique Tavares Queiroz; da Cruz, Daniel Marinho Cezar; Magna, Luis Alberto; Ferrigno, Iracema Serrat Vergotti
2013-08-01
Handwriting is a fundamental skill needed for the development of daily-life activities during lifetime and can be performed using different forms to hold the writing object. In this study, we monitored the sEMG activity of trapezius, biceps brachii, extensor carpi radialis brevis and flexor digitorum superficialis during a handwriting task with two groups of subjects using different grasp patterns. Twenty-four university students (thirteen males and eleven females; mean age of 22.04±2.8years) were included in this study. We randomly invited 12 subjects that used the Dynamic Tripod grasp and 12 subjects that used the Static Tripod grasp. The static tripod group showed statistically significant changes in the sEMG activity of trapezium and biceps brachii muscles during handwriting when compared to dynamic tripod group's subjects. No significant differences were found in extensor carpi radialis brevis and flexor digitorum superficialis activities among the two groups. The findings in this study suggest an increased activity of proximal muscles among subjects using a transitional grasp, indicating potential higher energy expenditure and muscular harm with the maintenance of this motor pattern in handwriting tasks, especially during the progression in academic life. Copyright © 2013 Elsevier Ltd. All rights reserved.
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Kyriazis, Thomas A; Terzis, Gerasimos; Boudolos, Konstantinos; Georgiadis, Georgios
2009-09-01
The aim of this study was to investigate changes in shot put performance, muscular power, and neuromuscular activation of the lower extremities, between the preseason and the competition period, in skilled shot put athletes using the rotational technique. Shot put performance was assessed at the start of the pre-season period as well as after 12 weeks, at the competition period, in nine shot putters. Electromyographic (EMG) activity of the right vastus lateralis muscle was recorded during all shot put trials. Maximum squat strength (1RM) and mechanical parameters during the countermovement jump (CMJ) on a force platform were also determined at pre-season and at competition period. Shot put performance increased 4.7% (p phase was increased significantly (p training period. Shot put performance was significantly related with muscular power and takeoff velocity during the CMJ, at competition period (r = 0.66, p competition period.
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Analysis of the Hamstring Muscle Activation During two Injury Prevention Exercises
Monajati, Alireza; Larumbe-Zabala, Eneko; Goss-Sampson, Mark
2017-01-01
Abstract The aim of this study was to perform an electromyographic and kinetic comparison of two commonly used hamstring eccentric strengthening exercises: Nordic Curl and Ball Leg Curl. After determining the maximum isometric voluntary contraction of the knee flexors, ten female athletes performed 3 repetitions of both the Nordic Curl and Ball Leg Curl, while knee angular displacement and electromyografic activity of the biceps femoris and semitendinosus were monitored. No significant differences were found between biceps femoris and semitendinosus activation in both the Nordic Curl and Ball Leg Curl. However, comparisons between exercises revealed higher activation of both the biceps femoris (74.8 ± 20 vs 50.3 ± 25.7%, p = 0.03 d = 0.53) and semitendinosus (78.3 ± 27.5 vs 44.3 ± 26.6%, p = 0.012, d = 0.63) at the closest knee angles in the Nordic Curl vs Ball Leg Curl, respectively. Hamstring muscles activation during the Nordic Curl increased, remained high (>70%) between 60 to 40° of the knee angle and then decreased to 27% of the maximal isometric voluntary contraction at the end of movement. Overall, the biceps femoris and semitendinosus showed similar patterns of activation. In conclusion, even though the hamstring muscle activation at open knee positions was similar between exercises, the Nordic Curl elicited a higher hamstring activity compared to the Ball Leg Curl. PMID:29339983
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African Journals Online (AJOL)
Anaesthesia for Oesophageal Replacement with Colonconduit– A Review of Forty Six Cases Abstract · Vol 49, No 4 (2008) - Articles Mordified Submental Endotracheal Intubation Technique in Maxillofacial Injuries Abstract · Vol 50, No 3 (2009) - Articles Managing Sacrococcygeal Teratoma in a New Born of a Psychopathic ...
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African Journals Online (AJOL)
mwakagugu
immobilization e.g. parietal-submental bandage, interdental wiring and second; permanent method ... otherwise compression ulcer will occur on the gum. Splint should be firmly fixed to each tooth using stainless wire ... forming sores from rubber band pressure. When preparing stainless wire splint with hooks, through ...
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Baba, K; Yugami, K; Akishige, S; Ai, M
2000-01-01
The aim of this study was to investigate the effect of experimental alterations of nonworking-side occlusal contacts on jaw-elevator muscle activity. Individual devices were fabricated to simulate various lateral occlusal relationships. Twelve human subjects were asked to carry out submaximal lateral clenching, and electromyographic (EMG) activity of the masseter and anterior and posterior temporalis muscles was measured. Clenching in a lateral mandibular position under natural conditions induced an activity pattern with a clear dominance of the anterior and posterior temporalis muscles on the working side. Working-side dominance in the anterior temporalis was reduced moderately when an experimental nonworking-side occlusal contact was added. Dominance decreased dramatically when an experimental nonworking-side interference was added. The working-side activity in the posterior temporalis was also reduced dramatically by an experimental nonworking-side interference, but not by a nonworking-side occlusal contact. None of the experimental contact patterns had a significant effect on the masseter activity. These results suggest that the nonworking-side occlusal contacts have a significant effect on clenching-induced temporalis muscle activity.
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Negar Koorosh-fard
2015-07-01
Full Text Available Objective: The aim of this study was assessing the effect of feedback correcting exercise in front of mirror during running on frontal plane knee and pelvic kinematic and electromyography activity of some lower extremity muscles in single leg squat (SLS. Materials & Methods: This study was quasi experimental. 23 active female subjects participated in two experimental and control groups with mean age (21.86± 2.43 years .experimental group contains subjects with knee valgus and pelvic drop angle more than a mean plus one standard deviation of the population in functional SLS. Muscular activity (RMS of gluteus maximus, Gluteus medius, rectus femoris, vastus medialis, vastus lateralis, biceps femoris and semitendinosus, angle of knee valgus and pelvic drop were register in end of SLS Pre and post of 8 training sessions. Comparing Variable has done with independent t statistical test between 2 groups and pair sample t test within each groups with significant level of 0.05. Results: Statistical analysis Before training showed no significant differences in pelvic drop between two groups (P&ge0.05, but knee valgus angle was significantly more than control group (P&le0.05. In spit that most muscle activities (% MVC except biceps femoris (P&le0.05, were greater in experimental group, no significant difference (P&ge0.05 has seen in two groups. Comparing pre and post test has showed no significant difference in knee valgus of experimental group, however it decreased around 2 degrees and although %MVC decreased in all muscles, just rectuse femoris has shown significant difference (P&le0.05. No significant difference has seen in control group in all variables (P&ge0.05. Conclusion: Findings showed poor neuromuscular control in experimental group which improved to some extent after training because lower muscle activity and energy consumption in specific movement with similar kinematic indicate improvement of motor control or cause learning. It seems that
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Abdominal muscle activity during a standing long jump.
Okubo, Yu; Kaneoka, Koji; Shiina, Itsuo; Tatsumura, Masaki; Miyakawa, Shumpei
2013-08-01
Experimental laboratory study. To measure the activation patterns (onset and magnitude) of the abdominal muscles during a standing long jump using wire and surface electromyography. Activation patterns of the abdominal muscles, especially the deep muscles such as the transversus abdominis (TrA), have yet to be examined during full-body movements such as jumping. Thirteen healthy men participated. Wire electrodes were inserted into the TrA with the guidance of ultrasonography, and surface electrodes were attached to the skin overlying the rectus abdominis (RA) and external oblique (EO). Electromyographic signals and video images were recorded while each subject performed a standing long jump. The jump task was divided into 3 phases: preparation, push-off, and float. For each muscle, activation onset relative to the onset of the RA and normalized muscle activation levels (percent maximum voluntary contraction) were analyzed during each phase. Comparisons between muscles and phases were assessed using 2-way analyses of variance. The onset times of the TrA and EO relative to the onset of the RA were -0.13 ? 0.17 seconds and -0.02 ? 0.07 seconds, respectively. Onset of TrA activation was earlier than that of the EO. The activation levels of all 3 muscles were significantly greater during the push-off phase than during the preparation and float phases. Consistent with previously published trunk-perturbation studies in healthy persons, the TrA was activated prior to the RA and EO. Additionally, the highest muscle activation levels were observed during the push-off phase.
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Yoshimura, Sayaka; Sato, Wataru; Uono, Shota; Toichi, Motomi
2015-01-01
Previous electromyographic studies have reported that individuals with autism spectrum disorders (ASD) exhibited atypical patterns of facial muscle activity in response to facial expression stimuli. However, whether such activity is expressed in visible facial mimicry remains unknown. To investigate this issue, we videotaped facial responses in…
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Control of leg movements driven by EMG activity of shoulder muscles
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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.
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El Sibai Olfat
2004-09-01
Full Text Available Abstract Background The role of the crural diaphragm during increased intra-abdominal pressure is not exactly known. We investigated the hypothesis that the crural diaphragm undergoes reflex phasic contraction on elevation of the intra-abdominal pressure with a resulting increase of the lower esophageal pressure and prevention of gastro-esophageal reflux. Methods The esophageal pressure and crural diaphragm electromyographic responses to straining were recorded in 16 subjects (10 men, 6 women, age 36.6 ± 11.2 SD years during abdominal hernia repair. The electromyogram of crural diaphragm was recorded by needle electrode inserted into the crural diaphragm, and the lower esophageal pressure by a saline-perfused catheter. The study was repeated after crural anesthetization and after crural infiltration with saline. Results The crural diaphragm exhibited resting electromyographic activity which showed a significant increase on sudden (coughing, p Conclusions Straining effected an increase of the electromyographic activity of the crural diaphragm and of the lower esophageal pressure. This effect is suggested to be reflex in nature and to be mediated through the "straining-crural reflex". The crural diaphragm seems to play a role in the lower esophageal competence mechanism. Further studies are required to assess the clinical significance of the current results in gastro-esophageal reflux disease and hiatus hernia.
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Adriana Rahal
2009-01-01
Full Text Available OBJETIVO: Analisar a diferença entre os lados na atividade eletromiográfica do masseter em indivíduos adultos com oclusão dentária normal. MÉTODOS: Foram avaliados 30 indivíduos saudáveis entre 21 e 30 anos e realizou-se eletromiografia de superfície nos músculos masseteres direito e esquerdo, durante apertamento em máxima intercuspidação e mastigação habitual com uva passa. Foram computados os valores médios dos três apertamentos dentários e dos 15 segundos da mastigação habitual para cada indivíduo. Foram considerados para a análise: o lado de maior valor e o de menor valor eletromiográfico. RESULTADOS: Durante o apertamento dentário, a diferença média entre os dois lados foi de 20,0 microvolts (μV com intervalo de confiança (95% entre 14,0 e 26,0 μV e durante a mastigação habitual, a diferença média entre os dois lados foi de 10,3 μV com intervalo de confiança (95% entre 6,7 e 13,8 μV. CONCLUSÃO: Houve diferença estatisticamente significante entre os lados, com relação entre eles de 24% para o apertamento dentário e de 27% para a mastigação habitual, em indiv duos adultos saudáveis.PURPOSE: To analyze the difference between both sides of the face during the electromyographic activity of the masseter muscle in adults with normal occlusion. METHODS: Thirty healthy individuals with ages ranging from 21 to 30 years old were selected. Surface electromyography was performed on right and left masseter muscles during maximal voluntary clenching and habitual chewing with raisins. The mean values of three teeth clenching and fifteen seconds of habitual chewing were calculated for each subject. The analysis considered the sides with higher and lower electromyographic activity. RESULTS: During maximal voluntary clenching, the mean difference between sides was 20.0 microvolts (μV, with confidence interval (95% between 14.0 and 26.0 μV. During habitual chewing, the mean difference between sides was 10.3
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Pasinato, Fernanda; Santos-Couto-Paz, Clarissa C; Zeredo, Jorge Luis Lopes; Macedo, Sergio Bruzadelli; Corrêa, Eliane C R
2016-12-01
The aim of this study was to verify the effects of induced masseter-muscle pain on the amplitude of muscle activation, symmetry and coactivation of jaw- and neck-muscles during mastication. Twenty-eight male volunteers, mean age±SD 20.6±2.0years, participated in this study. Surface electromyography of the masseter and sternocleidomastoid (SCM) muscles was performed bilaterally during mastication of a gummy candy before and after injections of monosodium glutamate solution and isotonic saline solution. As a result, we observed a decrease in the amplitude of activation of the masseter muscle on the working side (p=0.009; d=0.34) and a reduction in the asymmetry between the working and the balancing side during mastication (p=0.007; d=0.38). No changes were observed either on the craniocervical electromyographic variables. In conclusion, experimentally induced pain reduced the masseter muscle activation on the working side, thereby reducing the physiological masseters' recruitment asymmetry between the two sides during mastication. No effects on SCM activity were detected. These results may partly explain the initial maladaptative changes underlying TMD conditions. Copyright © 2016 Elsevier Ltd. All rights reserved.
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Scapular kinematics and muscle activities during pushing tasks.
Huang, Chun-Kai; Siu, Ka-Chun; Lien, Hen-Yu; Lee, Yun-Ju; Lin, Yang-Hua
2013-01-01
Pushing tasks are functional activities of daily living. However, shoulder complaints exist among workers exposed to regular pushing conditions. It is crucial to investigate the control of shoulder girdles during pushing tasks. The objective of the study was to demonstrate scapular muscle activities and motions on the dominant side during pushing tasks and the relationship between scapular kinematics and muscle activities in different pushing conditions. Thirty healthy adults were recruited to push a four-wheel cart in six pushing conditions. The electromyographic signals of the upper trapezius (UT) and serratus anterior (SA) muscles were recorded. A video-based system was used for measuring the movement of the shoulder girdle and scapular kinematics. Differences in scapular kinematics and muscle activities due to the effects of handle heights and weights of the cart were analyzed using two-way ANOVA with repeated measures. The relationships between scapular kinematics and muscle activities were examined by Pearson's correlation coefficients. The changes in upper trapezius and serratus anterior muscle activities increased significantly with increased pushing weights in the one-step pushing phase. The UT/SA ratio on the dominant side decreases significantly with increased handle heights in the one-step pushing phase. The changes in upward rotation, lateral slide and elevation of the scapula decreased with increased pushing loads in the trunk-forward pushing phase. This study indicated that increased pushing loads result in decreased motions of upward rotation, lateral slide and elevation of the scapula; decreased handle heights result in relatively increased activities of the serratus anterior muscles during pushing tasks.
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Acute intestinal obstruction: an electromyographic study in dogs.
Summers, R W; Yanda, R; Prihoda, M; Flatt, A
1983-12-01
We have investigated the motility effects of acute experimental canine intestinal obstruction. A 30-min midjejunal obstruction was produced by clamping a Biebl loop or by inflating an intraluminal balloon. Spike bursts from serosal electrodes proximal to the site of obstruction increased markedly, while those from distal electrodes decreased. When the obstruction from an intraluminal Foley catheter was continued for 5.5 h, the inhibition persisted distally but the proximal contractile activity gradually fell to control levels. The reduced proximal activity after prolonged obstruction was largely due to clusters of regular intense spike bursts preceded and followed by lengthening periods of absent motor activity. Similar clustered contractions obliterated the lumen when the passage of barium through a Thiry-Vella loop was monitored fluoroscopically. Significant motility changes occur in intestinal obstruction, but an increased understanding of the mechanisms involved awaits future studies.
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Luczak, Joshua; Bosak, Andy; Riemann, Bryan L.
2013-01-01
Previous research has compared the effects of trunk inclination angle on muscle activation using barbells and Smith machines in men. Whether similar effects occur with the use of dumbbells or in women remains unknown. The purpose was to compare upper extremity surface electromyographical (EMG) activity between dumbbell bench, incline, and shoulder presses. Dominate arm EMG data were recorded for collegiate-aged female resistance trained individuals (n = 12) and novice female resistance trained exercisers (n = 12) from which average EMG amplitude for each repetition phase (concentric, eccentric) was computed. No significant differences were found between experienced and novice resistance trained individuals. For the upper trapezius and anterior deltoid muscles, shoulder press activation was significantly greater than incline press which in turn was significantly greater than bench press across both phases. The bench and incline presses promoted significantly greater pectoralis major sternal activation compared to the shoulder press (both phases). While pectoralis major clavicular activation during the incline press eccentric phase was significantly greater than both the bench and shoulder presses, activation during the bench press concentric phase promoted significantly greater activation than the incline press which in turn was significantly greater than the shoulder press. These results provide evidence for selecting exercises in resistance and rehabilitation programs. PMID:26464884
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Joshua Luczak
2013-01-01
Full Text Available Previous research has compared the effects of trunk inclination angle on muscle activation using barbells and Smith machines in men. Whether similar effects occur with the use of dumbbells or in women remains unknown. The purpose was to compare upper extremity surface electromyographical (EMG activity between dumbbell bench, incline, and shoulder presses. Dominate arm EMG data were recorded for collegiate-aged female resistance trained individuals ( and novice female resistance trained exercisers ( from which average EMG amplitude for each repetition phase (concentric, eccentric was computed. No significant differences were found between experienced and novice resistance trained individuals. For the upper trapezius and anterior deltoid muscles, shoulder press activation was significantly greater than incline press which in turn was significantly greater than bench press across both phases. The bench and incline presses promoted significantly greater pectoralis major sternal activation compared to the shoulder press (both phases. While pectoralis major clavicular activation during the incline press eccentric phase was significantly greater than both the bench and shoulder presses, activation during the bench press concentric phase promoted significantly greater activation than the incline press which in turn was significantly greater than the shoulder press. These results provide evidence for selecting exercises in resistance and rehabilitation programs.
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de Araújo, Rodrigo Cappatode; Pirauá, André Luiz Torres; Beltrão, Natália Barros; Pitangui, Ana Carolina Rodarti
2018-03-01
Scapular dyskinesis is the term used to describe changes in the positioning or movement of the scapula. Such dysfunction is associated with changes in the activation of the scapular muscles. However, the influence of the axial muscles on the scapular muscles activity of subjects with scapular dyskinesis is unknown. This study aimed to compare the electromyography (EMG) activity of periscapular muscles and its correlation with the external oblique muscle during the execution of push-up performed in different surfaces, in volunteers with and without scapular dyskinesis. Thirty-six men, divided in two groups (control and dyskinesis), performed push-up on stable and unstable surface. The EMG activity of serratus anterior (SA_5th and SA_7th fibers), upper (UT) and lower (LT) trapezius, external oblique (EO) was recorded during execution of each task condition. Statistical analyzes were performed using two way ANOVA repeated measures and Pearson correlation. It was observed effect of interaction between factors, being evidenced increased activity of UT, SA_7th and OE for the control group and decreased activity of SA_5th, SA_7th and EO for dyskinesis group during execution of push-up on unstable surface. In both groups positive correlations (r > 0.47) were observed between EMG activity of SA and EO. In the exercises tested, there seems to be an anatomical and functional relationship between the SA and EO muscles. The use of the unstable surface promotes increased neuromuscular demand, but the neuromuscular strategies appear to differ between groups.
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Afshin Samani
Full Text Available The design of an industrial workstation tends to include ergonomic assessment steps based on a digital mock-up and a virtual reality setup. Lack of interaction and system fidelity is often reported as a main issue in such virtual reality applications. This limitation is a crucial issue as thorough ergonomic analysis is required for an investigation of the biomechanics. In the current study, we investigated the biomechanical responses of the shoulder joint in a simulated assembly task for comparison with the biomechanical responses in virtual environments. Sixteen male healthy novice subjects performed the task on three different platforms: real (RE, virtual (VE, and virtual environment with force feedback (VEF with low and high precision demands. The subjects repeated the task 12 times (i.e., 12 cycles. High density electromyography from the upper trapezius and rotation angles of the shoulder joint were recorded and split into the cycles. The angular trajectories and velocity profiles of the shoulder joint angles over a cycle were computed in 3D. The inter-subject similarity in terms of normalized mutual information on kinematics and electromyography was investigated. Compared with RE the task in VE and VEF was characterized by lower kinematic maxima. The inter-subject similarity in RE compared with intra-subject similarity across the platforms was lower in terms of movement trajectories and greater in terms of trapezius muscle activation. The precision demand resulted in lower inter- and intra-subject similarity across platforms. The proposed approach identifies biomechanical differences in the shoulder joint in both VE and VEF compared with the RE platform, but these differences are less marked in VE mostly due to technical limitations of co-localizing the force feedback system in the VEF platform.
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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.
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Muscle activation patterns in acceleration-based phases during reach-to-grasp movement.
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.
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1986-05-01
Besides these technical matters of localizing and quantifying the activity there is a theoretical concern about the nature of the muscle processes being...of myofascial pain dysfunction. Northwest Dentistry, 61: 18-20. Graham, G.S. 1983. Clinical evaluation of temporomandibular disorders. General
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Effect of Seat Tube Angle and Exercise Intensity on Muscle Activity Patterns in Cyclists
DUGGAN, WILL; DONNE, BERNARD; FLEMING, NEIL
2017-01-01
Previous studies have reported improved efficiency at steeper seat tube angle (STA) during ergometer cycling; however, neuromuscular mechanisms have yet to be fully determined. The current study investigated effects of STA on lower limb EMG activity at varying exercise intensities. Cyclists (n=11) were tested at 2 workloads; 160W and an individualised workload (IWL) equivalent to lactate threshold (TLac) minus 10%δ (derived from maximal incremental data), using 3 STA (70, 75 and 80°). Electromyographic data from Vastus Medialis (VM), Rectus Femoris (RF), Vastus Lateralis (VL) and Biceps Femoris (BF) were assessed. The timing and magnitude of activation were quantified and analysed using a two-way ANOVA. STA had significant (P pedal stroke is generated during the mid-section of the down-stroke, movement of the activation range of knee extensors into the predominantly power phase of the pedal stroke would potentially account for increased efficiency and decreased cardio-respiratory costs. Greater activity of bi-articular RF, in the first 108º of the crank cycle at IWL (80 vs. 70º) may more closely resemble the pelvic stabilising activity of RF in running biomechanics; and potentially explain the more effective transition from cycling to running reported in triathletes using steeper STA. PMID:29399245
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Masticatory muscle activity during deliberately performed oral tasks
International Nuclear Information System (INIS)
Farella, M; Palla, S; Erni, S; Gallo, L M; Michelotti, A
2008-01-01
The aim of this study was to investigate masticatory muscle activity during deliberately performed functional and non-functional oral tasks. Electromyographic (EMG) surface activity was recorded unilaterally from the masseter, anterior temporalis and suprahyoid muscles in 11 subjects (5 men, 6 women; age = 34.6 ± 10.8 years), who were accurately instructed to perform 30 different oral tasks under computer guidance using task markers. Data were analyzed by descriptive statistics, repeated measurements analysis of variance (ANOVA) and hierarchical cluster analysis. The maximum EMG amplitude of the masseter and anterior temporalis muscles was more often found during hard chewing tasks than during maximum clenching tasks. The relative contribution of masseter and anterior temporalis changed across the tasks examined (F ≥ 5.2; p ≤ 0.001). The masseter muscle was significantly (p ≤ 0.05) more active than the anterior temporalis muscle during tasks involving incisal biting, jaw protrusion, laterotrusion and jaw cupping, the difference being statistically significant (p ≤ 0.05). The anterior temporalis muscle was significantly (p ≤ 0.01) more active than the masseter muscle during tasks performed in intercuspal position, during tooth grinding, and during hard chewing on the working side. Based upon the relative contribution of the masseter, anterior temporalis, and suprahyoid muscles, the investigated oral tasks could be grouped into six separate clusters. The findings provided further insight into muscle- and task-specific EMG patterns during functional and non-functional oral behaviors
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Khowailed, Iman Akef; Petrofsky, Jerrold; Lohman, Everett; Daher, Noha; Mohamed, Olfat
2015-08-01
We investigate the effects of 17β-Estradiol across phases of menstrual cycle on the laxness of the anterior cruciate ligament (ACL) and the neuromuscular control patterns around the knee joint in female runners. Twelve healthy female runners who reported normal menstrual cycles for the previous 6 months were tested twice across one complete menstrual cycle for serum levels of 17β-estradiol, and knee joint laxity (KJL). Electromyographic (EMG) activity of the quadriceps and hamstrings muscles was also recorded during running on a treadmill. The changes in the EMG activity, KJL, and hormonal concentrations were recorded for each subject during the follicular and the ovulatory phases across the menstrual cycle. An observed increase in KJL in response to peak estradiol during the ovulatory phase was associated with increased preactivity of the hamstring muscle before foot impact (pneuromuscular control around the knee during running. Female runners utilize different neuromuscular control strategies during different phases of the menstrual cycle, which may contribute to increased ACL injury risk.
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Shirley S. M. Fong
2015-01-01
Full Text Available This study aimed to examine the effects of kinesiology taping (KT and different TRX suspension workouts on the amplitude of electromyographic (EMG activity in the core muscles among people with chronic low back pain (LBP. Each participant (total n=21 was exposed to two KT conditions: no taping and taping, while performing four TRX suspension exercises: (1 hamstring curl, (2 hip abduction in plank, (3 chest press, and (4 45-degree row. Right transversus abdominis/internal oblique (TrAIO, rectus abdominis (RA, external oblique (EO, and superficial lumbar multifidus (LMF activity was recorded with surface EMG and expressed as a percentage of the EMG amplitude recorded during a maximal voluntary isometric contraction of the respective muscles. Hip abduction in plank increased TrAIO, RA, and LMF EMG amplitude compared with other TRX positions (P0.05. Hip abduction in plank most effectively activated abdominal muscles, whereas the hamstring curl most effectively activated the paraspinal muscles. Applying KT conferred no immediate benefits in improving the core muscle activation during TRX training in adults with chronic LBP.
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Giédre Berretin-Felix
2005-12-01
Full Text Available Temporomandibular dysfunction (TMD is a complex disturbance that involves the masticatory muscles and/or temporomandibular joint, causing damage to the masticatory function. This study evaluated the electromyographic activity of the masseter muscle during habitual mastication of bread, apple, banana, cashew nut and paraffin film (Parafilm M in 25 adult subjects, of both gender, with TMD. The results were compared to those of a control group, composed of 15 adult subjects, of both sexes, free of signs and/or symptoms of TMD. The MYO-TRONICS Inc., K6-I computer software was used for electromyographic processing and analyzed the following parameters: duration of the act, duration of the masticatory cycle and number of cycles. No significant differences were found between subjects in the control group and individuals with TMD as to duration of the masticatory act and of the masticatory cycle, considering all materials used for mastication. The duration of the masticatory act and cycle was longer during mastication of paraffin film in both groups. The number of masticatory cycles was higher for mastication of apple in comparison to mastication of banana, in both groups. It can be concluded that the consistency of foods influences the duration parameters of the act, duration of the cycle and the number of masticatory cycles, and the behavior of the masticatory muscles in individuals with TMD during habitual mastication is similar to that verified in individuals without TMD.A disfunção temporomandibular (DTM representa um quadro complexo que envolve os músculos mastigatórios e/ou a articulação temporomandibular, causando prejuízos à função mastigatória. Este estudo avaliou a atividade eletromiográfica do músculo masseter durante a mastigação habitual de pão, maçã, banana, castanha de caju e folha de parafilme (Parafilm M em 25 indivíduos adultos, de ambos os gêneros, com DTM. Os resultados foram comparados com os obtidos para o
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Kim, Yu-Ri; Yoo, Won-Gyu
2016-01-01
[Purpose] The purpose of this study was to investigate activities of the hip extensors and erector spinae during bridging exercise by using instruments with a laser pointer on the pelvic belt. [Subjects] Twelve subjects (age, 23 to 33 years) with non-specific low back pain volunteered for this study. [Methods] Subjects performed bridging exercises with and without trajectory exercises by using a laser pointer fixed to a pelvic strap. The erector spinae, gluteus maximus and hamstring activities with and without trajectory exercises using a laser pointer were recorded on using electromyography. [Results] Compared to the without laser pointer group, the group that underwent bridging with trajectory exercises using a laser pointer had significantly higher gluteus maximus activity and significantly lower erector spinae activity. Significantly higher gluteus maximus/erector spinae activity ratios were observed when performing trajectory exercises using a laser pointer during bridging exercises. [Conclusion] This result suggests that trajectory exercises using a laser pointer during a bridging exercise would be effective for improving gluteus maximus activity.
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Trunk muscle activation during moderate- and high-intensity running.
Behm, David G; Cappa, Dario; Power, Geoffrey A
2009-12-01
Time constraints are cited as a barrier to regular exercise. If particular exercises can achieve multiple training functions, the number of exercises and the time needed to achieve a training goal may be decreased. It was the objective of this study to compare the extent of trunk muscle electromyographic (EMG) activity during running and callisthenic activities. EMG activity of the external obliques, lower abdominals (LA), upper lumbar erector spinae (ULES), and lumbosacral erector spinae (LSES) was monitored while triathletes and active nonrunners ran on a treadmill for 30 min at 60% and 80% of their maximum heart rate (HR) reserve, as well as during 30 repetitions of a partial curl-up and 3 min of a modified Biering-Sørensen back extension exercise. The mean root mean square (RMS) amplitude of the EMG signal was monitored over 10-s periods with measures normalized to a maximum voluntary contraction rotating curl-up (external obliques), hollowing exercise (LA), or back extension (ULES and LSES). A main effect for group was that triathletes had greater overall activation of the external obliques (p runs, respectively, than with the curl-ups (p = 0.001). The back extension exercise provided less ULES (p = 0.009) and LSES (p = 0.0001) EMG activity than the 60% and 80% runs, respectively. In conclusion, triathletes had greater trunk activation than nonrunners did while running, which could have contributed to their better performance. Back-stabilizing muscles can be activated more effectively with running than with a prolonged back extension activity. Running can be considered as an efficient, multifunctional exercise combining cardiovascular and trunk endurance benefits.
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Wanibuchi, Masahiko; Akiyama, Yukinori; Mikami, Takeshi; Komatsu, Katsuya; Sugino, Toshiya; Suzuki, Kengo; Kanno, Aya; Ohtaki, Shunya; Noshiro, Shouhei; Mikuni, Nobuhiro
2016-06-01
Damage to the motor division of the lower cranial nerves that run into the jugular foramen leads to hoarseness, dysphagia, and the risk of aspiration pneumonia; therefore, its functional preservation during surgical procedures is important. Intraoperative mapping and monitoring of the motor rootlets at the cerebellomedullary cistern using endotracheal tube electrodes is a safe and effective procedure to prevent its injury. To study the location of the somatic and autonomic motor fibers of the lower cranial nerves related to vocal cord movement. Twenty-four patients with pathologies at the cerebellopontine lesion were studied. General anesthesia was maintained with fentanyl and propofol. A monopolar stimulator was used at amplitudes of 0.05 to 0.1 mA. Both acoustic and visual signals were displayed as vocalis muscle electromyographic activity using endotracheal tube surface electrodes. The average number of rootlets was 7.4 (range, 5-10); 75% of patients had 7 or 8 rootlets. As many as 6 rootlets (2-4 in most cases) were responsive in each patient. In 23 of the 24 patients, the responding rootlets congregated on the caudal side. The maximum electromyographic response was predominantly in the most caudal or second most caudal rootlet in 79%. The majority of motor fibers of the lower cranial nerves run through the caudal part of the rootlets at the cerebellomedullary cistern, and the maximal electromyographic response was elicited at the most caudal or second most caudal rootlet. EMG, electromyographic.
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HALBERTSMA, JPK; GOEKEN, LNH
Passive muscle stretch tests are common practice in physical therapy and rehabilitation medicine. However, the effects of stretching exercises are not well known. With an instrumental straight-leg-raising set-up the extensibility, stiffness, and electromyographic activity of the hamstring muscles
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Meyns, P.; Van de Crommert, H. W. A. A.; Rijken, H.; van Kuppevelt, D. H. J. M.; Duysens, J.
2014-01-01
Study design: Case series. Objectives: To determine the optimal testing speed at which the recovery of the EMG (electromyographic) activity should be assessed during and after body weight supported (BWS) locomotor training. Setting: Tertiary hospital, Sint Maartenskliniek, Nijmegen, The Netherlands.
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Changes in corticospinal drive to spinal motoneurones following visuo-motor skill learning in humans
DEFF Research Database (Denmark)
Perez, Monica A.; Jensen, Jesper Lundbye; Nielsen, Jens Bo
2006-01-01
learning. Here we investigated the effect of visuo-motor skill training involving the ankle muscles on the coupling between electroencephalographic (EEG) activity recorded from the motor cortex (Cz) and electromyographic (EMG) activity recorded from the left tibialis anterior (TA) muscle in 11 volunteers...... between cortex and muscle as part of the motor learning process....
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Activity of masticatory muscles in subjects with different orofacial pain conditions.
Bodéré, Céline; Téa, Say Hack; Giroux-Metges, Marie Agnes; Woda, Alain
2005-07-01
The existence of a pathophysiological link between tonic muscle activity and chronic muscle pain is still being debated. The purpose of this retrospective, controlled study was to evaluate the electromyographic (EMG) activity of masticatory muscles in subjects with different orofacial pain conditions. The temporal and masseter EMG activity at rest and the masseteric reflex were recorded in two groups of patients with either myofascial pain (n=33) or neuropathic pain (n=20), one group of non-pain patients with disc derangement disorders (n=27) and one control group of healthy, asymptomatic subjects (n=32). The EMG activities of both muscles at rest were significantly higher in the pain patient groups compared to the asymptomatic control group. There was no significant difference between the disc derangement disorder group and the control group. The masseteric reflex amplitude was reduced in all patient groups when compared with the control group. In pain patient groups, the increased EMG activity at rest and the reduction of the masseteric reflex amplitude were equally distributed in the pain and non-pain sides. In addition, subjects presenting with bilateral pain showed higher EMG activity at rest than those with unilateral pain. These results suggested that the modulation of muscle activity was not the direct consequence of a peripheral nociceptive mechanism and seemed to indicate that a central mechanism was at work. The contrast between the increased EMG activity at rest and the reduction of the masseteric reflex amplitude may reflect modulations of motoneurones that differed in tonic versus phasic conditions in chronic pain patients.
