研究目的：本研究主要目的是比較正向下階梯與背向下階梯在支撐期下肢肌肉活化情形。方法：本研究是以一年內無受過傷害之六位男大學生為研究對象，受試者平均年齡22.88±1.46歲，平均身高174.63±4.47公分，平均體重67.63±3.46公斤。利用Vicon動作分析系統，十部攝影機進行步態分期，並同步使用無線肌電圖測量儀，收取下肢右腿股直肌、股二頭肌、脛前肌、腓腸肌的肌肉活化情形。結果：在正向下階梯在支撐期膝關節彎曲時，肌肉活化順序是股二頭肌→腓腸肌→脛前肌→股直肌，沒有達到同時活化作用，較為不穩固。在背向下階梯支撐期膝關節彎曲時，肌肉活化順序是由股二頭肌、腓腸肌與脛前肌三條肌肉同時活化，有達到肌肉同時活化的作用，使膝關節較為穩固以確保不會造成受傷。最後則是股直肌肌肉活化較不明顯。結論：下肢受傷者可以利用背向下階梯做為復健治療或加強個別的肌肉群之訓練，以達到復健或訓練的效果。
Purpose: The purpose of this study is more positive ladder and retrogression situation ladder in support of lower limb muscle activation. Method: Six male college students having no injures of lower limb within one year were used as subjects of this study. The mean age of 22.88±1.46 years, mean height of 174.63±4.47cm, average weight of 67.63±3.46kg. This study used Vicon Motion Analysis System with 10 cameras for gait analysis, used wireless electromyography synchronously to examine the muscle activation sequence about rectus femoris, biceps femoris, tibialis anterior, gastrocnemius. Result: During the knee flexion in supporting phase for forward downstairs, muscle activation sequences are biceps femoris, gastrocnemius, tibialis anterior, rectus femoris which do not activate simultaneously and are more unstable.During the knee flexion in supporting phase for backward downstairs, three muscles, i.e. the biceps femoris, gastrocnemius and tibialis anterior, activate simultaneously to make knee joint more stable and thus, to ensure no injury caused. Finally the rectus femoris activation is less obvious. Conclusion: Lower extremity injuries can take advantage of retrogression in the next step as the rehabilitation or strengthening the training of individual muscle groups, in order to achieve the effect of rehabilitation or training.
