Ferdinands René E D, Doljin Batdelger, Fuss Franz Konstantin
Discipline of Exercise and Sports Science, Sydney School of Health Sciences, Faculty of Medicine & Health, University of Sydney, Sydney, NSW 2141, Australia.
Smart Products Engineering Program, Swinburne University, Melbourne, VIC 3000, Australia.
Sensors (Basel). 2023 Sep 21;23(18):8012. doi: 10.3390/s23188012.
Spin bowling deliveries in cricket, finger spin and wrist spin, are usually (Type 1, T1) performed with forearm supination and pronation, respectively, but can also be executed with opposite movements (Type 2, T2), specifically forearm pronation and supination, respectively. The aim of this study is to identify the differences between T1 and T2 using an advanced smart cricket ball, as well as to assess the dynamics of T1 and T2. With the hand aligned to the ball's coordinate system, the angular velocity vector, specifically the x-, y- and z-components of its unit vector and its yaw and pitch angles, were used to identify time windows where T1 and T2 deliveries were clearly separated. Such a window was found 0.44 s before the peak torque, and maximum separation was achieved when plotting the y-component against the z-component of the unit vector, or the yaw angle against the pitch angle. In terms of physical performance, T1 deliveries are easier to bowl than T2; in terms of skill performance, wrist spin deliveries are easier to bowl than finger spin. Because the smart ball allows differentiation between T1 and T2 deliveries, it is an ideal tool for talent identification and improving performance through more efficient training.
在板球运动中，旋转投球，即手指旋转和手腕旋转，通常（类型1，T1）分别通过前臂旋后和旋前来完成，但也可以用相反的动作（类型2，T2）来执行，具体来说分别是前臂旋前和旋后。本研究的目的是使用先进的智能板球来识别T1和T2之间的差异，以及评估T1和T2的动力学。将手与球的坐标系对齐，利用角速度矢量，特别是其单位矢量的x、y和z分量以及偏航角和俯仰角，来确定T1和T2投球明显分开的时间窗口。在峰值扭矩前0.44秒发现了这样一个窗口，当绘制单位矢量的y分量与z分量的关系图，或偏航角与俯仰角的关系图时，实现了最大分离。在体能方面，T1投球比T2更容易投出；在技术表现方面，手腕旋转投球比手指旋转投球更容易投出。由于智能球能够区分T1和T2投球，它是人才识别以及通过更高效训练提高表现的理想工具。