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Kinematics in newly walking toddlers does not depend upon postural stability
Ivanenko, Yuri P; Dominici, Nadia; Cappellini, Germana; Lacquaniti, Francesco
When a toddler starts to walk without support, gait kinematics and electromyographic (EMG) activity differ from those of older children and the body displays considerable oscillations due to poor equilibrium. Postural instability clearly affects motor patterns in adults, but does instability explain
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Directory of Open Access Journals (Sweden)
Mariana Felipe Silva
2013-04-01
Full Text Available The use of Pilates-based exercises for trunk strengthening has been reported in the literature. The objective of this study was to analyze and compare the electrical activity of the rectus abdominis and external oblique muscles during a traditional abdominal exercise program and an exercise program based on the Pilates method using a ball and an elastic band. The sample was composed of 10 healthy women, non-practitioners of Pilates, who performed the traditional abdominal exercise and roll-up with the ball and elastic band. The sign was normalized by the electromyographic peak of the dynamics activity and was adjusted for 2000 samples/s; the filter was set in a frequency band from 20 to 450 Hz. In the comparison between exercises, the external oblique muscle in the concentric phase had a higher recruitment in the roll-up with the ball (P =0.042. In the comparison between muscles in each exercise, the rectus abdominis showed a higher activation in the concentric phase (P = 0.009 and in the eccentric phase (P = 0.05 of the traditional abdominal exercise. Activation percentages ranged from 15% to 22%. The traditional abdominal exercise had the largest activation percentage.
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Actis, Jason A; Honegger, Jasmin D; Gates, Deanna H; Petrella, Anthony J; Nolasco, Luis A; Silverman, Anne K
2018-02-08
Low back mechanics are important to quantify to study injury, pain and disability. As in vivo forces are difficult to measure directly, modeling approaches are commonly used to estimate these forces. Validation of model estimates is critical to gain confidence in modeling results across populations of interest, such as people with lower-limb amputation. Motion capture, ground reaction force and electromyographic data were collected from ten participants without an amputation (five male/five female) and five participants with a unilateral transtibial amputation (four male/one female) during trunk-pelvis range of motion trials in flexion/extension, lateral bending and axial rotation. A musculoskeletal model with a detailed lumbar spine and the legs including 294 muscles was used to predict L4-L5 loading and muscle activations using static optimization. Model estimates of L4-L5 intervertebral joint loading were compared to measured intradiscal pressures from the literature and muscle activations were compared to electromyographic signals. Model loading estimates were only significantly different from experimental measurements during trunk extension for males without an amputation and for people with an amputation, which may suggest a greater portion of L4-L5 axial load transfer through the facet joints, as facet loads are not captured by intradiscal pressure transducers. Pressure estimates between the model and previous work were not significantly different for flexion, lateral bending or axial rotation. Timing of model-estimated muscle activations compared well with electromyographic activity of the lumbar paraspinals and upper erector spinae. Validated estimates of low back loading can increase the applicability of musculoskeletal models to clinical diagnosis and treatment. Copyright © 2017 Elsevier Ltd. All rights reserved.
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Effect of a jig on EMG activity in different orofacial pain conditions.
Bodere, Celine; Woda, Alain
2008-01-01
The bite stop (jig) is commonly used in clinical practice. It has been recommended as a simple means to routinely record or provide centric relation closure and, more recently, to reduce migraines and tension-type headaches. However, the reason for the jig effect has yet to be explained. This study tested the hypothesis that it works through a decrease in masticatory muscle activity. The effect of a jig placed on the maxillary anterior teeth was investigated by recording the electromyographic (EMG) activity of the superficial masseter and anterior temporal muscles at postural position and when swallowing on the jig. EMG recordings were obtained from 2 groups of pain patients (myofascial and neuropathic) and from 2 groups of pain-free patients (disc derangement and controls) unaware of the role of dental occlusion treatments. EMG activity in postural position was higher in pain groups than in pain-free groups. The jig strongly but temporarily decreased the postural EMG activity for masseter muscles in all groups except for the neuropathic group and for temporal muscles in the myofascial group. The EMG activity when swallowing with the jig was reduced in control, disc derangement, and myofascial groups; however, EMG "hyperactivity" in the neuropathic pain group seemed to be locked. The decrease of postural EMG activity, especially in the myofascial group, was short lasting and cannot be considered as evidence to support the hypothesis of a long-term muscle relaxation jig effect. However, the results may uphold certain short-term clinical approaches.
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Differences in muscle activity between natural forefoot and rearfoot strikers during running.
Yong, Jennifer R; Silder, Amy; Delp, Scott L
2014-11-28
Running research has focused on reducing injuries by changing running technique. One proposed method is to change from rearfoot striking (RFS) to forefoot striking (FFS) because FFS is thought to be a more natural running pattern that may reduce loading and injury risk. Muscle activity affects loading and influences running patterns; however, the differences in muscle activity between natural FFS runners and natural RFS runners are unknown. The purpose of this study was to measure muscle activity in natural FFS runners and natural RFS runners. We tested the hypotheses that tibialis anterior activity would be significantly lower while activity of the plantarflexors would be significantly greater in FFS runners, compared to RFS runners, during late swing phase and early stance phase. Gait kinematics, ground reaction forces and electromyographic patterns of ten muscles were collected from twelve natural RFS runners and ten natural FFS runners. The root mean square (RMS) of each muscle׳s activity was calculated during terminal swing phase and early stance phase. We found significantly lower RMS activity in the tibialis anterior in FFS runners during terminal swing phase, compared to RFS runners. In contrast, the medial and lateral gastrocnemius showed significantly greater RMS activity in terminal swing phase in FFS runners. No significant differences were found during early stance phase for the tibialis anterior or the plantarflexors. Recognizing the differences in muscle activity between FFS and RFS runners is an important step toward understanding how foot strike patterns may contribute to different types of injury. Copyright © 2014 Elsevier Ltd. All rights reserved.
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Directory of Open Access Journals (Sweden)
Roghayeh Mohammadi
2017-01-01
Full Text Available Introduction: Plantarflexor muscles produce propulsive force in the second half of stance phase; deficient motor output from these muscles would lead to inadequate propulsion at push off phase of gait following stroke. It is important to develop strategies to improve plantarflexor output. This study examined the effects of walking on a treadmill at varying gradients and speeds on medial gastrocnemius (MG muscle activation in stroke survivors. Materials and Methods: Nineteen stroke survivors (13M/6F: average age 55.37±7.54 years; body mass index 29.10±4.52kg/m2 participated in the study. Participants walked on a standard treadmill at three different positive inclines (0°, 3°, and 6° and speeds (self-selected, self-selected+20%, self-selected+40%. The electromyographic activity of MG recorded at push off phase of the gait. Results: A linear mixed model regression analysis was used to analysis. The paretic MG muscle activity increased at faster speeds irrespective of incline (p0.05. Conclusion: It would appear that stroke survivors employ distinct muscle activation strategies on the paretic and non-paretic sides in response to different walking speeds and inclines
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Ferrario, Virgilio F; Tartaglia, Gianluca M; Luraghi, Francesca E; Sforza, Chiarella
2007-11-01
The aim of this study was to assess the electromyographic characteristics of the masticatory muscles (masseter and temporalis) of patients with either "temporomandibular joint disorder" or "neck pain". Surface electromyography of the right and left masseter and temporalis muscles was performed during maximum teeth clenching in 38 patients aged 21-67 years who had either (a) temporomandibular joint disorder (24 patients); (b) "neck pain" (13 patients). Ninety-five control, healthy subjects were also examined. During clenching, standardized total muscle activities (electromyographic potentials over time) were significantly different in the three groups: 75 microV/microVs% in the temporomandibular joint disorder patients, 124 microV/microVs% in the neck pain patients, and 95 microV/microVs% in the control subjects (analysis of variance, Ptemporomandibular joint disorder patients also had significantly (Pneck pain patients (87%) or control subjects (92%). A linear discriminant function analysis allowed a significant separation between the two patient groups, with a single patient error of 18.2%. Surface electromyographic analysis during clenching allowed to differentiate between patients with a temporomandibular joint disorder and patients with a neck pain problem.
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How do tablet properties influence swallowing behaviours?
Yamamoto, Shinya; Taniguchi, Hiroshige; Hayashi, Hirokazu; Hori, Kazuhiro; Tsujimura, Takanori; Nakamura, Yuki; Sato, Hideaki; Inoue, Makoto
2014-01-01
Behavioural performance of tablet swallowing was evaluated with different tablet conditions in terms of size, number and surface coating. Four different types of tablets were prepared: small or large, and with or without a surface coating. Fourteen normal male adults were instructed to swallow the prepared tablets with 15 ml of water. The number of tablets in one trial was changed from one to three. To evaluate swallowing and tablet transport, electromyographic activity was recorded in the left suprahyoid muscles, and videofluorographic images were examined. All tablet conditions (size, number and surface coating) affected the swallowing performance in terms of total number of swallows, electromyographic burst patterns and location of remaining tablets. Increases in the size and number of tablets increased the number of swallows and electromyographic burst area and duration. In addition, all of these parameters increased while swallowing tablets without a coating compared with tablets with a coating. Location of the remaining tablets was mainly within the mouth. This study only clarified the normal pattern of tablet swallowing under several conditions in healthy subjects, but the results may facilitate comprehensive evaluation and treatment planning in terms of administering medication to dysphagic patients. © 2013 Royal Pharmaceutical Society.
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Duff, S V; Sargent, B; Kutch, J J; Berggren, J; Leiby, B E; Fetters, L
2017-10-20
Examine the feasibility of increasing muscle activation with electromyographically (EMG)-triggered musical-video as reinforcement for children with perinatal brachial plexus injury (PBPI). Six children with PBPI (9.3 ± 6.3 months; 5 female, 1 male) and 13 typically developing (TD) controls (7.8 ± 3.5 months; 4 female, 9 males) participated. The left arm was affected in 5/6 children with PBPI. We recorded the integral (Vs) of biceps activation with surface EMG during two conditions per arm in one session: (1) 100 second (s) baseline without reinforcement and (2) 300 s reinforcement (musical-video triggered to play with biceps activation above threshold [V]). We examined the relation between the mean integral with reinforcement and hand preference. Mean biceps activation significantly increased from baseline in the affected arm of the group with PBPI by the 2nd (p < .008) and 3rd (p < .0004) 100 s intervals of reinforcement. Six of 6 children with PBPI and 12/13 TD controls increased activation in at least one arm. A lower integral was linked with hand preference for the unaffected right side in the PBPI group. This study supports contingent reinforcement as a feasible method to increase muscle activation. Future work will examine training dose and intensity to increase arm function.
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Altenburg, T.M.; de Haan, A.; Verdijk, P.W.; van Mechelen, W.; de Ruiter, C.J.
2009-01-01
Single motor unit electromyographic (EMG) activity of the knee extensors was investigated at different knee angles with subjects (n = 10) exerting the same absolute submaximal isometric torque at each angle. Measurements were made over a 20° range around the optimum angle for torque production
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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...
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Lower-limb and trunk muscle activation with back squats and weighted sled apparatus.
Maddigan, Meaghan E; Button, Duane C; Behm, David G
2014-12-01
The back squat is a traditional resistance training exercise, whereas the resisted sled exercise is a relatively new resistance exercise. However, as there are no studies comparing muscle activation between the exercises, the objective of this study was to examine activity of leg and trunk muscles for both exercises. Ten healthy resistance-trained men participated in a randomized crossover design study consisting of 2 preparation sessions and 2 testing sessions. Electromyographic (EMG) activity of the rectus femoris, biceps femoris, gastrocnemius, lower erector spinae, and the transversus abdominis/internal obliques (TrA/IO) were monitored during a 20-step maximum push with the weighted sled apparatus and a 10 repetition maximum with a bilateral back squat. There were nonsignificant trends for the rectus femoris (p = 0.092: 8.6-16.7%) and biceps femoris (p = 0.09: 10.5-32.8%) to demonstrate higher activity with the sled and squat exercises, respectively. There were main effects for condition with 61.2% greater gastrocnemius EMG with the sled exercise (p = 0.01) and 74.5% greater erector spinae EMG activity with the squat (p = 0.002). There were no significant differences between the exercises for the TrA/IO. In summary, the sled and squat exercises provided similar EMG activity for the quadriceps, hamstrings, and TrA/IO. The squat provided higher lower erector spinae activation, whereas the sled had superior gastrocnemius activation. Depending on the movement-training specificity of the sport, either exercise may be used in a training program while acknowledging the differences in gastrocnemius and erector spinae activity.
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Effect of a pelvic belt on EMG activity during manual load lifting
Directory of Open Access Journals (Sweden)
Marcelo Pinto Pereira
2009-04-01
Full Text Available Manual lifting (ML capacity is still a matter of concern for industry administrators and electromyography (EMG seems to be a good alternative for the evaluation of muscles involved in this task. However, the reliability of these measures is very important. Thus, the objective of this study was to evaluate the influence of a pelvic belt on EMG activity of the erector spinus (ES and rectus femoralis (RF muscles during ML and during maximal voluntary contractions (MVC of trunk extension performed before (baseline and after ML. In addition, the variabilityin the EMG signal normalized by the following three different methods was evaluated: peak EMG activity, mean EMG activity, and EMG activity obtained during MVC. Eight volunteers performed ML of 15% and 25% of their body weight for 1 minute in the presence or absence of a pelvic belt. The coefficient of variation (CV of the EMG signal obtained for the ES and RF muscles was calculated during ML. Load cell traction values and the electromyographic variables RMS, median frequency, mean power frequency and total power of the ES muscle were obtained during MVC. The results showed lower CV (smaller variability when the EMG signal was normalized by peak activity, with this method thus being preferable. During MVC, only the load cell traction value differed from baseline after ML of 25% body weight without the pelvic belt (p=0.035, a finding suggesting rapid recovery of ES muscle after ML for 1 minute.
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Fong, Shirley S M; Tam, Y T; Macfarlane, Duncan J; Ng, Shamay S M; Bae, Young-Hyeon; Chan, Eleanor W Y; Guo, X
2015-01-01
This study aimed to examine the effects of kinesiology taping (KT) and different TRX suspension workouts on the amplitude of electromyographic (EMG) activity in the core muscles among people with chronic low back pain (LBP). Each participant (total n = 21) was exposed to two KT conditions: no taping and taping, while performing four TRX suspension exercises: (1) hamstring curl, (2) hip abduction in plank, (3) chest press, and (4) 45-degree row. Right transversus abdominis/internal oblique (TrAIO), rectus abdominis (RA), external oblique (EO), and superficial lumbar multifidus (LMF) activity was recorded with surface EMG and expressed as a percentage of the EMG amplitude recorded during a maximal voluntary isometric contraction of the respective muscles. Hip abduction in plank increased TrAIO, RA, and LMF EMG amplitude compared with other TRX positions (P hamstring curl was effective in inducing a high EMG amplitude of LMF (P 0.05). Hip abduction in plank most effectively activated abdominal muscles, whereas the hamstring curl most effectively activated the paraspinal muscles. Applying KT conferred no immediate benefits in improving the core muscle activation during TRX training in adults with chronic LBP.
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Dafkin, Chloe; Green, Andrew; Olivier, Benita; McKinon, Warrick; Kerr, Samantha
2018-05-01
To assess if there is a circadian variation in electromyographical (EMG) muscle activity during gait in restless legs syndrome (RLS) patients and healthy control participants. Gait assessment was done in 14 RLS patients and 13 healthy control participants in the evening (PM) and the morning (AM). Muscle activity was recorded bilaterally from the tibialis anterior (TA), lateral gastrocnemius (GL), rectus femoris (RF) and biceps femoris (BF) muscles. A circadian variation during the stance phase in only TA (PM > AM, p Controls, p < 0.05) during early stance and decreased GL activity (RLS < Controls, p < 0.01) during terminal stance in comparison to control participants in the evening. No other significant differences were noted between RLS patients and control participants. Activation of GL during the swing phase was noted in 79% of RLS patients and in 23% of control participants in the morning compared to 71% and 38% in the evening, respectively. EMG muscle activity shows no circadian variation in RLS patients. Evening differences in gait muscle activation patterns between RLS patients and control participants are evident. These results extend our knowledge about alterations in spinal processing during gait in RLS. A possible explanation for these findings is central pattern generator sensitization caused by increased sensitivity in cutaneous afferents in RLS patients. Copyright © 2018 Elsevier B.V. All rights reserved.
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CORE MUSCLE ACTIVITY DURING THE CLEAN AND JERK LIFT WITH BARBELL VERSUS SANDBAGS AND WATER BAGS.
Calatayud, Joaquin; Colado, Juan C; Martin, Fernando; Casaña, José; Jakobsen, Markus D; Andersen, Lars L
2015-11-01
While the traditional clean and jerk maneuver implies simultaneous participation of a large number of muscle groups, the use of this exercise with some variations to enhance core muscle activity remains uninvestigated. The purpose of this study was to compare the muscle activity during clean and jerk lift when performed with a barbell, sandbag and a water bag at same absolute load. Descriptive, repeated-measures study. Twenty-one young fit male university students (age: 25 ± 2.66 years; height: 180.71 ± 5.42 cm; body mass: 80.32 ± 9.8 kg; body fat percentage: 12.41 ± 3.56 %) participated. Surface electromyographic (EMG) signals were recorded from the anterior deltoid (AD), external oblique (OBLIQ), lumbar erector spinae (LUMB), and gluteus medius (GM) and were expressed as a percentage of the maximum voluntary isometric contraction (MVIC). There were no significantly significant differences for AD muscle activity between conditions, whereas muscle activation values for OBLIQ (60%MVIC), GM (29%MVIC) and LUMB (85%MVIC) were significantly higher during the water bag power clean and jerk maneuver when compared with the other conditions. The clean and jerk is an exercise that may be used to enhance core muscle activity. Performing the maneuver with water bags resulted in higher core muscle activity compared with sandbag and standard barbell versions. 3.
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Suica, Zorica; Romkes, Jacqueline; Tal, Amir; Maguire, Clare
2016-01-01
To investigate the immediate effect of four-wheeled- walker(rollator)walking on lower-limb muscle activity and trunk-sway in healthy subjects. In this cross-sectional design electromyographic (EMG) data was collected in six lower-limb muscle groups and trunk-sway was measured as peak-to-peak angular displacement of the centre-of-mass (level L2/3) in the sagittal and frontal-planes using the SwayStar balance system. 19 subjects walked at self-selected speed firstly without a rollator then in randomised order 1. with rollator 2. with rollator with increased weight-bearing. Rollator-walking caused statistically significant reductions in EMG activity in lower-limb muscle groups and effect-sizes were medium to large. Increased weight-bearing increased the effect. Trunk-sway in the sagittal and frontal-planes showed no statistically significant difference between conditions. Rollator-walking reduces lower-limb muscle activity but trunk-sway remains unchanged as stability is likely gained through forces generated by the upper-limbs. Short-term stability is gained but the long-term effect is unclear and requires investigation. Copyright © 2015 Elsevier Ltd. All rights reserved.
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Rapid eye movement sleep behavior disorder--diagnostik, årsager og behandling
DEFF Research Database (Denmark)
Zoetmulder, Marielle; Jennum, Poul Jørgen
2009-01-01
Rapid eye movement (REM) sleep behaviour disorder (RBD) is characterized by loss of REM sleep and related electromyographic atonia with marked muscular activity and dream enactment behaviour. RBD is seen in 0.5% of the population. It occurs in an idiopathic form and secondarily to medical...
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Rapid eye movement sleep behavior disorder
DEFF Research Database (Denmark)
Zoetmulder, Marielle; Jennum, Poul
2009-01-01
Rapid eye movement (REM) sleep behaviour disorder (RBD) is characterized by loss of REM sleep and related electromyographic atonia with marked muscular activity and dream enactment behaviour. RBD is seen in 0.5% of the population. It occurs in an idiopathic form and secondarily to medical...
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Directory of Open Access Journals (Sweden)
Żebrowska Kinga
2016-09-01
Full Text Available Introduction: This study sought to assess the influence of proper foot arch on electromyographic activity of selected lower limb muscles. The aim of this work was to evaluate the effects of foot arch on the activity of selected muscles and to determine whether electromyography might help to identify types of flat feet resulting from muscle- or ligament-related causes.
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Bench Press Upper-Body Muscle Activation Between Stable and Unstable Loads.
Dunnick, Dustin D; Brown, Lee E; Coburn, Jared W; Lynn, Scott K; Barillas, Saldiam R
2015-12-01
The bench press is one of the most commonly used upper-body exercises in training and is performed with many different variations, including unstable loads (ULs). Although there is much research on use of an unstable surface, there is little to none on the use of an UL. The purpose of this study was to investigate muscle activation during the bench press while using a stable load (SL) vs. UL. Twenty resistance-trained men (age = 24.1 ± 2 years; ht = 177.5 ± 5.8 cm; mass = 88.7 ± 13.7 kg) completed 2 experimental conditions (SL and UL) at 2 different intensities (60 and 80% one repetition maximum). Unstable load was achieved by hanging 16 kg kettlebells by elastic bands from the end of the bar. All trial lifts were set to a 2-second cadence with a slight pause at the bottom. Subjects had electrodes attached to 5 muscles (pectoralis major, anterior deltoid, medial deltoid, triceps brachii, and latissimus dorsi) and performed 3 isometric bench press trials to normalize electromyographic data. All 5 muscles demonstrated significantly greater activation at 80% compared with 60% load and during concentric compared with eccentric actions. These results suggest that upper body muscle activation is not different in the bench press between UL and SL. Therefore, coaches should use their preference when designing training programs.
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DEFF Research Database (Denmark)
Rathleff, M S; Samani, Afshin; Olesen, C G
2011-01-01
Medial tibial stress syndrome is a common overuse injury characterized by pain located on the medial side of the lower leg during weight bearing activities such as gait. The purpose of this study was to apply linear and nonlinear methods to compare the structure of variability of midfoot kinematics...... and surface electromyographic (SEMG) signals between patients with medial tibial stress syndrome and healthy controls during gait. Fourteen patients diagnosed with medial tibial stress syndrome and 11 healthy controls were included from an orthopaedic clinic. SEMG from tibialis anterior and the soleus muscles...... as well as midfoot kinematics were recorded during 20 consecutive gait cycles. Permuted sample entropy and permutation entropy were used as a measure of complexity from SEMG signals and kinematics. SEMG signals in patients with medial tibial stress syndrome were characterized by higher structural...
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EMG analysis tuned for determining the timing and level of activation in different motor units.
Lee, Sabrina S M; Miara, Maria de Boef; Arnold, Allison S; Biewener, Andrew A; Wakeling, James M
2011-08-01
Recruitment patterns and activation dynamics of different motor units greatly influence the temporal pattern and magnitude of muscle force development, yet these features are not often considered in muscle models. The purpose of this study was to characterize the recruitment and activation dynamics of slow and fast motor units from electromyographic (EMG) recordings and twitch force profiles recorded directly from animal muscles. EMG and force data from the gastrocnemius muscles of seven goats were recorded during in vivo tendon-tap reflex and in situ nerve stimulation experiments. These experiments elicited EMG signals with significant differences in frequency content (p<0.001). The frequency content was characterized using wavelet and principal components analysis, and optimized wavelets with centre frequencies, 149.94 Hz and 323.13 Hz, were obtained. The optimized wavelets were used to calculate the EMG intensities and, with the reconstructed twitch force profiles, to derive transfer functions for slow and fast motor units that estimate the activation state of the muscle from the EMG signal. The resulting activation-deactivation time constants gave r values of 0.98-0.99 between the activation state and the force profiles. This work establishes a framework for developing improved muscle models that consider the intrinsic properties of slow and fast fibres within a mixed muscle, and that can more accurately predict muscle force output from EMG. Copyright © 2011 Elsevier Ltd. All rights reserved.
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Lesinski, Melanie; Prieske, Olaf; Borde, Ron; Beurskens, Rainer; Granacher, Urs
2018-04-13
Lesinski, M, Prieske, O, Borde, R, Beurskens, R, and Granacher, U. Effects of different footwear properties and surface instability on neuromuscular activity and kinematics during jumping. J Strength Cond Res XX(X): 000-000, 2018-The purpose of this study was to examine sex-specific effects of different footwear properties vs. barefoot condition during the performance of drop jumps (DJs) on stable and unstable surfaces on measures of jump performance, electromyographic (EMG) activity, and knee joint kinematics. Drop jump performance, EMG activity of lower-extremity muscles, as well as sagittal and frontal knee joint kinematics were tested in 28 healthy male (n = 14) and female (n = 14) physically active sports science students (23 ± 2 years) during the performance of DJs on stable and unstable surfaces using different footwear properties (elastic vs. minimal shoes) vs. barefoot condition. Analysis revealed a significantly lower jump height and performance index (Δ7-12%; p footwear conditions (Δ29%; p footwear-surface interactions were detected. Our findings revealed that surface instability had an impact on DJ performance, thigh/shank muscle activity, and knee joint kinematics. In addition, the single factors "footwear" and "sex" modulated knee joint kinematics during DJs. However, hardly any significant interaction effects were found. Thus, additional footwear-related effects can be neglected when performing DJs during training on different surfaces.
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Operator State Estimation for Adaptive Aiding in Uninhabited Combat Air Vehicles
2005-09-01
1992). Van Boxtel, A., W. Waterink, and I.J.T. Veldhuizen . “Tonic Facial EMG Activity As An Index of Mental Effort: Effects of Work Rate, Time-On...the ‘normal’ functioning of brain activity (Beaumont, Burov, Carter, Cheuvront, Sawka, Wilson, Van Orden, Hockey, Balkin and Gundel, 2004). For...by the sympathetic nervous system. Electromyographic activity has been shown to predict arousal accurately ( Veldhuizen , Gaillard, and de Vries, 2003
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Shim, Je-Myung; Kwon, Hae-Yeon; Kim, Ha-Roo; Kim, Bo-In; Jung, Ju-Hyeon
2013-12-01
[Purpose] The aim of this study was to assess the effect of Nordic pole walking on the electromyographic activities of upper extremity and lower extremity muscles. [Subjects and Methods] The subjects were randomly divided into two groups as follows: without Nordic pole walking group (n=13) and with Nordic pole walking group (n=13). The EMG data were collected by measurement while the subjects walking on a treadmill for 30 minutes by measuring from one heel strike to the next. [Results] Both the average values and maximum values of the muscle activity of the upper extremity increased in both the group that used Nordic poles and the group that did not use Nordic poles, and the values showed statistically significant differences. There was an increase in the average value for muscle activity of the latissimus dorsi, but the difference was not statistically significant, although there was a statistically significant increase in its maximum value. The average and maximum values for muscle activity of the lower extremity did not show large differences in either group, and the values did not show any statistically significant differences. [Conclusion] The use of Nordic poles by increased muscle activity of the upper extremity compared with regular walking but did not affect the lower extremity.
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Rapid eye movement sleep behavior disorder--diagnostik, årsager og behandling
DEFF Research Database (Denmark)
Zoetmulder, Marielle; Jennum, Poul Jørgen
2009-01-01
Rapid eye movement (REM) sleep behaviour disorder (RBD) is characterized by loss of REM sleep and related electromyographic atonia with marked muscular activity and dream enactment behaviour. RBD is seen in 0.5% of the population. It occurs in an idiopathic form and secondarily to medical and neu...
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Are cervical multifidus muscles active during whiplash and startle? An initial experimental study
Directory of Open Access Journals (Sweden)
Carpenter Mark G
2008-06-01
Full Text Available Abstract Background The cervical multifidus muscles insert onto the lower cervical facet capsular ligaments and the cervical facet joints are the source of pain in some chronic whiplash patients. Reflex activation of the multifidus muscle during a whiplash exposure could potentially contribute to injuring the facet capsular ligament. Our goal was to determine the onset latency and activation amplitude of the cervical multifidus muscles to a simulated rear-end collision and a loud acoustic stimuli. Methods Wire electromyographic (EMG electrodes were inserted unilaterally into the cervical multifidus muscles of 9 subjects (6M, 3F at the C4 and C6 levels. Seated subjects were then exposed to a forward acceleration (peak acceleration 1.55 g, speed change 1.8 km/h and a loud acoustic tone (124 dB, 40 ms, 1 kHz. Results Aside from one female, all subjects exhibited multifidus activity after both stimuli (8 subjects at C4, 6 subjects at C6. Neither onset latencies nor EMG amplitude varied with stimulus type or spine level (p > 0.13. Onset latencies and amplitudes varied widely, with EMG activity appearing within 160 ms of stimulus onset (for at least one of the two stimuli in 7 subjects. Conclusion These data indicate that the multifidus muscles of some individuals are active early enough to potentially increase the collision-induced loading of the facet capsular ligaments.
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Electrocorticographic activity over sensorimotor cortex and motor function in awake behaving rats.
Boulay, Chadwick B; Chen, Xiang Yang; Wolpaw, Jonathan R
2015-04-01
Sensorimotor cortex exerts both short-term and long-term control over the spinal reflex pathways that serve motor behaviors. Better understanding of this control could offer new possibilities for restoring function after central nervous system trauma or disease. We examined the impact of ongoing sensorimotor cortex (SMC) activity on the largely monosynaptic pathway of the H-reflex, the electrical analog of the spinal stretch reflex. In 41 awake adult rats, we measured soleus electromyographic (EMG) activity, the soleus H-reflex, and electrocorticographic activity over the contralateral SMC while rats were producing steady-state soleus EMG activity. Principal component analysis of electrocorticographic frequency spectra before H-reflex elicitation consistently revealed three frequency bands: μβ (5-30 Hz), low γ (γ1; 40-85 Hz), and high γ (γ2; 100-200 Hz). Ongoing (i.e., background) soleus EMG amplitude correlated negatively with μβ power and positively with γ1 power. In contrast, H-reflex size correlated positively with μβ power and negatively with γ1 power, but only when background soleus EMG amplitude was included in the linear model. These results support the hypothesis that increased SMC activation (indicated by decrease in μβ power and/or increase in γ1 power) simultaneously potentiates the H-reflex by exciting spinal motoneurons and suppresses it by decreasing the efficacy of the afferent input. They may help guide the development of new rehabilitation methods and of brain-computer interfaces that use SMC activity as a substitute for lost or impaired motor outputs. Copyright © 2015 the American Physiological Society.
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Directory of Open Access Journals (Sweden)
Daniel Cury Ribeiro
2005-01-01
electromyography, the interference of angular speed and different ways of fixing the elastic tube on the quadriceps activity. Ten male subjects without any kind of muscle or joint injury participated in this study. Subjects with a Q angle value out of 10-15° were excluded from this study. The elastic tube was fixed parallel and oblique to the subjects' body. Knee extensions were performed at 60°/sec and 120°/sec. No selective activity of the VMO was found. By comparing the levels of muscular activity, there was an increase of the electromyographic activity level in all portions of the quadriceps at the two angular speeds, only for parallel-fixed elastic tubes. These results suggest a synergic activity between VMO and the other portions of the quadriceps.
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An electromyographic study of aspects of 'deprogramming' of human jaw muscles.
Donegan, S J; Carr, A B; Christensen, L V; Ziebert, G J
1990-11-01
Surface electromyograms from the right and left masseter and anterior temporalis muscles were used to detect peripheral correlates of deprogramming, also known as programming and reprogramming, of jaw elevator muscles. Putative deprogramming was attempted through the clinically recommended use of a leaf gauge, placed for 15 min between the maxillary and mandibular anterior teeth and disoccluding the posterior teeth by about 2 mm. Studied contractile activities were those of postural activity (subconscious, semi-isometric, minimal activity) and intercuspal teeth clenching (conscious, isometric, maximal activity). Use of the leaf gauge did not affect normalized postural activity (about 4%), the duration (about 900 ms) and static work efforts of clenching (about 1200 microV.s), the time to peak mean voltage of clenching (about 400 ms), and the peak mean voltage of clenching (about 300 microV). Activity and asymmetry indices showed that the studied motor innervation patterns were not changed by the leaf gauge.
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Muscular activation during plyometric exercises in 90° of glenohumeral joint abduction.
Ellenbecker, Todd S; Sueyoshi, Tetsuro; Bailie, David S
2015-01-01
Plyometric exercises are frequently used to increase posterior rotator cuff and periscapular muscle strength and simulate demands and positional stresses in overhead athletes. The purpose of this study was to provide descriptive data on posterior rotator cuff and scapular muscle activation during upper extremity plyometric exercises in 90° of glenohumeral joint abduction. Levels of muscular activity in the posterior rotator cuff and scapular stabilizers will be high during plyometric shoulder exercises similar to previously reported electromyographic (EMG) levels of shoulder rehabilitation exercises. Descriptive laboratory study. Twenty healthy subjects were tested using surface EMG during the performance of 2 plyometric shoulder exercises: prone external rotation (PERP) and reverse catch external rotation (RCP) using a handheld medicine ball. Electrode application included the upper and lower trapezius (UT and LT, respectively), serratus anterior (SA), infraspinatus (IN), and the middle and posterior deltoid (MD and PD, respectively) muscles. A 10-second interval of repetitive plyometric exercise (PERP) and 3 repetitions of RCP were sampled. Peak and average normalized EMG data were generated. Normalized peak and average IN activity ranged between 73% and 102% and between 28% and 52% during the plyometric exercises, respectively, with peak and average LT activity measured between 79% and 131% and between 31% and 61%. SA activity ranged between 76% and 86% for peak and between 35% and 37% for average activity. Muscular activity levels in the MD and PD ranged between 49% and 72% and between 12% and 33% for peak and average, respectively. Moderate to high levels of muscular activity were measured in the rotator cuff and scapular stabilizers during these plyometric exercises with the glenohumeral joint abducted 90°.
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Directory of Open Access Journals (Sweden)
Hugo Cesar Martins-Costa
2016-03-01
Full Text Available Abstract This study analyzed the effect of different repetition durations on electromyographic and blood lactate responses of the bench press exercise. Fifteen recreationally trained male volunteers completed two training protocols, matched for intensity (% one-repetition maximum; 1RM, number of sets, number of repetitions, and rest intervals. One of the protocols was performed with a repetition duration of 4 s (2 s concentric: 2 s eccentric; 2:2 protocol, whereas the second protocol had a repetition duration of 6 s (2 s concentric: 4 s eccentric; 2:4 protocol. The results showed higher normalized integrated electromyography (pectoralis major and triceps brachii for the 2:4 protocol. Blood lactate concentration was also higher in the 2:4 protocol across all sets. These results show that adding 2 s to the eccentric action in matched training protocols increases muscle activation and blood lactate response, which reinforces the notion that increasing repetition duration is an alternative load progression in resistance training.
