青少棒選手打擊動作對打擊表現之影響

Abstract

青少棒選手打擊動作對打擊表現之影響 2009年6月 研 究 生：陳河吉 指導教授：張家豪 摘要 目的：探討青少棒選手打擊動作對打擊表現之影響。方法：以台北縣某國中棒球隊9位先發選手為研究對象（平均年齡14.33±1.00歲、身高170.22±6.41公分、體重65.56±6.4公斤），並以參加2008年縣級以上比賽打擊表現為評估依據，其平均打擊率為0.326±0.089。於室外球場中利用兩台Redlake高速攝影機(250Hz)，拍攝打擊動作；以Kwon3D動作分析系統分析所拍攝之打擊動作，針對揮擊時之手肘關節角度、身體軸心線位移、揮擊時間及球棒揮擊軌跡等進行分析。所得運動學參數資料皆以SPSS 軟體進行統計分析。實驗中定義之參數以Pearson 探討參數之相關程度，顯著水準定為α =.05。結果：一、跨步期開始至揮擊期結束止之揮擊時間與打擊表現無顯著之相關(p = .110)；但跨步期結束瞬間至揮擊期結束之揮棒時間與打擊表現呈顯著相關(r = -.696, p = .037)。二、擊中球瞬間揮棒速度與打擊表現呈顯著之相關(r = .702, p = .035)；揮棒軌跡水平揮擊距離對水平揮擊速度相關值呈顯著相關(r = .763, p = .017)。三、擊中球瞬間手肘角度與球棒的水平揮擊速度和球的初速度呈顯著之相關(r = .893, p = .001; r = .724, p = .027)。四、揮擊時身體軸心水平位移與打擊表現呈顯著之相關(r = -.669, p = .049)。結論：球棒揮擊之時間越短、擊中球瞬間棒頭速度越快、身體旋轉時水平位移愈小、揮擊時球棒軌跡的水平距離越長，則打擊表現就越好。建議：訓練時應多利用定位訓練針對打擊動作做調整，加強其揮擊時身體旋轉中心軸固定，並調整擊球時手肘角度變化。

關鍵詞：揮棒時間、手肘關節角度、揮擊軌跡、水平揮擊

Influence of the batting performance to the batting average for junior league baseball players

Graduate student：Ho-Chi Chen Professor：Jia-Hao Chang Abstract Purpose:to evaluate the relation between the batting performance and the batting average of the junior league baseball players. Methods: nine junior league baseball lineup players (age: 14.33±1.0 years, height: 170.22 ± 6.41 cm, and weight: 65.56 ± 6.4 Kg) in Taipei County participated in this study. The batting average (0.326 ± 0.089) of all participants was reported from the games held by the Taipei County in 2008. Two Redlake high-speed cameras (sampling at 250 Hz) were utilized to capture the player’s batting movements. Kwon3D was used to calculate the kinematical data including elbow angle, translation of the long axis of the trunk, duration of hitting, and the path of hitting. Pearson method was used to assess the relationship of the kinematics data by using SPSS. The significant level was set as α = .05. Results: (1) no correlation between the batting average and batting duration, from the beginning of stepping forward to the end of batting swing, was found (p = .110), however, the correlation between the batting average and batting duration, from the end of stepping forward to the end of batting swing, was found (r = -.696, p = . 037); (2) significant correlation between the swing speed in the impact phase and the batting average was found (r = .702, p = . 035), and the result also showed significant correlation between horizontal swing path and horizontal batting speed (r = .763, p = .017); (3) significant correlations between the elbow angle in the initial ball impact and horizontal batting speed, and between the elbow angle in the initial ball impact and ball speed were found (r = .893, p = .001; r = .724, p = .027, respectively); (4) significant correlation was also found between the translation of the long axis of the trunk in horizontal and the batting average. (r = -.669, p = .049). Conclusion: shorter batting duration, faster swing in the initial ball impact, less translation of the long axis of the trunk in horizontal, and more horizontal swing path, would improve the batting performance of the junior league baseball players. Suggestion: the player should practice to adjust the batting posture, fix the rotation axis of the trunk, and adjust the elbow angle at ball impact.

Keywords: Swing duration, elbow angle, swing path, horizontal swing