Impaired Firing Behavior of Individually Tracked Paretic Motor Units During Fatiguing Contractions of the Dorsiflexors and Functional Implications Post Stroke
| Autor: | Allison S. Hyngstrom, Jennifer N Nguyen, Claudio Orizio, Francesco Negro, Cassidy G Bannon, Kathleen E Bathon, Sandra K. Hunter |
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| Jazyk: | angličtina |
| Rok vydání: | 2020 |
| Předmět: |
medicine.medical_specialty
Contraction (grammar) medicine.medical_treatment Electromyography Isometric exercise lcsh:RC346-429 rehabilitation motor unit (MU) 03 medical and health sciences 0302 clinical medicine Physical medicine and rehabilitation Medicine Chronic stroke lcsh:Neurology. Diseases of the nervous system Rehabilitation decomposition medicine.diagnostic_test exercise business.industry tibialis anterior 030229 sport sciences Brief Research Report tracking stroke Preferred walking speed Motor unit body regions Neurology Post stroke fatigue Neurology (clinical) business 030217 neurology & neurosurgery |
| Zdroj: | Frontiers in Neurology Frontiers in Neurology, Vol 11 (2020) |
| Popis: | Introduction: This study quantified stroke-related changes in the following: (1) the averaged discharge rate of motor units (individually tracked and untracked) identified from high-density electromyography (HD-EMG) recordings, (2) global muscle EMG properties of the dorsiflexors during a fatiguing contraction, and the relationship between task endurance and measures of leg function. Methods: Ten individuals with chronic stroke performed a sustained sub-maximal, isometric, fatiguing dorsiflexion contraction in paretic and non-paretic legs. Motor-unit firing behavior, task duration, maximal voluntary contraction strength (MVC), and clinical measures of leg function were obtained. Results: Compared to the non-paretic leg, the paretic leg task duration was shorter, and there was a larger exercise-related reduction in motor unit global rates, individually tracked discharge rates, and overall magnitude of EMG. Task duration of the paretic leg was more predictive of walking speed and lower extremity Fugl-Meyer scores compared to the non-paretic leg. Discussion: Paretic leg muscle fatigability is increased post stroke. It is characterized by impaired rate coding and recruitment and relates to measures of motor function. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
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