手指等尺性屈曲保持における負荷タイプの違いによる疲労差

概要

論文の詳細を見る
We measured the endurance time and force and assessed the electromyograms of the flexor digitorum muscle and extensor digitorum muscle in response to 2 types of submaximal fatiguing. The 2 tasks involved isometric contraction of the proximal interphalangeal joint flexor muscles at 50% of the maximum voluntary contraction (MVC) force, which was achieved either by maintaining a constant force while pulling a force transducer (force task) or by supporting an equivalent load while maintaining a constant proximal interphalangeal joint angle (position task). Seven men performed the 2 tasks with their index, middle, and ring fingers. For all 3 fingers, the endurance time for the force task (79 ± 22, 93 ± 46, and 96 ± 56 s for the index, middle, and ring fingers, respectively) was shorter than the corresponding values for the position task (141 ± 105, 147 ± 82, and 212 ± 91 s). The rate of change in amplitude and mean power frequency in the electromyogram did not significantly differ across the 2 tasks. Physiological tremor was computed from the recorded force signal. The physiological tremor initially decreased during both tasks; however, the subsequent increase occurred earlier during the force task.