鏈球投擲動作之運動學分析

Abstract

鏈球為高技術性的投擲競賽項目之一，理論上影響投擲水平距離的運動變數主要 為投擲高度、出手速度以及出手角度等三個條件; 本研究的目的為探討國內鏈球紀錄保持人 侯金賢的鏈球投擲動作中，影響水平距離的三種運動學變數在旋轉加速過程中所產生的波動 情形， 以兩台高速攝影機 (120Hz) 拍攝受試者在校運會的實際比賽情況，進行三度空間分 析。受試者使用四圈旋轉投擲動作中高度與速度的波動情形，除了每一圈的高低差有逐漸增 大的趨勢外，高度的增加出現在單支撐期。而速度的增加則出現在雙支撐期，受試者的出手 時初始條件分別為速度為 25.34 公尺 / 秒， 角度為 39.17 度與出手高度為 1.82 公尺， 透過運功學公式的運算。相較於高度，得知速度為影響投擲距離最大的因素。

Hammer throw is one of the competitive events with high techniques in track and field. Theoretically, the most important factors contributing to distance are initial speed, hight and angle at release. The purpose of this study was to investigate the fluctuation of three dominant parameters of hammer throw motion. A elite hammer thrower, who is the present Taiwan record holder, was filmed simultaneously with two high speed (120 Hz) cameras during the university athletic meet. The 3D kinematic data were transformed, and the selected parameters were calculated by Peak Motus motion analysis software. The results indicated that hammer speed and vertical displacement increases gradually during a throw, but this increasing trend has one fluctuation superimposed in each turn. The increase in hammer speed within each cyclic fluctuation coincides approximately with the doublesupport phase of throw. The three initial parameters speed, hight and angle were 25.34 m/s, 1.82 m and 39.17 deg respectively.