本研究目的在探討肌肉牧縮的模式（向心和離心收縮）和測試的速度對肩部肌群的功率和總功量量測的影響。以肩部沒有受傷記錄，也沒有受過上肢重量訓練之國立成功大學女子軟式網球隊隊員十五名為受試對象（平均年齡21.3±1.9歲、平均身高160.8±6.2公分和平均體重52.3±8.5公斤）。使用Kin-Com肌力測試儀來量測肩部肌群，在肩胛平面外展九十度的坐姿測試，測試速度分別為60度／秒、120度／秒和240度／秒。 使用ANOVA來分析肩部旋轉肌群內旋和外旋時的功率和總功量是否受到旋轉動作、收縮形式以及測試速度的影響。在向心和離心收縮(p<.05)方面，肩部肌群的旋轉功率明顯地隨著角速度的增加而增加、同時，肩部的轉功率在離心收縮方面比向心收縮大(p<.001)。肩部的總功量方面，外旋肌群消耗了比內旋肌群更多的功(p<.05)。 本研究客觀地量測和比較的結果，肩部肌群在不同收縮模式下，旋轉功率都隨著速度的增加而增加，高速度的東有較大受傷的可能性，最好的訓練速度仍有爭議的。在本研究中，每次十回不間斷量測得到值得參考的結果可作為擬定軟式網球隊肌力訓練計畫的參考，將有助於提升訓練成效及避免運動傷的造成。

The purpose of this study was to measure the rotation power and energy of the shoulder in different testing speed in college soft-tennis players. More specifically, the study was performed to test the hypothesis that the mode of contraction (concentric and eccentric) and testing velocities would have significant effects on power and energy measurement of the shoulder. Fifteen female college soft-tennis players (men age 21.3±1.9 years, height 160.8±6.2 cm and weight 52.3±8.5kg) without any shoulder pathology took part in this study. The Kin-Com isokinetic dynamometer was used to measure the rotation power and energy of the shoulder at 60°/sec, 120°/sec, and 240°/sec isokinetic test and 90° of shoulder abduction scapular plane. Each testing consisted of ten nonstop cycles, and three repetitions were made at each velocity. Both concentric and eccentric tests of the dominant and non-dominant sides were performed. Three-Way ANOVA was used to analyze whether the power and energy of the shoulder in external/internal rotation were different in contraction mode, type of rotation and velocity. The rotation power of the shoulder significantly increased with increasing angular velocity in both concentric and eccentric contraction (p<0.05). The rotation power of shoulder was also significantly greater in eccentric contraction than concentric contraction (p<0.05). Furthermore, the external rotation power was greater than internal rotation power statistically. In the energy consumption, external rotators did more energy than internal rotators (p<0.05). However, there were no significant differences in testing speed and contraction mode. This study objectively quantified and compared the rotation power and energy consumption of the shoulder in different contractions. The rotation power increased with increasing testing velocities in both contraction modes. High-velocity training had greater injury possibility. The best training velocity is still controversial. The other finding is that the power was greater in external rotation than in internal rotation. Ten nonstop-cycles measurement for each test in this study should give reliable results. The results of this study may help in planning muscle training for soft-tennis players.