Hubbard M, Alaways L W
Department of Mechanical Engineering, University of California, Davis.
J Biomech. 1989;22(6-7):583-95. doi: 10.1016/0021-9290(89)90010-9.
We have developed a system to measure initial conditions in the javelin throw rapidly enough to be used by the thrower for feedback in performance improvement. The system consists of three subsystems whose main tasks are: (A) acquisition of automatically digitized high speed (200 Hz) video x, y position data for the first 0.1-0.2 s of the javelin flight after release (B) estimation of five javelin release conditions from the x, y position data and (C) graphical presentation to the thrower of these release conditions and a simulation of the subsequent flight together with optimal conditions and flight for the sam release velocity. The estimation scheme relies on a simulation model and is at least an order of magnitude more accurate than previously reported measurements of javelin release conditions. The system provides, for the first time ever in any throwing event, the ability to critique nearly instantly in a precise, quantitative manner the crucial factors in the throw which determine the range. This should be expected to much greater control and consistency of throwing variables by athletes who use system and could even lead to an evolution of new throwing techniques.
我们开发了一种系统，能够足够快速地测量标枪投掷的初始条件，以便投掷者用于改进成绩的反馈。该系统由三个子系统组成，其主要任务是：(A) 在标枪释放后飞行的前0.1 - 0.2秒内，自动采集数字化的高速（200赫兹）视频x、y位置数据；(B) 根据x、y位置数据估算五个标枪释放条件；(C) 向投掷者以图形方式展示这些释放条件，以及后续飞行的模拟，同时展示相同释放速度下的最佳条件和飞行情况。该估算方案依赖于一个模拟模型，其准确性比之前报道的标枪释放条件测量至少高出一个数量级。该系统有史以来首次在任何投掷项目中，能够以精确、定量的方式几乎即时地评判决定投掷距离的关键因素。使用该系统的运动员有望更好地控制和统一投掷变量，甚至可能导致新投掷技术的发展。
