Identification of the roles of wrist snap in baseball pitching

一些研究报告说，前臂和手腕的运动有几个滚轮来执行棒球投球。然而，其动力学机制尚不清楚。作为了解棒球投球中前臂和手的滚动的一步，我们调查了每个环节的非肌肉力量是如何产生、吸收和传递机械能量以产生最大速度的。手的机械能是由前臂离心力控制的非肌肉力。然而，手腕的肌肉扭矩吸收了手的机械能量。结果表明，只有手腕不能产生较高的球速。因此，手腕配备了一种自卫机制，为外部手指控制提供了一个相对稳定的基础。也有人认为，手腕关节有一个滚动，以应用旋转球。手腕关节可能影响球的旋转速度，而不是平移速度。

Some studies have reported that movements of forearm and wrist has several rolls to perform a baseball pitching. However dynamical mechanism are still unclear. As a step toward understanding the rolls of forearm and hand in baseball pitching, we investigated how non-muscular forces of the each link generates, absorbs, and transfers mechanical energy in order to produce maximum velocity. The mechanical energy of the hand was supplied the non-muscular force, which is governed by the centrifugal force of the forearm. However, the muscle torque of the wrist absorbs the mechanical energy of the hand. It is concluded that only the wrist cannot generate a high ball velocity. The wrist, therefore, is equipped with a self-defense mechanism and provides a relatively stable base for extrinsic finger control. It is also thought that the wrist joint have a roll to apply spin a ball. The wrist joint may contribute to the rotational velocity and not the translational velocity of a ball.