Electrical Concepts in the Surface Electromyographic Signal

Bolek, Jeffrey E.

doi:10.1007/s10484-009-9118-x

Cited by 6 publications

(3 citation statements)

References 11 publications

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“…Electromyography (EMG) biofeedback is an effective tool for exploring the limits of volitional motor control. During walking, biofeedback of the tibialis anterior or gastrocnemius can help restore normal ankle dorsiflexion or plantarflexion moments for individuals with stroke or cerebral palsy 27,28 . Humans can also gain selective control over several motor units within a single biofeedback session 29,30 , but most individuals lose this selective control during dynamic tasks 31 .…”

Section: Muscle Coordination Retraining Inspired By Musculoskeletal S...mentioning

confidence: 99%

Muscle coordination retraining inspired by musculoskeletal simulations reduces knee contact force

Uhlrich

Jackson

Seth

et al. 2022

Sci Rep

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Humans typically coordinate their muscles to meet movement objectives like minimizing energy expenditure. In the presence of pathology, new objectives gain importance, like reducing loading in an osteoarthritic joint, but people often do not change their muscle coordination patterns to meet these new objectives. Here we use musculoskeletal simulations to identify simple changes in coordination that can be taught using electromyographic biofeedback, achieving the therapeutic goal of reducing joint loading. Our simulations predicted that changing the relative activation of two redundant ankle plantarflexor muscles—the gastrocnemius and soleus—could reduce knee contact force during walking, but it was unclear whether humans could re-coordinate redundant muscles during a complex task like walking. Our experiments showed that after a single session of walking with biofeedback of summary measures of plantarflexor muscle activation, healthy individuals reduced the ratio of gastrocnemius-to-soleus muscle activation by 25 ± 15% (p = 0.004, paired t test, n = 10). Participants who walked with this “gastrocnemius avoidance” gait pattern reduced late-stance knee contact force by 12 ± 12% (p = 0.029, paired t test, n = 8). Simulation-informed coordination retraining could be a promising treatment for knee osteoarthritis and a powerful tool for optimizing coordination for a variety of rehabilitation and performance applications.

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Section: Muscle Coordination Retraining Inspired By Musculoskeletal S...mentioning

confidence: 99%

Muscle coordination retraining inspired by musculoskeletal simulations reduces knee contact force

Uhlrich

Jackson

Seth

et al. 2022

Sci Rep

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“…18 Surface EMG is a widely accepted and commonly used electrophysiological modality in research 19 that measures neuromuscular electrical activity deep to the electrode. 20 However, this modality has several limitations, including cross-talk from surrounding muscles, electromechanical delay, and irritation or discomfort (fine-wire EMG). 19 Electromyography is frequently used in the research setting, but few practicing clinicians have access to or the training to employ this modality in clinical practice.…”

mentioning

confidence: 99%

Ultrasonography of Gluteal and Fibularis Muscles During Exercises in Individuals With a History of Lateral Ankle Sprain