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Cervico-mandibular muscle activity in females with chronic cervical pain
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T. Lang
2013-12-01
Full Text Available Pathophysiological mechanisms behind pain in chroniccervical musculoskeletal conditions (MSC in office workers remainunclear. Chronic cervical pain has established links with temporomandibular(TM disorders. Yet there is no current published evidence to reportwhether individuals with cervical dysfunction exhibit altered masseterand cervical extensor (CE muscle activity. Objective: To explore CE andmasseter surface electromyographic (sEMG activity and teeth clenchinghabits in females with chronic cervical dysfunction and no TM disorder.Design: Descriptive cross-sectional correlational study with singleblinding.Participants: University students and staff with or without chroniccervical pain and no TM involvement. Methods: Descriptive and paindata captured from Research Diagnostic Criteria for TM disorders, NeckDisability Index, Computer Usage, Brief Pain Inventory, and EuroQoL-5Dquestionnaires. Female participants allocated to a chronic cervical (n = 20 and a control group (n = 22. Investigator blindedto the study groups recorded sEMG of bilateral masseter and CE muscles (C4/5 level at rest and during light teeth clenching.Results: No differences in socio-demographic profile; or in masseter or CE sEMG activity at rest or during light clench betweengroups. The pain group had higher scores for pain, reported a daytime teeth clenching habit, and had worse scores for the healthrelatedquality of life (HRQoL sub-sections for pain, anxiety/depression, and lower scores for perceived health status. Conclusion:No relationship established between cervico-mandibular sEMG activity and reported disability in females with chronic cervicaldysfunction and no TM disorder. Association between biopsychosocial factors of teeth clenching and anxiety/depression highlightscomplex pathophysiological mechanisms in chronic recurrent cervical pain.
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Directory of Open Access Journals (Sweden)
Marcelo Vitor da Costa
2012-10-01
Full Text Available http://dx.doi.org/10.5007/1980-0037.2012v14n6p660 The aim of this study was to compare the electromyographic indices of fatigue (slope of median frequency calculated with the fast Fourier transform (FFT and wavelet transform (WT in trained and untrained individuals during cycle exercise. A second objective was to compare the variance of the spectral parameters (median frequency - MF obtained by the FFT and WT during exercise. Twelve cyclists and non-cyclists performed a maximal incremental test to determine the peak power (Wp and electromyographic activity of the vastus lateralis (VL, rectus femoris (RF, biceps femoris (BF, semitendinous (ST and tibialis anterior (TA. Mean values of median frequency, determined by the FFT and WT, were used for the spectral analysis of the electromyographic signals of the studied muscles. The analyzed parameters were obtained for each time period corresponding to 0, 25, 50, 75, and 100% of total duration of the maximal incremental test. No statistically significant differences were found in the values of MF and electromyographic indices of fatigue between the two techniques (FT and WT both in the cyclists and non-cyclists group (P>0.05. Regarding the MF variance, statistically significant differences were found in all analyzed muscles, as well as in different time periods, both in the cyclists and non-cyclists groups when comparing the FFT and WT techniques (P<0.05. The WT seems to be more adequate to dynamic tasks, since it does not require the signal to be quasi-stationary, unlike the limitation imposed upon the use of the FFT.
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Delahunt, Eamonn; McGroarty, Mark; De Vito, Giuseppe; Ditroilo, Massimiliano
2016-04-01
To investigate the kinematic and muscle activation adaptations during performance of the Nordic hamstring exercise (NHE) to a 6-week eccentric hamstring training programme using the NHE as the sole mode of exercise. Twenty-nine healthy males were randomly allocated to a control (CG) or intervention (IG) group. The IG participated in a 6-week eccentric hamstring exercise programme using the NHE. The findings of the present study were that a 6-week eccentric hamstring training programme improved eccentric hamstring muscle strength (202.4 vs. 177.4 nm, p = 0.0002, Cohen's d = 0.97) and optimized kinematic (longer control of the forward fall component of the NHE, 68.1° vs. 73.7°, p = 0.022, Cohen's d = 0.90) and neuromuscular parameters (increased electromyographic activity of the hamstrings, 83.2 vs. 56.6 % and 92.0 vs. 54.2 %, p 1.25) associated with NHE performance. This study provides some insight into potential mechanisms by which an eccentric hamstring exercise programme utilizing the NHE as the mode of exercise may result in an improvement in hamstring muscle control during eccentric contractions.
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EMG activities and plantar pressures during ski jumping take-off on three different sized hills.
Virmavirta, M; Perttunen, J; Komi, P V
2001-04-01
Different profiles of ski jumping hills have been assumed to make the initiation of take-off difficult especially when moving from one hill to another. Neuromuscular adaptation of ski jumpers to the different jumping hills was examined by measuring muscle activation and plantar pressure of the primary take-off muscles on three different sized hills. Two young ski jumpers volunteered as subjects and they performed several trials from each hill (K-35 m, K-65 m and K-90 m) with the same electromyographic (EMG) electrode and insole pressure transducer set-up. The results showed that the differences in plantar pressure and EMGs between the jumping hills were smaller than expected for both jumpers. The small changes in EMG amplitudes between the hills support the assumption that the take-off was performed with the same intensity on different jumping hills and the timing of the gluteus EMG demonstrates well the similarity of the muscle activation on different hills. On the basis of the results obtained it seems that ski jumping training on small hills does not disturb the movement patterns for bigger hills and can also be helpful for special take-off training with low speed.
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Oblique abdominal muscle activity in response to external perturbations when pushing a cart.
Lee, Yun-Ju; Hoozemans, Marco J M; van Dieën, Jaap H
2010-05-07
Cyclic activation of the external and internal oblique muscles contributes to twisting moments during normal gait. During pushing while walking, it is not well understood how these muscles respond to presence of predictable (cyclic push-off forces) and unpredictable (external) perturbations that occur in pushing tasks. We hypothesized that the predictable perturbations due to the cyclic push-off forces would be associated with cyclic muscle activity, while external perturbations would be counteracted by cocontraction of the oblique abdominal muscles. Eight healthy male subjects pushed at two target forces and two handle heights in a static condition and while walking without and with external perturbations. For all pushing tasks, the median, the static (10th percentile) and the peak levels (90th percentile) of the electromyographic amplitudes were determined. Linear models with oblique abdominal EMGs and trunk angles as input were fit to the twisting moments, to estimate trunk stiffness. There was no significant difference between the static EMG levels in pushing while walking compared to the peak levels in pushing while standing. When pushing while walking, the additional dynamic activity was associated with the twisting moments, which were actively modulated by the pairs of oblique muscles as in normal gait. The median and static levels of trunk muscle activity and estimated trunk stiffness were significantly higher when perturbations occurred than without perturbations. The increase baseline of muscle activity indicated cocontraction of the antagonistic muscle pairs. Furthermore, this cocontraction resulted in an increased trunk stiffness around the longitudinal axis. Copyright 2010 Elsevier Ltd. All rights reserved.
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Ivanenko, Y P; Cappellini, G; Poppele, R E; Lacquaniti, F
2008-06-01
Here we studied the spatiotemporal organization of motoneuron (MN) activity during different human gaits. We recorded the electromyographic (EMG) activity patterns in 32 ipsilateral limb and trunk muscles from normal subjects while running and walking on a treadmill (3-12 km/h). In addition, we recorded backward walking and skipping, a distinct human gait that comprises the features of both walking and running. We mapped the recorded EMG activity patterns onto the spinal cord in approximate rostrocaudal locations of the MN pools. The activation of MNs tends to occur in bursts and be segregated by spinal segment in a gait-specific manner. In particular, sacral and cervical activation timings were clearly gait-dependent. Swing-related activity constituted an appreciable fraction (> 30%) of the total MN activity of leg muscles. Locomoting at non-preferred speeds (running and walking at 5 and 9 km/h, respectively) showed clear differences relative to preferred speeds. Running at low speeds was characterized by wider sacral activation. Walking at high non-preferred speeds was accompanied by an 'atypical' locus of activation in the upper lumbar spinal cord during late stance and by a drastically increased activation of lumbosacral segments. The latter findings suggest that the optimal speed of gait transitions may be related to an optimal intensity of the total MN activity, in addition to other factors previously described. The results overall support the idea of flexibility and adaptability of spatiotemporal activity in the spinal circuitry with constraints on the temporal functional connectivity of hypothetical pulsatile burst generators.
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Re-irradiation of metastatic disease in the neck from xeroderma pigmentosum.
Wei, C C; Sanfilippo, N J; Myssiorek, D
2010-06-01
Xeroderma pigmentosum, an autosomal recessive disease that occurs with a frequency of 1:250,000, is caused by a genetic defect in nucleotide excision repair enzymes. Mutation of these enzymes leads to the development of multiple basal cell and squamous cell carcinomas. We present a case of xeroderma pigmentosum in a patient with cervical and intraparotid metastatic disease from recurrent cutaneous squamous cell carcinomas of the face and scalp, treated with neck dissection and re-irradiation. With the illustrative case report, we include a literature review of diagnosis, prognostic factors, and treatment, with emphasis on surgical and radiation treatment of cervical metastatic disease from recurrent skin carcinomas. A xeroderma pigmentosum patient presented to our clinic with a 2-cm right submental and 1-cm right infra-auricular mass after resection of multiple squamous cell carcinomas of the scalp and face, and external-beam radiation therapy to the right face and neck. Fine-needle aspiration biopsy of the submental mass revealed poorly differentiated squamous cell carcinoma. The patient was brought to the operating room for a right modified radical neck dissection and excision of the right submental and intraparotid mass. Surgical pathology revealed 3 level ia and supraclavicular lymph nodes that were positive for metastatic squamous cell carcinoma. Re-irradiation to the entire right hemi-neck and left submandibular nodal region was performed using opposed oblique portals for the upper neck and a low anterior en face hemi-neck portal. The left parotid region was also included in the re-irradiation volume. Treatment was completed without delayed complications or recurrences to date. To our knowledge, this is the first case report in the literature of a patient with xeroderma pigmentosum who subsequently developed metastatic disease from recurrent cutaneous squamous cell carcinoma. Because of the rarity of xeroderma pigmentosum, this case report is also the first
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Ground reaction forces, kinematics, and muscle activations during the windmill softball pitch.
Oliver, Gretchen D; Plummer, Hillary
2011-07-01
The aims of the present study were to examine quantitatively ground reaction forces, kinematics, and muscle activations during the windmill softball pitch, and to determine relationships between knee valgus and muscle activations, ball velocity and muscle activation as well as ball velocity and ground reaction forces. It was hypothesized that there would be an inverse relationship between degree of knee valgus and muscle activation, a direct relationship between ground reaction forces and ball velocity, and non-stride leg muscle activations and ball velocity. Ten female windmill softball pitchers (age 17.6 ± 3.47 years, stature 1.67 ± 0.07 m, weight 67.4 ± 12.2 kg) participated. Dependent variables were ball velocity, surface electromyographic (sEMG), kinematic, and kinetic data while the participant was the independent variable. Stride foot contact reported peak vertical forces of 179% body weight. There were positive relationships between ball velocity and ground reaction force (r = 0.758, n = 10, P = 0.029) as well as ball velocity and non-stride leg gluteus maximus (r = 0.851, n = 10, P = 0.007) and medius (r = 0.760, n = 10, P = 0.029) muscle activity, while there was no notable relationship between knee valgus and muscle activation. As the windmill softball pitcher increased ball velocity, her vertical ground reaction forces also increased. Proper conditioning of the lumbopelvic-hip complex, including the gluteals, is essential for injury prevention. From the data presented, it is evident that bilateral strength and conditioning of the gluteal muscle group is salient in the windmill softball pitch as an attempt to decrease incidence of injury.
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Marini, Ida; Alessandri Bonetti, Giulio; Bortolotti, Francesco; Bartolucci, Maria Lavinia; Gatto, Maria Rosaria; Michelotti, Ambra
2015-06-01
It has been hypothesized that different plantar sensory inputs could influence the whole body posture and dental occlusion but there is a lack of evidence on this possible association. To investigate the effects of experimental insoles redistributing plantar pressure on body posture, mandibular kinematics and electromyographic (EMG) activity of masticatory muscles on healthy subjects. A pilot study was conducted on 19 healthy volunteers that wore custom-made insoles normalizing the plantar pressure distribution for 2 weeks. Body posture parameters were measured by means of an optoelectronic stereophotogrammetric analysis; mandibular kinematics was analyzed by means of gothic arch tracings; superficial EMG activity of head and neck muscles was performed. Measurements were carried out 10 days before the insertion of the insoles, immediately before the insertion, the day after, 7 and 14 days after, in four different exteroceptive conditions. The outcomes of the present study show that insoles do not modify significantly over time the parameters of body posture, SEMG activity of head and neck muscles and mandibular kinematics. In this pilot study the experimental insoles did not significantly influence the body posture, the mandibular kinematics and the activity of masticatory muscles during a 14-day follow up period. Copyright © 2015 Elsevier Ltd. All rights reserved.
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Cheung, J.; Veldhuizen, A.G.; Halbertsma, J.P.; Maurits, N.M.; Sluiter, W.J.; Cool, J.C.; van Horn, J.R.
2004-01-01
Study Design. A prospective study in which patients with idiopathic scoliosis were examined longitudinally by radiographic and electromyographic measurements according to a protocol. Objectives. To measure the growth velocity of the spine and the electromyographic ratio of the paraspinal muscles to
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Matsuo, Kiyoshi; Ban, Ryokuya
2013-02-01
Proprioceptively innervated intramuscular connective tissues in Müller's muscle function as exterior mechanoreceptors to induce reflex contraction of the levator and occipitofrontalis muscles. In aponeurotic blepharoptosis, since the levator aponeurosis is disinserted from the tarsus, stretching of the mechanoreceptors in Müller's muscle is increased even on primary gaze to induce phasic and tonic reflexive contraction of the occipitofrontalis muscle. It was hypothesised that in certain patients with aponeurotic blepharoptosis, the presence of tonic reflexive contraction of the occipitofrontalis muscle due to the sensitised mechanoreceptors in Müller's muscle, can cause chronic tension-type headache (CTTH) associated with occipitofrontalis tenderness. To verify this hypothesis, this study evaluated (1) what differentiates patients with CTTH from patients without CTTH, (2) how pharmacological contraction of Müller's smooth muscle fibres as a method for desensitising the mechanoreceptors in Müller's muscle affects electromyographic activity of the frontalis muscle, and (3) how surgical aponeurotic reinsertion to desensitise the mechanoreceptors in Müller's muscle electromyographically or subjectively affects activities of the occipitofrontalis muscle or CTTH. It was found that patients had sustained CTTH when light eyelid closure did not markedly reduce eyebrow elevation. However, pharmacological contraction of Müller's smooth muscle fibres or surgery to desensitise the mechanoreceptor electromyographically reduced the tonic contraction of the occipitofrontalis muscle on primary gaze and subjectively relieved aponeurotic blepharoptosis-associated CTTH. Over-stretching of the mechanoreceptors in Müller's muscle on primary gaze may induce CTTH due to tonic reflexive contraction of the occipitofrontalis muscle. Therefore, surgical desensitisation of the mechanoreceptors in Müller's muscle appears to relieve CTTH.
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Muscle activity and inactivity periods during normal daily life.
Directory of Open Access Journals (Sweden)
Olli Tikkanen
Full Text Available Recent findings suggest that not only the lack of physical activity, but also prolonged times of sedentary behaviour where major locomotor muscles are inactive, significantly increase the risk of chronic diseases. The purpose of this study was to provide details of quadriceps and hamstring muscle inactivity and activity during normal daily life of ordinary people. Eighty-four volunteers (44 females, 40 males, 44.1±17.3 years, 172.3±6.1 cm, 70.1±10.2 kg were measured during normal daily life using shorts measuring muscle electromyographic (EMG activity (recording time 11.3±2.0 hours. EMG was normalized to isometric MVC (EMG(MVC during knee flexion and extension, and inactivity threshold of each muscle group was defined as 90% of EMG activity during standing (2.5±1.7% of EMG(MVC. During normal daily life the average EMG amplitude was 4.0±2.6% and average activity burst amplitude was 5.8±3.4% of EMG(MVC (mean duration of 1.4±1.4 s which is below the EMG level required for walking (5 km/h corresponding to EMG level of about 10% of EMG(MVC. Using the proposed individual inactivity threshold, thigh muscles were inactive 67.5±11.9% of the total recording time and the longest inactivity periods lasted for 13.9±7.3 min (2.5-38.3 min. Women had more activity bursts and spent more time at intensities above 40% EMG(MVC than men (p<0.05. In conclusion, during normal daily life the locomotor muscles are inactive about 7.5 hours, and only a small fraction of muscle's maximal voluntary activation capacity is used averaging only 4% of the maximal recruitment of the thigh muscles. Some daily non-exercise activities such as stair climbing produce much higher muscle activity levels than brisk walking, and replacing sitting by standing can considerably increase cumulative daily muscle activity.
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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
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Muscle activation patterns of the upper and lower extremity during the windmill softball pitch.
Oliver, Gretchen D; Plummer, Hillary A; Keeley, David W
2011-06-01
Fast-pitch softball has become an increasingly popular sport for female athletes. There has been little research examining the windmill softball pitch in the literature. The purpose of this study was to describe the muscle activation patterns of 3 upper extremity muscles (biceps, triceps, and rhomboids [scapular stabilizers]) and 2 lower extremity muscles (gluteus maximus and medius) during the 5 phases of the windmill softball pitch. Data describing muscle activation were collected on 7 postpubescent softball pitchers (age 17.7 ± 2.6 years; height 169 ± 5.4 cm; mass 69.1 ± 5.4 kg). Surface electromyographic data were collected using a Myopac Jr 10-channel amplifier (RUN Technologies Scientific Systems, Laguna Hills, CA, USA) synchronized with The MotionMonitor™ motion capture system (Innovative Sports Training Inc, Chicago IL, USA) and presented as a percent of maximum voluntary isometric contraction. Gluteus maximus activity reached (196.3% maximum voluntary isometric contraction [MVIC]), whereas gluteus medius activity was consistent during the single leg support of phase 3 (101.2% MVIC). Biceps brachii activity was greatest during phase 4 of the pitching motion. Triceps brachii activation was consistently >150% MVIC throughout the entire pitching motion, whereas the scapular stabilizers were most active during phase 2 (170.1% MVIC). The results of this study indicate the extent to which muscles are activated during the windmill softball pitch, and this knowledge can lead to the development of proper preventative and rehabilitative muscle strengthening programs. In addition, clinicians will be able to incorporate strengthening exercises that mimic the timing of maximal muscle activation most used during the windmill pitching phases.
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A comparison of free weight squat to Smith machine squat using electromyography.
Schwanbeck, Shane; Chilibeck, Philip D; Binsted, Gordon
2009-12-01
The purpose of this experiment was to determine whether free weight or Smith machine squats were optimal for activating the prime movers of the legs and the stabilizers of the legs and the trunk. Six healthy participants performed 1 set of 8 repetitions (using a weight they could lift 8 times, i.e., 8RM, or 8 repetition maximum) for each of the free weight squat and Smith machine squat in a randomized order with a minimum of 3 days between sessions, while electromyographic (EMG) activity of the tibialis anterior, gastrocnemius, vastus medialis, vastus lateralis, biceps femoris, lumbar erector spinae, and rectus abdominus were simultaneously measured. Electromyographic activity was significantly higher by 34, 26, and 49 in the gastrocnemius, biceps femoris, and vastus medialis, respectively, during the free weight squat compared to the Smith machine squat (p free weight and Smith machine squat for any of the other muscles; however, the EMG averaged over all muscles during the free weight squat was 43% higher when compared to the Smith machine squat (p free weight squat may be more beneficial than the Smith machine squat for individuals who are looking to strengthen plantar flexors, knee flexors, and knee extensors.
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Effects of physical activity and inactivity on muscle fatigue
Directory of Open Access Journals (Sweden)
Gregory C. Bogdanis
2012-05-01
Full Text Available The aim of this review was to examine the mechanisms by which physical activity and inactivity modify muscle fatigue. It is well known that acute or chronic increases in physical activity result in structural, metabolic, hormonal, neural and molecular adaptations that increase the level of force or power that can be sustained by a muscle. These adaptations depend on the type, intensity and volume of the exercise stimulus, but recent studies have highlighted the role of high intensity, short duration exercise as a time-efficient method to achieve both anaerobic and aerobic/endurance type adaptations. The factors that determine the fatigue profile of a muscle during intense exercise include muscle fibre composition, neuromuscular characteristics high energy metabolite stores, buffering capacity, ionic regulation, capillarization and mitochondrial density. Muscle fiber type transformation during exercise training is usually towards the intermediate type IIA at the expense of both type I and type IIx myosin heavy chain isoforms. High intensity training results in increases of both glycolyic and oxidative enzymes, muscle capilarization, improved phosphocreatine resynthesis and regulation of K+, H+ and lactate ions. Decreases of the habitual activity level due to injury or sedentary lifestyle result in partial or even compete reversal of the adaptations due to previous training, manifested by reductions in fibre cross-sectional area, decreased oxidative capacity and capillarization. Complete immobilization due to injury results in markedly decreased force output and fatigue resistance. Muscle unloading reduces electromyographic activity and causes muscle atrophy and significant decreases in capillarization and oxidative enzymes activity. The last part of the review discusses the beneficial effects of intermittent high intensity exercise training in patients with different health conditions to demonstrate the powerful effect exercise on health and well
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SELECTIVE ACTIVATION OF THE RECTUS ABDOMINIS MUSCLE DURING LOW-INTENSITY AND FATIGUING TASKS
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Paulo H. Marchetti
2011-06-01
Full Text Available In order to understand the potential selective activation of the rectus abdominis muscle, we conducted two experiments. In the first, subjects performed two controlled isometric exercises: the curl up (supine trunk raise and the leg raise (supine bent leg raise at low intensity (in which only a few motor units are recruited. In the second experiment, subjects performed the same exercises, but they were required to maintain a certain force level in order to induce fatigue. We recorded the electromyographic (EMG activities of the lower and upper portions of the rectus abdominis muscle during the exercises and used spatial-temporal and frequency analyses to describe muscle activation patterns. At low-intensity contractions, the ratio between the EMG intensities of the upper and lower portions during the curl up exercise was significantly larger than during the leg raise exercise (p = 0.02. A cross-correlation analysis indicated that the signals of the abdominal portions were related to each other and this relation did not differ between the tasks (p = 0.12. In the fatiguing condition, fatigue for the upper portion was higher than for the lower portion during the curl up exercise (p = 0.008. We conclude that different exercises evoked, to a certain degree, individualized activation of each part of the rectus abdominis muscle, but different portions of the rectus abdominis muscle contributed to the same task, acting like a functional unit. These results corroborate the relevance of varying exercise to modify activation patterns of the rectus abdominis muscle
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Krygiel, Rebecca G.; Waye, Abigail B.; Baptista, Rafael Reimann; Heidner, Gustavo Sandri; Rehnberg, Lucas; Russomano, Thais
2014-04-01
BACKGROUND: This original study evaluated the electromyograph (EMG) activity of four upper body muscles: triceps brachii, erector spinae, upper rectus abdominis, and pectoralis major, while external chest compressions (ECCs) were performed in simulated Martian hypogravity using a Body Suspension Device, counterweight system, and standard full body cardiopulmonary resuscitation (CPR) mannequin. METHOD: 20 young, healthy male subjects were recruited. One hundred compressions divided into four sets, with roughly six seconds between each set to indicate 'ventilation', were performed within approximately a 1.5 minute protocol. Chest compression rate, depth and number were measured along with the subject's heart rate (HR) and rating of perceived exertion (RPE). RESULTS: All mean values were used in two-tailed t-tests using SPSS to compare +1 Gz values (control) versus simulated hypogravity values. The AHA (2005) compression standards were maintained in hypogravity. RPE and HR increased by 32% (p training regimes in case of a serious cardiac event in hypogravity.
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The vastus lateralis neuromuscular activity during all-out cycling exercise.
Bercier, Stephane; Halin, Renaud; Ravier, Philippe; Kahn, Jean-Francois; Jouanin, Jean-Claude; Lecoq, Anne-Marie; Buttelli, Olivier
2009-10-01
The objective of this work was to study modifications in motor control through surface electromyographic (sEMG) activity during a very short all-out cycling exercise. Twelve male cyclists (age 23+/-4 years) participated in this study. After a warm-up period, each subject performed three all-out cycling exercises of 6s separated by 2 min of complete rest. This protocol was repeated three times with a minimum of 2 days between each session. The braking torque imposed on cycling motion was 19 Nm. The sEMG of the vastus lateralis was recorded during the first seven contractions of the sprint. Time-frequency analysis of sEMG was performed using continuous wavelet transform. The mean power frequency (MPF, qualitative modifications in the recruitment of motor units) and signal energy (a quantitative indicator of modifications in the motor units recruitment) were computed for the frequency range 10-500 Hz. sEMG energy increased (P0.05) between contraction number 1 and 2, decreased (P recruitment of motor units (MUs) at the beginning of the sprint followed by a preferential recruitment of faster MUs at the end of the sprint, respectively.
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Yamakawa, Keisuke Kobayashi; Shimojo, Hirofumi; Takagi, Hideki; Tsubakimoto, Shozo; Sengoku, Yasuo
2017-10-01
We investigated the effects of synchronizing kick frequency with the beat of a metronome on kinematic and electromyographic (EMG) parameters during the underwater dolphin kick as a pilot study related to the research that entitled " Effect of increased kick frequency on propelling efficiency and muscular co-activation during underwater dolphin kick" (Yamakawa et al., 2017) [1]. Seven collegiate female swimmers participated in this experiment. The participants conducted two underwater dolphin kick trials: swimming freely at maximum effort, and swimming while synchronizing the kick frequency of maximum effort with the beat of a metronome. The kinematic parameters during the underwater dolphin kick were calculated by 2-D motion analysis, and surface electromyographic measurements were taken from six muscles (rectus abdominis, erector spinae, rectus femoris, biceps femoris, tibialis anterior, and gastrocnemius). The results revealed no significant differences in the kinematic and EMG parameters between trials of the two swimming techniques. Therefore, the action of synchronizing the kick frequency with the beat of a metronome did not affect movement or muscle activity during the underwater dolphin kick in this experiment.
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Directory of Open Access Journals (Sweden)
Keisuke Kobayashi Yamakawa
2017-10-01
Full Text Available We investigated the effects of synchronizing kick frequency with the beat of a metronome on kinematic and electromyographic (EMG parameters during the underwater dolphin kick as a pilot study related to the research that entitled “Effect of increased kick frequency on propelling efficiency and muscular co-activation during underwater dolphin kick” (Yamakawa et al., 2017 [1]. Seven collegiate female swimmers participated in this experiment. The participants conducted two underwater dolphin kick trials: swimming freely at maximum effort, and swimming while synchronizing the kick frequency of maximum effort with the beat of a metronome. The kinematic parameters during the underwater dolphin kick were calculated by 2-D motion analysis, and surface electromyographic measurements were taken from six muscles (rectus abdominis, erector spinae, rectus femoris, biceps femoris, tibialis anterior, and gastrocnemius. The results revealed no significant differences in the kinematic and EMG parameters between trials of the two swimming techniques. Therefore, the action of synchronizing the kick frequency with the beat of a metronome did not affect movement or muscle activity during the underwater dolphin kick in this experiment.
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The effects of poliomyelitis on motor unit behavior during repetitive muscle actions: a case report.
Trevino, Michael A; Herda, Trent J; Cooper, Michael A
2014-09-06
Acute paralytic poliomyelitis is caused by the poliovirus and usually results in muscle atrophy and weakness occurring in the lower limbs. Indwelling electromyography has been used frequently to investigate the denervation and innervation characteristics of the affected muscle. Recently developed technology allows the decomposition of the raw surface electromyography signals into the firing instances of single motor units. There is limited information regarding this electromyographic decomposition in clinical populations. In addition, regardless of electromyographic methods, no study has examined muscle activation parameters during repetitive muscle actions in polio patients. Therefore, the purpose of this study was to examine the motor unit firing rates and electromyographic amplitude and center frequency of the vastus lateralis during 20 repetitive isometric muscle actions at 50% maximal voluntary contraction in healthy subjects and one patient that acquired acute paralytic poliomyelitis. One participant that acquired acute type III spinal poliomyelitis (Caucasian male, age = 29 yrs) at 3 months of age and three healthy participants (Caucasian females, age = 19.7 ± 2.1 yrs) participated in this study. The polio participant reported neuromuscular deficiencies as a result of disease in the hips, knees, buttocks, thighs, and lower legs. None of the healthy participants reported any current or ongoing neuromuscular diseases or musculoskeletal injuries. An acute bout of poliomyelitis altered motor unit behavior, such as, healthy participants displayed greater firing rates than the polio patient. The reduction in motor unit firing rates was likely a fatigue protecting mechanism since denervation via poliomyelitis results in a reduction of motorneurons. In addition, the concurrent changes in motor unit firing rates, electromyography amplitude and frequency for the polio participant would suggest that the entire motorneuron pool was utilized in each contraction unlike
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"Footdrop in the farmers: Clinical and electromyographical study "
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Ghaffarpour M
2002-08-01
Full Text Available Footdrop is a relatively common deficit among the neurological disorders, which has different causes with various levels of involvement in neuromuscular system, including central nervous system (brain cortex, spinal cord, fifth lumbar root, peripheral nerves and muscles. Peroneal nerve injury at the fibular head has been reported to the most common cause of foot drop, which can be due to infarct, tumor or leprosy but the vast majority of lesions are traumatic. In this article, we report seventeen patients with foot drop in farmers. All of the patients except one, were male with age ranges between 15 to 25 years. They had been doing certain farming activities (harvesting or weeding for 1-5 days before developing foot drop. Electrophysiological studies have been done in only seven of them due to patient’s unwillingness. Nerve conduction velocity and amplitudes distal to the fibular head were normal, but stimulation above the fibular head showed reduced nerve conduction velocity and amplitudes (mean 22.4 m/s in the abnormal side versus 51.5 m/s in the normal side, mean peak to peak amplitude 3.6 mv in the symptomatic side versus 10.4 in the contralateral side respectively. Forty-three percent of patients had also conduction block. F wave latency increased on the affected side in comparison to the normal side (mean 4.7 m/s. The new and perhaps interesting findings in our cases are unilateral involvement and occurrence of peroneal palsy on the side of dominant hand, indicating that type of the hand activity is probably more important in inducing foot drop than the position of seating during harvesting or weeding. We suggest further investigation in this setting in order to find the mechanisms of nerve injury and prophylactic measures.
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Stiffness and position control of a prosthetic wrist by means of an EMG interface
Rao, S.; Carloni, Raffaella; Stramigioli, Stefano
In this paper, we present a novel approach for decoding electromyographic signals from an amputee and for interfacing them with a prosthetic wrist. The model for the interface makes use of electromyographic signals from electrodes placed in agonistic and antagonistic sides of the forearm. The model
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Increased active hamstring stiffness after exercise in women with a history of low back pain.
Bedard, Rebecca J; Kim, Kyung-Min; Grindstaff, Terry L; Hart, Joseph M
2013-02-01
To compare active hamstring stiffness in female subjects with and without a history of low back pain (LBP) after a standardized 20-min aerobic-exercise session. Case control. Laboratory. 12 women with a history of recurrent episodes of LBP (age = 22.4 ± 2.1 y, mass = 67.1 ± 11.8 kg, height = 167.9 ± 8 cm) and 12 matched healthy women (age = 21.7 ± 1.7 y, mass = 61.4 ± 8.8 kg, height = 165.6 ± 7.3 cm). LBP subjects reported an average 6.5 ± 4.7 on the Oswestry Disability Index. Participants walked at a self-selected speed (minimum 3.0 miles/h) for 20 min. The treadmill incline was raised 1% grade per minute for the first 15 min. During the last 5 min, participants adjusted the incline of the treadmill so they would maintain a moderate level of perceived exertion through the end of the exercise protocol. During session 1, active hamstring stiffness, hamstring and quadriceps isometric strength, and concurrently collected electromyographic activity were recorded before and immediately after the exercise protocol. For session 2, subjects returned 48-72 h after exercise for repeat measure of active hamstring stiffness. Hamstring active stiffness (Nm/rad) taken immediately postexercise was not significantly different between groups. However, individuals with a history of recurrent LBP episodes presented significantly increased hamstring stiffness 48-72 h postexercise compared with controls. For other outcomes, there was no group difference. Women with a history of recurrent LBP episodes presented greater active hamstring stiffness 48-72 h after aerobic exercise.
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Loading, electromyograph, and motion during exercise
Figueroa, Fernando
1993-01-01
A system is being developed to gather kineto-dynamic data for a study to determine the load vectors applied to bone during exercise on equipment similar to that used in space. This information will quantify bone loading for exercise countermeasures development. Decreased muscle loading and external loading of bone during weightlessness results in cancellous bone loss of 1 percent per month in the lower extremities and 2 percent per month in the calcaneous. It is hypothesized that loading bone appropriately during exercise may prevent the bone loss. The system consists of an ergometer instrumented to provide position of the pedal (foot), pedaling forces on the foot (on the sagittal plane), and force on the seat. Accelerometers attached to the limbs will provide acceleration. These data will be used as input to an analytical model of the limb to determine forces on the bones and on groups of muscles. EMG signals from activity in the muscles will also be used in conjunction with the equations of mechanics of motion to be able to discern forces exerted by specific muscles. The tasks to be carried out include: design of various mechanical components to mount transducers, specification of mechanical components, specification of position transducers, development of a scheme to control the data acquisition instruments (TEAC recorder and optical encoder board), development of a dynamic model of the limbs in motion, and development of an overall scheme for data collection analysis and presentation. At the present time, all the hardware components of the system are operational, except for a computer board to gather position data from the pedals and crank. This board, however, may be put to use by anyone with background in computer based instrumentation. The software components are not all done. Software to transfer data recorded from the EMG measurements is operational, software to drive the optical encoder card is mostly done. The equations to model the kinematics and
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'Nordic' Hamstrings Exercise - Engagement Characteristics and Training Responses
Iga, J; Fruer, C S; Deighan, Martine A; De Ste Croix, Mark B; James, David V
2012-01-01
The present study examined the neuromuscular activation characteristics of the hamstrings during the 'Nordic' hamstrings exercise (NHE) and changes in the eccentric strength of the knee flexors with NHE training. Initially, the normalised root mean square electromyographic (EMG) activity of the hamstrings of both limbs during various phases (90-61 degrees, 60-31 degrees and 30-0 degrees of knee extension) of the NHE were determined in 18 soccer players. Subsequently participants were randomly...
