優秀大專女子網球選手不同方向正拍擊球之運動學分析

Kinematics analysis of tennis forehand strokes in different directions for the elite female college tennis players

目的：探討優秀大專女子網球選手執行正拍直線球、對角球與閃正拍外角球之動作分期時間、軀幹旋轉特徵與擊球位置之動作技術差異。方法：以 9 名台灣大專甲組之女子網球選手為研究對象，透過 Motion 動作分析系統與十台紅外線高速攝影機 (取樣頻率為 200 Hz) 記錄網球正拍擊球執行直線球、對角球、閃正拍外角球之動作技術，以相依樣本單因子變異數分析進行統計分析。結果：在擊球動作期別上僅在加速期達顯著差異且對角球大於閃正拍球；軀幹與站姿軸的運動學參數中，除了肩軸沒有達顯著差異外，球拍長軸與底線夾角、髖軸、站姿軸設定皆達顯著差異；此外，擊球點與肩膀的前後距離以及髖部的前後、左右距離的相對位置皆達顯著差異。結論：當球員針對不同方向擊球時，球拍開始向前加速的加速期是影響方向的關鍵時期。在擊球瞬間肩部旋轉並不是影響擊球方向的主要因子，且選手在執行閃正拍外角擊球會採取較大幅度的軀幹旋轉策略進行調節。此外，擊球點與身體的相對位置關係，不論肩部或是髖部的前後距離是影響擊球方向的關鍵因素，在左右側的擊球點位置閃正拍相較於直線與對角球會更靠近軀幹。本研究結果希望讓教練與選手了解，在執行不同擊球方向或閃正拍外角球策略時，身體軀幹特徵之異同，且可以作為球員在比賽中預判對手擊球策略時的參考因素之一。

 

Purpose: This study identified and compared the kinematic difference of each phase, trunk, and stance when balls were hit cross-court, down-the-line, and inside-out forehand for the elite college female tennis players. Methods: Nine female tennis players from Taiwan college Division 1 players were recorded using a ten-cameras with motion analysis system (200 Hz). The techniques of hit down-the-line, cross-court, and inside-out forehand were recorded, and statistically analyzed by one-way ANOVA with repeated measured. Results: The only significant difference was found in the acceleration phase and the cross-court was larger than inside-out forehand. For the kinematic parameters, the angle of the long axis of the racket, hip alignment, stance alignment were statistically different. In addition, in the relative positions of the contact point, there was no significant difference in vertical height on shoulder and hip, and the shoulder was only significant in the hitting direction, but the hip was significantly different in the hitting direction and the side direction. Conclusion: In the situation of different directions, the acceleration phase when the racket starts to accelerate forward, is the key phase that affects the direction. At impact, shoulder alignment angle is not the main factor affecting the direction of the shot. The players will adopt more trunk rotation when performing inside-out forehand shots. In addition, the relative position of ball impact, the distance between the contact point with shoulder and hip on the front direction is the key factor. On the side direction, the inside-out forehand is closer to the trunk than the cross-court and down-the-line shots. This study provides coaches and players with strategies of different directions and inside-out forehand. The body characteristics can be a reference for players to predict the opponent’s strategy in the matches.