背景及目的：閉鎖動力鏈運動被認為是前十字韌帶重建手術後的最佳膝關節運動方式，但閉鎖動力鏈運動的種類很多，並非所有的運動都得到研究證據的支持。因此，本研究選擇四種常用的閉鎖動力鏈運動，比較運動中大腿肌群的活動情形，希望可提供前十字韌帶受傷與重建手術後運動治療選擇的參考。方法：本研究以24名沒有下肢病變或傷害的健康人為研究對象，隨機進行下蹲、弓箭步、正面登階與側面登階(階高4吋)四種運動，利用表面電極記錄股直肌、股內側肌、股外側肌、半腱半膜肌與股二頭肌在運動中的的肌電訊號，以最大自主等長收縮時的肌電訊號百分比表示。以重複量數單因子變異數分析進行四種運動間的比較(包括膝關節最大屈曲角度、各肌肉在運動中之平均肌電訊號百分比)，若達顯著水準再以Bonferroni多重比較(bonferroni multiple comparisons)做逐項配對考驗。結果：股直肌與股外側肌的平均活動程度在側面登階運動中最高(分別為16.1%,36.5%)，顯著高於其他三種運動(p<0.008)。在股內側肌方面，側面登階運動的平均活動程度(34.3%)高於下蹲(19.6%)與正面登階運動(19.7%)(p<0.008)，但與弓箭步運動(23.8%)之間的差異並未達顯著。半鍵半膜肌與股二頭肌平均活動程度的差異較不一致，半腱半膜肌僅在下蹲(2.5%)與弓箭步運動(3.8%)間、股二頭肌則僅在弓箭步(4.7%)與側面登階運動(6.3%)間達顯著差異(p<0.008)。結論:股四頭肌的平均活動程度在側面登階運動中最高，而大腿後肌的平均活動程度在各運動間的差異較不明顯，所以，以大腿肌群共同作用程度而言，下蹲、弓箭步與正面登階運動是優於側面登階運動的。（物理治療2003;28(6):308-316）

Background and purpose: Closed kinetic chain exercise (CKCE) is a major component of most anterior cruciate ligament (ACL) rehabilitation. An understanding of muscle recruitment patterns during various CKCEs should make exercise prescription easier and rehabilitation more effective. The purpose of this study was to determine if significant differences in level of electrical activity in the thigh muscles occurred during four kinds of CKCEs. Methods: Twenty-four healthy subjects without prior pathological condition of the lower extremities volunteered for this study. Surface electrodes were used to monitor the electromyographic (EMG) activity of rectus femoris (RF), vastus medialis (VM), vastus lateralis (VL), semitendinosus/semimembranosus (ST/SM), and biceps femoris (BF) muscles during exercises which including squat, lunge, forward and lateral step-ups. The root mean square EMG activity was obtained and normalized to percent of maximal voluntary isometric contraction for all exercises. For each muscle, one-way repeated measures analysis of variance was used for between exercise comparisons. Results: Mean RF and VL activity were used for between exercise comparisons. Results: Mean RF and VL activity were significantly highest during lateral step-up exercise. Mean VM activity was significantly greater for lateral step-up exercise(34.3%) than squat(19.6%) and forward step-up exercises(19.7%) (p<0.08). Mean ST/SM and BF activities did not show consistent differences between exercises. Conclusions: The activity level of quadriceps was highest during lateral step-ups. Since the hamstrings appeared to be relatively inactive during all exercises, the hamstring-quadriceps coactivation in squat, lunge, lunge, and forward step-up exercises was superior to that of lateral step-up exercises. (FJPT 2003; 28(6): 308-316)