高中女子快速壘球風車式投球之運動學分析

Kinematic Analysis of Windmill softball pitching in High School Female Pitchers

目的：本研究為分析高中女子快速壘球風車式投球的運動學，比較各投手間的球速與動作特徵。方法：以6位高中女子快速壘球專長投手參與實驗，以Vicon T40動作捕捉系統拍攝，頻率為300Hz。經由Matlab計算分析快速壘球風車式投手之球速、跨步距離、重心位移速度、加速期完成時間，及投擲臂的肩、肘與腕關節角速度等運動學參數。每位受試者各拍攝10次成功投擲，將10次結果進行平均做分析比較。結果：本研究發現跨步距離、重心位移速度及加速期完成時間與球速有顯著相關，而肩、肘與腕關節角速度方面與球速則無顯著相關。結論與建議：從本實驗分析結果推測，增加球速的關鍵可能是跨步距離與重心位移速度，肩、肘與腕關節角速度則影響較少。建議壘球投手教練可加強選手在增加跨步距離以及增加整體重心位移速度方面的訓練。

Purpose：The purpose of this study was to analyze the kinematics of the windmill softball pitching and to compare ball velocity and throwing arm movement among different pitchers. Methods: Six high school female students were recruited to participate in this study. Kinematic data were recorded via Vicon motion capture system (300 Hz). Moreover, Matlab was used to calculate the ball velocity, stride length, horizontal velocity of center of mass, acceleration time and the angular velocity of upper limb. Each pitcher threw successfully for ten times.Average data of each variable was used for data analysis. Results: Six pitchers’ horizontal velocity of center of mass was correlated with stride length and acceleration stage time, respectively. Ball velocity in this study was significantly correlated with stride length, horizontal velocity of center of mass, and acceleration time. There were no significant correlation between angular velocity of each upper extremity joint and ball velocity. Conclusions: From the results of this experiment, we found that the key to increase the ball velocity is to increase the stride length and horizontal velocity of center of mass. There is no obviuos effects of angular velocity on ball velocity. We might suggest coach of the pitchers to strengthen player’s stride length and horizontal velocity of center of mass during training.