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The Effect of Mental Practice on Coordination of Upper Limb Movements in Hemiplegic Patients
Zahra Isargar; Mohammad Reza Nourbakhsh; Hassan A'shayeri; Nader Ma'roufi
2000-01-01
Objective: Mental Practice (MP) can be defined as the symbolic, covert, mental rehearsal of a task in the absence, overt physical rehearsal. Elements such as similar time between actual execution and mental performance of a task, the increase of regional cerebral blood flow, vegetative activation, and enhancement in muscle electromyographic (EMG) activity during mental practice suggests that mental practice imitates physical performance of a task. Since physical practice (PP) can, to some ext...
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Submandibular salivary gland transfer prevents radiation-induced xerostomia
International Nuclear Information System (INIS)
Jha, Naresh; Seikaly, Hadi; McGaw, Timothy; Coulter, Linda
2000-01-01
Background: Xerostomia is a significant morbidity of radiation therapy in the management of head and neck cancers. We hypothesized that the surgical transfer of one submandibular salivary gland to submental space, outside the proposed radiation field, prior to starting radiation treatment, would prevent xerostomia. Methods: We are conducting a prospective clinical trial where the submandibular gland is transferred as part of the surgical intervention. The patients are followed clinically, with salivary flow studies and University of Washington quality of life questionnaire. Results: We report early results of 16 patients who have undergone this procedure. Seven patients have finished and 2 patients are currently undergoing radiation treatment. In 2 patients, no postoperative radiation treatment was indicated. Two patients are waiting to start radiation treatment and 2 patients refused treatment after surgery. The surgical transfer was abandoned in 1 patient. All of the transferred salivary glands were positioned outside the proposed radiation fields and were functional. The patients did not complain of any xerostomia and developed only minimal oral mucositis. There were no surgical complications. Conclusions: Surgical transfer of a submandibular salivary gland to the submental space (outside the radiation field) preserves its function and prevents the development of radiation-induced xerostomia
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Kinney, Brian M; Andriessen, Anneke; DiBernardo, Barry E; Bloom, Jason; Branson, Dennis F; Gentile, Richard D; Goldberg, David J; Lorenc, Paul Z; Nestor, Mark; Wu, Douglas
2017-12-01
A new temperature-controlled device has been used as a percutaneous radio frequency probe to treat lax submental and other facial areas. It has significant advantages over other esthetic devices as it provides the dual benefit of fat lipolysis and skin tightening. Our goal here is to present consensus recommendations for treating the aging neck. A panel of 11 expert physicians convened in Dallas, Texas, on October 15, 2016 to arrive at a consensus on the best current practice for submental skin tightening and contour improvement. Prior to the meeting, a comprehensive review of the literature was performed and a survey was sent to esthetic dermatologists and plastic surgeons who were queried about various aspects of neck rejuvenation. The literature search revealed 10 different technologies for neck rejuvenation evaluated in double-blind (n = 2) and single-blind (n = 1) clinical trials and other clinical evaluations (n = 21). The survey was sent via an email to 1248 individuals and was completed by 92 respondents. Review of the data and discussion by meeting attendees generated eight consensus recommendations. Subdermal monopolar radio frequency represents an effective means for disrupting fat volume and skin tightening of the face, neck, and jawline. For suitable patients, this treatment can be used to achieve significant esthetic improvements.
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Farina, Dario; Leclerc, Frédéric; Arendt-Nielsen, Lars; Buttelli, Olivier; Madeleine, Pascal
2008-02-01
The aim of the study was to confirm the hypothesis that the longer a contraction is sustained, the larger are the changes in the spatial distribution of muscle activity. For this purpose, surface electromyographic (EMG) signals were recorded with a 13 x 5 grid of electrodes from the upper trapezius muscle of 11 healthy male subjects during static contractions with shoulders 90 degrees abducted until endurance. The entropy (degree of uniformity) and center of gravity of the EMG root mean square map were computed to assess spatial inhomogeneity in muscle activation and changes over time in EMG amplitude spatial distribution. At the endurance time, entropy decreased (mean+/-SD, percent change 2.0+/-1.6%; Pgrid) root mean square was positively correlated with the shift in the center of gravity (R(2)=0.51, P<0.05). Moreover, the shift in the center of gravity was negatively correlated to both initial and final (at the endurance) entropy (R(2)=0.54 and R(2)=0.56, respectively; P<0.01 in both cases), indicating that subjects with less uniform root mean square maps had larger shift of the center of gravity over time. The spatial changes in root mean square EMG were likely due to spatially-dependent changes in motor unit activation during the sustained contraction. It was concluded that the changes in spatial muscle activity distribution play a role in the ability to maintain a static contraction.
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Pantall, Annette; Teulier, Caroline; Ulrich, Beverly D
2012-12-01
Infants with myelomeningocele (MMC) increase step frequency in response to modifications to the treadmill surface. The aim was to investigate how these modifications impacted the electromyographic (EMG) patterns. We analyzed EMG from 19 infants aged 2-10 months, with MMC at the lumbosacral level. We supported infants upright on the treadmill for 12 trials, each 30 seconds long. Modifications included visual flow, unloading, weights, Velcro and lcriction. Surface electrodes recorded EMG from tibialis anterior, lateral gastrocnemius, rectus femoris and biceps femoris. We determined muscle bursts for each stride cycle and from these calculated various parameters. Results indicated that each of the five sensory conditions generated different motor patterns. Visual flow and friction which we previously reported increased step frequency impacted lateral gastrocnemius most. Weights, which significantly decreased step frequency increased burst duration and co-activity of the proximal muscles. We also observed an age effect, with all conditions increasing muscle activity in younger infants whereas in older infants visual flow and unloading stimulated most activity. In conclusion, we have demonstrated that infants with myelomeningocele at levels which impact the myotomes of major locomotor muscles find ways to respond and adapt their motor output to changes in sensory input. Copyright © 2012 Elsevier B.V. All rights reserved.
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Directory of Open Access Journals (Sweden)
Aline Ferla
2008-08-01
Full Text Available A respiração bucal tem sido estudada por causar sérios efeitos no desenvolvimento do sistema estomatognático. OBJETIVO: Estudar, através da análise eletromiográfica, o padrão de atividade elétrica dos músculos temporal anterior e masseter em crianças com respiração bucal, comparando-os com o de crianças com respiração nasal. MATERIAL E MÉTODO: Foram estudados dois grupos de crianças: 17 respiradoras bucais (RB e 12 respiradoras nasais (RN. As crianças foram submetidas à avaliação eletromiográfica bilateral dos músculos supracitados nas situações de máxima intercuspidação e mastigação habitual. Utilizou-se o eletromiógrafo Myosystem Br-1, com 12 canais de aquisição, amplificação com ganho total de 5938, taxa de aquisição de 4000Hz e filtro passa-faixa de 20-1000Hz. O sinal foi processado em RMS, mensurado em µV e analisado e expresso em %, normalizado. Os dados foram tratados estatisticamente através do Teste t (Student. RESULTADOS: Observou-se que o nível de atividade elétrica do grupo RB foi inferior para todos os músculos e estatisticamente significante somente para o temporal esquerdo; os respiradores bucais apresentaram predomínio de atividade elétrica no lado direito e no músculo temporal durante a mastigação habitual. CONCLUSÃO: A respiração bucal interferiu na atividade elétrica dos músculos estudados nas situações funcionais de máxima intercuspidação e mastigação habitual.Mouth breathing has been associated with severe impact on the development of the stomatognathic system. AIM: This paper aims to analyze the electromyographical findings and patterns of electrical activity of the anterior temporal and masseter muscles in mouth and nasal breathing children. MATERIAL AND METHOD: The patients were divided into two groups: mouth breathers (n=17 and nasal breathers (n=12. The children underwent bilateral electromyographic examination of the anterior temporal and masseter muscles at
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Intra-cranial recordings of brain activity during language production
Directory of Open Access Journals (Sweden)
Anais eLlorens
2011-12-01
Full Text Available Recent findings in the neurophysiology of language production have provided a detailed description of the brain network underlying this behavior, as well as some indications about the timing of operations. Despite their invaluable utility, these data generally suffer from limitations either in terms of temporal resolution, or in terms of spatial localization. In addition, studying the neural basis of speech is complicated by the presence of articulation artifacts such as electro-myographic activity that interferes with the neural signal. These difficulties are virtually absent in a powerful albeit much less frequent methodology, namely the recording of intra-cranial brain activity (iEEG. Such recordings are only possible under very specific clinical circumstances requiring functional mapping before brain surgery, most notably patients that suffer for pharmaco-resistant epilepsy. Here we review the research conducted with this methodology in the field of language production, with explicit consideration of its advantages and drawbacks. The available evidence is shown to be diverse, both in terms of the tasks and cognitive processes tested and in terms of the brain localizations being studied. Still, the review provides valuable information for characterizing the dynamics of the neural events occurring in the language production network. Following modality specific activities (in auditory or visual cortices, there is a convergence of activity in superior temporal sulcus, which is a plausible neural correlate of phonological encoding processes. Later, between 500 and 800 ms, inferior frontal gyrus (around Broca's area is involved. Peri-rolandic areas are recruited in the two modalities relatively early (200-500 ms window, suggesting a very early involvement of (pre- motor processes. We discuss how some of these findings may be at odds with conclusions drawn from available meta-analysis of language production.
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Directory of Open Access Journals (Sweden)
Valeria Regina Silva
Full Text Available ABSTRACT Introduction and objectives: Several studies have been investigated co-activation can enhance the effectveness of PFM training protocols allowing preventive and therapeutic goals in pelvic floor dysfunctions. The objective of the present study was to investigate if an abdominal-pelvic protocol of training (APT using gametherapy would allow co-activation of PFM and transversus abdominis/oblique internal (TrA/OI muscles. Patients and methods: Twenty-five nulliparous, continent, young females, with median age 24.76 (±3.76 years were evaluated using digital palpation (DP of PFM and surface electromyography of PFM and TrA/OI simultaneously, during maximal voluntary contraction (MVC, alternating PFM and TrA/OI contraction requests. All women participated on a supervised program of APT using gametherapy, that included exercises of pelvic mobilization associated to contraction of TrA/OI muscles oriented by virtual games, for 30 minutes, three times a week, in a total of 10 sessions. Electromyographic data were processed and analyzed by ANOVA - analysis of variance. Results: When MVC of TrA/OI was solicited, it was observed simultaneous increase of electromyographic activity of PFM (p=0.001 following ATP. However, EMG activity did not change significantly during MVC of PFM. Conclusion: Training using gametherapy allowed better co-activation of pelvic floor muscles in response to contraction of TrA, in young nulliparous and continent women.
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A glasses-type wearable device for monitoring the patterns of food intake and facial activity
Chung, Jungman; Chung, Jungmin; Oh, Wonjun; Yoo, Yongkyu; Lee, Won Gu; Bang, Hyunwoo
2017-01-01
Here we present a new method for automatic and objective monitoring of ingestive behaviors in comparison with other facial activities through load cells embedded in a pair of glasses, named GlasSense. Typically, activated by subtle contraction and relaxation of a temporalis muscle, there is a cyclic movement of the temporomandibular joint during mastication. However, such muscular signals are, in general, too weak to sense without amplification or an electromyographic analysis. To detect these oscillatory facial signals without any use of obtrusive device, we incorporated a load cell into each hinge which was used as a lever mechanism on both sides of the glasses. Thus, the signal measured at the load cells can detect the force amplified mechanically by the hinge. We demonstrated a proof-of-concept validation of the amplification by differentiating the force signals between the hinge and the temple. A pattern recognition was applied to extract statistical features and classify featured behavioral patterns, such as natural head movement, chewing, talking, and wink. The overall results showed that the average F1 score of the classification was about 94.0% and the accuracy above 89%. We believe this approach will be helpful for designing a non-intrusive and un-obtrusive eyewear-based ingestive behavior monitoring system.
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Abnormal reflex activation of hamstring muscles in dogs with cranial cruciate ligament rupture.
Hayes, Graham M; Granger, Nicolas; Langley-Hobbs, Sorrel J; Jeffery, Nick D
2013-06-01
The mechanisms underlying cranial cruciate ligament rupture (CCLR) in dogs are poorly understood. In this study hamstring muscle reflexes in response to cranial tibial translation were analysed to determine whether these active stabilisers of the stifle joint are differently activated in dogs with CCLR compared to control dogs. In a prospective clinical study reflex muscle activity from the lateral and medial hamstring muscles (biceps femoris and semimembranosus) was recorded using surface electrodes in control dogs (n=21) and dogs with CCLR (n=22). These electromyographic recordings were analysed using an algorithm previously validated in humans. The hamstring reflex was reliably and reproducibly recorded in normal dogs. Both a short latency response (SLR, 17.6±2.1ms) and a medium latency response (MLR, 37.7±2.7ms) could be identified. In dogs with unilateral CCLR, the SLR and MLR were not significantly different between the affected and the unaffected limbs, but the MLR latency of both affected and unaffected limbs in CCLR dogs were significantly prolonged compared to controls. In conclusion, the hamstring reflex can be recorded in dogs and the MLR is prolonged in dogs with CCLR. Since both affected and unaffected limbs exhibit prolonged MLR, it is possible that abnormal hamstring reflex activation is a mechanism by which progressive CCL damage may occur. The methodology allows for further investigation of the relationship between neuromuscular imbalance and CCLR or limitations in functional recovery following surgical intervention. Copyright © 2012 Elsevier Ltd. All rights reserved.
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Johnston, Jamie A; Bobich, Lisa R; Santello, Marco
2010-04-26
Fingertip forces result from the activation of muscles that cross the wrist and muscles whose origins and insertions reside within the hand (extrinsic and intrinsic hand muscles, respectively). Thus, tasks that involve changes in wrist angle affect the moment arm and length, hence the force-producing capabilities, of extrinsic muscles only. If a grasping task requires the exertion of constant fingertip forces, the Central Nervous System (CNS) may respond to changes in wrist angle by modulating the neural drive to extrinsic or intrinsic muscles only or by co-activating both sets of muscles. To distinguish between these scenarios, we recorded electromyographic (EMG) activity of intrinsic and extrinsic muscles of the thumb and index finger as a function of wrist angle during a two-digit object hold task. We hypothesized that changes in wrist angle would elicit EMG amplitude modulation of the extrinsic and intrinsic hand muscles. In one experimental condition we asked subjects to exert the same digit forces at each wrist angle, whereas in a second condition subjects could choose digit forces for holding the object. EMG activity was significantly modulated in both extrinsic and intrinsic muscles as a function of wrist angle (both pextrinsic and intrinsic muscles as a muscle synergy. These findings are discussed within the theoretical frameworks of synergies and common neural input across motor nuclei of hand muscles. Copyright 2010 Elsevier Ireland Ltd. All rights reserved.
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Park, Byoung-Sun; Noh, Ji-Woong; Kim, Mee-Young; Lee, Lim-Kyu; Yang, Seung-Min; Lee, Won-Deok; Shin, Yong-Sub; Kim, Ju-Hyun; Lee, Jeong-Uk; Kwak, Taek-Yong; Lee, Tae-Hyun; Kim, Ju-Young; Park, Jaehong; Kim, Junghwan
2015-11-01
[Purpose] The purpose of this study was to investigate the relationship between muscle activity and gait function following aquatic trunk exercise in hemiplegic stroke patients. [Subjects and Methods] This study's participants included thirteen hemiplegic patients (ten males and three females). The aquatic therapy consisted of administering concentrative aquatic therapy for four weeks in a therapeutic pool. Gait parameters were measured using a gait analysis system adjusted to each subject's comfortable walking speed. Electromyographic signals were measured for the rectus abdominis, external abdominal oblique, transversus abdominis/internal-abdominal oblique, and erector spine of each patients. [Results] The pre- and post-training performances of the transversus abdominis/internal-abdominal oblique were compared statistically. There was no statistical difference between the patients' pre- and post-training values of maximal voluntary isometric contraction of the rectus abdominis, but the external abdominal oblique values tended to improve. Furthermore, gait factors improved significantly in terms of walking speeds, walking cycles, affected-side stance phases, affected-stride lengths, and stance-phase symmetry indices, respectively. [Conclusion] These results suggest that the trunk exercise during aquatic therapy may in part contribute to clinically relevant improvements in muscle activities and gait parameters.
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Pantall, Annette; Teulier, Caroline; Ulrich, Beverly D.
2012-01-01
Infants with myelomeningocele (MMC) increase step frequency in response to modifications to the treadmill surface. The aim was to investigate how these modifications impacted the electromyographic (EMG) patterns. We analyzed EMG from 19 infants aged 2–10 months, with MMC at the lumbosacral level. We supported infants upright on the treadmill for 12 trials, each 30 seconds long. Modifications included visual flow, unloading, weights, Velcro and lcriction. Surface electrodes recorded EMG from t...
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Rathi, Sangeeta; Taylor, Nicholas F; Soo, Brendan; Green, Rodney A
2018-03-02
To determine whether patients with symptomatic rotator cuff pathology had more glenohumeral joint translation and different patterns of rotator cuff muscle activity compared to controls. Repeated measurements of glenohumeral translation and muscle activity in two positions and six testing conditions in two groups. Twenty participants with a symptomatic and diagnosed rotator cuff tear and 20 age, and gender matched controls were included. Neuromuscular activity was tested by inserting intramuscular electrodes in the rotator cuff muscles. Anterior and posterior glenohumeral translations were measured using real time ultrasound in testing conditions (with and without translation force, with and without isometric internal and external rotation), in two positions (shoulder neutral, 90° of abduction) and two force directions (anterior, posterior). Symptomatic pathology group demonstrated increased passive glenohumeral translation with posterior translation force (protator cuff muscle contraction in the pathology group limited joint translation in a similar manner to the control group, but they did not show the normal direction specific pattern in the neutral posterior position (protator cuff still controlled glenohumeral translation. These results highlight the need to consider joint translation in the assessment and management of patients with rotator cuff injury. Copyright © 2018 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.
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Franettovich Smith, Melinda M; Bonacci, Jason; Mendis, M Dilani; Christie, Craig; Rotstein, Andrew; Hides, Julie A
2017-02-01
To investigate if size and activation of the gluteal muscles is a risk factor for hamstring injuries in elite AFL players. Prospective cohort study. Twenty-six elite male footballers from a professional Australian Football League (AFL) club participated in the study. At the beginning of the season bilateral gluteus medius (GMED) and gluteus maximus (GMAX) muscle volume was measured from magnetic resonance images and electromyographic recordings of the same muscles were obtained during running. History of hamstring injury in the pre-season and incidence of hamstring injury during the season were determined from club medical data. Nine players (35%) incurred a hamstring injury during the season. History of hamstring injury was comparable between those players who incurred a season hamstring injury (2/9 players; 22%) and those who did not (3/17 players; 18%). Higher GMED muscle activity during running was a risk factor for hamstring injury (p=0.03, effect sizes 1.1-1.5). There were no statistically significant differences observed for GMED volume, GMAX volume and GMAX activation (P>0.05). This study identified higher activation of the GMED muscle during running in players who sustained a season hamstring injury. Whilst further research is required to understand the mechanism of altered muscle control, the results of this study contribute to the developing body of evidence that the lumbo-pelvic muscles may be important to consider in hamstring injury prevention and management. Copyright © 2016 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.
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Directory of Open Access Journals (Sweden)
Barbara Pellegrini
Full Text Available Nordic Walking (NW owes much of its popularity to the benefits of greater energy expenditure and upper body engagement than found in conventional walking (W. Muscle activation during NW is still understudied, however. The aim of the present study was to assess differences in muscle activation and physiological responses between NW and W in level and uphill walking conditions. Nine expert Nordic Walkers (mean age 36.8±11.9 years; BMI 24.2±1.8 kg/m2 performed 5-minute treadmill trials of W and NW at 4 km/h on inclines of 0% and 15%. The electromyographic activity of seven upper body and five leg muscles and oxygen consumption (VO2 were recorded and pole force during NW was measured. VO2 during NW was 22.3% higher at 0% and only 6.9% higher at 15% than during W, while upper body muscle activation was 2- to 15-fold higher under both conditions. Lower body muscle activation was similarly increased during NW and W in the uphill condition, whereas the increase in erector spinae muscle activity was lower during NW than W. The lack of a significant increase in pole force during uphill walking may explain the lower extra energy expenditure of NW, indicating less upper body muscle activation to lift the body against gravity. NW seemed to reduce lower back muscle contraction in the uphill condition, suggesting that walking with poles may reduce effort to control trunk oscillations and could contribute to work production during NW. Although the difference in extra energy expenditure between NW and W was smaller in the uphill walking condition, the increased upper body muscle involvement during exercising with NW may confer additional benefit compared to conventional walking also on uphill terrains. Furthermore, people with low back pain may gain benefit from pole use when walking uphill.
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Pellegrini, Barbara; Peyré-Tartaruga, Leonardo Alexandre; Zoppirolli, Chiara; Bortolan, Lorenzo; Bacchi, Elisabetta; Figard-Fabre, Hélène; Schena, Federico
2015-01-01
Nordic Walking (NW) owes much of its popularity to the benefits of greater energy expenditure and upper body engagement than found in conventional walking (W). Muscle activation during NW is still understudied, however. The aim of the present study was to assess differences in muscle activation and physiological responses between NW and W in level and uphill walking conditions. Nine expert Nordic Walkers (mean age 36.8±11.9 years; BMI 24.2±1.8 kg/m2) performed 5-minute treadmill trials of W and NW at 4 km/h on inclines of 0% and 15%. The electromyographic activity of seven upper body and five leg muscles and oxygen consumption (VO2) were recorded and pole force during NW was measured. VO2 during NW was 22.3% higher at 0% and only 6.9% higher at 15% than during W, while upper body muscle activation was 2- to 15-fold higher under both conditions. Lower body muscle activation was similarly increased during NW and W in the uphill condition, whereas the increase in erector spinae muscle activity was lower during NW than W. The lack of a significant increase in pole force during uphill walking may explain the lower extra energy expenditure of NW, indicating less upper body muscle activation to lift the body against gravity. NW seemed to reduce lower back muscle contraction in the uphill condition, suggesting that walking with poles may reduce effort to control trunk oscillations and could contribute to work production during NW. Although the difference in extra energy expenditure between NW and W was smaller in the uphill walking condition, the increased upper body muscle involvement during exercising with NW may confer additional benefit compared to conventional walking also on uphill terrains. Furthermore, people with low back pain may gain benefit from pole use when walking uphill.
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Guilhem, Gaël; Hug, François; Couturier, Antoine; Regnault, Stéphanie; Bournat, Laure; Filliard, Jean-Robert; Dorel, Sylvain
2013-08-01
Localized cooling has been proposed as an effective strategy to limit the deleterious effects of exercise-induced muscle damage on neuromuscular function. However, the literature reports conflicting results. This randomized controlled trial aimed to determine the effects of a new treatment, localized air-pulsed cryotherapy (-30°C), on the recovery time-course of neuromuscular function following a strenuous eccentric exercise. Controlled laboratory study. A total of 24 participants were included in either a control group (CONT) or a cryotherapy group (CRYO). Immediately after 3 sets of 20 maximal isokinetic eccentric contractions of elbow flexors, and then 1, 2, and 3 days after exercise, the CRYO group received a cryotherapy treatment (3 × 4 minutes at -30°C separated by 1 minute). The day before and 1, 2, 3, 7, and 14 days after exercise, several parameters were quantified: maximal isometric torque and its associated maximal electromyographic activity recorded by a 64-channel electrode, delayed-onset muscle soreness (DOMS), biceps brachii transverse relaxation time (T2) measured using magnetic resonance imaging, creatine kinase activity, interleukin-6, and C-reactive protein. Maximal isometric torque decreased similarly for the CONT (-33% ± 4%) and CRYO groups (-31% ± 6%). No intergroup differences were found for DOMS, electromyographic activity, creatine kinase activity, and T2 level averaged across the whole biceps brachii. C-reactive protein significantly increased for CONT (+93% at 72 hours, P cryotherapy delayed the significant increase of T2 and the decrease of electromyographic activity level for CRYO compared with CONT (between day 1 and day 3) in the medio-distal part of the biceps brachii. Although some indicators of muscle damage after severe eccentric exercise were delayed (ie, local formation of edema and decrease of muscle activity) by repeated air-pulsed cryotherapy, we provide evidence that this cooling procedure failed to improve long
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1995-05-01
military literature. The areas of focus were: epidemiology; subjective response; physiology; biochemistry ; muscle activity; biomechanics; biodynamic...which in turn cause a generalised stress response, and other specific outcomes as detailed in the Biochemistry Section. An increase in heart rate...by EMG and kinematic profiles. pp. 247-250. In: Electromyographical Kinesiology . Anderson, P.A., Hobart, D.J., and Danoff, J.V., Editors. Baltimore
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Effect of Strength Training on Rate of Force Development in Older Women
Gurjao, Andre Luiz Demantova; Gobbi, Lilian Teresa Bucken; Carneiro, Nelson Hilario; Goncalves, Raquel; Ferreira de Moura, Rodrigo; Cyrino, Edilson Serpeloni; Altimari, Leandro Ricardo; Gobbi, Sebastiao
2012-01-01
We analyzed the effect of an 8-week strength training (ST) program on the rate of force development (RFD) and electromyographic activity (EMG) in older women. Seventeen women (M age = 63.4 years, SD = 4.9) without previous ST experience were randomly assigned to either a control (n = 7) or training (n = 10) group. A leg-press isometric test was…
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Gymnasts and non-athletes muscle activation and torque production at the ankle joint
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Natália Batista Albuquerque Goulart
2014-07-01
Full Text Available http://dx.doi.org/10.5007/1980-0037.2014v16n5p555 Artistic Gymnasts (AG execute specific movements that require substantial movement control and force production at the ankle joint. This high demand might change the neuromechanical properties of the ankle joint muscles in these athletes compared to non-athlete girls (NAG. The aim of this study was to compare muscle activation and torque production at the ankle joint between AG and NAG. Ten AG (11.70 ± 1.06 years of age and 10 NAG (11.70 ± 1.49 years of age participated in the study. Electromyographic (EMG signals of medial gastrocnemius (MG, soleus (SO and tibialis anterior (TA were obtained simultaneously to the maximal isometric plantarflexion (PFT and dorsiflexion (DFT torques of the dominant limb during a maximal voluntary isometric contraction (MVIC at five different joint angles (20°, 10°, 0°, -10° e -20°. Neuromuscular efficiency was also calculated by the Torque/EMG ratio. AG presented higher PFT (p0.05. In addition, AG showed higher values for plantar flexion neuromuscular efficiency and smaller values of dorsiflexion neuromuscular efficiency compared to the NAG (p<0.01. Higher sports demands of AG determined higher PFT, higher plantar flexor efficiency, smaller DFT but similar activation of MG, SO and TA compared to NAG.
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MS Patiño
2007-02-01
points of the lower limbs in order to acquire kinematic data, and surface electrodes were attached to the tibialis anterior and gastrocnemius medialis muscles in order to record electromyographic muscle activity. RESULTS: Significant differences among the five experimental conditions were observed with regard to spatial-temporal variables, the maximum and minimum angles for the thigh, knee, and ankle, and the amplitudes of the anteroposterior horizontal and vertical GRF components. Generally, the greatest changes occurred with PBWS of 30%. CONCLUSION: It is important to take into consideration the compensations to walking patterns that occur with PBWS, in planning therapeutic interventions. Moreover, to better define the use of suspended weight systems in rehabilitation programs, further investigations should be conducted in order to verify the walking patterns on fixed platforms among populations with movement disorders.
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Cioffi, Iacopo; Farella, Mauro; Festa, Paola; Martina, Roberto; Palla, Sandro; Michelotti, Ambrosina
2015-01-01
To investigate the effects of the application of an acute alteration of the occlusion (ie, interference) on the habitual masseter electromyographic (EMG) activity of females with temporomandibular disorders (TMD)-related muscular pain during wakefulness. Seven female volunteers with masticatory myofascial pain participated in a crossover randomized clinical trial. Gold foils were glued on an occlusal contact area (active occlusal interference, AI) or on the vestibular surface of the same molar (dummy interference, DI) and left for 8 days. The masseter electromyogram was recorded during wakefulness in the natural environment by portable recorders under interference-free, dummy-interference, and active-interference conditions. The number, amplitude, and duration of EMG signal fractions with amplitudes above 10% of the maximum voluntary contraction (activity periods, APs) were computed in all experimental conditions. Muscle pain, headache, and perceived stress were each assessed with a visual analog scale (VAS), and an algometer was used to assess masseter and temporalis pressure pain thresholds. Data were analyzed by means of analysis of variance. The frequency and duration of the recorded APs did not differ significantly between the experimental conditions (P>.05), but a small and significant reduction of the EMG mean amplitude of the APs occurred with AI (P.05). An active occlusal interference in female volunteers with masticatory muscle pain had little influence on the masseter EMG activity pattern during wakefulness and did not affect the pressure tenderness of the masseter and temporalis.
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Coordination of deep hip muscle activity is altered in symptomatic femoroacetabular impingement.
Diamond, Laura E; Van den Hoorn, Wolbert; Bennell, Kim L; Wrigley, Tim V; Hinman, Rana S; O'Donnell, John; Hodges, Paul W
2017-07-01
Diagnosis of femoroacetabular impingement (FAI) is increasing, yet the associated physical impairments remain poorly defined. This morphological hip condition can cause joint pain, stiffness, impaired function, and eventually hip osteoarthritis. This exploratory study compared coordination of deep hip muscles between people with and without symptomatic FAI using analysis of muscle synergies (i.e., patterns of activity of groups of muscles activated in synchrony) during gait. Fifteen individuals (11 males) with symptomatic FAI (clinical examination and imaging) and 14 age- and sex-comparable controls without morphological FAI underwent testing. Intramuscular fine-wire and surface electrodes recorded electromyographic activity of selected deep and superficial hip muscles. A non-negative matrix factorization algorithm extracted three synergies which were compared between groups. Information regarding which muscles were activated together in the FAI group (FAI group synergy vector) was used to reconstruct individual electromyography patterns and compare groups. Variance accounted for (VAF) by three synergies was less for the control (94.8 [1.4]%) than FAI (96.0 [1.0]%) group (p = 0.03). VAF of obturator internus was significantly higher in the FAI group (p = 0.02). VAF of the reconstructed individual electromyography patterns with the FAI or control group vector were significantly higher for the FAI group (p hip muscles in the synergy related to hip joint control during early swing differed between groups. This phase involves movement towards the impingement position, which has relevance for the interpretation of synergy differences and potential clinical importance. © 2016 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 35:1494-1504, 2017. © 2016 Orthopaedic Research Society. Published by Wiley Periodicals, Inc.
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Firing patterns of spontaneously active motor units in spinal cord-injured subjects.
Zijdewind, Inge; Thomas, Christine K
2012-04-01
Involuntary motor unit activity at low rates is common in hand muscles paralysed by spinal cord injury. Our aim was to describe these patterns of motor unit behaviour in relation to motoneurone and motor unit properties. Intramuscular electromyographic activity (EMG), surface EMG and force were recorded for 30 min from thenar muscles of nine men with chronic cervical SCI. Motor units fired for sustained periods (>10 min) at regular (coefficient of variation ≤ 0.15, CV, n =19 units) or irregular intervals (CV>0.15, n =14). Regularly firing units started and stopped firing independently suggesting that intrinsic motoneurone properties were important for recruitment and derecruitment. Recruitment (3.6 Hz, SD 1.2), maximal (10.2 Hz, SD 2.3, range: 7.5-15.4 Hz) and derecruitment frequencies were low (3.3 Hz, SD 1.6), as were firing rate increases after recruitment (~20 intervals in 3 s). Once active, firing often covaried, promoting the idea that units received common inputs.Half of the regularly firing units showed a very slow decline (>40 s) in discharge before derecruitment and had interspike intervals longer than their estimated after hyperpolarisation potential (AHP) duration (estimated by death rate and breakpoint analyses). The other units were derecruited more abruptly and had shorter estimated AHP durations. Overall, regularly firing units had longer estimated AHP durations and were weaker than irregularly firing units, suggesting they were lower threshold units. Sustained firing of units at regular rates may reflect activation of persistent inward currents, visible here in the absence of voluntary drive, whereas irregularly firing units may only respond to synaptic noise.
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Directory of Open Access Journals (Sweden)
O'Sullivan Kieran
2010-07-01
Full Text Available Abstract Background Gluteus medius (GM dysfunction is associated with many musculoskeletal disorders. Rehabilitation exercises aimed at strengthening GM appear to improve lower limb kinematics and reduce pain. However, there is a lack of evidence to identify which exercises best activate GM. In particular, as GM consists of three distinct subdivisions, it is unclear if GM activation is consistent across these subdivisions during exercise. The aim of this study was to determine the activation of the anterior, middle and posterior subdivisions of GM during weight-bearing exercises. Methods A single session, repeated-measures design. The activity of each GM subdivision was measured in 15 pain-free subjects using surface electromyography (sEMG during three weight-bearing exercises; wall squat (WS, pelvic drop (PD and wall press (WP. Muscle activity was expressed relative to maximum voluntary isometric contraction (MVIC. Differences in muscle activation were determined using one-way repeated measures ANOVA with post-hoc Bonferroni analysis. Results The activation of each GM subdivision during the exercises was significantly different (interaction effect; p Discussion Posterior GM displayed higher activation across all three exercises than both anterior and middle GM. The WP produced the highest %MVIC activation for all GM subdivisions, and this was most pronounced for posterior GM. Clinicians may use these results to effectively progress strengthening exercises for GM in the rehabilitation of lower extremity injuries.
