不同揮拍速度及練習情境對於桌球正手抽球時宜表現之影響

The effect of driving speeds and practice conditions on the performance of the table tennis forehand drives

緒論 : 桌球正手抽球是一種快速截斷性動作，其揮拍速度扮演著攻擊致勝的因素。改變揮拍速度需要調整動作時間以及距離，進而可能影響正手抽球的時宜表現。不同送球方式的練習可能也是影響時宜表現的因素之一，單球訓練的模式較接近於比賽情境，而多球練習則是利用大量的送球來幫助選手有效率地反覆練習正手抽球。本研究目的在探討多球練習中不同揮拍速度以及在正常揮拍速度下不同練習方式對於動作結果、動作表現和時宜表現的影響。方法：8名大專院校男子一般組桌球隊員，兩台高速攝影機和動作擷取系統來取得球跟球拍的運動學資料。選手分別在快速度-多球練習、正常速度-多球練習及正常速度-單球練習等情境下進行各10次的正手抽球，以相依樣本t檢定進行考驗。結果：不同揮拍速度的要求下揮拍速度、動作時間達顯著差異，且不影響時宜表現及命中率。不同練習方式揮拍速度、動作距離、命中率及時宜表現變異性皆達顯著差異。以球落至桌面為參考點，開始向前揮拍的時間與擊到球的時間成線性相關，且兩者間的比例可視為正手抽球時宜表現的指標。結論：穩定的多球練習中選手增加揮拍速度會調整時、空間的參數，但不影響時宜表現和命中率。單球練習類似比賽，來球較不穩定，選手會不自覺減少動作距離降低揮拍速度，且命中率下降及時宜表現變異性提高。未來可進一步檢驗不同層級、來球特質及練習方式對於動作表現及時宜表現之影響。

Introduction: The table tennis forehand drive is a fast interceptive action that plays an important role of attacking-to-score in table tennis games. For an effective scoring forehand drive, the speed of the driving movement becomes the most important factor. The timing performance may be affected when the player adjusts the temporal-spatial characteristics of the movement to change the driving speed. In addition, performing under multi-ball or rally drill practice conditions may also play an effective factor on timing performance. For table tennis training, the rally drill is closer to the game situation while the multi-ball drill provides repetitive practice opportunity where the coach uses large number of balls for the player to practice. The study was to examine the movement outcome, movement performance, and the timing performance of the table tennis forehand drive under different practice conditions and difference driving speeds. Methods: Eight male collegiate division B table tennis players participated in this study. Two high-speed cameras (200fps) and the Known 3D motion digitizing system were used to capture the ball/racket kinematic data. Ten strokes were analyzed in each of the three conditions and compared with different driving speeds and different practice conditions using the paired t test. Results: The driving speed had significant effect on the forehand driving speed and movement time but not on the timing performance and the success rate. For the practice conditions, the participants showed significant differences on the driving speed, the movement displacement, the success rate, and timing variability. Conclusions: The success rate and timing performance were not influenced by the increased driving speed, indicating that the athletes were able to perform forehand drive successfully even though the temporal-spatial parameter of the movement were adjusted. The rally practice is similar to the game situation. The players responded to the variable shots in the rally drill condition by reducing the movement displacement and the driving speed that affected the movement timing performance and the success rate. Future study will continue to examine the timing performance of table tennis forehand drive in different practice conditions and different levels of athletes.