本研究主要目的在探討打擊者於揮擊不同擊球點時，其揮棒動作的各項運動學參數之差異情形。研究以六名輔仁大學棒球隊隊員為研究對象，以採用兩部Sony數位攝影機拍攝不同擊球點的揮棒動作，再以Kwon3D動作分析軟體計算與擷取各項運動學參數。研究結果顯示：（一）「前手肘關節角度」變項中，以「正中直球」揮棒動作與「外角直球」揮棒動作，以及「內角直球」揮棒動作與「外角直球」揮棒動作具有顯著差異；在「後手肘關節角度」變項中，以「正中直球」揮棒動作與「外角直球」揮棒動作，以及「內角直球」揮棒動作與「外角直球」揮棒動作具有顯著差異；在「後手下臂與球棒之夾角」變項中，揮擊三種不同擊球點的揮棒動作皆具有顯著差異。（二）經過單因子變異數分析後發現，發現不同擊球點在揮棒速度上有顯著差異存在，經進行事後比較發現「外角直球」與「內角直球」具有顯著差異。（三）整體而言，不同的擊球點會產生不同的肘關節角度、後手下臂與球棒角度、以及球棒速度，故手部關節的動作即為不同擊球點的揮棒動作差異的主要因素。

The purpose of the study is to explore the differences of baseball hitters' hitting points when they wave sticks. Six baseball team members were selected as research participants for analyses. Two Sonly digital cameras were adopted to videotape different hitting points of waving actions. Kwon3D was used to analyze and obtain sport parameters. Results are as follows:1. In the variable, the angle of elbow joint in leading hand, the comparison between center straight and outside corner straight as well as inside corner straight and outside corner straight reached the significant level. In the variable, the angle of elbow joint in trail hand, the comparison between center straight and outside corner straight as well as inside corner straight and outside corner straight reached the significant level. In terms of the variable, the included angle formed by forearm and bat in trail hand, the waving actions in three hitting points reach the significant level.2. After the analyses of One-Way ANOVA, the difference of hitting points in waving speed reached the significant level. Post Hoc Analysis indicated that outside corner straight and inside corner straight reached the significant level.3. No matter where the hitting point is, the speed and distance of the center of gravity will not significantly change. Thus, the hitting force which was driven from bodies is one of the unnegligible factors in hitting processes.4. Generally speaking, different hitting points will cause different angles of elbow joints, the included angle formed by forearm and bat in trail hand and bat velocity. Hence, the actions of hands' joints are the key factor of waving action difference of different hitting points.