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Electromyographic Analysis of the Hip Extension Pattern in Visually Impaired Athletes
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Halski Tomasz
2015-12-01
Full Text Available The objective of the study was to determine the order of muscle recruitment during the active hip joint extension in particular positions in young visually impaired athletes. The average recruitment time (ART of the gluteus maximus (GM and the hamstring muscle group (HMG was assessed by the means of surface electromyography (sEMG. The sequence of muscle recruitment in the female and male group was also taken into consideration. This study followed a prospective, cross – sectional, randomised design, where 76 visually impaired athletes between the age of 18–25 years were enrolled into the research and selected on chosen inclusion and exclusion criteria. Finally, 64 young subjects (32 men and 32 women were included in the study (age: 21.1 ± 1.05 years; body mass: 68.4 ± 12.4 kg; body height: 1.74 ± 0.09 m; BMI: 22.20 ± 2.25 kg/m2. All subjects were analysed for the ART of the GM and HMG during the active hip extension performed in two different positions, as well as resting and functional sEMG activity of each muscle. Between gender differences were comprised and the correlations between the ART of the GM and HMG with their functional sEMG activity during hip extension in both positions were shown. No significant differences between the ART of the GM and HMG were found (p>0.05. Furthermore, there was no significant difference of ART among both tested positions, as well in male as female subjects (p>0.05.
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Manipulation and selective exercises decrease pelvic anteversion and low-back pain: a pilot study.
Barbosa, Alexandre Carvalho; Martins, Fábio Luiz Mendonça; Barbosa, Michelle Cristina Sales Almeida; Dos Santos, Rúbia Tenile
2013-01-01
To study the effect of a protocol involving joint manipulation and specific exercises for pelvic stability to influence proprioceptive input to the spinal tissues and to observe the effects on sensorimotor function. Seven patients with pelvic anteversion and low back pain participated in an eight-week protocol (three sessions per week/nonconsecutive days). At each session, a high-velocity, low-amplitude manipulative thrust was applied to the sacroiliac joint, followed by quadriceps eccentric and hamstring concentric contractions. The perceived pain symptoms, pelvic anteversion as determined by photogrammetry analysis, and the electromyographic activity of the rectus femoris and lateral and medial hamstrings during flexion and extension exercises were assessed before and after treatment. Non-parametric tests were used to compare the groups before and after treatment with α=0.05. Perceived pain symptoms decreased after treatment (p=0.0007). The differences in the pelvis angles (p=0.0130) suggested significant differences between the assessments, and the electromyographic activities of all the muscles during isometric voluntary contraction increased. The eight-week manipulation/exercise protocol was effective for these subjects' needs. Further research should include a greater sample size to confirm the results and to determine the lead factors of pelvic stability.
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An electromyographic study of abdominal muscle activity in children with spastic cerebral palsy
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Saviour Adjenti
2017-10-01
Conclusion: The findings from this study suggest that the RA could be targeted during rehabilitation regimens; however, the force generated by this muscle may not be sufficient for the maintenance of trunk stability without optimal support from the EO and IO muscles.
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LENUS (Irish Health Repository)
Amengual, Julià L
2012-06-08
AbstractBackgroundWe report the case of a chronic stroke patient (62 months after injury) showing total absence of motor activity evoked by transcranial magnetic stimulation (TMS) of spared regions of the left motor cortex, but near-to-complete recovery of motor abilities in the affected hand.Case presentationMultimodal investigations included detailed TMS based motor mapping, motor evoked potentials (MEP), and Cortical Silent period (CSP) as well as functional magnetic resonance imaging (fMRI) of motor activity, MRI based lesion analysis and Diffusion Tensor Imaging (DTI) Tractography of corticospinal tract (CST). Anatomical analysis revealed a left hemisphere subinsular lesion interrupting the descending left CST at the level of the internal capsule. The absence of MEPs after intense TMS pulses to the ipsilesional M1, and the reversible suppression of ongoing electromyographic (EMG) activity (indexed by CSP) demonstrate a weak modulation of subcortical systems by the ipsilesional left frontal cortex, but an inability to induce efficient descending volleys from those cortical locations to right hand and forearm muscles. Functional MRI recordings under grasping and finger tapping patterns involving the affected hand showed slight signs of subcortical recruitment, as compared to the unaffected hand and hemisphere, as well as the expected cortical activations.ConclusionsThe potential sources of motor voluntary activity for the affected hand in absence of MEPs are discussed. We conclude that multimodal analysis may contribute to a more accurate prognosis of stroke patients.
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Amengual Julià L
2012-06-01
Full Text Available Abstract Background We report the case of a chronic stroke patient (62 months after injury showing total absence of motor activity evoked by transcranial magnetic stimulation (TMS of spared regions of the left motor cortex, but near-to-complete recovery of motor abilities in the affected hand. Case presentation Multimodal investigations included detailed TMS based motor mapping, motor evoked potentials (MEP, and Cortical Silent period (CSP as well as functional magnetic resonance imaging (fMRI of motor activity, MRI based lesion analysis and Diffusion Tensor Imaging (DTI Tractography of corticospinal tract (CST. Anatomical analysis revealed a left hemisphere subinsular lesion interrupting the descending left CST at the level of the internal capsule. The absence of MEPs after intense TMS pulses to the ipsilesional M1, and the reversible suppression of ongoing electromyographic (EMG activity (indexed by CSP demonstrate a weak modulation of subcortical systems by the ipsilesional left frontal cortex, but an inability to induce efficient descending volleys from those cortical locations to right hand and forearm muscles. Functional MRI recordings under grasping and finger tapping patterns involving the affected hand showed slight signs of subcortical recruitment, as compared to the unaffected hand and hemisphere, as well as the expected cortical activations. Conclusions The potential sources of motor voluntary activity for the affected hand in absence of MEPs are discussed. We conclude that multimodal analysis may contribute to a more accurate prognosis of stroke patients.
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MODERN TAKE-OFF POWER DIAGNOSTICS
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Milan Čoh
2008-08-01
Full Text Available Take-off power is one of the main biomotor abilities for predicting the results of many sport disciplines. It plays a particularly important role in motor situations when the take-off power is combined with the velocity of movement. The core aim of this study was to establish and analyse the fundamental kinematic, dynamic and electromyographic parameters which generate the results of selected take-off power tests. The experimental procedure involved two elite female triple jumpers. According to Bosco’s protocol the following tests were selected: squat jump, countermovement jump and drop jump – 25 cm. The following were analysed: jump height, take-off time, flight time, take-off velocity, maximum take-off force, angle velocity of the ankle, knee and hip joints, force impulse and duration of the eccentric and concen ric phases of take-off. The 3D-kinematic analysis of jumps was based on a system of nine SMART-e 600 video-cameras (BTS Bioengineering, with a 60 Hz frequency and a 768 x 576 pixel resolution. The kinematic parameters were processed using the BTS SMART Suite programme. Dynamic parameters were established by means of two separate force-plat forms, namely Kistler, Type 9286A. The analysis of the electromyographic activity (EMG of the following muscles: m. erector spinae, m. gluteus maximus, m. rectus femoris, m. vastus medialis, m. vastus lateralis, m. biceps femoris, m. tibialis anterior and m. gastrocnemius medialis was made using a 16-channel electromyograph (BTS Pocket EMG, MYOLAB. The research showed that the jump height (h as a criterion of explosive power was generated by: the velocity of take-off, flight time, force impulse in the concentric phase and optimal knee joint angle. The analysis of the EMG activation in vertical jumps showed the proximaldistal principle of muscle activation. In the first phase of the take-off action, the trunk extensors (m. erector spinae and hip extensors (m. gluteus maximus are activated. In the
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S Ebrahimi Takamjani
2005-05-01
Full Text Available Background: One of the most important concerns in orthopedic medicine is the low back. Considering the importance of muscle function in preventing LBT by controlling too much load and stress applied on the spinal joints and ligaments. Materials and Methods: The aim of this research was to determine the timing and level of activities of lumbopelvic muscles in response to postural perturbations caused by unexpected loading of the upper limbs in standing on three different supporting surfaces (neutral, positive slope, negative slope in 20 healthy females 18 to 30 years old ( = 23.20 SD = 2.55 . The electromyographic signals were recorded from the deltoid, gluteus maximus, internal oblique abdominis and lumbar paraspinal muscles of the dominant side of the body to evaluate the onset time, end time, level of muscle activity (RMS and duration of different muscles in one task and one muscle in different tasks. Results: The results showed that the agonists (posterior muscles activated at first to compensate the flexor torque caused by loading and then the antagonists (anterior muscles switched-on to compensate the reaction forces caused by agonist activities. With regards to continuous activity of internal oblique and its attachments via thoracalumbar fascia to the transverse processes of the lumbar vertebrae, it can be considered as one of the major stabilizer muscles of the trunk . Conclusion: Finally the results indicated that supporting surface type didn’t have any effect on timing and scaling of muscle activities in different tasks suggesting that probably spinal and trunk priprioceptors are just responsible for triggering postural responses and they don’t have any role in determining timing and scaling.
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Salonen, M A; Raustia, A M; Huggare, J A
1994-10-01
A clinical stomatognathic, cephalometric and electromyographic (EMG) study was performed in relation to 14 subjects (10 women, 4 men), each with an edentulous maxilla and residual mandibular dentition before and six months after treatment with complete upper and partial lower dentures. The mean age of the subjects was 54.4 years (range 43-64 years). The mean period of edentulousness and age of dentures were 22.5 years (range 15-33 years) and 14.1 (range 1.5-30 years), respectively. Natural head position was recorded (using a fluid-level method) and measured from cephalograms. EMG activity was measured in relation to masseter and temporal muscles. A decrease in clinical dysfunction index was noted in 12 of 14 subjects (86%). There was no change in cervical inclination, but a slight extension of the head was noted after treatment. Rapid recovery of the masticatory muscles was reflected in increased EMG activity, especially when biting in the maximal intercuspal position. In cases of edentulous maxilla and residual mandibular anterior dentition, treatment with a complete upper and lower partial denture had a favorable effect on craniomandibular disorders and masticatory-muscle function.
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Age-related differences in twitch properties and muscle activation of the first dorsal interosseous.
Miller, Jonathan D; Herda, Trent J; Trevino, Michael A; Sterczala, Adam J; Ciccone, Anthony B; Nicoll, Justin X
2017-06-01
To examine twitch force potentiation and twitch contraction duration, as well as electromyographic amplitude (EMG RMS ) and motor unit mean firing rates (MFR) at targeted forces between young and old individuals in the first dorsal interosseous (FDI). Ultrasonography was used to assess muscle quality. Twenty-two young (YG) (age=22.6±2.7years) and 14 older (OD) (age=62.1±4.7years) individuals completed conditioning contractions at 10% and 50% maximal voluntary contraction, (MVC) during which EMG RMS and MFRs were assessed. Evoked twitches preceded and followed the conditioning contractions. Ultrasound images were taken to quantify muscle quality (cross-sectional area [CSA] and echo intensity [EI]). No differences were found between young and old for CSA, pre-conditioning contraction twitch force, or MFRs (P>0.05). However, OD individuals exhibited greater EI and contraction duration (PMFRs. Ultrasonography suggested age-related changes in muscle structure contributed to altered contractile properties in the OD. Greater muscle activation requirements can have negative implications on fatigue resistance at low to moderate intensities in older individuals. Copyright © 2017 International Federation of Clinical Neurophysiology. Published by Elsevier B.V. All rights reserved.
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Gabriel Ribeiro
2007-02-01
Full Text Available O objetivo principal deste estudo foi quantificar a atividade muscular durante a realização de agachamento unipodal com variações na técnica. Oito voluntários saudáveis realizaram agachamentos associados a cinco tipos de posição do pé: posição neutra, sobre cunha com 10º de declive, sobre cunha com 10º de aclive, sobre cunha com 10º de inclinação medial e sobre cunha com 10º de inclinação lateral. Foram avaliados os dados eletromiográficos dos músculos vasto medial oblíquo, vasto lateral, reto femoral, bíceps femoral, gastrocnêmio lateral e tibial anterior, utilizando a ANOVA fator único. O valor eletromiográfico integrado de todos os músculos não foi estatisticamente diferente nos cinco tipos de posição do pé. Os resultados deste estudo sugerem que diferentes tipos de posicionamento do pé durante o agachamento unipodal não provocam alterações no padrão de recrutamento muscular.El objetivo principal de este estudio ha sido cuantificar la actividad muscular durante la realización de agachamiento unipodal con variaciones en la técnica. Ocho voluntarios saludables realizaron agachamientos asociados a cinco tipos de posición del pie: posición neutra, sobre cuña con 10º de declive, sobre cuña con 10º de elevación, sobre cuña con 10º de inclinación media y sobre cuña con 10º de inclinación lateral. Fueron evaluados los datos electromiográficos de los músculos vasto medial oblicuo, vasto lateral, recto femoral, bíceps femoral, gastrocnemio lateral y tibial anterior, utilizando ANOVA factor único. El valor electromiográfico integrado de todos los músculos no fue estadísticamente diferente en los cinco tipos de posición del pie. Los resultados de este estudio sugieren que diferentes tipos de posicionamiento del pie durante el proceso de agachamiento unipodal no provocan alteraciones en el padrón de reclutamiento muscular.The specific aim of this study was to quantify muscle activity while
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Neck movement and muscle activity characteristics in female office workers with neck pain.
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.
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Human spinal locomotor control is based on flexibly organized burst generators.
Danner, Simon M; Hofstoetter, Ursula S; Freundl, Brigitta; Binder, Heinrich; Mayr, Winfried; Rattay, Frank; Minassian, Karen
2015-03-01
Constant drive provided to the human lumbar spinal cord by epidural electrical stimulation can cause local neural circuits to generate rhythmic motor outputs to lower limb muscles in people paralysed by spinal cord injury. Epidural spinal cord stimulation thus allows the study of spinal rhythm and pattern generating circuits without their configuration by volitional motor tasks or task-specific peripheral feedback. To reveal spinal locomotor control principles, we studied the repertoire of rhythmic patterns that can be generated by the functionally isolated human lumbar spinal cord, detected as electromyographic activity from the legs, and investigated basic temporal components shared across these patterns. Ten subjects with chronic, motor-complete spinal cord injury were studied. Surface electromyographic responses to lumbar spinal cord stimulation were collected from quadriceps, hamstrings, tibialis anterior, and triceps surae in the supine position. From these data, 10-s segments of rhythmic activity present in the four muscle groups of one limb were extracted. Such samples were found in seven subjects. Physiologically adequate cycle durations and relative extension- and flexion-phase durations similar to those needed for locomotion were generated. The multi-muscle activation patterns exhibited a variety of coactivation, mixed-synergy and locomotor-like configurations. Statistical decomposition of the electromyographic data across subjects, muscles and samples of rhythmic patterns identified three common temporal components, i.e. basic or shared activation patterns. Two of these basic patterns controlled muscles to contract either synchronously or alternatingly during extension- and flexion-like phases. The third basic pattern contributed to the observed muscle activities independently from these extensor- and flexor-related basic patterns. Each bifunctional muscle group was able to express both extensor- and flexor-patterns, with variable ratios across the
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Oliver, Gretchen D
2014-03-01
As the biomechanical literature concerning softball pitching is evolving, there are no data to support the mechanics of softball position players. Pitching literature supports the whole kinetic chain approach including the lower extremity in proper throwing mechanics. The purpose of this project was to examine the gluteal muscle group activation patterns and their relationship with shoulder and elbow kinematics and kinetics during the overhead throwing motion of softball position players. Eighteen Division I National Collegiate Athletic Association softball players (19.2 ± 1.0 years; 68.9 ± 8.7 kg; 168.6 ± 6.6 cm) who were listed on the active playing roster volunteered. Electromyographic, kinematic, and kinetic data were collected while players caught a simulated hit or pitched ball and perform their position throw. Pearson correlation revealed a significant negative correlation between non-throwing gluteus maximus during the phase of maximum external rotation to maximum internal rotation (MIR) and elbow moments at ball release (r = -0.52). While at ball release, trunk flexion and rotation both had a positive relationship with shoulder moments at MIR (r = 0.69, r = 0.82, respectively) suggesting that the kinematic actions of the pelvis and trunk are strongly related to the actions of the shoulder during throwing.
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Modulation of the Muscle Activity During Sleep in Cervical Dystonia.
Antelmi, Elena; Ferri, Raffaele; Provini, Federica; Scaglione, Cesa M L; Mignani, Francesco; Rundo, Francesco; Vandi, Stefano; Fabbri, Margherita; Pizza, Fabio; Plazzi, Giuseppe; Martinelli, Paolo; Liguori, Rocco
2017-07-01
Impaired sleep has been reported as an important nonmotor feature in dystonia, but so far, self-reported complaints have never been compared with nocturnal video-polysomnographic (PSG) recording, which is the gold standard to assess sleep-related disorders. Twenty patients with idiopathic isolated cervical dystonia and 22 healthy controls (HC) underwent extensive clinical investigations, neurological examination, and questionnaire screening for excessive daytime sleepiness and sleep-related disorders. A full-night video PSG was performed in both patients and HC. An ad hoc montage, adding electromyographic leads over the muscle affected with dystonia, was used. When compared to controls, patients showed significantly increased pathological values on the scale assessing self-reported complaints of impaired nocturnal sleep. Higher scores of impaired nocturnal sleep did not correlate with any clinical descriptors but for a weak correlation with higher scores on the scale for depression. On video-PSG, patients had significantly affected sleep architecture (with decreased sleep efficiency and increased sleep latency). Activity over cervical muscles disappears during all the sleep stages, reaching significantly decreased values when compared to controls both in nonrapid eye movements and rapid eye movements sleep. Patients with cervical dystonia reported poor sleep quality and showed impaired sleep architecture. These features however cannot be related to the persistence of muscle activity over the cervical muscles, which disappears in all the sleep stages, reaching significantly decreased values when compared to HC. © Sleep Research Society 2017. Published by Oxford University Press on behalf of the Sleep Research Society. All rights reserved. For permissions, please e-mail journals.permissions@oup.com.
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International Nuclear Information System (INIS)
Touboul, F.; Ben Jdidia, M.; Acker, D.
1989-01-01
Design rules for class 1 piping components are based on stress indices (B, C, K) and flexibility factors (k). For elbows, adjacent straight parts and internal pressure inhibit ovalization of the cross-section, so reducing the sub-mentioned indices. Published theoretical works and experimental results allow for improvement of coded values. End effect may be represented by a suitable function of the elbow angle. The favourable effect of pressure on C 2 , for fatigue damage evaluation, can be taken into account
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Rubio-Arias, Jacobo Ángel; Ramos-Campo, Domingo Jesús; Peña Amaro, José; Esteban, Paula; Mendizábal, Susana; Jiménez, José Fernando
2017-11-01
The purpose of this study was to analyse gender differences in neuromuscular behaviour of the gastrocnemius and vastus lateralis during the take-off phase of a countermovement jump (CMJ), using direct measures (ground reaction forces, muscle activity and dynamic ultrasound). Sixty-four young adults (aged 18-25 years) participated voluntarily in this study, 35 men and 29 women. The firing of the trigger allowed obtainment of data collection vertical ground reaction forces (GRF), surface electromyography activity (sEMG) and dynamic ultrasound gastrocnemius of both legs. Statistically significant gender differences were observed in the jump performance, which appear to be based on differences in muscle architecture and the electrical activation of the gastrocnemius muscles and vastus lateralis. So while men developed greater peak power, velocity take-offs and jump heights, jump kinetics compared to women, women also required a higher electrical activity to develop lower power values. Additionally, the men had higher values pennation angles and muscle thickness than women. Men show higher performance of the jump test than women, due to significant statistical differences in the values of muscle architecture (pennation angle and thickness muscle), lower Neural Efficiency Index and a higher amount of sEMG activity per second during the take-off phase of a CMJ. © 2016 Scandinavian Society of Clinical Physiology and Nuclear Medicine. Published by John Wiley & Sons Ltd.
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Jakobsen, Markus Due; Sundstrup, Emil; Andersen, Christoffer H; Bandholm, Thomas; Thorborg, Kristian; Zebis, Mette K; Andersen, Lars L
2012-12-01
While elastic resistance training, targeting the upper body is effective for strength training, the effect of elastic resistance training on lower body muscle activity remains questionable. The purpose of this study was to evaluate the EMG-angle relationship of the quadriceps muscle during 10-RM knee-extensions performed with elastic tubing and an isotonic strength training machine. 7 women and 9 men aged 28-67 years (mean age 44 and 41 years, respectively) participated. Electromyographic (EMG) activity was recorded in 10 muscles during the concentric and eccentric contraction phase of a knee extension exercise performed with elastic tubing and in training machine and normalized to maximal voluntary isometric contraction (MVC) EMG (nEMG). Knee joint angle was measured during the exercises using electronic inclinometers (range of motion 0-90°). When comparing the machine and elastic resistance exercises there were no significant differences in peak EMG of the rectus femoris (RF), vastus lateralis (VL), vastus medialis (VM) during the concentric contraction phase. However, during the eccentric phase, peak EMG was significantly higher (ptubing (5.7±0.6) compared with knee extensions performed in training machine (5.9±0.5). Knee extensions performed with elastic tubing induces similar high (>70% nEMG) quadriceps muscle activity during the concentric contraction phase, but slightly lower during the eccentric contraction phase, as knee extensions performed using an isotonic training machine. During the concentric contraction phase the two different conditions displayed reciprocal EMG-angle patterns during the range of motion. 5.
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Embodiment and the origin of interval timing: kinematic and electromyographic data.
Addyman, Caspar; Rocha, Sinead; Fautrelle, Lilian; French, Robert M; Thomas, Elizabeth; Mareschal, Denis
2017-03-01
Recent evidence suggests that interval timing (the judgment of durations lasting from approximately 500 ms. to a few minutes) is closely coupled to the action control system. We used surface electromyography (EMG) and motion capture technology to explore the emergence of this coupling in 4-, 6-, and 8-month-olds. We engaged infants in an active and socially relevant arm-raising task with seven cycles and response period. In one condition, cycles were slow (every 4 s); in another, they were fast (every 2 s). In the slow condition, we found evidence of time-locked sub-threshold EMG activity even in the absence of any observed overt motor responses at all three ages. This study shows that EMGs can be a more sensitive measure of interval timing in early development than overt behavior.
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The Design of EMG Measurement System for Arm Strength Training Machine
Directory of Open Access Journals (Sweden)
Tze-Yee Ho
2015-01-01
Full Text Available The setup of interactive communication between arm strength training machine and the people will make exercise and rehabilitation therapy become more friendly. The employment of electromyographic not only can help physical therapy but also can achieve more effective rehabilitation. Both of the system hardware and software of the arm strength training machine with EMG system are well designed and described. The fundamental design of electromyographic measurement system based on a microcontroller is analyzed and discussed. The software programming is developed in MPLAB integrated development environment from the Microchip Technology Inc. and the friendly user interface is created as well. Finally, an arm strength training machine with electromyographic control system is realized and demonstrated. The experimental results show the feasibility and fidelity of the complete designed system.
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Macedo, Christiane S. G.; Alonso, Carolina S.; Liporaci, Rogério F.; Vieira, Fernando; Guirro, Rinaldo R. J.
2014-01-01
BACKGROUND: Cryotherapy has been associated with a significant decrease in nerve conduction velocity and muscle contraction with possible effects on exercise and physical training. OBJECTIVES: To quantify the electromyographic response of the lateral gastrocnemius, tibialis anterior, fibularis longus, rectus femoris and gluteus medius to ankle inversion following cold water immersion. METHOD: The peak values of the root mean square (RMS) were obtained from 35 healthy and active univ...
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Kawazoe, Y; Kobayashi, M; Tasaka, T; Tamamoto, M
1982-01-01
The slope of the curve relating integrated electromyographic activity of masseter muscle to biting force, the latency of the jaw-jerk reflex, and masticatory performance wee estimated in patients with Duchenne type of progressive muscular dystrophy before and during therapeutic exercise of the somatogenc system. The slope and latency were slightly decreased, and masticatory performance was increased during exercise. These results suggest that therapeutic exercise of the stomatognathic system ...
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Hsu, Chao-Jung; Kim, Janis; Tang, Rongnian; Roth, Elliot J; Rymer, William Z; Wu, Ming
2017-10-01
To determine whether applying a mediolateral corrective force to the pelvis during treadmill walking would enhance muscle activity of the paretic leg and improve gait symmetry in individuals with post-stroke hemiparesis. Fifteen subjects with post-stroke hemiparesis participated in this study. A customized cable-driven robotic system based over a treadmill generated a mediolateral corrective force to the pelvis toward the paretic side during early stance phase. Three different amounts of corrective force were applied. Electromyographic (EMG) activity of the paretic leg, spatiotemporal gait parameters and pelvis lateral displacement were collected. Significant increases in integrated EMG of hip abductor, medial hamstrings, soleus, rectus femoris, vastus medialis and tibialis anterior were observed when pelvic corrective force was applied, with pelvic corrective force at 9% of body weight inducing greater muscle activity than 3% or 6% of body weight. Pelvis lateral displacement was more symmetric with pelvic corrective force at 9% of body weight. Applying a mediolateral pelvic corrective force toward the paretic side may enhance muscle activity of the paretic leg and improve pelvis displacement symmetry in individuals post-stroke. Forceful weight shift to the paretic side could potentially force additional use of the paretic leg and improve the walking pattern. Copyright © 2017 International Federation of Clinical Neurophysiology. Published by Elsevier B.V. All rights reserved.
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Kahlaee, Amir H; Ghamkhar, Leila; Arab, Amir M
2017-02-01
The purpose of this study was to compare the effect of abdominal hollowing (AH) and abdominal bracing (AB) maneuvers on the activity pattern of lumbopelvic muscles during prone hip extension (PHE) in participants with or without nonspecific chronic low back pain (CLBP). Twenty women with or without CLBP participated in this cross-sectional observational study. The electromyographic activity (amplitude and onset time) of the contralateral erector spinae (CES), ipsilateral erector spinae (IES), gluteus maximus, and biceps femoris muscles was measured during PHE with and without abdominal maneuvers. A 3-way mixed model analysis of variance and post hoc tests were used for statistical analysis. Between-group comparisons showed that the CES onset delay during PHE alone was greater (P = .03) and the activity level of IES, CES, and biceps femoris in all maneuvers (P .05). Performance of the AH maneuver decreased the erector spinae muscle AMP in both groups, and neither maneuver altered the onset delay of any of the muscles in either group. The low back pain group showed higher levels of activity in all muscles (not statistically significant in gluteus maximus during all maneuvers). The groups were similar according to the onset delay of any of the muscles during either maneuver. Copyright © 2016. Published by Elsevier Inc.
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[Electromyographic study of mastication muscles in patients with TMG osteoarthrosis].
Silin, A V; Satygo, E A; Semeleva, E I; Lila, A M
2014-01-01
The aim of this study was to determine the functional activity of cranio-mandibular system in patients with TMG osteoarthrosis. The study included 20 patients with TMG osteoarthrosis and 20 healthy subjects representing control group. The EMG examination was performed according to standard protocol developed in Milan University. The symmetry index values in the group with TMG osteoarthrosis were lower than in the control group (78.76±12.29%), while Torque values were higher (8.53±14.62%). EMG standardized indexes allowed differentiating TMG osteoarthrosis.
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Directory of Open Access Journals (Sweden)
Luciana C. C. B. Silva
2013-06-01
Full Text Available BACKGROUND: The handling of materials, which occurs in the industrial sector, is associated with lesions on the lumbar spine and in the upper limbs. Inserting handles in industrial boxes is a way to reduce work-related risks. Although the position and angle of the handles are significant factors in comfort and safety during handling, these factors have rarely been studied objectively. OBJECTIVE: To compare the handling of a commercial box and prototypes with handles and to evaluate the effects on upper limb posture, muscle electrical activity, and perceived acceptability using different grips while handling materials from different heights. METHOD: Thirty-seven healthy volunteers evaluated the handles of prototypes that allowed for changes in position (top and bottom and angle (0°, 15°, and 30°. Wrist, elbow, and shoulder movements were evaluated using electrogoniometry and inclinometry. The muscle electrical activity in the wrist extensors, biceps brachii, and the upper portion of the trapezius was measured using a portable electromyographer. The recorded data on muscle movements and electrical activity were synchronized. Subjective evaluations of acceptability were evaluated using a visual analog scale. RESULTS AND CONCLUSIONS: The prototypes with handles at a 30° angle produced the highest acceptability ratings, more neutral wrist positions, lower levels of electromyographic activity for the upper trapezius, and lower elevation angles for the arms. The different measurement methods were complementary in evaluating the upper limbs during handling.
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Joshi, Mithun; Thigpen, Charles A.; Bunn, Kevin; Karas, Spero G.; Padua, Darin A.
2011-01-01
Context: Glenohumeral external rotation (GH ER) muscle fatigue might contribute to shoulder injuries in overhead athletes. Few researchers have examined the effect of such fatigue on scapular kinematics and muscle activation during a functional movement pattern. Objective: To examine the effects of GH ER muscle fatigue on upper trapezius, lower trapezius, serratus anterior, and infraspinatus muscle activation and to examine scapular kinematics during a diagonal movement task in overhead athletes. Setting: Human performance research laboratory. Design: Descriptive laboratory study. Patients or Other Participants: Our study included 25 overhead athletes (15 men, 10 women; age = 20 ± 2 years, height = 180 ± 11 cm, mass = 80 ± 11 kg) without a history of shoulder pain on the dominant side. Interventions: We tested the healthy, dominant shoulder through a diagonal movement task before and after a fatiguing exercise involving low-resistance, high-repetition, prone GH ER from 0° to 75° with the shoulder in 90° of abduction. Main Outcome Measure(s): Surface electromyography was used to measure muscle activity for the upper trapezius, lower trapezius, serratus anterior, and infraspinatus. An electromyographic motion analysis system was used to assess 3-dimensional scapular kinematics. Repeated-measures analyses of variance (phase × condition) were used to test for differences. Results: We found a decrease in ascending-phase and descending-phase lower trapezius activity (F1,25 = 5.098, P = .03) and an increase in descending-phase infraspinatus activity (F1,25 = 5.534, P = .03) after the fatigue protocol. We also found an increase in scapular upward rotation (F1,24 = 3.7, P = .04) postfatigue. Conclusions: The GH ER muscle fatigue protocol used in this study caused decreased lower trapezius and increased infraspinatus activation concurrent with increased scapular upward rotation range of motion during the functional task. This highlights the interdependence of scapular
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Sarasola-Sanz, Andrea; Irastorza-Landa, Nerea; Lopez-Larraz, Eduardo; Bibian, Carlos; Helmhold, Florian; Broetz, Doris; Birbaumer, Niels; Ramos-Murguialday, Ander
2017-07-01
Including supplementary information from the brain or other body parts in the control of brain-machine interfaces (BMIs) has been recently proposed and investigated. Such enriched interfaces are referred to as hybrid BMIs (hBMIs) and have been proven to be more robust and accurate than regular BMIs for assistive and rehabilitative applications. Electromyographic (EMG) activity is one of the most widely utilized biosignals in hBMIs, as it provides a quite direct measurement of the motion intention of the user. Whereas most of the existing non-invasive EEG-EMG-hBMIs have only been subjected to offline testings or are limited to one degree of freedom (DoF), we present an EEG-EMG-hBMI that allows the simultaneous control of 7-DoFs of the upper limb with a robotic exoskeleton. Moreover, it establishes a biologically-inspired hierarchical control flow, requiring the active participation of central and peripheral structures of the nervous system. Contingent visual and proprioceptive feedback about the user's EEG and EMG activity is provided in the form of velocity modulation during functional task training. We believe that training with this closed-loop system may facilitate functional neuroplastic processes and eventually elicit a joint brain and muscle motor rehabilitation. Its usability is validated during a real-time operation session in a healthy participant and a chronic stroke patient, showing encouraging results for its application to a clinical rehabilitation scenario.
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Directory of Open Access Journals (Sweden)
Takahito Suzuki
Full Text Available Behavioral evidence has suggested that a small number of muscle synergies may be responsible for activating a variety of muscles. Nevertheless, such dimensionality reduction may also be explained using the perspective of alternative hypotheses, such as predictions based on linear combinations of joint torques multiplied by corresponding coefficients. To compare the explanatory capacity of these hypotheses for describing muscle activation, we enrolled 12 male volunteers who performed isometric plantar flexor contractions at 10-100% of maximum effort. During each plantar flexor contraction, the knee extensor muscles were isometrically contracted at 0%, 50%, or 100% of maximum effort. Electromyographic activity was recorded from the vastus lateralis, medial gastrocnemius (MG, lateral gastrocnemius (LG, and soleus muscles and quantified using the average rectified value (ARV. At lower plantar flexion torque, regression analysis identified a clear linear relationship between the MG and soleus ARVs and between the MG and LG ARVs, suggesting the presence of muscle synergy (r2 > 0.65. The contraction of the knee extensor muscles induced a significant change in the slope of this relationship for both pairs of muscles (MG × soleus, P = 0.002; MG × LG, P = 0.006. Similarly, the slope of the linear relationship between the plantar flexion torque and the ARV of the MG or soleus changed significantly with knee extensor contraction (P = 0.031 and P = 0.041, respectively. These results suggest that muscle synergies characterized by non-mechanical constraints are selectively recruited according to whether contraction of the knee extensor muscles is performed simultaneously, which is relatively consistent with the muscle synergy hypothesis.
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Sestito, Mariateresa; Raballo, Andrea; Umiltà, Maria Alessandra; Leuci, Emanuela; Tonna, Matteo; Fortunati, Renata; De Paola, Giancarlo; Amore, Mario; Maggini, Carlo; Gallese, Vittorio
2015-01-01
Self-disorders (SDs) have been described as a core schizophrenia spectrum vulnerability phenotype, both in classic and contemporary psychopathological literature. However, such a core phenotype has not yet been investigated adopting a trans-domain approach that combines the phenomenological and the neurophysiological levels of analysis. The aim of this study is to investigate the relation between SDs and subtle, schizophrenia-specific impairments of emotional resonance that are supposed to reflect abnormalities in the mirror neurons mechanism. Specifically, we tested whether electromyographic response to emotional stimuli (i.e. a proxy for subtle changes in facial mimicry and related motor resonance mechanisms) would predict the occurrence of anomalous subjective experiences (i.e. SDs). Eighteen schizophrenia spectrum (SzSp) patients underwent a comprehensive psychopathological examination and were contextually tested with a multimodal paradigm, recording facial electromyographic activity of muscles in response to positive and negative emotional stimuli. Experiential anomalies were explored with the Bonn Scale for the Assessment of Basic Symptoms (BSABS) and then condensed into rational subscales mapping SzSp anomalous self-experiences. SzSp patients showed an imbalance in emotional motor resonance with a selective bias toward negative stimuli, as well as a multisensory integration impairment. Multiple regression analysis showed that electromyographic facial reactions in response to negative stimuli presented in auditory modality specifically and strongly correlated with SD subscore. The study confirms the potential of SDs as target phenotype for neurobiological research and encourages research into disturbed motor/emotional resonance as possible body-level correlate of disturbed subjective experiences in SzSp.
