本研究目的為探討長時間投球前、後，女子壘球投手投球加速期之跨步腳運動學的變化差異，以瞭解長時間投球對於投球加速期跨步腳運動學之影響。參與者為7位具有多年比賽經驗之國內大專球隊優秀投手，使用紅外線高速攝影機取樣頻率為300Hz拍攝投手進行最多10局之模擬比賽之投球動作，前測為第一局後測則為第十局或是達到自覺疲勞標準的該局，主要針對前、後測投球加速期之下肢運動學，分析髖、膝、踝關節餘個解剖平面之角度、關節活動範圍及角速度。結果顯示：經長時間投球後跨步腳著地瞬間膝關節屈曲角度後測顯著低於前測(p = .04)，出手瞬間踝關節外翻角度顯著低於前測(p = .03)，其餘關節角度及關節活動度則無差異，加速期過程各關節角速度前、後測皆未有差異。結論：經長時間投球後投手會以較僵直的方式進行跨步著地，在出手瞬間踝關節則以較少的角度及角速度提供髖、膝關節穩定的支點來進行後續動作。

The purpose of this study was to investigate the effect of long-term pitch on lower extremity kinematics of women’s softball pitchers.7collegate softball pitchers were recruited to pitch most 10 innings simulated game in biomechanics lab. Motion analysis system was captured lower extremity kinematics on pitching acceleration phase. All parameters were examined by nonparametric method (wilcoxon signed rank test)between pre(first inning) and post(last inning)pitching movement. The result was displayed the post stride leg knee flexion angle was significant smaller than pre test on leg landing moment. And the post ankle eversion angle also smaller than pre test significantly on ball release moment. However, the ROM and angular velocity was no significant in pre-post test or any moment. Concluded: The stride leg landing movement was more stiffness land after long-term pitch. And the ankle was decrease the sustain angle and angular velocity to maintain the knee and hip joint stability in order to facilitate the ball release.