Kimura Arata, Omura Leon, Yoshioka Shinsuke, Fukashiro Senshi
Department of Sports Research, Japan Institute of Sports Sciences, Japan; Department of Life Sciences, The University of Tokyo, Tokyo, Japan.
Department of Life Sciences, The University of Tokyo, Tokyo, Japan; Research Fellow of the Japan Society for the Promotion of Science, Tokyo, Japan.
Hum Mov Sci. 2021 Jun;77:102799. doi: 10.1016/j.humov.2021.102799. Epub 2021 Apr 21.
It is known that coordination between joint movements is crucial for the achievement of motor tasks and has been studied extensively. Especially, in sports biomechanics, researchers are interested in determining which joint movements are coordinated to achieve a motor task. However, this issue cannot be easily addressed with the methods employed in previous studies. Therefore, we aimed to propose a method for identifying joint coordination. Subsequently, we examined which joint movements were coordinated using accurate overhead throwing, which required reduction in vertical hand velocity variability. Fourteen baseball players participated by attempting throwing using a motion capture system. The index of coordination for each joint movement and the effect of deviation of one joint movement on vertical hand velocity were quantified. Our results showed that the shoulder internal/external rotation angle (θ) and the other joint movements or the shoulder horizontal flexion/extension angular velocity (ω) and the other joint movements were coordinated. These results could be explained by the fact that the effects of the deviation of the shoulder internal rotation angle (θ) and shoulder horizontal flexion angular velocity (ω) on vertical hand velocity were larger than those of the other joint movements. This meant that it was necessary to cancel the deviations of θ and ω by the other joint movements. These findings indicate that the method proposed in this study enables the identification of which joint movements are coordinated in multiple degrees of freedom.
众所周知，关节运动之间的协调对于完成运动任务至关重要，并且已经得到了广泛研究。特别是在运动生物力学领域，研究人员致力于确定哪些关节运动相互协调以完成一项运动任务。然而，以往研究中所采用的方法难以轻易解决这个问题。因此，我们旨在提出一种识别关节协调性的方法。随后，我们通过精确的过顶投掷动作来研究哪些关节运动是相互协调的，该动作要求降低手部垂直速度的变异性。14名棒球运动员参与实验，他们使用动作捕捉系统进行投掷尝试。对每个关节运动的协调指数以及一个关节运动的偏差对手部垂直速度的影响进行了量化。我们的结果表明，肩部内/外旋转角度（θ）与其他关节运动之间，或者肩部水平屈伸角速度（ω）与其他关节运动之间是相互协调的。这些结果可以通过以下事实来解释：肩部内旋角度（θ）和肩部水平屈伸角速度（ω）的偏差对手部垂直速度的影响比其他关节运动的影响更大。这意味着有必要通过其他关节运动来抵消θ和ω的偏差。这些发现表明，本研究中提出的方法能够识别在多个自由度中哪些关节运动是相互协调的。