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Directory of Open Access Journals (Sweden)
Soma Mukherjee
2013-01-01
Full Text Available Ludwig′s angina is an infectious process involving submandibular, sublingual, and submental spaces that can rapidly progress to hemodynamic instability and airway obstruction. A 38-year-old unbooked multipara of low socioeconomic status with a poor oral and dental hygiene presented with bilateral submandibular cellulitis and intrauterine fetal demise. She delivered vaginally, and subsequently drainage was done for cellulitis. The report highlights the importance of dental hygiene during pregnancy, lest life-threatening complications like Ludwig′s angina occur, complicating the course of pregnancy.
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The effect of an acute bout of rubber tube running constraint on kinematics and muscle activity.
Haudum, Anita; Birklbauer, Jürgen; Müller, Erich
2012-01-01
We examined the effect of an acute bout of treadmill running with rubber tube (RT) and without rubber tube (NT) elastic constraints on electromyographic (EMG), 3D kinematics variability, and blood lactate concentration (LA). In the RT test, the constraints were attached to the hips and ankles. The selected variables were compared between 30 min of NT running and 30 minutes of RT running in 13 healthy recreationally trained male runners who had no prior exposure to RT. Statistical analysis revealed significantly higher EMG variability (p running influences muscle recruitment and variability, but has only a minor influence on kinematics. Changes in LA were significant, although relatively small. The observed adaptations in EMG and kinematics suggest that the RTs provide a possibility to create within movement variability in various sports, and thus, variable training conditions may foster strategies to increase the ability to flexibly adapt to different and new situations. Key pointsAdaptation to training device occurred quite rapidly.Changes in muscle activity were more pronounced than kinematic changes due to the training device.Training device may be used to increase within-movement variability.Participants may learn to flexibly adapt to variable constraints.
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Directory of Open Access Journals (Sweden)
Stefano Toxiri
2018-05-01
Full Text Available Active exoskeletons are potentially more effective and versatile than passive ones, but designing them poses a number of additional challenges. An important open challenge in the field is associated to the assistive strategy, by which the actuation forces are modulated to the user’s needs during the physical activity. This paper addresses this challenge on an active exoskeleton prototype aimed at reducing compressive low-back loads, associated to risk of musculoskeletal injury during manual material handling (i.e., repeatedly lifting objects. An analysis of the biomechanics of the physical task reveals two key factors that determine low-back loads. For each factor, a suitable control strategy for the exoskeleton is implemented. The first strategy is based on user posture and modulates the assistance to support the wearer’s own upper body. The second one adapts to the mass of the lifted object and is a practical implementation of electromyographic control. A third strategy is devised as a generalized combination of the first two. With these strategies, the proposed exoskeleton can quickly adjust to different task conditions (which makes it versatile compared to using multiple, task-specific, devices as well as to individual preference (which promotes user acceptance. Additionally, the presented implementation is potentially applicable to more powerful exoskeletons, capable of generating larger forces. The different strategies are implemented on the exoskeleton and tested on 11 participants in an experiment reproducing the lifting task. The resulting data highlights that the strategies modulate the assistance as intended by design, i.e., they effectively adjust the commanded assistive torque during operation based on user posture and external mass. The experiment also provides evidence of significant reduction in muscular activity at the lumbar spine (around 30% associated to using the exoskeleton. The reduction is well in line with previous
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Directory of Open Access Journals (Sweden)
Adriana Moré Pacheco
2005-12-01
ésion y saludables. Se probaron tres grupos, uno de atletas normales (grupo 1, uno de atletas con la reciente historia de esguince del tobillo (grupo 2 y el otro de ningún atleta con la reciente historia de esguince del tobillo (grupo 3. Para cada sujeto de los tres grupos, se probaron ambos tobillos. Los atletas que sufrieron el esguince del tobillo (se agruparon en 2 y 3 estos no presentaron los síntomas de la lesión durante los últimos dos meses antes de la prueba. Se usó una plataforma capable di producir una inversión súbita lateral de 20° del tobillo en el plan delantero simulando, así, un evento de esguince del tobillo. Se pusieron electrodos de eletromiografia de la superficie en la piel en la región anexa de los músculos. Se obtuvieron registros eletromiográficos de la respuesta de las fibras de los músculos y se compararon, así, entre los grupos. Para el de grupo 1, el promedio de las veces de eletromiográfica de la respuesta fue de 71 ms por la pierna correcta y 69 ms para la pierna izquierda. Para el de grupo 2, el promedio de las veces de eletromiográfica de la respuesta fue de 72 malo por el tobillo sin la lesión y 74 malo para el tobillo con la lesión. Para el de grupo 3, el promedio de las veces de eletromiográfica de la respuesta fue de 72 malo por el tobillo sin la lesión y 73 malo para el tobillo con la lesión. Los resultados indicaron que no había diferencia estatisticamente significante entre las piernas sanas y lo hallado en el grupo 1 y entre los tobillos sin la lesión y con la lesión de los grupos 2 y 3 para las fibras de los músculos. Los descubrimientos del estudio presente sugieren que la eletromiográfía de la respuesta de las fibras de los músculos, durante el desplazamiento angular aguso del tobillo, no es influenciada por el esguince del tobillo.The purpose of this study was to examine the time for the electromyographic response of the fibular muscles in the sudden foot inversion in sprained and healthy ankles
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Estimation of tensile force in the hamstring muscles during overground sprinting.
Ono, T; Higashihara, A; Shinohara, J; Hirose, N; Fukubayashi, T
2015-02-01
The purpose of this study was to identify the period of the gait cycle during which the hamstring muscles were likely injured by estimating the magnitude of tensile force in each muscle during overground sprinting. We conducted three-dimensional motion analysis of 12 male athletes performing overground sprinting at their maximal speed and calculated the hamstring muscle-tendon length and joint angles of the right limb throughout a gait cycle during which the ground reaction force was measured. Electromyographic activity during sprinting was recorded for the biceps femoris long head, semitendinosus, and semimembranosus muscles of ipsilateral limb. We estimated the magnitude of tensile force in each muscle by using the length change occurred in the musculotendon and normalized electromyographic activity value. The study found a quick increase of estimated tensile force in the biceps femoris long head during the early stance phase of the gait cycle during which the increased hip flexion angle and ground reaction force occurred at the same time. This study provides quantitative data of tensile force in the hamstring muscles suggesting that the biceps femoris long head muscle is susceptible to a strain injury during the early stance phase of the sprinting gait cycle. © Georg Thieme Verlag KG Stuttgart · New York.
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Effects of intermittent theta burst stimulation on spasticity after stroke.
Kim, Dae Hyun; Shin, Ji Cheol; Jung, Seungsoo; Jung, Tae-Min; Kim, Deog Young
2015-07-08
Spasticity is a common cause of long-term disability in poststroke hemiplegic patients. We investigated whether intermittent theta burst stimulation (iTBS) could reduce upper-limb spasticity after a stroke. Fifteen hemiplegic stroke patients were recruited for a double-blind sham-controlled cross-over design study. A single session of iTBS or sham stimulation was delivered on the motor hotspot of the affected flexor carpi radialis muscle in a random and counterbalanced order with a 1-week interval. Modified Ashworth scale (MAS), modified Tardieu scale (MTS), H-wave/M-wave amplitude ratio, peak torque (PT), peak torque angle (PTA), work of affected wrist flexor, and rectified integrated electromyographic activity of the flexor carpi radialis muscle were measured before, immediately after, 30 min after, and 1 week after iTBS or sham stimulation. Repeated-measures analysis of variance showed a significant interaction between time and intervention for the MAS, MTS, PT, PTA, and rectified integrated electromyographic activity (PiTBS compared with sham stimulation. However, the H-wave/M-wave amplitude ratio and work were not affected. MAS and MTS significantly improved for at least 30 min after iTBS, but the other parameters only improved immediately after iTBS (PiTBS on the affected hemisphere may help to reduce poststroke spasticity transiently.
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Vega-Céliz, Jorge; Amilibia-Cabeza, Emili; Prades-Martí, José; Miró-Castillo, Nuria; Pérez-Grau, Marta; Pintanel Rius, Teresa; Roca-Ribas Serdà, Francesc
2015-01-01
Facial nerve monitoring is fundamental in the preservation of the facial nerve in vestibular schwannoma surgery. Our objective was to analyse the usefulness of facial nerve monitoring under partial neuromuscular blockade. This was a retrospective analysis of 69 patients operated in a tertiary hospital. We monitored 100% of the cases. In 75% of the cases, we could measure an electromyographic response after tumour resection. In 17 cases, there was an absence of electromyographic response. Fifteen of them had an anatomic lesion with loss of continuity of the facial nerve and, in 2 cases, there was a lesion with preservation of the nerve. Preoperative facial palsy (29% 7%; P=.0349), large tumour size (88 vs. 38%; P=.0276), and a non-functional audition (88 vs. 51%; P=.0276) were significantly related with an absence of electromyographic response. Facial nerve monitoring under neuromuscular blockade is possible and safe in patients without previous facial palsy. If the patient had an electromyographic response after tumour excision, they developed better facial function in the postoperative period and after a year of follow up. Copyright © 2014 Elsevier España, S.L.U. and Sociedad Española de Otorrinolaringología y Patología Cérvico-Facial. All rights reserved.
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2011-01-01
Vocal production requires complex planning and coordination of respiratory, laryngeal, and vocal tract movements, which are incompletely understood in most mammals. Rats produce a variety of whistles in the ultrasonic range that are of communicative relevance and of importance as a model system, but the sources of acoustic variability were mostly unknown. The goal was to identify sources of fundamental frequency variability. Subglottal pressure, tracheal airflow, and electromyographic (EMG) data from two intrinsic laryngeal muscles were measured during 22-kHz and 50-kHz call production in awake, spontaneously behaving adult male rats. During ultrasound vocalization, subglottal pressure ranged between 0.8 and 1.9 kPa. Pressure differences between call types were not significant. The relation between fundamental frequency and subglottal pressure within call types was inconsistent. Experimental manipulations of subglottal pressure had only small effects on fundamental frequency. Tracheal airflow patterns were also inconsistently associated with frequency. Pressure and flow seem to play a small role in regulation of fundamental frequency. Muscle activity, however, is precisely regulated and very sensitive to alterations, presumably because of effects on resonance properties in the vocal tract. EMG activity of cricothyroid and thyroarytenoid muscle was tonic in calls with slow or no fundamental frequency modulations, like 22-kHz and flat 50-kHz calls. Both muscles showed brief high-amplitude, alternating bursts at rates up to 150 Hz during production of frequency-modulated 50-kHz calls. A differentiated and fine regulation of intrinsic laryngeal muscles is critical for normal ultrasound vocalization. Many features of the laryngeal muscle activation pattern during ultrasound vocalization in rats are shared with other mammals. PMID:21832032
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Robotic Assistance of Human Motion Using Active-Backdrivability on a Geared Electromagnetic Motor
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Mario Jorge Claros
2016-03-01
Full Text Available In this research, we describe an actuation and control system designed for geared electromagnetic motors, which is characterized by its simple implementation, fast response to external input loads, reliable human-machine interaction features, no need for previous set-up or calibration from user to user and high portability due to the reduction of weight and space used. By the implementation of the proposed system, an electromagnetic motor can become a multitasking, wearable actuation system capable of: detecting the user's intentions regarding motion, tracking the limbs with minimal force interaction within a wide bandwidth and also providing controllable assistance and resistance forces to the user's movements, without the use of any biological signal. Validation of the proposed approach is shown by the construction of a powered orthosis for the knee, used to test the system's performance under real human motion conditions. The proposed system was tested on one healthy subject by measuring electromyographic levels both with and without the orthosis, under controlled flexion and extension cycles. Experimental results demonstrate the effectiveness of the proposed approach in detecting the user's intentions regarding motion, reducing and increasing muscular activity when configured for assistance and resistance, respectively, and also increasing the transparency of the actuation system when perfect tracking of the limbs is needed.
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Classification of rhythmic locomotor patterns in electromyographic signals using fuzzy sets
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Thrasher Timothy A
2011-12-01
Full Text Available Abstract Background Locomotor control is accomplished by a complex integration of neural mechanisms including a central pattern generator, spinal reflexes and supraspinal control centres. Patterns of muscle activation during walking exhibit an underlying structure in which groups of muscles seem to activate in united bursts. Presented here is a statistical approach for analyzing Surface Electromyography (SEMG data with the goal of classifying rhythmic "burst" patterns that are consistent with a central pattern generator model of locomotor control. Methods A fuzzy model of rhythmic locomotor patterns was optimized and evaluated using SEMG data from a convenience sample of four able-bodied individuals. As well, two subjects with pathological gait participated: one with Parkinson's Disease, and one with incomplete spinal cord injury. Subjects walked overground and on a treadmill while SEMG was recorded from major muscles of the lower extremities. The model was fit to half of the recorded data using non-linear optimization and validated against the other half of the data. The coefficient of determination, R2, was used to interpret the model's goodness of fit. Results Using four fuzzy burst patterns, the model was able to explain approximately 70-83% of the variance in muscle activation during treadmill gait and 74% during overground gait. When five burst functions were used, one function was found to be redundant. The model explained 81-83% of the variance in the Parkinsonian gait, and only 46-59% of the variance in spinal cord injured gait. Conclusions The analytical approach proposed in this article is a novel way to interpret multichannel SEMG signals by reducing the data into basic rhythmic patterns. This can help us better understand the role of rhythmic patterns in locomotor control.
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Frisk, Rasmus F; Jensen, Peter; Kirk, Henrik; Bouyer, Laurent J; Lorentzen, Jakob; Nielsen, Jens B
2017-12-01
Exaggerated sensory activity has been assumed to contribute to functional impairment following lesion of the central motor pathway. However, recent studies have suggested that sensory contribution to muscle activity during gait is reduced in stroke patients and children with cerebral palsy (CP). We investigated whether this also occurs in CP adults and whether daily treadmill training is accompanied by alterations in sensory contribution to muscle activity. Seventeen adults with CP and 12 uninjured individuals participated. The participants walked on a treadmill while a robotized ankle-foot orthosis applied unload perturbations at the ankle, thereby removing sensory feedback naturally activated during push-off. Reduction of electromyographic (EMG) activity in the soleus muscle caused by unloads was compared and related to kinematics and ankle joint stiffness measurements. Similar measures were obtained after 6 wk of gait training. We found that sensory contribution to soleus EMG activation was reduced in CP adults compared with uninjured adults. The lowest contribution of sensory feedback was found in participants with lowest maximal gait speed. This was related to increased ankle plantar flexor stiffness. Six weeks of gait training did not alter the contribution of sensory feedback. We conclude that exaggerated sensory activity is unlikely to contribute to impaired gait in CP adults, because sensory contribution to muscle activity during gait was reduced compared with in uninjured individuals. Increased passive stiffness around the ankle joint is likely to diminish sensory feedback during gait so that a larger part of plantar flexor muscle activity must be generated by descending motor commands. NEW & NOTEWORTHY Findings suggest that adults with cerebral palsy have less contribution of sensory feedback to ongoing soleus muscle activation during push-off than uninjured individuals. Increased passive stiffness around the ankle joint is likely to diminish sensory
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Pereira, Ivye L R; Queiroz, Bergson; Loss, Jefferson; Amorim, César; Sacco, Isabel C N
2017-06-01
The purpose of this study was to compare the electromyographic pattern of core muscles during intermediate Pilates mat exercises between healthy people and those with low back pain. We evaluated healthy participants (n = 19; mean ± standard deviation [SD]: age 28 ± 8 years, body mass 65 ± 10 kg, height 160.0 ± 9.1 cm) and a low back pain group (n = 13; mean ± SD: age 30 ± 9 years, body mass 67 ± 12 kg, height 170.0 ± 6.6 cm). Electromyographic analysis assessed the multifidus, external oblique, internal oblique, and rectus abdominis muscles during classical Pilates exercises (single leg stretch, criss-cross, and dead bug). We calculated the root mean square normalized by maximum voluntary contraction, and the time of peak activation was provided by a linear envelope and normalized by the total movement cycle. The criss-cross exercise presented the highest values of root mean square for trunk flexors (rectus abdominis and oblique) compared with the other exercises, followed by the single leg stretch and the dead bug, which had similar muscle activation. The single leg stretch presented more activation of the rectus abdominis and oblique, whereas the criss-cross and dead bug created more activation of the oblique compared with the multifidus and rectus. The Pilates exercises presented different muscle recruitment patterns, and allowed the activation of the lumbopelvic stabilizing muscles even in the first session for healthy individuals and those with chronic low back pain. Copyright © 2017. Published by Elsevier Inc.
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Directory of Open Access Journals (Sweden)
Valdinar A. R. Júnior
2010-04-01
unilateral knee extensions were performed, followed by 15 repetitions of the leg presses at 30% and 60% of one maximum repetition load (1-MR, respectively. In the high-intensity bout (R60, the same sequence was performed, but the applied load was 60% of 1-MR for both exercises. A single set of 15 repetitions of the leg press at 60% of 1-MR was performed as a control exercise (CR. The surface electromyographic signals of the vastus lateralis muscle were recorded by means of a linear electrode array. The root mean square (RMS values were determined for each repetition of the leg press, and linear regressions were calculated from these results. The slopes of the straight lines obtained were then normalized using the linear coefficients of the regression equations and compared using one-way ANOVAs for repeated measures. RESULTS: The slopes observed in the CR were significantly lower than those in the R30 and R60 (p<0.05. CONCLUSIONS: The results indicated that the recruitment of motor units was more effective when a single-joint exercise preceded the multi-joint exercise. Article registered in the Australian New Zealand Clinical Trials Registry (ANZCTR under the number ACTRN12609000413224.
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Jakobsen, Markus Due; Sundstrup, Emil; Andersen, Christoffer H; Aagaard, Per; Andersen, Lars L
2013-02-01
The present study's aim was to evaluate muscle activity during leg exercises using elastic vs. isoinertial resistance at different exertion and loading levels, respectively. Twenty-four women and eighteen men aged 26-67 years volunteered to participate in the experiment. Electromyographic (EMG) activity was recorded in nine muscles during a standardized forward lunge movement performed with dumbbells and elastic bands during (1) ballistic vs. controlled exertion, and (2) at low, medium and high loads (33%, 66% and 100% of 10 RM, respectively). The recorded EMG signals were normalized to MVC EMG. Knee joint angle was measured using electronic inclinometers. The following results were obtained. Loading intensity affected EMG amplitude in the order: lowBallistic contractions always produced greater EMG activity than slow controlled contractions, and for most muscles ballistic contractions with medium load showed similar EMG amplitude as controlled contractions with high load. At flexed knee joint positions with elastic resistance, quadriceps and gluteus EMG amplitude during medium-load ballistic contractions exceeded that recorded during high-load controlled contractions. Quadriceps and gluteus EMG amplitude increased at flexed knee positions. In contrast, hamstrings EMG amplitude remained constant throughout ROM during dumbbell lunge, but increased at more extended knee joint positions during lunges using elastic resistance. Based on these results, it can be concluded that lunges performed using medium-load ballistic muscle contractions may induce similar or even higher leg muscle activity than lunges using high-load slow-speed contractions. Consequently, lunges using elastic resistance appear to be equally effective in inducing high leg muscle activity as traditional lunges using isoinertial resistance. Copyright © 2012 Elsevier B.V. All rights reserved.
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Directory of Open Access Journals (Sweden)
Alessandra C. S. Ribeiro
2010-06-01
Full Text Available OBJETIVOS: Analisar a atividade elétrica (EMG dos músculos vasto medial oblíquo (VMO, vasto lateral longo (VLL e vasto lateral oblíquo (VLO de indivíduos com síndrome da dor femoropatelar (SDFP durante contração isométrica voluntária máxima (CIVM de extensão da perna com o joelho a 30(0, a dor por meio da Escala Visual Analógica (EVA e o posicionamento da patela por meio da ressonância magnética nuclear por imagem (RMNI. MÉTODOS: Avaliaram-se 12 mulheres com SDFP e 12 clinicamente normais, que realizaram cinco CIVM de extensão da perna no ângulo de 30(0 para análise da EMG. Avaliou-se o ângulo do sulco (AS, ângulo de congruência (AC, ângulo de inclinação patelar (AIP e deslocamento patelar (DP pela RMNI. Utilizaram-se testes estatísticos: ANOVA, análise de variância de medidas repetidas para EMG; o teste Mann-Whitney U para análise da RMNI; o teste de correlação de Pearson (r entre EMG e RMNI e análise de variância one-way para avaliação da dor (pOBJECTIVES: To analyze the electrical activity of the vastus medialis obliquus (VMO, vastus lateralis longus (VLL and vastus lateralis obliquus (VLO muscles of individuals with patellofemoral pain syndrome (PFPS during maximum voluntary isometric contraction (MVIC of lower leg extension with the knee at 30°; to assess pain using a visual analogue scale (VAS; and to assess patellar positioning using magnetic resonance imaging (MRI. METHODS: Twelve women with PFPS and 12 clinically normal women were evaluated. They performed five MVICs of lower leg extension at 30° for electromyographic (EMG analysis. Using MRI, the sulcus angle (SA, congruence angle (CA, patellar tilt angle (PTA and patellar displacement (PD were obtained. The following statistical tests were used: analysis of variance (ANOVA for repeated measurements to assess EMGs; Mann-Whitney U test to analyze MRIs; Pearson's (r correlation test between EMGs and MRIs; and one-way ANOVA to evaluate pain (p<0
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Saeterbakken, Atle H; Andersen, Vidar; van den Tillaar, Roland
2016-04-01
The purpose of the study was to compare kinematic muscle activation when performing 6 repetition maximum (6RM) squats using constant (free weights) or variable resistance (free weights + elastic bands). Twenty recreationally trained women were recruited with 4.6 ± 2.1 years of resistance training experience and a relative strength (6RM/body mass) of 1.1. After a familiarization session identifying the 6RM loads, the participants performed 6RM squats using constant and variable resistance in a randomized order. The total resistance in the variable resistance group was similar to the constant resistance in the presticking region (98%), but greater in the sticking region (105%) and the poststicking region (113%). In addition, the presticking barbell velocity was 21.0% greater using variable than constant resistance, but 22.8% lower in the poststicking region. No significant differences in muscle electromyographic activity, time occurrence, and vertical displacement between the squat modalities were observed, except for higher barbell displacement poststicking using variable resistance. It was concluded that, due to differences in total resistance in the different regions performing variable compared with constant resistance, greater barbell velocity was observed in the presticking region and lower resistance was observed in the poststicking region. However, the extra resistance in the sticking and poststicking regions during the variable resistance modality did not cause increased muscle activity. When performing squats with heavy resistance, the authors recommend using variable resistance, but we suggest increasing the percentage resistance from the elastic bands or using chains.
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Surface electrical stimulation in dysphagic Parkinson patients: a randomized clinical trial.
Baijens, Laura W J; Speyer, Renée; Passos, Valéria Lima; Pilz, Walmari; van der Kruis, Jolien; Haarmans, Saskia; Desjardins-Rombouts, Christel
2013-11-01
A new treatment for oropharyngeal dysphagia in Parkinson's disease was evaluated in the present study. Prospective randomized controlled trial. The study describes the effects of surface electrical stimulation (SES) of the neck (submental region) in dysphagic Parkinson patients using different intensities of electrical current. Quasi-random allocation was performed when assigning patients to treatment groups. Three groups consisting of dysphagic patients with idiopathic Parkinson's disease (N = 90) received daily treatment for 15 days with periods of no treatment during the weekend. All three received traditional logopedic dysphagia treatment. In addition, two groups received SES, either motor-level or sensory-level stimulation. A standardized measurement protocol, including fiber optic endoscopic evaluation of swallowing (FEES) and videofluoroscopy of swallowing (VFS), was performed before and after therapy. A team of experienced raters was blinded to the treatment group and to the moment of measurement. Intrarater and interrater reliability were calculated. Using proportional odds models (POMs), some of the visuoperceptual ordinal outcome variables showed significant improvement in all groups following treatment. Following 15 days of SES of the submental region, few significant effects were found, suggesting a therapy effect of traditional logopedic dysphagia treatment without any additional influence of SES. On the grounds of this study, it is concluded that further research is needed on the exact mechanism of SES and its effects on the neural pathways involved in swallowing. Copyright © 2013 The American Laryngological, Rhinological and Otological Society, Inc.
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Influence of an unstable shoe on compensatory postural adjustments: An experimental evaluation
Andreia S. P. Sousa; Rui Macedo; Rubim Santos; João Manuel R. S. Tavares
2010-01-01
This study attempted to evaluate the influence of using an unstable shoe in muscle re-cruitment strategies and center of pressure (CoP) displacement after the application of an external perturba-tion. Fourteen healthy female subjects participated in this study. The electromyographic activity of medial ga-strocnemius, tibialis anterior, rectus femoris, biceps femoris, rectus abdominis and erector spinae muscles and the kinetic values to calculate the CoP were collected and analyzed after the a...
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Xu, L.; Rabotti, C.; Mischi, M.
2012-01-01
Vibration exercise (VE) has been suggested as an effective methodology to improve muscle strength and power performance. Several studies link the effects of vibration training to enhanced neuromuscular demand, typically ascribed to involuntary reflex mechanisms. However, the underlying mechanisms
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Variant Anterior Digastric Muscle Transfer for Marginal Mandibular Branch of Facial Nerve Palsy
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Matthew J. Zdilla, DC
2014-02-01
Full Text Available Summary: Marginal mandibular branch of facial nerve (MMBFN palsy is a common consequence of head and neck surgeries. MMBFN palsy results in paralysis of muscles which depress the inferior lip. Current management of MMBFN palsy involves ruination of normal neuromuscular anatomy and physiology to restore symmetry to the mouth. The article outlines the possibility to transfer variant anterior digastric musculature to accomplish reanimation of the mouth without adversely affecting normal nonvariant anatomy. The procedure may have the additional cosmetic benefit of correcting asymmetrical muscular bulk in the submental region.
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Directory of Open Access Journals (Sweden)
Amir Pourmoghaddam
2015-01-01
Full Text Available Analysis of electromyographic (EMG data is a cornerstone of research related to motor control in Parkinson’s disease. Nonlinear EMG analysis tools have shown to be valuable, but analysis is often complex and interpretation of the data may be difficult. A previously introduced algorithm (SYNERGOS that provides a single index value based on simultaneous multiple muscle activations (MMA has been shown to be effective in detecting changes in EMG activation due to modifications of walking speeds in healthy adults. In this study, we investigated if SYNERGOS detects MMA changes associated with both different walking speeds and levodopa intake. Nine male Parkinsonian patients walked on a treadmill with increasing speed while on or off medication. We collected EMG data and computed SYNERGOS indices and employed a restricted maximum likelihood linear mixed model to the values. SYNERGOS was sensitive to neuromuscular modifications due to both alterations of gait speed and intake of levodopa. We believe that the current experiment provides evidence for the potential value of SYNERGOS as a nonlinear tool in clinical settings, by providing a single value index of MMA. This could help clinicians to evaluate the efficacy of interventions and treatments in Parkinson’s disease in a simple manner.
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Electromyographic evaluation of the lower limbs of patients with Down syndrome in hippotherapy
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Mariane Fernandes Ribeiro
2017-05-01
Full Text Available Hippotherapy is a therapeutic method that uses the horse’s movement to achieve functional results in practitioners with Down syndrome (DS, who present motor and neurophysiological changes that affect the musculoskeletal system. Evaluating the motor behavior related to the control and the improvement of muscle activation in practitioners with Down syndrome subjected to hippotherapy. 10 practitioners were divided into two groups: Down Group (DG – practitioners with DS, and Healthy Group (HG – practitioners with no physical impairment. The muscles gluteus medius, tensor fasciae latae, rectus femoris, vastus medialis, vastus lateralis, biceps femoris, tibialis anterior and gastrocnemius were evaluated by electromyography using gross RMS values, which correspond to muscle activation; the evaluations were performed on the 1st and 10th hippotherapy sessions (frequency: once a week, and after 2 months interval without treatment, they were performed on the 1st and 10th hippotherapy sessions (frequency: twice a week. It was noted that activation of the studied muscles increased with the passing of sessions, regardless the weekly frequency of attendance; however, the period without treatment resulted in reduction of this effect. Practitioners with DS presented satisfactory changes in muscle activation pattern, in learning and in motor behavior during hippotherapy sessions.
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Clinical significance of anismus in encopresis.
Catto-Smith, A G; Nolan, T M; Coffey, C M
1998-09-01
Treatments designed to relieve paradoxical contraction of the anal sphincters during defecation (anismus) have had limited success in children with encopresis. This has raised doubts as to the clinical relevance of this diagnosis in childhood as anorectal dysfunction. Our aim was to determine whether, in patients who had treatment-resistant encopresis, the presence of electromyographic anismus was associated with increased faecal retention. Sixty-eight children with soiling (mean age 8.7+/-2.06 years) were assessed by clinical examination, abdominal radiography and then with anorectal manometry. Patients with electromyographic anismus (n=32; 47%) had significantly increased radiographic rectal faecal retention and were significantly less likely to be able to defecate water-filled balloons. There were no significant differences in response to prior therapy, history of primary encopresis, behavioural adjustment or in sociodemographic data. Our results suggest that electromyographic anismus is associated with obstructed defecation and faecal retention.
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Sinclair, Jonathan; McCarthy, Derek; Bentley, Ian; Hurst, Howard Thomas; Atkins, Stephen
2015-01-01
The barbell back squat is commonly used by athletes participating in resistance training. The barbell squat is typically performed using standard athletic shoes, or specially designed weightlifting footwear, although there are now a large number of athletes who prefer to squat barefoot or in barefoot-inspired footwear. This study aimed to determine how these footwear influence 3-D kinematics and muscle activation potentials during the barbell back squat. Fourteen experienced male participants completed squats at 70% 1 rep max in each footwear condition. 3-D kinematics from the torso, hip, knee and ankle were measured using an eight-camera motion analysis system. In addition, electromyographical (EMG) measurements were obtained from the rectus femoris, tibialis anterior, gastrocnemius, erector spinae and biceps femoris muscles. EMG parameters and joint kinematics were compared between footwear using repeated-measures analyses of variance. Participants were also asked to subjectively rate which footwear they preferred when performing their squat lifts; this was examined a chi-squared test. The kinematic analysis indicated that, in comparison to barefoot the running shoe was associated with increased squat depth, knee flexion and rectus femoris activation. The chi-squared test was significant and showed that participants preferred to squat barefoot. This study supports anecdotal evidence of athletes who prefer to train barefoot or in barefoot-inspired footwear although no biomechanical evidence was found to support this notion.
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Electromyographic and cephalometric correlation with the predominant masticatory movement.
Coelho-Ferraz, Maria Julia P; Berzin, Fausto; Amorim, Cesar Ferreira; Romano, Fabio Lourenco; de Paula Queluz, Dagmar
2010-01-01
This study aimed to evaluate the chewing muscular dynamics and correlate the side of the masticatory movement that is more vertical and/or more horizontal established by the photomeasurement Masticatory Functional Angle (MFA) to the muscular activity behavior, showed in the surface electromyography and in the radiographic images. Seventeen people were selected of both genders, with the average age of 25 years, without signs or apparent symptoms of masticatory muscular disorders. The teleradiographies were done in lateral norm and surface electromyography of the masseter muscles, anterior portion of temporal and supra-hyoids in rest position and maximal bite. The bite force measured with a metallic transducer that was connected to a force sensor (Strain Gauge) to measure the deformation of the material model SF4 (EMG SYSTEM DO BRASIL). A mandibular goniometer of the EMG System of Brazil was used to measure the opening size. The comparison and correlation were established between the groups with MFA>5 degrees and MFAStudent or test of Mann-Whitney conform the distribution was normal or not, respectively. The results showed significant differences between groups, although without sexual dimorphism, to masseter muscle in maximal bite. In conclusion, the anatomic-physiological aspects of temporomandibular disorders are related to the asymmetrical mandible function.
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DEFF Research Database (Denmark)
Visser, Bart; Kofoed Nielsen, Pernille; de Kraker, Heleen
2006-01-01
loaded with 4.95 kg each) were combined with intermittent pinch forces at 0, 10 and 25% of the maximum voluntary contraction (MVC). Blood flow to the forearm was measured with Doppler ultrasound. Myoelectric activity of the forearm and neck-shoulder muscles was recorded to check for the workload levels....... Across all levels of shoulder load, blood flow increased significantly with increasing pinch force (21% at 10% MVC and by 44% at 25% MVC). Blood flow was significantly affected by shoulder load, with the lowest blood flow at the highest shoulder load. Interactions of pinch force and shoulder load were....... The results of this study indicate that shoulder load might influence blood flow to the forearm....
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Real-time feedback enhances forward propulsion during walking in old adults.
Franz, Jason R; Maletis, Michela; Kram, Rodger
2014-01-01
Reduced propulsive function during the push-off phase of walking plays a central role in the deterioration of walking ability with age. We used real-time propulsive feedback to test the hypothesis that old adults have an underutilized propulsive reserve available during walking. 8 old adults (mean [SD], age: 72.1 [3.9] years) and 11 young adults (age: 21.0 [1.5] years) participated. For our primary aim, old subjects walked: 1) normally, 2) with visual feedback of their peak propulsive ground reaction forces, and 3) with visual feedback of their medial gastrocnemius electromyographic activity during push-off. We asked those subjects to match a target set to 20% and 40% greater propulsive force or push-off muscle activity than normal walking. We tested young subjects walking normally only to provide reference ground reaction force values. Walking normally, old adults exerted 12.5% smaller peak propulsive forces than young adults (Ppush-off muscle activities when we provided propulsive feedback. Most notably, force feedback elicited propulsive forces that were equal to or 10.5% greater than those of young adults (+20% target, P=0.87; +40% target, P=0.02). With electromyographic feedback, old adults significantly increased their push-off muscle activities but without increasing their propulsive forces. Old adults with propulsive deficits have a considerable and underutilized propulsive reserve available during level walking. Further, real-time propulsive feedback represents a promising therapeutic strategy to improve the forward propulsion of old adults and thus maintain their walking ability and independence. © 2013.
