不同羽球拍勁度與平衡點 對於揮拍速度及球速表現之影響

Abstract

目的：探討四種球拍勁度 (stiffness)及三種球拍揮重 (swing weight)對於揮拍速度、球速以及恢復係數的影響，以做為日後球拍選擇及設計上的依據。方法：實驗將分為固定式撞擊實驗以及實際揮擊實驗兩部分，皆使用高速攝影機10000 Hz擷取頻率拍攝其撞擊與擊球畫面，利用動作分析軟體分析其擊球前後的揮拍速度及球速。以二因子相依樣本變異數考驗two-way ANOVA考驗球拍勁度與揮重對於揮拍速度、球速以及恢復係數的影響，顯著水準均訂為α＜.05。結果：固定式撞擊實驗部分：恢復係數會隨著撞擊速度的增加而上升，而中揮重球拍恢復係數顯著高於低揮重球拍。實際揮擊實驗：揮拍速度隨著揮重的增加而下降，而低揮重球拍球速顯著較中揮重球拍快；球拍勁度對於球速的影響力出現在90km以上的揮拍速度；高揮重球拍揮拍速度慢，但恢復係數相對於低揮重及中揮重球拍高。結論：球拍的揮重顯著影響揮拍速度、球速以及恢復係數，而球拍勁度的影響程度相對較小；建議未來在球拍選購及設計上可朝降低球拍揮重以提升揮拍速度，或者增加揮重以提升恢復係數。Purpose ：To understand the effect of four different kinds of stiffness and three different swing-weight on swing-velocity, ball-velocity and coefficient of restitution. The result of the study will be taken as index to the selection and design of badminton racket in the future. Methods: Two experiments were conducted in the study; In the first experiment, the ball was served and then collided the racket; in the second experiment, the ball is fastened with clamping, hanging in the air, and hit by players. The results were recorded by 10000 Hz high speed video camera, and analyzed by video analysis software, which helped researcher to compare swing velocity and ball velocity between pre-test and post-test. Statistical analysis were conducted by two-way ANOVA to examine the effects of stiffness and swing-weight on swing-velocity, ball-velocity and coefficient of restitution. The significant level was set at α<.05. Results: In the group impacted by server, the coefficient of restitution was in direct proportion to impact velocity, and the coefficient of restitution of middle swing weight was significantly higher than that of low swing weight. In the group hit by player, the swing velocity was in reverse proportion to swing weight, and the swing velocity of low swing weight was significantly faster than that of middle swing weight. Ball velocity was effected by the stiffness of the racket when swing velocity exceed 90 km; the Swing Velocity of high swing weight is slow, but its COR was higher than those of low swing weight and middle swing weight. Conclusion: The swing weight that significantly impacted on swing velocity, ball velocity and COR, and the influence of stiffness is comparatively less than swing weight. The users and designers would be advised to choose the racket with low swing weight in order to increase swing velocity, or high swing weight in order to increase COR.