手榴彈與棒球投擲加速與餘勢動作期主動肌與擷抗肌共同收縮之分析

本研究主要是在比較手榴彈與棒球投擲肌肉共同收縮之差異，以對於手榴彈投擲技巧與傷害之預防有更詳盡之了解。在研究方法上，以15名年屆役齡之男性為受試者，使用VICON動作分析系統界定投擲分期並以BIOPAC肌電扇系統分析肌肉共同收縮，結果顯示：（一）較棒球投擲大之斜方航與闊背肌共同收縮顯示投擲手榴彈的加速與餘勢動作期肩關節會有較大負擔。（二）加速期肱二頭肌與肱三頭肌共同收縮均在0.13左右，顯示減緩此處之共同收縮是投擲者需掌握之技巧。至於餘勢動作期較加速期大之肌共同收縮則讓我們了解肌肉共同收縮在此時必須扮演起減緩肘關節繼續伸展的角色。（三）較棒球投擲大之加速與餘勢動作期橈側伸腕肌與尺側屈腕肌共同收縮顯示，投擲手榴彈負荷較大而需要較大之共同收縮來進行緩衝。而加速期肌肉共同收縮較餘勢動作期大之現象則讓我們了解在該階段穩定腕隱節應該比使用腕關節來增加球速來的重要。

關鍵字

手榴彈投擲；棒球投擲；肌肉共同收縮

並列摘要

In this study, we compared the difference of muscle cocontraction (MC) in baseball and grenade throwing. Through these results, more detailed comprehension about grenade throwing technique and how to prevent injury were anticipated. 15 males who were mature and fitting to serve acted as the subjects. VICON motion analysis system and BIOPAC EMG system were used to define the throwing phases and analyze MC. Results showed: 1. Comparing with the MC between trapezius and latissimus dorsi in baseball throwing, the MC in the grenade throwing was bigger. This result indicated shoulder joint would has more bearing in the acceleration and follow through phase when throwing grenade. 2. In accelerating phase, MC between Biceps brachii and triceps brachii was 0.13. This resu1t indicated decreasing MC between these muscles was a technique thrower should master. Moreover, MC had to decrease the elbow extension due to bigger MC between these muscles was produced in follow through phase, too. 3. In grenade throwing, MC between extensoi carpi radialis and flexor carpi ulnaris in the acceleration and follow through phase were bigger than the MC in baseball throwing. So we could understand bigger MC between these muscles to overcome the bigger bearing was need in grenade throwing. Besides, bigger MC between these muscles in acceleration phase indicated stabilizing wrist joint was more important than using wrist joint to increase the velocity of projectile.