目的：探討四週上肢肌力訓練，對大專甲組棒球員肘關節伸屈力矩、肩關節外張內收力矩、揮棒速度之影響。方法：以六位男性大專甲組棒球選手為受試者，利用 Biodex System 3 等速肌力測量儀（60、180、300°/秒）檢測肘關節伸屈、肩關節外張內收之最大力矩； Motion Analysis System 動作分析系統（250Hz）擷取空揮棒、球座擊球、內外角球擊球之揮棒速度影像。以相依樣本T檢定（student’s T-test）比較各參數於上肢肌力訓練前後之差異。結果：除60°/秒、300°/秒左肘彎曲以外，後測肘關節伸直、彎曲力矩均有進步，且60°/秒右肘伸直力矩達顯著差異。後側肩關節外張、內收力矩均有進步，除180°/秒左肩外張以外。各種擊球之揮棒速度，後測均低於前測，其中球座擊球、內角擊球達顯著差異。結論：此階段之訓練內容主要以肌力訓練為主軸，訓練項目過程中強調動作的穩定與正確性，因此對上肢等速肌力表現有提升之效果。對於揮棒速度未有提升，可能是本階段訓練是以最大力量的開發為主，並非專項體能與專項技術而導致。

Purpose: The aim of this study was to compare the peak torque of elbow extension/flexion, shoulder abduction/adduction and swing velocity of collegiate baseball players before and after 4 weeks of upper-extremity strength training. Methods: Six collegiate male baseball players were enrolled into the study. The Biodex System 3 (60, 180, 300°/second) was diagnosis the peak torque of elbow extension/flexion and shoulder abd/add. The Motion Analysis System (250Hz) was used for captured the dry swing, tee-batting and in/out side ball hitting movement. The statistics was student’s T-test analysis. Results: The peak torque of elbow extension and flexion were increase in post-test, except 60 and 300°/second of L’t elbow flexion. There was significant difference in 60°/second of R’t elbow extension torque. In shoulder abduction and adduction torque were increase in post-test, except 180°/second of L’t shoulder abduction. Whatever hitting conditions, the swing velocity of post-test were lower than pre-test, and there were significant difference in tee-batting and inside location of strike zone batting. Conclusion: This training phase was focus on strength training, which emphasizes the motion in stable and correct. Therefore, it could increase the isokinetic performance of upper extremity. The main goal of our training was in strength build, not in specifics conditioning or technique. It might cause the swing velocity could not be increase.