Koldenhoven

Fraser

Saliba

et al. 2019

Journal of Athletic Training

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Context Individuals with a history of lateral ankle sprains (LASs) have ankle and hip neuromuscular changes compared with those who do not have a history of LAS. Objective To compare gluteus maximus (GMax), gluteus medius (GMed), and fibularis longus and brevis muscle activation using ultrasound imaging during tabletop exercises and lateral resistance-band walking in individuals with or without a history of LAS or chronic ankle instability (CAI). Design Cross-sectional study. Patients or Other Participants Sixty-seven young adults (27 males, 40 females). Groups were healthy = 16, coper = 17, LAS = 15, CAI = 19. The number of previous sprains was 0 ± 0 in the healthy group, 1.1 ± 0.3 in the coper group, 2.9 ± 2.4 in the LAS group, and 5.3 ± 5.9 in the CAI group. Main Outcome Measure(s) Ultrasound imaging measures of fibularis cross-sectional area (CSA) were collected during nonresisted and resisted ankle eversion. Gluteal muscle thicknesses were imaged during nonresisted and resisted side-lying abduction and during lateral resistance-band walking exercises (lower leg and forefoot band placement). Separate 4 × 2 repeated-measures analyses of variance and post hoc Fisher least significant difference tests were used to assess activation across groups and resistance conditions. Results All groups demonstrated 3.2% to 4.1% increased fibularis CSA during resisted eversion compared with nonresisted. During side-lying abduction, the LAS and CAI groups displayed increased GMax thickness (6.4% and 7.2%, respectively), and all but the CAI group (−0.4%) increased GMed thickness (5.3%–11.8%) with added resistance in hip abduction. During band walking, the healthy and LAS groups showed increased GMax thickness (4.8% and 8.1%, respectively), and all groups had increased GMed thickness (3.0%–5.8%) in forefoot position compared with the lower leg position. Although the values were not different, copers exhibited the greatest amount of GMed thickness during band-walking activities (copers = 23%–26%, healthy = 17%–23%, LAS = 11%–15%, CAI = 15%–19%). Conclusions All groups had increased fibularis CSA with resisted eversion. In side-lying hip abduction, individuals with CAI had greater GMax thickness than GMed thickness. Ultrasound imaging of fibularis CSA and gluteal muscle thickness may be clinically useful in assessing and treating patients with LAS or CAI.

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“…Indeed, feedback during functional activities was shown to induce alterations in the gait pattern of children with CP. [115][116][117][118] For example, repetitive gait training can cause changes in corticomotor pathways, 119,120 and is expected to achieve long-term effects. However, it is unknown whether this is through decreases in stretch hyperreflexia or by adjustments in supraspinal control.…”

Section: Biofeedback During Functional Activitiesmentioning

confidence: 99%

Stretch hyperreflexia in children with cerebral palsy

Flux

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Cerebral palsy (CP) is a neurological disorder and the most frequent cause of motor impairment in children in Europe. Around 85% of children with CP experience stretch hyperreflexia, also known as “spasticity”. Stretch hyperreflexia is an excessive response to muscle stretch, leading to increased joint resistance. The joint hyper-resistance causes limitations in activities such as walking. Multiple methods have been developed to measure stretch hyperreflexia, but evidence supporting the use of these methods for diagnostics and treatment evaluation in children with CP is insufficient. Furthermore, most methods are designed to assess stretch reflexes in passive conditions, which might not translate to the limitations encountered due to stretch reflexes during activities. Furthermore, while a broad range of stretch hyperreflexia treatments is available, many are invasive, non-specific, or temporary and might have adverse side effects. Training methods to reduce stretch reflexes using biofeedback are promising non-invasive methods with potential long-term sustained effects. Still, clinical feasibility needs to be improved before implementation in clinical rehabilitation of children with CP. This thesis aimed to develop methods to assess stretch hyperreflexia of the calf muscles during passive conditions, as well as in the context of walking. Additionally, this thesis aimed to develop clinically feasible methods to modulate stretch hyperreflexia in the calf muscle of children with CP. The outcomes are described in eight different studies presented in this thesis. All in all, the work presented in this thesis shows that sagittal plane clinical gait analysis can be performed using the human body model and can be complemented with ultrasound imaging of the calf muscle. Motorized methods to assess stretch hyperreflexia in passive conditions might be useful for evaluation in adults after SCI/Stroke. Still, limitations regarding feasibility and validity limit clinical application for children with CP. Furthermore, this thesis provides additional evidence that the deviating muscle activation patterns during walking, particularly the increased activation around initial contact, are caused by stretch hyper-reflexes in children with CP. The deviating muscle activation patterns, with increased activation during early stance and reduced activation around push-off, can be modulated within one session by several children with CP. Therefore, the next step is to develop a training program to modulate the activation pattern and potentially decrease stretch hyper-reflexes in children with CP to improve the gait pattern

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Electrical Concepts in the Surface Electromyographic Signal

Cited by 6 publications

References 11 publications

Muscle coordination retraining inspired by musculoskeletal simulations reduces knee contact force

Muscle coordination retraining inspired by musculoskeletal simulations reduces knee contact force

Ultrasonography of Gluteal and Fibularis Muscles During Exercises in Individuals With a History of Lateral Ankle Sprain

Stretch hyperreflexia in children with cerebral palsy

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