Biomechanical reorganisation of stepping initiation during acute dorsiflexor fatigue
| Autor: | Eric Yiou, S. Le Bozec, S. Ditcharles |
|---|---|
| Rok vydání: | 2011 |
| Předmět: |
Adult
Male medicine.medical_specialty Movement Biophysics Neuroscience (miscellaneous) Isometric exercise Electromyography Cog mental disorders medicine Postural Balance Humans Muscle Skeletal Muscle fatigue medicine.diagnostic_test business.industry Biomechanics Muscle weakness Anticipation Psychological Biomechanical Phenomena medicine.anatomical_structure Lower Extremity Muscle Fatigue Physical therapy Female Neurology (clinical) medicine.symptom Ankle business |
| Zdroj: | Journal of electromyography and kinesiology : official journal of the International Society of Electrophysiological Kinesiology. 21(5) |
| ISSN: | 1873-5711 |
| Popis: | During voluntary step initiation (SI), propulsive forces are generated during anticipatory postural adjustments (APA) which displace the centre-of-gravity (CoG) in the desired direction. These propulsive forces are implemented by ankle synergy, bilateral soleus inhibition followed by activation of tibialis anterior (TA). The aim of this study was to investigate the effect of fatigue applied to ankle dorsiflexors on APA associated with SI and on related motor performance. Eight young healthy participants initiated stepping before and after a protocol designed to generate fatigue in ankle dorsiflexors. Fatigue was induced by series of high-level isometric contractions performed until exhaustion. Results showed that, with fatigue, the level of TA activation during APA, anticipatory postural dynamics (backward centre-of-pressure displacement and forward CoG velocity) and related motor performance (peak of CoG velocity) were attenuated, while APA duration and total SI duration increased. These changes were interpreted as reflecting a protective strategy aiming to preserve the integrity of the fatigued muscles, rather than an impairment associated with muscle weakness. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
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