The purpose of this study was to determine whether stride length and knee angle of the leading leg at foot contact, at the instant of maximal external rotation of the shoulder, and at ball release are associated with ball speed in elite youth baseball pitchers. In this study, fifty-two elite youth baseball pitchers (mean age 15.2 SD (standard deviation) 1.7 years) pitched ten fastballs. Data were collected with three high-speed video cameras at a frequency of 240 Hz. Stride length and knee angle of the leading leg were calculated at foot contact, maximal external rotation, and ball release. The associations between these kinematic variables and ball speed were separately determined using generalized estimating equations. Stride length as percentage of body height and knee angle at foot contact were not significantly associated with ball speed. However, knee angles at maximal external rotation and ball release were significantly associated with ball speed. Ball speed increased by 0.45 m/s (1 mph) with an increase in knee extension of 18 degrees at maximal external rotation and 19.5 degrees at ball release. In conclusion, more knee extension of the leading leg at maximal external rotation and ball release is associated with higher ball speeds in elite youth baseball pitchers.
展开▼
机译:这项研究的目的是确定精英青年棒球投手在脚接触时,肩膀最大外旋时和放球时前腿的步幅长度和膝盖角度是否与球速相关。在这项研究中,有52名精英青年棒球投手(平均年龄15.2 SD(标准差)为1.7岁)投了10个快球。用三个高速摄像机以240 Hz的频率收集数据。在脚接触,最大外旋和放球时计算前腿的步幅长度和膝盖角度。这些运动学变量和球速度之间的关联是使用广义估计方程分别确定的。步长(以身高和脚部接触时的膝盖角度的百分比表示)与球速没有显着相关。但是,最大外旋和放球时的膝盖角度与球速显着相关。球速度增加了0.45 m / s(1 mph),最大外旋时膝盖伸展度增加了18度,释放球时膝盖伸展度增加了19.5度。总而言之,精英青年棒球投手在最大的外部旋转和球释放时,前腿更多的膝盖伸展与较高的球速相关。
展开▼