Quantitative evaluation of visual-motor coordination while receiving a ball with both hands

Sight is important for controlling the musculoskeletal system and maintaining posture because it is a sense that collects external environmental information away from the body. In daily life and sports, humans obtain most of their external environmental information from sight. Therefore, analyzing the gaze during movement is expected to clarify the relation between gaze and falls among elderly people and to improve performance on the sports field. This study measured the gaze and upper limb posture of a catcher while receiving a basketball with both hands. Results clarified the visual-motor coordination during catching. Singular value decomposition was applied to the observation matrix constructed using the upper limb joint angles and the pixel coordinates of gaze point obtained in the experiment. We evaluated the cooperative relation between a gaze and upper limb posture quantitatively using the space basis vector of the first mode, which has a high contribution ratio. Results demonstrated that the movement of upper limb was coordinated with the gaze while receiving a ball. Visual-motor coordination in various sports can be clarified using the proposed method.