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Kim, Gye-Yeop; Kin, Se-Hun
2013-12-01
[Purpose] The purpose of this study was to examine the effect of lumbar stability exercises on chronic low back pain by using sling exercise and push-ups. [Subjects] Thirty adult subjects with chronic back pain participated, with 10 adults being assigned to each of 3 exercise groups: general physical therapy (PT), lumbar stability using sling exercises (Sling Ex), and sling exercise plus push-ups (Sling Ex+PU). Each group trained for 30 minutes 3 times a week for 6 weeks. The Oswestry Disability Index (ODI), surface electromyographic (sEMG) activity of the lumbar muscles, and cross-sectional area of the multifidus muscle on computed tomography (CT) were evaluated before and at 2, 4, and 6 weeks of therapy. [Results] A significant decrease in ODI was seen in all therapy groups, and this change was greater in the Sling Ex and Sling Ex+PU groups than in the PT group. No changes in sEMG activity were noted in the PT group, whereas significant increases in the sEMG activities of all lumbar muscles were found in the other 2 groups. The increases in the sEMG activities of the rectus abdominis and internal and external oblique muscles of the abdomen were greater in the Sling Ex+PU group than in the other 2 groups. [Conclusion] These findings demonstrate that Sling Ex+PU, similar to normal lumbar stabilization exercise, is effective in activating and improving the function of the lumbar muscles. These results suggest that Sling Ex+PU has a positive impact on stabilization of the lumbar region.
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Does insertion of intramuscular electromyographic electrodes alter motor behavior during locomotion?
Armour Smith, Jo; Kulig, Kornelia
2015-06-01
Intramuscular electromyography (EMG) is commonly used to quantify activity in the trunk musculature. However, it is unclear if the discomfort or fear of pain associated with insertion of intramuscular EMG electrodes results in altered motor behavior. This study examined whether intramuscular EMG affects locomotor speed and trunk motion, and examined the anticipated and actual pain associated with electrode insertion in healthy individuals and individuals with a history of low back pain (LBP). Before and after insertion of intramuscular electrodes into the lumbar and thoracic paraspinals, participants performed multiple repetitions of a walking turn at self-selected and controlled average speed. Low levels of anticipated and actual pain were reported in both groups. Self-selected locomotor speed was significantly increased following insertion of the electrodes. At the controlled speed, the amplitude of sagittal plane lumbo-pelvic motion decreased significantly post-insertion, but the extent of this change was the same in both groups. Lumbo-pelvic motion in the frontal and axial planes and thoraco-lumbar motion in all planes were not affected by the insertions. This study demonstrates that intramuscular EMG is an appropriate methodology to selectively quantify the activation patterns of the individual muscles in the paraspinal group, both in healthy individuals and individuals with a history of LBP. Copyright © 2015 Elsevier Ltd. All rights reserved.
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Wong, Arnold Y L; Parent, Eric C; Prasad, Narasimha; Huang, Christopher; Chan, K Ming; Kawchuk, Gregory N
2016-05-01
While some patients with low back pain demonstrate increased spinal stiffness that decreases as pain subsides, this observation is inconsistent. Currently, the relation between spinal stiffness and low back pain remains unclear. This study aimed to investigate the effects of experimental low back pain on temporal changes in posteroanterior spinal stiffness and concurrent trunk muscle activity. In separate sessions five days apart, nine asymptomatic participants received equal volume injections of hypertonic or isotonic saline in random order into the L3-L5 interspinous ligaments. Pain intensity, spinal stiffness (global and terminal stiffness) at the L3 level, and the surface electromyographic activity of six trunk muscles were measured before, immediately after, and 25-minute after injections. These outcome measures under different saline conditions were compared by generalized estimating equations. Compared to isotonic saline injections, hypertonic saline injections evoked significantly higher pain intensity (mean difference: 5.7/10), higher global (mean difference: 0.73N/mm) and terminal stiffness (mean difference: 0.58N/mm), and increased activity of four trunk muscles during indentation (Ppain subsided. While previous clinical research reported inconsistent findings regarding the association between spinal stiffness and low back pain, our study revealed that experimental pain caused temporary increases in spinal stiffness and concurrent trunk muscle co-contraction during indentation, which helps explain the temporal relation between spinal stiffness and low back pain observed in some clinical studies. Our results substantiate the role of spinal stiffness assessments in monitoring back pain progression. Copyright © 2016 Elsevier Ltd. All rights reserved.
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Directory of Open Access Journals (Sweden)
Sâmia Najara Freitas Bessa
2008-01-01
Full Text Available A síndrome da dor patelofemoral (SDPF é uma das afecções que mais acometem a articulação do joelho. Embora sua etiologia não seja completamente conhecida, uma disfunção do músculo vasto medial oblíquo (VMO tem sido apontada como possível fator desencadeante. Este estudo visou avaliar, por meio de eletromiografia, se algum exercício, dentre dez exercícios resistidos usuais, produz ativação seletiva do VMO, com vistas a sua utilização clínica. Vinte voluntárias do sexo feminino, sendo dez com SDPF (24,7±4,35 anos e dez saudáveis, controle (22,5±1,58 anos, foram submetidas à avaliação eletromiográfica dos músculos VMO, vasto lateral longo e vasto lateral oblíquo (VLO durante a realização de 10 exercícios, incluindo cadeia cinética aberta e fechada, em diferentes angulações do joelho e posições do quadril. Os resultados mostram que nenhum dos exercícios se revelou seletivo para o VMO, tendo alguns mostrado ativação seletiva do VLO. No grupo com SDPF observou-se menor atividade eletromiográfica de todos os vastos em oito dos dez exercícios propostos, quando comparado ao controle; observou-se ainda, no grupo SDPF, menor relação VMO/VLO (0,63 do que no grupo controle (0,82, pThe patellofemoral pain syndrome (PFPS is among the most common knee pathologies. Although its etiology is not fully known, a dysfunction of the vastus medialis oblique (VMO muscle has been pointed out as a possible cause. This study aimed at assessing, by means of electromyography, whether one or more, among ten usual resisted exercises, might produce VMO selective activation, in view of its clinic application. Twenty female volunteers, ten with PFPS (aged 24.7±4.35 and ten healthy ones (aged 22.5±1.58 were submitted to electromyographic evaluation of VMO, vastus lateralis longus and vastus lateralis oblique (VLO muscles during ten exercises, including open and closed kinetic chain, at different degrees of knee flexion and of hip
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PRIMARY HEMANGIOMA OF A SUBMENTAL LYMPH NODE –A RARE ENTITY
Directory of Open Access Journals (Sweden)
Shri LakshmiS, Durga PrasadD, Subba Rao D, PrasanthiC, Vandana Gangadharan, Kishore Kumar C
2015-04-01
Full Text Available ABSTRACT Primary vascular tumors occurring in lymph nodes are extremely rare. Nodal hemangiomas are benign vascular tumors that can occur at any age and seen mostly in females. It is usually asymptomatic, affects only one node, and does not recur. Four histologic types of hemangioma have been identified: capillary/cavernous, lobular capillary, cellular, and epithelioid. This case has been reported for its rarity
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Tan, L. K.; Miller, A. D.
1986-01-01
The extent of the region of the diaphragm around the esophagus that displays greatly reduced activity during the expulsive phase of vomiting was determined from electromyographic studies in cats to be about 0.75-1.0 cm from the esophagus. Horseradish peroxidase injected into this region retrogradely labeled motoneurons throughout most of the rostral-caudal extent of the phrenic nucleus, with the exception of caudal C6 and rostral C7. This widespread intermingling of motoneurons that innervate the region of reduced activity with other phrenic motoneurons creates a difficulty for needed follow-up studies of diaphragmatic control during vomiting.
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Directory of Open Access Journals (Sweden)
Tom Maudrich
2017-09-01
Full Text Available During unimanual motor tasks, muscle activity may not be restricted to the contracting muscle, but rather occurs involuntarily in the contralateral resting limb, even in healthy individuals. This phenomenon has been referred to as mirror electromyographic activity (MEMG. To date, the physiological (non-pathological form of MEMG has been observed predominately in upper extremities (UE, while remaining sparsely described in lower extremities (LE. Accordingly, evidence regarding the underlying mechanisms and modulation capability of MEMG, i.e., the extent of MEMG in dependency of exerted force during unilateral isometric contractions are insufficiently investigated in terms of LE. Furthermore, it still remains elusive if and how MEMG is affected by long-term exercise training. Here, we provide novel quantitative evidence for physiological MEMG in homologous muscles of LE (tibialis anterior (TA, rectus femoris (RF during submaximal unilateral dorsiflexion in healthy young adults. Furthermore, endurance athletes (EA, n = 11 show a higher extent of MEMG in LE compared to non-athletes (NA, n = 11 at high force demands (80% MVC, maximum voluntary contraction. While the underlying neurophysiological mechanisms of MEMG still remain elusive, our study indicates, at least indirectly, that sport-related long-term training might affect the amount of MEMG during strong isometric contractions specifically in trained limbs. To support this assumption of exercise-induced limb-specific MEMG modulation, future studies including different sports disciplines with contrasting movement patterns and parameters should additionally be performed.
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Maudrich, Tom; Kenville, Rouven; Lepsien, Jöran; Villringer, Arno; Ragert, Patrick; Steele, Christopher J
2017-01-01
During unimanual motor tasks, muscle activity may not be restricted to the contracting muscle, but rather occurs involuntarily in the contralateral resting limb, even in healthy individuals. This phenomenon has been referred to as mirror electromyographic activity (MEMG). To date, the physiological (non-pathological) form of MEMG has been observed predominately in upper extremities (UE), while remaining sparsely described in lower extremities (LE). Accordingly, evidence regarding the underlying mechanisms and modulation capability of MEMG, i.e., the extent of MEMG in dependency of exerted force during unilateral isometric contractions are insufficiently investigated in terms of LE. Furthermore, it still remains elusive if and how MEMG is affected by long-term exercise training. Here, we provide novel quantitative evidence for physiological MEMG in homologous muscles of LE (tibialis anterior (TA), rectus femoris (RF)) during submaximal unilateral dorsiflexion in healthy young adults. Furthermore, endurance athletes (EA, n = 11) show a higher extent of MEMG in LE compared to non-athletes (NA, n = 11) at high force demands (80% MVC, maximum voluntary contraction). While the underlying neurophysiological mechanisms of MEMG still remain elusive, our study indicates, at least indirectly, that sport-related long-term training might affect the amount of MEMG during strong isometric contractions specifically in trained limbs. To support this assumption of exercise-induced limb-specific MEMG modulation, future studies including different sports disciplines with contrasting movement patterns and parameters should additionally be performed.
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Li, Yan; Alam, Monzurul; Guo, Shanshan; Ting, K H; He, Jufang
2014-07-03
Lower motor neurons in the spinal cord lose supraspinal inputs after complete spinal cord injury, leading to a loss of volitional control below the injury site. Extensive locomotor training with spinal cord stimulation can restore locomotion function after spinal cord injury in humans and animals. However, this locomotion is non-voluntary, meaning that subjects cannot control stimulation via their natural "intent". A recent study demonstrated an advanced system that triggers a stimulator using forelimb stepping electromyographic patterns to restore quadrupedal walking in rats with spinal cord transection. However, this indirect source of "intent" may mean that other non-stepping forelimb activities may false-trigger the spinal stimulator and thus produce unwanted hindlimb movements. We hypothesized that there are distinguishable neural activities in the primary motor cortex during treadmill walking, even after low-thoracic spinal transection in adult guinea pigs. We developed an electronic spinal bridge, called "Motolink", which detects these neural patterns and triggers a "spinal" stimulator for hindlimb movement. This hardware can be head-mounted or carried in a backpack. Neural data were processed in real-time and transmitted to a computer for analysis by an embedded processor. Off-line neural spike analysis was conducted to calculate and preset the spike threshold for "Motolink" hardware. We identified correlated activities of primary motor cortex neurons during treadmill walking of guinea pigs with spinal cord transection. These neural activities were used to predict the kinematic states of the animals. The appropriate selection of spike threshold value enabled the "Motolink" system to detect the neural "intent" of walking, which triggered electrical stimulation of the spinal cord and induced stepping-like hindlimb movements. We present a direct cortical "intent"-driven electronic spinal bridge to restore hindlimb locomotion after complete spinal cord injury.
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Hubley-Kozey, Cheryl L; Butler, Heather L; Kozey, John W
2012-08-01
Muscle synergies are important for spinal stability, but few studies examine temporal responses of spinal muscles to dynamic perturbations. This study examined activation amplitudes and temporal synergies among compartments of the back extensor and among abdominal wall muscles in response to dynamic bidirectional moments of force. We further examined whether responses were different between men and women. 19 women and 18 men performed a controlled transfer task. Surface electromyograms from bilateral sites over 6 back extensor compartments and 6 abdominal wall muscle sites were analyzed using principal component analysis. Key features were extracted from the measured electromyographic waveforms capturing amplitude and temporal variations among muscle sites. Three features explained 97% of the variance. Scores for each feature were computed for each measured waveform and analysis of variance found significant (pWomen had more differences among muscle sites than men for the lateral flexion moment feature. For the abdominal wall muscles the oblique muscles responded with synergies related to fiber orientation, with women having higher amplitudes and more responsiveness to the lateral flexion moment than men. Synergies between the abdominal and back extensor sites as the moment demands change are discussed. These findings illustrate differential activation among erector spinae compartments and abdominal wall muscle sites supporting a highly organized pattern of response to bidirectional external moments with asynchronies more apparent in women. Copyright © 2012 Elsevier B.V. All rights reserved.
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Longitudinal study of the effects of chronic hypothyroidism on skeletal muscle in dogs.
Rossmeisl, John H; Duncan, Robert B; Inzana, Karen D; Panciera, David L; Shelton, G Diane
2009-07-01
To study the effects of experimentally induced hypothyroidism on skeletal muscle and characterize any observed myopathic abnormalities in dogs. 9 female, adult mixed-breed dogs; 6 with hypothyroidism induced with irradiation with 131 iodine and 3 untreated control dogs. Clinical examinations were performed monthly. Electromyographic examinations; measurement of plasma creatine kinase, alanine aminotransferase, aspartate aminotransferase, lactate, and lactate dehydrogenase isoenzyme activities; and skeletal muscle morphologic-morphometric examinations were performed prior to and every 6 months for 18 months after induction of hypothyroidism. Baseline, 6-month, and 18-month assessments of plasma, urine, and skeletal muscle carnitine concentrations were also performed. Hypothyroid dogs developed electromyographic and morphologic evidence of myopathy by 6 months after treatment, which persisted throughout the study, although these changes were subclinical at all times. Hypothyroid myopathy was associated with significant increases in plasma creatine kinase, aspartate aminotransferase, and lactate dehydrogenase 5 isoenzyme activities and was characterized by nemaline rod inclusions, substantial and progressive predominance of type I myofibers, decrease in mean type II fiber area, subsarcolemmal accumulations of abnormal mitochondria, and myofiber degeneration. Chronic hypothyroidism was associated with substantial depletion in skeletal muscle free carnitine. Chronic, experimentally induced hypothyroidism resulted in substantial but subclinical phenotypic myopathic changes indicative of altered muscle energy metabolism and depletion of skeletal muscle carnitine. These abnormalities may contribute to nonspecific clinical signs, such as lethargy and exercise intolerance, often reported in hypothyroid dogs.
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Directory of Open Access Journals (Sweden)
Denise Hollanda Iunes
2015-01-01
Full Text Available Introduction. The aim of this study was to evaluate the role of auriculotherapy with mustard seeds in the treatment of temporomandibular disorders (TMDs, anxiety, and electromyographic (EMG activity in university students. Methodology. The State Trait Anxiety Inventory (STAI, Research Diagnostic Criteria (RDC for TMDs (RDC/TMDs, and electromyography were used in this study of 44 college students with high levels of anxiety and TMDs. The subjects were divided into two groups: an auriculotherapy (AA group (n=31 and an AA sham group (n=13. The mustard seeds were applied to the shenmen, rim, sympathetic, brain stem, and temporomandibular joint (TMJ points in the AA group and to sham points in the external ear and wrist in the AA sham group. The treatment protocol was 10 sessions (two treatments per week. Results. Anxiety (p<0.01 was significantly reduced in the AA group. This group also showed a decrease in tender points in the mandibular posterior region (p=0.04 and in the right side of the submandibular region (p=0.02. Complaints of bilateral pain were reduced in the temporal tendon (p≤0.01 and in the left side of the ATM (p<0.01. In addition, electromyographic (EMG activity was reduced during temporal muscle contraction (p=0.03. Conclusion. Auriculotherapy was effective in the treatment of students with anxiety and TMDs.
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Looney, David P; Kraemer, William J; Joseph, Michael F; Comstock, Brett A; Denegar, Craig R; Flanagan, Shawn D; Newton, Robert U; Szivak, Tunde K; DuPont, William H; Hooper, David R; Häkkinen, Keijo; Maresh, Carl M
2016-03-01
This investigation examined peak motor unit activity during sets that differed in resistance (50, 70, or 90% 1 repetition maximum [1RM]). Ten resistance-trained men (age, 23 ± 3 years; height, 187 ± 7 cm; body mass, 91.5 ± 6.9 kg; squat 1RM, 141 ± 28 kg) were assessed by electromyography (EMG) on the vastus lateralis and vastus medialis muscles in a randomized within-subject experiment consisting of 2 test visits: a drop-set day and a single-set day using only the 50% of 1RM intensity performed to failure. At the start of each day, subjects performed 2 submaximal repetition sets (50% 1RM × 10 repetitions and 70% 1RM × 7 repetitions). On the drop-set day, subjects performed 3 consecutive maximal repetition sets at 90%, 70%, and 50% 1RM to failure with no rest periods in between. On the single-set day, subjects performed a maximal repetition set at 50% 1RM to failure. Overall, the maximal repetition sets to failure at 50% and 70% 1RM resulted in higher peak EMG amplitude than during submaximal repetition sets with the same resistance. However, peak EMG amplitude was significantly (p ≤ 0.05) greater in the maximal 90% 1RM set than all other sets performed. When sets were performed to failure, ratings of perceived exertion (CR-10) did not differ over the intensity range of loads and suggests that perception is not capable of accurately detecting the actual amount of motor unit activation. The results of this investigation indicate that using higher external resistance is a more effective means of increasing motor unit activity than increasing the number of repetitions performed with lighter weights even when the end point is muscular failure. Accordingly, previous recommendations for the use of heavier loads during resistance training programs to stimulate the maximal development of strength and hypertrophy are further supported.
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Falla, Deborah; Gizzi, Leonardo; Tschapek, Marika; Erlenwein, Joachim; Petzke, Frank
2014-05-01
This study investigated change in the distribution of lumbar erector spinae muscle activity and pressure pain sensitivity across the low back in individuals with low back pain (LBP) and healthy controls. Surface electromyographic (EMG) signals were recorded from multiple locations over the lumbar erector spinae muscle with a 13×5 grid of electrodes from 19 people with chronic nonspecific LBP and 17 control subjects as they performed a repetitive lifting task. The EMG root mean square (RMS) was computed for each location of the grid to form a map of the EMG amplitude distribution. Pressure pain thresholds (PPT) were recorded before and after the lifting task over a similar area of the back. For the control subjects, the EMG RMS progressively increased more in the caudal region of the lumbar erector spinae during the repetitive task, resulting in a shift in the distribution of muscle activity. In contrast, the distribution of muscle activity remained unaltered in the LBP group despite an overall increase in EMG amplitude. PPT was lower in the LBP group after completion of the repetitive task compared to baseline (average across all locations: pre: 268.0±165.9 kPa; post: 242.0±166.7 kPa), whereas no change in PPT over time was observed for the control group (320.1±162.1 kPa; post: 322.0±179.5 kPa). The results demonstrate that LBP alters the normal adaptation of lumbar erector spinae muscle activity to exercise, which occurs in the presence of exercise-induced hyperalgesia. Reduced variability of muscle activity may have important implications for the provocation and recurrence of LBP due to repetitive tasks. Copyright © 2014 International Association for the Study of Pain. Published by Elsevier B.V. All rights reserved.
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Schweizer, Katrin; Romkes, Jacqueline; Brunner, Reinald
2013-09-01
This study provides an overview on the association between premature plantarflexor muscle activity (PPF), muscle strength, and equinus gait in patients with various pathologies. The purpose was to evaluate whether muscular weakness and biomechanical alterations are aetiological factors for PPF during walking, independent of the underlying pathology. In a retrospective design, 716 patients from our clinical database with 46 different pathologies (orthopaedic and neurologic) were evaluated. Gait analysis data of the patients included kinematics, kinetics, electromyographic activity (EMG) data, and manual muscle strength testing. All patients were clustered three times. First, patients were grouped according to their primary pathology. Second, all patients were again clustered, this time according to their impaired joints. Third, groups of patients with normal EMG or PPF, and equinus or normal foot contact were formed to evaluate the association between PPF and equinus gait. The patient groups derived by the first two cluster methods were further subdivided into patients with normal or reduced muscle strength. Additionally, the phi correlation coefficient was calculated between PPF and equinus gait. Independent of the clustering, PPF was present in all patient groups. Weak patients revealed PPF more frequently. The correlations of PPF and equinus gait were lower than expected, due to patients with normal EMG during loading response and equinus. These patients, however, showed higher gastrocnemius activity prior to foot strike together with lower peak tibialis anterior muscle activity in loading response. Patients with PPF and a normal foot contact possibly apply the plantarflexion-knee extension couple during loading response. While increased gastrocnemius activity around foot strike seems essential for equinus gait, premature gastrocnemius activity does not necessarily produce an equinus gait. We conclude that premature gastrocnemius activity is strongly associated
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2014-01-01
Background The aim of this study was to evaluate the clinical efficacy of submandibular gland transfer for the prevention of xerostomia after radiotherapy for nasopharyngeal carcinoma. Methods Using the randomized controlled clinical research method, 65 patients with nasopharyngeal carcinoma were randomly divided into an experimental group consisting of 32 patients and a control group consisting of 33 patients. The submandibular glands were averted to the submental region in 32 patients with nasopharyngeal carcinoma before they received conventional radiotherapy; a lead block was used to shield the submental region during therapy. Prior to radiotherapy, the function of the submandibular glands was assessed using imaging. Submandibular gland function was measured using 99mTc radionuclide scanning at 60 months after radiotherapy. The data in the questionnaire regarding the degree of xerostomia were investigated and saliva secretion was measured at 3, 6, 12, and 60 months after radiotherapy. In addition, the 5-year survival rate was calculated. Results After follow-up for 3, 6, and 12 months, the incidence of moderate to severe xerostomia was significantly lower in the experimental group than in the control group. The average amount of saliva produced by the experimental and control groups was 1.60 g and 0.68 g, respectively (P xerostomia was significantly lower than in the control group (15.4% and 76.9%, respectively; P xerostomia after radiotherapy for nasopharyngeal carcinoma, we found that clinical efficacy was good. This approach could improve the quality of life of nasopharyngeal carcinoma patients after radiotherapy and would not affect long-term treatment efficacy. PMID:24555575
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Directory of Open Access Journals (Sweden)
Alison M Greig
Full Text Available This study explored inter-relationships between vertebral fracture, thoracic kyphosis and trunk muscle control in elderly people with osteoporosis. Osteoporotic vertebral fractures are associated with increased risk of further vertebral fractures; but underlying mechanisms remain unclear. Several factors may explain this association, including changes in postural alignment (thoracic kyphosis and altered trunk muscle contraction patterns. Both factors may increase risk of further fracture because of increased vertebral loading and impaired balance, which may increase falls risk. This study compared postural adjustments in 24 individuals with osteoporosis with and without vertebral fracture and with varying degrees of thoracic kyphosis. Trunk muscle electromyographic activity (EMG associated with voluntary arm movements was recorded and compared between individuals with and without vertebral fracture, and between those with low and high thoracic kyphosis. Overall, elderly participants in the study demonstrated co-contraction of the trunk flexor and extensor muscles during forwards arm movements, but those with vertebral fractures demonstrated a more pronounced co-contraction than those without fracture. Individuals with high thoracic kyphosis demonstrated more pronounced alternating flexor and extensor EMG bursts than those with less kyphosis. Co-contraction of trunk flexor and extensor muscles in older individuals contrasts the alternating bursts of antagonist muscle activity in previous studies of young individuals. This may have several consequences, including altered balance efficacy and the potential for increased compressive loads through the spine. Both of these outcomes may have consequences in a population with fragile vertebrae who are susceptible to fracture.
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Kaufman, Matthew R; Elkwood, Andrew I; Aboharb, Farid; Cece, John; Brown, David; Rezzadeh, Kameron; Jarrahy, Reza
2015-06-01
Patients who are ventilator dependent as a result of combined cervical spinal cord injury and phrenic nerve lesions are generally considered to be unsuitable candidates for diaphragmatic pacing due to loss of phrenic nerve integrity and denervation of the diaphragm. There is limited data regarding efficacy of simultaneous nerve transfers and diaphragmatic pacemakers in the treatment of this patient population. A retrospective review was conducted of 14 consecutive patients with combined lesions of the cervical spinal cord and phrenic nerves, and with complete ventilator dependence, who were treated with simultaneous microsurgical nerve transfer and implantation of diaphragmatic pacemakers. Parameters of interest included time to recovery of diaphragm electromyographic activity, average time pacing without the ventilator, and percent reduction in ventilator dependence. Recovery of diaphragm electromyographic activity was demonstrated in 13 of 14 (93%) patients. Eight of these 13 (62%) patients achieved sustainable periods (> 1 h/d) of ventilator weaning (mean = 10 h/d [n = 8]). Two patients recovered voluntary control of diaphragmatic activity and regained the capacity for spontaneous respiration. The one patient who did not exhibit diaphragmatic reinnervation remains within 12 months of initial treatment. Surgical intervention resulted in a 25% reduction (p nerve transfers and pacemaker implantation can result in reinnervation of the diaphragm and lead to successful ventilator weaning. Our favorable outcomes support consideration of this surgical method for appropriate patients who would otherwise have no alternative therapy to achieve sustained periods of ventilator independence. Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.
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Rapid eye movement sleep behavior disorder--diagnostik, årsager og behandling
DEFF Research Database (Denmark)
Zoetmulder, Marielle; Jennum, Poul Jørgen
2009-01-01
Rapid eye movement (REM) sleep behaviour disorder (RBD) is characterized by loss of REM sleep and related electromyographic atonia with marked muscular activity and dream enactment behaviour. RBD is seen in 0.5% of the population. It occurs in an idiopathic form and secondarily to medical...... and neurological disease. RBD is related to brainstem pathology. Furthermore, it is increasingly recognized that RBD is frequently related to Parkinsonian disorders and narcolepsy. This article reviews recent knowledge about RBD with focus on the diagnostic process and management....
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[Biofeedback treatment for acute whiplash patients].
Gálvez-Hernández, Carmen Lizette; Rodríguez-Ortiz, María Dolores; Del Río-Portilla, Yolanda
2016-01-01
The aim of this study is to evaluate the physiological and psychological effect after an electromyographic biofeedback treatment in combination with progressive muscular relaxation training in patients with acute whiplash. Twelve patients with acute whiplash volunteered to participate in a quasi-experimental design and a control group. Two months maximum after car accident, severity levels II and I. previous history of persistent pain or serious previous injury. The groups were randomly divided in two (treatment and waiting list groups). We used electromyographic measures of the trapezius muscles with psychometric tests: Beck Anxiety and Depression Inventory; Oswestry Pain Disability Questionnaire; Visual Analog Scale of Pain; TAMPA Scale for Kinesiophobia. The treatment consisted in electromyographic biofeedback after progressive muscular relaxation training. There were significant intra-group differences before and after treatment in muscular symmetry and subjective pain perception in the treatment group. We achieved a significant change (clinical and statistical) in subjective pain perception and muscular symmetry. This study highlights the importance of multidisciplinary work in acute pain patients and the effectiveness of clinical psychophysiological strategies with acute whiplash patients.
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Wang, Chin-Man; Shieh, Wann-Yun; Weng, Yi-Hsin; Hsu, Yi-Hsuan; Wu, Yih-Ru
2017-09-01
Dysphagia is common among patients with Parkinson's disease. Swallowing and its coordination with respiration is extremely important to achieve safety swallowing. Different tools have been used to assess this coordination, however the results have been inconsistent. We aimed to investigate this coordination in patients with Parkinson's disease using a non-invasive method. Signals of submental muscle activity, thyroid cartilage excursion, and nasal airflow during swallowing were recorded simultaneously. Five different water boluses were swallowed three times, and the data were recorded and analyzed. Thirty-seven controls and 42 patients with early-stage Parkinson's disease were included. The rates of non-expiratory/expiratory pre- and post-swallowing respiratory phase patterns were higher in the patients than in the controls (P Parkinson's disease, and safety compensation mechanisms were used more than efficiency during swallowing. The results of this study may serve as a baseline for further research into new treatment regimens and to improve the management of swallowing in patients with Parkinson's disease. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.
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Piao, YongJun; Choi, YounJung; Kim, JungJa; Kwan, TaeKyu; Kim, Nam-Gyun
2009-03-01
Adequate postural balance depends on the spatial and temporal integration of vestibular, visual, and somatosensory information. Especially, the musculoskeletal function (range of joint, flexibility of spine, muscular strength) is essential in maintaining the postural balance. Muscular strength training methods include the use of commercialized devices and repeatable resistance training tools (rubber band, ball, etc). These training systems cost high price and can't control of intensity. Thus we suggest a new training system which can adjust training intensity and indicate the center of pressure of a subject while the training was passively controlled by applying controlled electric current to the Magneto- Rheological damper. And we performed experimental studies on the muscular activities in the lower extremities during maintaining, moving and pushing exercises on an unstable platform with Magneto rheological dampers. A subject executed the maintaining, moving and pushing exercises which were displayed in a monitor. The electromyographic signals of the eight muscles in lower extremities were recorded and analyzed in the time and frequency domain: the muscles of interest were rectus femoris, biceps femoris, tensor fasciae latae, vastus lateralis, vastus medialis, gastrocnemius, tibialis anterior, and soleus. The experimental results showed the difference of muscular activities at the four moving exercises and the nine maintaining exercises. The rate of the increase in the muscular activities was affected by the condition of the unstable platform with MR dampers for the maintaining and moving exercises. The experimental results suggested the choice of different maintaining and moving exercises could selectively train different muscles with varying intensity. Furthermore, the findings also suggested the training using this system can improve the ability of postural balance.
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Raouafi, Sana; Achiche, Sofiane; Begon, Mickael; Sarcher, Aurélie; Raison, Maxime
2018-01-01
Treatment for cerebral palsy depends upon the severity of the child's condition and requires knowledge about upper limb disability. The aim of this study was to develop a systematic quantitative classification method of the upper limb disability levels for children with spastic unilateral cerebral palsy based on upper limb movements and muscle activation. Thirteen children with spastic unilateral cerebral palsy and six typically developing children participated in this study. Patients were matched on age and manual ability classification system levels I to III. Twenty-three kinematic and electromyographic variables were collected from two tasks. Discriminative analysis and K-means clustering algorithm were applied using 23 kinematic and EMG variables of each participant. Among the 23 kinematic and electromyographic variables, only two variables containing the most relevant information for the prediction of the four levels of severity of spastic unilateral cerebral palsy, which are fixed by manual ability classification system, were identified by discriminant analysis: (1) the Falconer index (CAI E ) which represents the ratio of biceps to triceps brachii activity during extension and (2) the maximal angle extension (θ Extension,max ). A good correlation (Kendall Rank correlation coefficient = -0.53, p = 0.01) was found between levels fixed by manual ability classification system and the obtained classes. These findings suggest that the cost and effort needed to assess and characterize the disability level of a child can be further reduced.
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Does the Dumbbell-Carrying Position Change the Muscle Activity in Split Squats and Walking Lunges?
Stastny, Petr; Lehnert, Michal; Zaatar, Amr M Z; Svoboda, Zdenek; Xaverova, Zuzana
2015-11-01
The forward walking lunge (WL) and split squat (SSq) are similar exercises that have differences in the eccentric phase, and both can be performed in the ipsilateral or contralateral carrying conditions. This study aimed to determine the effects of dumbbell-carrying position on the kinematics and electromyographic (EMG) amplitudes of the gluteus medius (Gmed), vastus medialis (VM), vastus lateralis (VL), and biceps femoris during WLs and SSqs. The resistance-trained (RT) and the non-resistance-trained (NT) groups (both n = 14) performed ipsilateral WLs, contralateral WLs, ipsilateral SSqs, and contralateral SSqs in a randomized order in a simulated training session. The EMG amplitude, expressed as a percentage of the maximal voluntary isometric contraction (%MVIC), and the kinematics, expressed as the range of motion (ROM) of the hip and knee, were measured during 5 repetition maximum for both legs. The repeated measure analyses of variance showed significant differences between the RT and NT groups. The NT group showed a smaller knee flexion ROM (p < 0.001, η = 0.36) during both types of WLs, whereas the RT group showed a higher eccentric Gmed amplitude (p < 0.001, η = 0.46) during all exercises and a higher eccentric VL amplitude (p < 0.001, η = 0.63) during contralateral WLs. Further differences were found between contralateral and ipsilateral WLs in both the RT (p < 0.001, η = 0.69) and NT groups (p < 0.001, η = 0.80), and contralateral WLs resulted in higher eccentric Gmed amplitudes. Contralateral WLs highly activated the Gmed (90% MVIC); therefore, this exercise can increase the Gmed maximal strength. The ipsilateral loading condition did not increase the Gmed or VM activity in the RT or NT group.
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Expiratory muscle control during vomiting - Role of brain stem expiratory neurons
Miller, A. D.; Tan, L. K.
