American Sports Medicine Institute, Birmingham, AL 35205, USA.
Department of Orthopaedic Surgery, Feinberg School of Medicine, Northwestern University, Chicago, IL, USA.
Sports Biomech. 2013 Nov;12(4):324-33. doi: 10.1080/14763141.2013.838693.
The purpose of this study was to quantify trunk axial rotation and angular acceleration in pitching and batting of elite baseball players. Healthy professional baseball pitchers (n = 40) and batters (n = 40) were studied. Reflective markers attached to each athlete were tracked at 240 Hz with an eight-camera automated digitizing system. Trunk axial rotation was computed as the angle between the pelvis and the upper trunk in the transverse plane. Trunk angular acceleration was the second derivative of axial rotation. Maximum trunk axial rotation (55 +/- 6 degrees) and angular acceleration (11,600 +/- 3,100 degrees/s2) in pitching occurred before ball release, approximately at the instant the front foot landed. Maximum trunk axial rotation (46 +/- 9 degrees) and angular acceleration (7,200 +/- 2,800 degrees/s2) in batting occurred in the follow-through after ball contact. Thus, the most demanding instant for the trunk and spine was near front foot contact for pitching and after ball contact for batting.
本研究旨在定量分析优秀棒球运动员投球和击球时的躯干轴向旋转和角加速度。研究对象为健康的职业棒球投手（n=40）和击球手（n=40）。使用八台摄像机自动数字化系统以 240Hz 的频率追踪附着在每个运动员身上的反光标记。躯干轴向旋转定义为横截面上骨盆和上躯干之间的角度。躯干角加速度是轴向旋转的二阶导数。投球时，最大躯干轴向旋转（55 +/- 6 度）和角加速度（11,600 +/- 3,100 度/s2）发生在球释放之前，大约在前脚着地的瞬间。击球时，最大躯干轴向旋转（46 +/- 9 度）和角加速度（7,200 +/- 2,800 度/s2）发生在球接触后的随球动作中。因此，对于躯干和脊柱来说，最具挑战性的时刻是投球时前脚接触，击球时球接触后。
