Hand-motion Analysis for Development of Double-unders Skill

Double-unders is one of interesting physical skills combining multiple primitive motions of different frequencies. This paper discusses an analyzing method of trajectory on hand-motion in double-unders. It also tackles to design an environment for the staged learning in acquisition process of the skill. We focus on the radius of motion-trajectory of the hand and spatial positions of moving hand. We measure some parameters relating to the hand-motions, and observe relative hand positions to the body. Then, we observe the difference of them between persons who have acquired the skill and others who have not acquired the skill yet. As a result, it has clarified that our proposal relating to the hand-motions is not irrelevant to success or failure of double-unders.