1987-01-01
The neural mechanisms controlling the muscles involved during vomiting were examined using decerebrated cats. In one experiment, the activity of the ventral respiratory group (VRG) expiratory (E) neurons was recorded during induced 'fictive vomiting' (i.e., a series of bursts of coactivation of abdominal and phrenic nerves that would be expected to produce expulsion in unparalyzed animals) and vomiting. In a second, abdominal muscle electromyographic and nerve activity were compared before and after sectioning the axons of descending VRG E neurons as they cross the midline between C1 and the obex (the procedure that is known to abolish expiratory modulation of internal intercostal muscle activity). The results of the study indicate that the abdominal muscles are controlled differently during respiration and vomiting.
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DEFF Research Database (Denmark)
Jakobsen, M. D.; Sundstrup, E.; Andersen, C. H.
2014-01-01
Objective The aim of this study was to evaluate muscle activity during hamstring rehabilitation exercises performed in training machine compared with elastic resistance. Design Six women and 13 men aged 28-67 yrs participated in a crossover study. Electromyographic (EMG) activity was recorded...... inclinometers. Results Training machines and elastic resistance showed similar high levels of muscle activity (biceps femoris and semitendinosus peak normalized EMG >80%). EMG during the concentric phase was higher than during the eccentric phase regardless of exercise and muscle. However, compared with machine.......001) during hamstring curl performed with elastic resistance (7.58 +/- 0.08) compared with hamstring curl performed in a machine (5.92 +/- 0.03). Conclusions Hamstring rehabilitation exercise performed with elastic resistance induces similar peak hamstring muscle activity but slightly lower EMG values at more...
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DEFF Research Database (Denmark)
Sundstrup, E; Jakobsen, M D; Andersen, C H
2014-01-01
these findings. However, pain in the lower back decreased muscular activity of the gluteus maximus and vastus medialis (P resistance induce high levels of muscle activity in all the large muscle groups at the hip, knee, and back. Importantly, the efficiency of these exercises......Therapists commonly use elastic bands in resistance exercises during rehabilitation of smaller muscles, such as in the shoulder. However, the effectiveness has not yet been investigated for larger muscle groups. This study investigates muscle activity during lower extremity exercises....... Electromyographic (EMG) activity of 10 muscles was measured in 24 women and 18 men during lunges with elastic resistance, lunges with dumbbells, and unilateral leg press in machine using 10 repetition maximum loadings, and normalized to maximal voluntary isometric contraction EMG. Lunges with dumbbells and leg...
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Chronic cheek ulcer caused by odontogenic cutaneous sinus tract
Directory of Open Access Journals (Sweden)
Tomoya Sato
2015-06-01
Odontogenic cutaneous sinus tracts are often misdiagnosed, and they lead to facial wounds and scarring. Therefore, we must be aware of the possibility of this condition. A dental origin must be considered for chronic ulcers involving the cheek, chin and submental areas. The clinical course of this patient suggests two important clinical issues for prompt diagnosis. First, physical examination, including palpation and probing, are helpful for exploration of sinus tracts. Second, computed tomography is useful to detect the sinus tract and affected teeth. Computed tomography provides radiographic evidence of the relationship between the tooth and cutaneous region, and it may be superior to radiography.
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Kinetics and Muscle Activity Patterns during Unweighting and Reloading Transition Phases in Running.
Directory of Open Access Journals (Sweden)
Patrick Sainton
Full Text Available Amongst reduced gravity simulators, the lower body positive pressure (LBPP treadmill is emerging as an innovative tool for both rehabilitation and fundamental research purposes as it allows running while experiencing reduced vertical ground reaction forces. The appropriate use of such a treadmill requires an improved understanding of the associated neuromechanical changes. This study concentrates on the runner's adjustments to LBPP-induced unweighting and reloading during running. Nine healthy males performed two running series of nine minutes at natural speed. Each series comprised three sequences of three minutes at: 100% bodyweight (BW, 60 or 80% BW, and 100% BW. The progressive unweighting and reloading transitions lasted 10 to 15 s. The LBPP-induced unweighting level, vertical ground reaction force and center of mass accelerations were analyzed together with surface electromyographic activity from 6 major lower limb muscles. The analyses of stride-to-stride adjustments during each transition established highly linear relationships between the LBPP-induced progressive changes of BW and most mechanical parameters. However, the impact peak force and the loading rate systematically presented an initial 10% increase with unweighting which could result from a passive mechanism of leg retraction. Another major insight lies in the distinct neural adjustments found amongst the recorded lower-limb muscles during the pre- and post-contact phases. The preactivation phase was characterized by an overall EMG stability, the braking phase by decreased quadriceps and soleus muscle activities, and the push-off phase by decreased activities of the shank muscles. These neural changes were mirrored during reloading. These neural adjustments can be attributed in part to the lack of visual cues on the foot touchdown. These findings highlight both the rapidity and the complexity of the neuromechanical changes associated with LBPP-induced unweighting and reloading
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Kinetics and Muscle Activity Patterns during Unweighting and Reloading Transition Phases in Running
Sainton, Patrick; Nicol, Caroline; Cabri, Jan; Barthèlemy-Montfort, Joëlle; Chavet, Pascale
2016-01-01
Amongst reduced gravity simulators, the lower body positive pressure (LBPP) treadmill is emerging as an innovative tool for both rehabilitation and fundamental research purposes as it allows running while experiencing reduced vertical ground reaction forces. The appropriate use of such a treadmill requires an improved understanding of the associated neuromechanical changes. This study concentrates on the runner’s adjustments to LBPP-induced unweighting and reloading during running. Nine healthy males performed two running series of nine minutes at natural speed. Each series comprised three sequences of three minutes at: 100% bodyweight (BW), 60 or 80% BW, and 100% BW. The progressive unweighting and reloading transitions lasted 10 to 15 s. The LBPP-induced unweighting level, vertical ground reaction force and center of mass accelerations were analyzed together with surface electromyographic activity from 6 major lower limb muscles. The analyses of stride-to-stride adjustments during each transition established highly linear relationships between the LBPP-induced progressive changes of BW and most mechanical parameters. However, the impact peak force and the loading rate systematically presented an initial 10% increase with unweighting which could result from a passive mechanism of leg retraction. Another major insight lies in the distinct neural adjustments found amongst the recorded lower-limb muscles during the pre- and post-contact phases. The preactivation phase was characterized by an overall EMG stability, the braking phase by decreased quadriceps and soleus muscle activities, and the push-off phase by decreased activities of the shank muscles. These neural changes were mirrored during reloading. These neural adjustments can be attributed in part to the lack of visual cues on the foot touchdown. These findings highlight both the rapidity and the complexity of the neuromechanical changes associated with LBPP-induced unweighting and reloading during running
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Mitchell, Patrick; Krotish, Debra; Shin, Yong-June; Hirth, Victor
2010-12-01
The effects of hypertension are chronic and continuous; it affects gait, balance, and fall risk. Therefore, it is desirable to assess gait health across hypertensive and nonhypertensive subjects in order to prevent or reduce the risk of falls. Analysis of electromyography (EMG) signals can identify age related changes of neuromuscular activation due to various neuropathies and myopathies, but it is difficult to translate these medical changes to clinical diagnosis. To examine and compare geriatrics patients with these gait-altering diseases, we acquire EMG muscle activation signals, and by use of a timesynchronized mat capable of recording pressure information, we localize the EMG data to the gait cycle, ensuring identical comparison across subjects. Using time-frequency analysis on the EMG signal, in conjunction with several parameters obtained from the time-frequency analyses, we can determine the statistical discrepancy between diseases. We base these parameters on physiological manifestations caused by hypertension, as well as other comorbities that affect the geriatrics community. Using these metrics in a small population, we identify a statistical discrepancy between a control group and subjects with hypertension, neuropathy, diabetes, osteoporosis, arthritis, and several other common diseases which severely affect the geriatrics community.
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Sorbie, Graeme G; Grace, Fergal M; Gu, Yaodong; Baker, Julien S; Ugbolue, Ukadike C
2018-04-01
The purpose of this study was to compare the electromyography (EMG) patterns of the thoracic and lumbar regions of the erector spinae (ES) muscle during the golf swing whilst using four different golf clubs. Fifteen right-handed male golfers performed a total of twenty swings in random order using the driver, 4-iron, 7-iron and pitching-wedge. Surface EMG was recorded from the lead and trail sides of the thoracic and lumbar regions of the ES muscle (T8, L1 and L5 lateral to the spinous-process). Three-dimensional high-speed video analysis was used to identify the backswing, forward swing, acceleration, early and late follow-through phases of the golf swing. No significant differences in muscle-activation levels from the lead and trail sides of the thoracic and lumbar regions of the ES muscle were displayed between the driver, 4-iron, 7-iron and pitching-wedge (P > 0.05). The highest mean thoracic and lumbar ES muscle-activation levels were displayed in the forward swing (67-99% MVC) and acceleration (83-106% MVC) phases of the swing for all clubs tested. The findings from this study show that there were no significant statistical differences between the driver, 4-iron, 7-iron and pitching-wedge when examining muscle activity from the thoracic and lumbar regions of the ES muscle.
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Rutherford, Derek; Moreside, Janice; Wong, Ivan
2015-07-01
Knee replacements are common after hip replacement for end stage osteoarthritis. Whether abnormal knee mechanics exist in moderate hip osteoarthritis remains undetermined and has implications for understanding early osteoarthritis joint mechanics. The purpose of this study was to determine whether three-dimensional (3D) knee motion and muscle activation patterns in individuals with moderate hip osteoarthritis differ from an asymptomatic cohort and whether these features differ between contra- and ipsilateral knees. 3D motions and medial and lateral quadriceps and hamstring surface electromyography were recorded on 20 asymptomatic individuals and 20 individuals with moderate hip osteoarthritis during treadmill walking, using standardized collection and processing procedures. Principal component analysis was used to derive electromyographic amplitude and temporal waveform features. 3D stance-phase range of motion was calculated. A 2-factor repeated analysis of variance determined significant within-group leg and muscle differences. Student's t-tests identified between group differences, with Bonferroni corrections where applicable (α=0.05). Lower sagittal plane motion between early and mid/late stance (5°, P=0.004, effect size: 0.96) and greater mid-stance quadriceps activity was found in the osteoarthritis group (P=0.01). Compared to the ipsilateral knee, a borderline significant increase in mid-stance hamstring activity was found in the contra-lateral knee of the hip osteoarthritis group (P=0.018). Bilateral knee mechanics were altered, suggesting potentially increased loads and knee muscle fatigue. There was no indication that one knee is more susceptible to osteoarthritis than the other, thus clinicians should include bilateral knee analysis when treating patients with hip osteoarthritis. Copyright © 2015 Elsevier Ltd. All rights reserved.
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De Cicco, Vincenzo
2012-09-03
A patient affected by asymmetric hemodynamics of cerebro-afferent vessels underwent duplex color scanner investigations in occlusal proprioceptive un- and rebalance conditions. Pupillometric video-oculographic examinations were performed in order to spot connected trigeminal proprioceptive motor patterns able to interfere on sympathetic autonomic activity. The aim of this case report is to verify if involuntary jaw closing during swallowing, executed in unbalance and rebalance myoelectric activity, would be able to modify cerebral hemodynamics. A 56-year-old Caucasian Italian woman affected by asymmetric blood flow of cerebro-afferent vessels underwent an electromyographic investigation of her occlusal muscles in order to assess their occlusal functional balance. The extreme asymmetry of myoelectric activity in dental occlusion evidenced by electromyographic values suggested the rebalancing of the functions of occlusal muscles through concurrent transcutaneous stimulation of the trigeminal nerve supra- and submandibular motor branches. The above-mentioned method allowed the detection of a symmetric craniomandibular muscular relation that can be kept constant through the use of a cusp bite modeled on the inferior dental arch: called orthotic-syntropic bite for its peculiar use of electrostimulation. A few days later, the patient underwent a duplex color scanner investigation and pupillometric video-oculographic examinations in occlusal unbalance and rebalance conditions. A comparative data analysis showed that an unbalanced dental occlusal function may represent an interferential pattern on cerebral hemodynamics velocity and pupillometric evaluations have proved useful both in the analysis of locus coeruleus functional modalities and as a diagnostic tool in the assessment of pathologies involving locus coeruleus and autonomic systems. The inclusion of myoelectric masseter examinations can be useful in patients with asymmetric hemodynamics of cerebro
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Directory of Open Access Journals (Sweden)
Ursula S Hofstoetter
Full Text Available Epidural electrical stimulation of the lumbar spinal cord is currently regaining momentum as a neuromodulation intervention in spinal cord injury (SCI to modify dysregulated sensorimotor functions and augment residual motor capacity. There is ample evidence that it engages spinal circuits through the electrical stimulation of large-to-medium diameter afferent fibers within lumbar and upper sacral posterior roots. Recent pilot studies suggested that the surface electrode-based method of transcutaneous spinal cord stimulation (SCS may produce similar neuromodulatory effects as caused by epidural SCS. Neurophysiological and computer modeling studies proposed that this noninvasive technique stimulates posterior-root fibers as well, likely activating similar input structures to the spinal cord as epidural stimulation. Here, we add a yet missing piece of evidence substantiating this assumption. We conducted in-depth analyses and direct comparisons of the electromyographic (EMG characteristics of short-latency responses in multiple leg muscles to both stimulation techniques derived from ten individuals with SCI each. Post-activation depression of responses evoked by paired pulses applied either epidurally or transcutaneously confirmed the reflex nature of the responses. The muscle responses to both techniques had the same latencies, EMG peak-to-peak amplitudes, and waveforms, except for smaller responses with shorter onset latencies in the triceps surae muscle group and shorter offsets of the responses in the biceps femoris muscle during epidural stimulation. Responses obtained in three subjects tested with both methods at different time points had near-identical waveforms per muscle group as well as same onset latencies. The present results strongly corroborate the activation of common neural input structures to the lumbar spinal cord-predominantly primary afferent fibers within multiple posterior roots-by both techniques and add to unraveling the
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Hacad, Claudia R; Glazer, Howard I; Zambon, João Paulo C; Burti, Juliana S; Almeida, Fernando G
2015-03-01
The aim of this study is to determine electromyographic pelvic floor muscles activity during the first 6 months post RRP and its relationship to urinary continence. Thirty-eight men (mean age of 63.1 ± 5.7 year) with prostate cancer scheduled for open radical retropubic prostatectomy were evaluated. pelvic radiotherapy, systemic or neurologic diseases, pre-operative International Prostate Symptoms Score (IPSS) >7 and OABq ≥8. Surface electromyography (sEMG) evaluation, IPSS, Urinary Distress Inventory, Incontinence Impact Questionnaire, and Overactive Bladder Questionnaire-short form were applied before and at 1, 3, and 6 months after RRP. Six months after surgery, 18 men (47.4 %) presented urinary leakage. The sEMG evaluations within the first 6 months presented changes in fast contraction amplitude (p = 0.006), rest amplitude after fast contraction (p = 0.04), 10 s sustained contraction mean amplitude (p = 0.024) and final rest amplitude (p = 0.011). We observed that continent and incontinent patients as a group presented electromyographic changes during the first 6 months after radical prostatectomy that could be justified by the denervation/reinnervation of the external urethral sphincter. This finding is consistent with the adaptation of the pelvic floor musculature to the new urethral sphincter condition following surgery.
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Surface EMG system for use in long-term vigorous activities
de Luca, G.; Bergman, P.; de Luca, C.
The purpose of the project was to develop an advanced surface electromyographic (EMG) system that is portable, un-tethered, and able to detect high-fidelity EMG signals from multiple channels. The innovation was specifically designed to extend NASA's capability to perform neurological status monitoring for long-term, vigorous activities. These features are a necessary requirement of ground-based and in-flight studies planned for the International Space Station and human expeditions to Mars. The project consisted of developing 1) a portable EMG digital data logger using a handheld PC for acquiring the signal and storing the data from as many as 8 channels, and 2) an EMG electrode/skin interface to improve signal fidelity and skin adhesion in the presence of sweat and mechanical disturbances encountered during vigorous activities. The system, referred to as a MyoMonitor, was configured with a communication port for downloading the data from the data logger to the PC computer workstation. Software specifications were developed and implemented for programming of acquisition protocols, power management, and transferring data to the PC for processing and graphical display. The prototype MyoMonitor was implemented using a handheld PC that features a color LCD screen, enhanced keyboard, extended Lithium Ion battery and recharger, and 128 Mbytes of F ash Memory. The system was designed to be belt-worn,l thereby allowing its use under vigorous activities. The Monitor utilizes up to 8 differential surface EMG sensors. The prototype allowed greater than 2 hours of continuous 8-channel EMG data to be collected, or 17.2 hours of continuous single channel EMG data. Standardized tests in human subjects were conducted to develop the mechanical and electrical properties of the prototype electrode/interface system. Tests conducted during treadmill running and repetitive lifting demonstrated that the prototype interface significantly reduced the detrimental effects of sweat
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DEFF Research Database (Denmark)
Sennels, Søren; Biering-Sørensen, Fin; Andersen, Ole Trier
1997-01-01
In order to use the volitional electromyography (EMG) as a control signal for the stimulation of the same muscle, it is necessary to eliminate the stimulation artifacts and the muscle responses caused by the stimulation. The stimulation artifacts, caused by the electric field in skin and tissue...
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Alonso, Joan Francesc; Mañanas, Miguel A; Hoyer, Dirk; Topor, Zbigniew L; Bruce, Eugene N
2007-09-01
Analysis of respiratory muscles activity is an effective technique for the study of pulmonary diseases such as obstructive sleep apnea syndrome (OSAS). Respiratory diseases, especially those associated with changes in the mechanical properties of the respiratory apparatus, are often associated with disruptions of the normally highly coordinated contractions of respiratory muscles. Due to the complexity of the respiratory control, the assessment of OSAS related dysfunctions by linear methods are not sufficient. Therefore, the objective of this study was the detection of diagnostically relevant nonlinear complex respiratory mechanisms. Two aims of this work were: (1) to assess coordination of respiratory muscles contractions through evaluation of interactions between respiratory signals and myographic signals through nonlinear analysis by means of cross mutual information function (CMIF); (2) to differentiate between functioning of respiratory muscles in patients with OSAS and in normal subjects. Electromyographic (EMG) and mechanomyographic (MMG) signals were recorded from three respiratory muscles: genioglossus, sternomastoid and diaphragm. Inspiratory pressure and flow were also acquired. All signals were measured in eight patients with OSAS and eight healthy subjects during an increased respiratory effort while awake. Several variables were defined and calculated from CMIF in order to describe correlation between signals. The results indicate different nonlinear couplings of respiratory muscles in both populations. This effect is progressively more evident at higher levels of respiratory effort.
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Directory of Open Access Journals (Sweden)
Bianca Callegari
2010-12-01
Full Text Available Propriocepção refere-se à percepção dos mecanorreceptores para discriminar a posição do corpo e movimentos articulares, bem como tensões sobre os tendões na fase estática ou dinâmica da marcha. Objetivou-se avaliar por eletromiografia a ativação muscular do gastrocnêmio e tibial anterior em diferentes exercícios de propriocepção do tornozelo em apoio unipodal, comparando graus de dificuldade. Foram selecionados 54 voluntários, sedentários, destros, do sexo masculino (20-35 anos. Exercícios foram feitos no balancinho, prancha de equilíbrio, cama elástica e solo, à razão de três repetições de 15 segundos cada, com intervalo de 15 segundos entre as repetições. Ao final dos testes os voluntários indicaram a maior dificuldade. A atividade elétrica de ambos os músculos foi significativamente maior durante o teste no balancinho. No solo, ambos os músculos apresentaram menor atividade, mas apenas no gastrocnêmio essa diferença foi significativa. No exercício na prancha de equilíbrio e na cama elástica não se encontrou diferença quanto à ativação dos músculos. Na análise intermúsculo foi observada maior atividade do tibial anterior, exceto no balancinho. Assim, para o treino do apoio unipodal na aquisição do ganho proprioceptivo, o equipamento adotado deve ser escolhido com cuidado: no balancinho é maior o recrutamento dos músculos tibial anterior e gastrocnêmio, assim como é maior o grau de dificuldade para manutenção do equilíbrio.Proprioception refers to the ability of mechanoreceptors to discriminate body position and joint movements, as well as tensions during static or dynamic phases. The aim of this study was to assess, by means of surface electromyography, activation patterns of the gastrocnemius and tibialis anterior muscles in proprioception exercises, also comparing difficulty levels. Fifty-four sedentary, right-handed, 20-to-35 year-old male volunteers performed single-leg stance
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The Potential Risk Factors Relevant to Lateral Epicondylitis by Wrist Coupling Posture.
Directory of Open Access Journals (Sweden)
Su-Ya Lee
Full Text Available The use of awkward wrist postures and unskilled techniques might induce lateral epicondylitis. This study thus investigated the effects of wrist deviation combined with extension and movement velocity on the dynamic performances of the wrist muscles during the coupling posture via a custom-made bi-planar isokinetic dynamometer. Thirty subjects were recruited to perform the isokinetic testing. We measured the muscle strengths and activities for the wrist extensors and flexors during concentric and eccentric contractions at three movement velocities, 30°s-1, 90°s-1, and 180°s-1, combined with three wrist postures, neutral position (NP, radial deviation (RD, and ulnar deviation (UD. The root mean square (RMS of the electromyographic signal in the extensor digitorum communis (EDC, normalized peak torque of extensors, and ratio of normalized peak torque between wrist extensors and flexors, were all greater in the NP than RD and UD in both contractions. The ratio of RMS between EDC and flexor digitorum superficialis (FDS had a significantly greater value in RD than UD during the concentric contraction. The EDC showed significantly higher activity at the fast velocity in both contractions. Nevertheless, a significantly higher RMS of the electromyographic signal between EDC and FDS and the ratio of strength between wrist extensors and flexors were found at slow velocity in both contractions. The wrist deviation combined with extension and movement velocity of the wrist joint should thus be considered as influential factors which might alter the dynamic performances, and may result in further injury of the elbow joint.
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Effect of experimental stress in 2 different pain conditions affecting the facial muscles.
Woda, Alain; L'heveder, Gildas; Ouchchane, Lemlih; Bodéré, Céline
2013-05-01
Chronic facial muscle pain is a common feature in both fibromyalgia (FM) and myofascial (MF) pain conditions. In this controlled study, a possible difference in the mode of deregulation of the physiological response to a stressing stimulus was explored by applying an acute mental stress to FM and MF patients and to controls. The effects of the stress test were observed on pain, sympathetic variables, and both tonic and reflex electromyographic activities of masseteric and temporal muscles. The statistical analyses were performed through a generalized linear model including mixed effects. Painful reaction to the stressor was stronger (P < .001) and longer (P = .011) in FM than in MF independently of a higher pain level at baseline. The stress-induced autonomic changes only seen in FM patients did not reach significance. The electromyographic responses to the stress test were strongest for controls and weakest for FM. The stress test had no effect on reflex activity (area under the curve [AUC]) or latency, although AUC was high in FM and latencies were low in both pain groups. It is suggested that FM is characterized by a lower ability to adapt to acute stress than MF. This study showed that an acute psychosocial stress triggered several changes in 2 pain conditions including an increase in pain of larger amplitude in FM than in MF pain. Similar stress-induced changes should be explored as possible mechanisms for differentiation between dysfunctional pain conditions. Copyright © 2013 American Pain Society. Published by Elsevier Inc. All rights reserved.
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Pharmacological Modulation of Hemodynamics in Adult Zebrafish In Vivo.
Directory of Open Access Journals (Sweden)
Daniel Brönnimann
Full Text Available Hemodynamic parameters in zebrafish receive increasing attention because of their important role in cardiovascular processes such as atherosclerosis, hematopoiesis, sprouting and intussusceptive angiogenesis. To study underlying mechanisms, the precise modulation of parameters like blood flow velocity or shear stress is centrally important. Questions related to blood flow have been addressed in the past in either embryonic or ex vivo-zebrafish models but little information is available for adult animals. Here we describe a pharmacological approach to modulate cardiac and hemodynamic parameters in adult zebrafish in vivo.Adult zebrafish were paralyzed and orally perfused with salt water. The drugs isoprenaline and sodium nitroprusside were directly applied with the perfusate, thus closely resembling the preferred method for drug delivery in zebrafish, namely within the water. Drug effects on the heart and on blood flow in the submental vein were studied using electrocardiograms, in vivo-microscopy and mathematical flow simulations.Under control conditions, heart rate, blood flow velocity and shear stress varied less than ± 5%. Maximal chronotropic effects of isoprenaline were achieved at a concentration of 50 μmol/L, where it increased the heart rate by 22.6 ± 1.3% (n = 4; p < 0.0001. Blood flow velocity and shear stress in the submental vein were not significantly increased. Sodium nitroprusside at 1 mmol/L did not alter the heart rate but increased blood flow velocity by 110.46 ± 19.64% (p = 0.01 and shear stress by 117.96 ± 23.65% (n = 9; p = 0.03.In this study, we demonstrate that cardiac and hemodynamic parameters in adult zebrafish can be efficiently modulated by isoprenaline and sodium nitroprusside. Together with the suitability of the zebrafish for in vivo-microscopy and genetic modifications, the methodology described permits studying biological processes that are dependent on hemodynamic alterations.
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Oni, Georgette; Hoxworth, Ron; Teotia, Sumeet; Brown, Spencer; Kenkel, Jeffrey M
2014-09-01
The Ulthera System (Ulthera, Inc, Mesa, Arizona) employs microfocused ultrasound to cause discrete focal heating of the dermis and stimulate neocollagenesis and elastin remodeling. The authors investigated tightening and lifting of cheek tissue, improvement in jawline definition, and reduction in submental skin laxity in patients treated with the Ulthera System. A total of 103 adults were enrolled in this prospective nonrandomized clinical trial. Three-dimensional photographs obtained at baseline and 3 months posttreatment were assessed qualitatively by 3 blinded reviewers and quantitatively with AutoCAD software (Informer Technologies, Redwood City, California). The relationship between outcomes and body mass index (BMI) was examined as well. Patients rated pain during the procedure and provided subjective assessment of their outcome at 90 days. Adverse events were documented. Ninety-three patients were evaluated. Blinded reviewers observed improvement in skin laxity in 58.1% of patients. During quantitative assessments, overall improvement in skin laxity was noted in 63.6% of evaluated patients. No change was detected in 54.5% of patients whose BMI exceeded 30 kg/m2 or in 12.2% of patients whose BMI was ≤30 kg/m2. At day 90, 65.6% of patients perceived improvement in the skin laxity of the lower half of their face/neck. The average procedural pain scores for the cheek, submental, and submandibular regions were 5.68, 6.09, and 6.53, respectively. Wheals, which resolved without intervention or long-term sequelae, were reported for 3 patients. To the authors' knowledge, this is the largest clinical study of the effectiveness of the Ulthera System for rejuvenation of the lower face. At day 90, improvements were reported by two-thirds of patients and by nearly 60% of blinded reviewers. Outcomes were better in patients with BMI≤30 kg/m2. 2. © 2014 The American Society for Aesthetic Plastic Surgery, Inc.
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A study on the lateral cephalometric tomography of TMJ arthrosis
Energy Technology Data Exchange (ETDEWEB)
Lee, Ki Hoon; Yoon, Jung Ho [Dept. of Dental Science, Graduate School, Yonsei University, Seoul (Korea, Republic of)
1987-11-15
The author obtained individualizes lateral cephalometric tomograms form 23 young adults (46 of left and right normal TMJ) with normal occlusion and 20 patients (14 of patient asymptomatic TMJ and 26 of patient symptomatic TMJ) with clicking and painful TMJ after the analysis of submental vertex view. Individualized lateral cephalometric tomogram analysis and TMJ space analysis were performed after tracing each film. All data form these analysis was recorded and statistically processed with CYBER computer system. The results were obtained as follows: 1. In submental vertex view, the mean condylar angulation of Rt. side in normal group was 20.348 degrees {+-} 6.358 degrees, Lt. si de was 18.870 degrees {+-} 7.777 degrees and Rt. side in patient group was 19.350 degrees {+-} 7.576 degrees, Lt, side was 17.750 degrees {+-} 6.146 degrees respectively. The mean condylar angulation of Rt. side was larger than Lt, side in normal and patient group. 2. When the mandible was moved from centric occlusion to centric relation, condylar position relating to the glenoid fossa was placed posteriorly and superiorly in normal TMJ group and patient symptomatic TMJ group. 3. In centric relation position, the proportion of anterior space to posterior space was 1.593 for normal TMJ group , 1.604 for patient asymptomatic TMJ group and 1.671 for patient symptomatic TMJ group. In centric occlusion position, 1.390 for normal TMJ group, 1.539 for patient asymptomatic TMJ group and 1.196 for patient asymptomatic group. 4. Normal TMJ group, patient asymptomatic TMJ group and patient symptomatic TMJ group and patient symptomatic TMJ group revealed significant difference in C2 measurement. (ANOVA-test, P<0.05) br> 5. Normal group and patient group revealed significant in Fh, C1 and C2 measurement. (T-test, P<0.05)>
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A study on the lateral cephalometric tomography of TMJ arthrosis
International Nuclear Information System (INIS)
Lee, Ki Hoon; Yoon, Jung Ho
1987-01-01
The author obtained individualizes lateral cephalometric tomograms form 23 young adults (46 of left and right normal TMJ) with normal occlusion and 20 patients (14 of patient asymptomatic TMJ and 26 of patient symptomatic TMJ) with clicking and painful TMJ after the analysis of submental vertex view. Individualized lateral cephalometric tomogram analysis and TMJ space analysis were performed after tracing each film. All data form these analysis was recorded and statistically processed with CYBER computer system. The results were obtained as follows: 1. In submental vertex view, the mean condylar angulation of Rt. side in normal group was 20.348 degrees ± 6.358 degrees, Lt. si de was 18.870 degrees ± 7.777 degrees and Rt. side in patient group was 19.350 degrees ± 7.576 degrees, Lt, side was 17.750 degrees ± 6.146 degrees respectively. The mean condylar angulation of Rt. side was larger than Lt, side in normal and patient group. 2. When the mandible was moved from centric occlusion to centric relation, condylar position relating to the glenoid fossa was placed posteriorly and superiorly in normal TMJ group and patient symptomatic TMJ group. 3. In centric relation position, the proportion of anterior space to posterior space was 1.593 for normal TMJ group , 1.604 for patient asymptomatic TMJ group and 1.671 for patient symptomatic TMJ group. In centric occlusion position, 1.390 for normal TMJ group, 1.539 for patient asymptomatic TMJ group and 1.196 for patient asymptomatic group. 4. Normal TMJ group, patient asymptomatic TMJ group and patient symptomatic TMJ group and patient symptomatic TMJ group revealed significant difference in C2 measurement. (ANOVA-test, P 5. Normal group and patient group revealed significant in Fh, C1 and C2 measurement. (T-test, P
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Lepilin, A V; Raĭgorodckiĭ, Iu M; Nozdrachev, V G; Erokina, N L
2007-01-01
145 patients (60 with phlegmons of submandibular and submental regions, 85--with fractures of mandible) were observed and treated with the use of moving pulse magnetic field (MPMF) produced by special apparatus (AMO-ATOS-E, , Saratov-city), 60 patients with the same pathology were treated by traditional physical methods and served as control. Use of MPMF led to quicker patient recovery: quicker reduction (if compared with traditional physical methods of treatment) of oedema and soft tissue inflammatory infiltration, quicker relief from inflammatory reaction (according to data of cytokinin profile), improvement of tissue blood supply in the region of fractures in patients with mandible fractures. As the result--we had shortening treatment terms of such patients and complication number reduction.
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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
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Farias, Déborah de Araújo; Willardson, Jeffrey M; Paz, Gabriel A; Bezerra, Ewertton de S; Miranda, Humberto
2017-07-01
Farias, DdA, Willardson, JM, Paz, GA, Bezerra, EdS, and Miranda, H. Maximal strength performance and muscle activation for the bench press and triceps extension exercises adopting dumbbell, barbell and machine modalities over multiple sets. J Strength Cond Res 31(7): 1879-1887, 2017-The purpose of this study was to investigate muscle activation, total repetitions, and training volume for 3 bench press (BP) exercise modes (Smith machine [SMBP], barbell [BBP], and dumbbell [DBP]) that were followed by a triceps extension (TE) exercise. Nineteen trained men performed 3 testing protocols in random order, which included: (P1) SMBP + TE; (P2) BBP + TE; and (P3) DBP + TE. Each protocol involved 4 sets with a 10-repetition maximum (RM) load, immediately followed by a TE exercise that was also performed for 4 sets with a 10RM load. A 2-minute rest interval was adopted between sets and exercises. Surface electromyographic activity was assessed for the pectoralis major (PM), anterior deltoid (AD), biceps brachii (BB), and triceps brachii (TB). The results indicated that significantly higher total repetitions were achieved for the DBP (31.2 ± 3.2) vs. the BBP (27.8 ± 4.8). For the TE, significantly greater volume was achieved when this exercise was performed after the BBP (1,204.4 ± 249.4 kg) and DBP (1,216.8 ± 287.5 kg) vs. the SMBP (1,097.5 ± 193 kg). The DBP elicited significantly greater PM activity vs. the BBP. The SMBP elicited significantly greater AD activity vs. the BBP and DBP. During the different BP modes, the SMBP and BBP elicited significantly greater TB activity vs. the DBP. However, the DBP elicited significantly greater BB activity vs. the SMBP and BBP, respectively. During the succeeding TE exercise, significantly greater activity of the TB was observed when this exercise was performed after the BBP vs. the SMBP and DBP. Therefore, it seems that the variation in BP modes does influence both repetition performance and muscle activation patterns during the
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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...
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Directory of Open Access Journals (Sweden)
Mahdi Mahjur
2016-05-01
Full Text Available The aim of this study was to evaluate effects of hydrotherapy on postural control and electromyography parameters in men with chronic non-specific low back pain. Thirty men with chronic non-specific LBP divided into two hydrotherapy and control groups, randomly and equally. Electromyographic activity of erector spinae muscles and balance measured for both of groups before and after intervention. Hydrotherapy program was consisted of 24 sessions. Subjects in control group didn’t have any special activity. Two-way variance was used to interpret the data and correlated and independent T-tests were used for analysis of data at the significance level of (P0.05. However, a significant difference observed between two groups in balance index (P<0.05.