The vestibulomyogenic balance response is elevated following high-intensity lengthening contractions of the lower limb
| Autor: | Emily I. McIntosh, Brian H. Dalton, Geoffrey A. Power |
|---|---|
| Rok vydání: | 2018 |
| Předmět: |
Adult
Male Weakness medicine.medical_specialty Electromyography Lower limb Young Adult 03 medical and health sciences 0302 clinical medicine Physical medicine and rehabilitation medicine Humans Muscle Skeletal Exercise Postural Balance Balance (ability) Vestibular system Muscle Weakness medicine.diagnostic_test business.industry General Neuroscience High intensity Muscle weakness 030229 sport sciences Electric Stimulation body regions Standing balance Lower Extremity Vestibule Labyrinth medicine.symptom business 030217 neurology & neurosurgery Muscle Contraction |
| Zdroj: | Neuroscience Letters. 675:120-126 |
| ISSN: | 0304-3940 |
| DOI: | 10.1016/j.neulet.2018.03.056 |
| Popis: | The purpose was to investigate whether exercise-induced muscle weakness of the plantar and dorsiflexors through high-intensity lengthening contractions increases the vestibulomyogenic balance response. Nine males (∼25 years) participated in three experimental testing days to evaluate the vestibular control of standing balance and neuromuscular function of the plantar and dorsiflexors pre- and post (30 min, and 1 and 7 days) high-intensity lengthening plantar and dorsiflexions. To evaluate the vestibular-evoked balance response, participants stood quietly on a force plate while exposed to continuous, random electrical vestibular stimulation (EVS) for two 90-s trials. Relationships between EVS-antero-posterior (AP) forces and EVS-medial gastrocnemius electromyography (EMG) were estimated in the frequency domain (i.e., coherence). Weakness of the right plantar and dorsiflexors were assessed using maximal voluntary contraction (MVC) torque. The lengthening contractions induced a 13 and 24% reduction in plantar and dorsiflexor MVC torque, respectively ( p 0.05) of the exercised leg, which did not recover by 1 day post. The EVS-EMG coherence increased over a range of frequencies up to 7 days post compared to pre-lengthening contractions. Conversely, EVS-AP forces coherence exhibited limited changes. The greater EVS-EMG coherence post exercise-induced muscle weakness may be a compensatory mechanism to maintain the whole-body vestibular-evoked balance response when muscle strength is reduced. |
| Databáze: | OpenAIRE |
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