Elliott B, Marshall R, Noffal G
Department of Human Movement, University of Western Australia, Nedlands, Australia.
J Sports Sci. 1996 Apr;14(2):159-65. doi: 10.1080/02640419608727697.
In the squash forehand drive, the contribution that each of the upper limb segment's anatomical rotations make to racket-head velocity towards the front wall (x-direction) during the forward swing and at impact were calculated. Eight squash players (3 females, 5 males) capable of hitting a high-performance squash forehand drive were filmed at a nominal rate of 300 Hz by two phase-locked Photosonics cameras. The three-dimensional displacement histories of 12 selected landmarks were then calculated using the direct linear transformation approach and three-dimensional individual segment rotations were calculated using vector equations. Internal rotation of the upper arm at the shoulder joint (46.1%), hand flexion at the wrist joint (18.2%) and forearm pronation at the radio-ulnar joint (12.0%) were the major contributors to the mean 30.8 m s-1 x-direction velocity of the centre of the racket-head at impact. Pronation of the forearm at the radio-ulnar joint and extension at the elbow joint both played a significant role in generating racket velocity in the period prior to impact.
在壁球正手击球动作中，计算了在前摆和击球瞬间，上肢各节段的解剖学旋转对球拍头朝着前墙方向（x 方向）速度的贡献。由两台锁相的 Photonics 相机以 300Hz 的标称速率拍摄了八名能够打出高性能壁球正手击球的壁球运动员（3 名女性，5 名男性）。然后使用直接线性变换方法计算 12 个选定标志点的三维位移历程，并使用矢量方程计算三维个体节段旋转。肩关节处上臂的内旋（46.1%）、腕关节处手部的屈曲（18.2%）以及桡尺关节处前臂的旋前（12.0%）是击球瞬间球拍头中心在 x 方向平均速度 30.8m/s 的主要贡献因素。桡尺关节处前臂的旋前和肘关节处的伸展在击球前的时间段内对产生球拍速度均起到了重要作用。
