The Effects of Fatigue and Task Repetition on the Surface Electromyographic Signal

Publisher Website
Google Scholar
Abstract
The effects of fatigue and repetition of the task on the surface electromyographic signal were examined during 4 sessions using an isometric motor control task. The muscle chosen for this study was one of the main ankle dorsiflexors (m. tibialis anterior). The electromyographic output and a functional (force) output of this muscle were recorded during two conditions: a SHORT‐F condition in which the effect of task repetition on the relationship between force and IEMG was studied, and a LONG‐F condition in which the effect of fatigue was studied. The results indicated that repetition of the task resulted in a significant increase in the ratio between the electromyographic and functional output of the m. tibialis anterior, indicating an increase in efficiency across the 4 sessions. Fatigue on the other hand resulted in a significant decrease in the ratio between the electromyographic and functional output of the m. tibialis anterior, indicating a decrease in efficiency. Fatigue also resulted in a significant and rapid increase in the electromyographic activity. The implications of these results for the therapeutic use of the electromyographic signal were discussed.