目的：在於了解不同擊球高度對於大專選手打擊動作的影響，提供教練及選手訓練依據。方法：以大 專公開組第一級 (身高：174.3 ± 6.8 公分；體重：71.1 ± 8.5 公斤；年齡：23.0 ± 2.1 年) 及公開組第 二級 (身高：175.0 ± 5.8 公分；體重：68.9 ± 5.8 公斤；年齡：22.7 ± 2.8 年) 棒球選手各 10 名，使用 Vicon Motion 三維動作分析系統、Kistler 測力板系統及 Fastec 高速攝影機同時進行數據擷取。地面反 作用以體重進行百分比標準化，並以混合二因子變異數分析做為統計方式，事後比較採用 Tukey 法， 顯著水準定為 α= .05。結果：高擊球高度之重心內移、上移較多、前導腳著地瞬間之前導腳與擊球瞬 間之軸心腳膝關節較為伸展，造成骨盆旋轉角速度下降，肘關節較為屈曲使力臂較短。公開組第一級 有較大的前後地面反作用力峰值，其發生點也早於公開組第二級，而著地瞬間之軸心腳膝關角度較 為屈曲，骨盆之角速度峰值也較大。結論：高擊球高度之棒頭最大合速度較小、揮棒時間較長，壓縮 了用於判斷及調整姿勢的時間，因此擊球高度越高越不易揮擊。公開組第一級骨盆角速度較快，整體 而言有較好的打擊表現。

Purpose: This study aimed to investigate the effect of baseball batting among different hitting-point heights. This information could be provided to the coaches and players for improving the batting technique. Methods: Ten university baseball players from Division 1 (Height: 174.3 ± 6.8cm, weight: 71.1 ± 8.5kg, age: 23.0 ± 2.1 years) and Division 2 (Height: 175.0 ± 5.8cm, weight: 68.9 ± 5.8kg, age: 22.7 ± 2.8 years) participated in this study. The Vicon Motion System, Kistler force platform, and Fastec high speed video were used synchronously to collect data. Ground reaction force was normalized by body weight. A two-way mixed ANONVA was used for statistical analysis. Tukey’s test was used for post-hoc analysis. The significance level was set as .05. Results: In the high hitting point task, more medial and upward translation of the center of gravity, more extended of knee of stride leg when stride leg landing, and more extended of knee on pivot leg when ball impact were noted to decrease the angular speed of pelvis. The flexed elbow that made the moment arm shorter was also found in the high hitting-point task. Compared to Division 2, in Division 1, the peak value of anterior-posterior ground reaction force was larger, the timing of peak value was earlier, the knee flexion angle of the stride leg was larger when the stride leg landed, and the peak angular speed of pelvis was higher. Conclusion: The lower maximum speed of beat and longer time of swing shortened the time of determine and position adjustment. Therefore, the higher the hitting-point is, the harder is the player’s swing. In general, the hitting performance was better in Division 1 than 2.

運動學; 地面反作用力; 揮擊

kinematics; ground reaction force; swing