輕艇水球過肩投擲動作之三度空間運動學分析

Three-Dimensional Kinematics Analysis of Overarm Throwing in Canoe Polo

目的：在於探討輕艇水球過肩投擲動作之特徵。方法：以八名男子國家代表隊選手為研究對象，利用兩部高速攝影機（120Hz），拍攝受試者採用過肩投擲之射門動作，來分析從揮臂準備期到加速期的動作。利用APAS動作分析系統進行影片的數位化處理，並以直接線性轉換的方法，來獲得三度空間的運動學參數。結果：發現在球離手瞬間，球速為15.93±0.63m/s。肩關節在球離手前0.043s，達到最大外旋角度141.22±11.83°。而在球離手瞬間，身體軀幹呈現向後傾斜與水平面接近垂直的姿勢，而肩關節則處於外展、水平內收與內旋，肘關節伸展至150.42±9.83°的姿勢。在投擲過程中，身體各肢體的移動從軀幹旋轉、肩關節水平內收、肘關節伸展一直到肩關節內旋呈現依序的向前加速，進而達到該肢體的最大角速度。而肩關節最大內旋角速度為-1981.40±210.93o/s，則是出現在球離手瞬間之前。結論：輕艇水球和其他採用過肩投擲動作的運動很類似，但仍有差異存在。而這些差異的原因，主要由於選手是坐在輕艇裏，並在水面上執行投擲以及水球的重量較重所造成。

Purpose: To investigate the characteristics of overarm throwing in Canoe Polo. Method: Eight male national team players participated in this study. The overarm throwing of shot was filmed by two high-speed video cameras, which were set to collect data at a rate of 120Hz. Only the images from arm cocking phase and acceleration phase were analyzed in this study. Images were digitalized by Ariel Performance Analysis System (APAS) and the 3D kinematics parameters were obtained by using the Direct Linear Transformation (DLT) method. Results: At the instant of ball release, the ball velocity was: 15.93±0. 63m/s. The shoulder joint reached its maximal external rotation of 141.22±11.83° was 43ms before ball release. At the instant of ball release, the trunk leaned backward and was still perpendicular to the water surface. The shoulder joint was also in a position of abduction, horizontal adduction and internal rotation with the elbow extension at 150.42±9.83°. During throwing, the maximal segmental angular velocity was achieved via sequential movement of body segments in order of trunk rotation, shoulder horizontal adduction, elbow extension and shoulder internal rotation. However, the shoulder reached its maximal internal rotation angular velocity of -1981.40±210.93 o/s was appeared earlier before the instant of ball release. Conclusion: It appears that the Canoe Polo has similar throwing motion with other overarm throwing sports. However, some differences do exist. The differences are likely due to the sitting position in the canoe, making throws above the water, and the increased weight of the water ball.