高、低表現蹲踞跳之運動生物力學與肌電圖研究

The biomechanical and EMG analysis of highest and lowest performance in squat jump

目的：透過不同跳躍表現間下肢生物力學參數與肌電現象，了解造成低跳躍表現的因素。方法：受試對象為10名受過運動專項訓練的體育系男性。一臺Redlake高速攝影機（125Hz；1／625）、一塊Kilster測力板（1250Hz）與Biovision肌電系統（1250Hz）同步，擷取跳躍動作過程中的運動生物力學參數，並透過模式運算獲得進一步之動力學參數。採用重複量數t-test來檢測「高表現蹲踞跳」與「低表現蹲踞跳」間是否有差異，統計顯著水準定為α=.05。結果：「低表現蹲踞跳」之跳躍高度顯著少4公分。低跳躍表現時股骨肌、腓腸肌與比目魚肌肌肉活動時宜出現延遲的現象，髖關節最大角速度時宜的提早與踝關節最大淨肌肉力矩時宜的延遲，影響能量的形成，使得髖關節處對蹬伸能量的貢獻由59.39焦耳的功降為50.57焦耳，踝關節處對蹬伸能量的貢獻由76.39焦耳的功降為67.98焦耳。結論：關節活動範圍、最大淨關節肌肉力矩與最大垂直地面反作用力並不是造成低跳躍表現的因素，故動作時宜的不佳是影響跳躍表現的一大要素，在運動訓練上動作的熟練與穩定度是不容忽視的層面。

Purposes: The purpose of this study was to investigate the factors of the effect by comparing the biomechanical differences between the highest and lowest performances in regular squat jump. Methods: Ten healthy males were conducted as subjects for this study. Redlake high-speed camera (125Hz; 1/625), and Biovision EMG system (1250Hz) were synchronized with Kistler force plate (1250Hz) to collect the biomechanics parameters during the subjects performing squat jump movement. The net muscle joint moments were calculated by using inverse dynamics process. Differences between mean values of jumping performance were evaluated by means of Student's t-test for repeat subjects. Statistical significance was set at α= .05. Results: During the lowest performance of squat jump the initial times of EMG signals on m. vasti, m. gastrocentius, and m. soleus were delayed while compared them to those signals on highest performance of squat jump. Similarly, the peak angular velocity of hip joint appeared earlier than that in the highest performance, and the peak net muscle joint moment appeared later than that in the highest performance. These phenomena caused the work of hip joint to reduce from 59.39 J to 50.57 J, and the work of ankle joint to reduce from 76.39 J to 67.98 J in the take - off activity. Conclusion: The range of motion, peak net muscle joint moment, and peak ground reaction force were not the effect factors of the lowest performance of squat jump. Hence, the coordination ability during jump was the important factor of jumping performance.