幼児の両足連続跳び越しにおける両足同時性が時空間的な身体コントロールに及ぼす影響

抄録

　The purpose of this study was to clarify the actual situation of two-footed takeoff and landing (i.e., twofooted synchronism) during continuous two-footed hopping in young children (aged 4—5 years) and the effect of two-footed synchronism on spatiotemporal body control.
　The participants performed continuous two-footed hops for 10 blocks as quickly as possible. The total movement time required to hop 10 blocks was measured, and the participant’s hopping movement was recorded. The accomplishment rate of two-footed takeoff and landing, the flight and ground contact times, and the displacement of the trochanterion were analyzed for each hopping movement. The main results were as follows.
　1. The rate of accomplishment of two-footed takeoff was higher than that of two-footed landing, and there was a significant correlation between the rates of accomplishment of two-footed takeoff and landing.
　2. The ground contact time was longer than the flight time, and showed temporal variation. There was spatial variation in the anterior movement because the coefficient of variation of horizontal displacement of the trochanterion was greater than that of the vertical displacement.
　3. The higher rate of accomplishment of two-footed landing was related to a shorter ground contact time, a smaller horizontal displacement, and a shorter total movement time.
　In particular, the accomplishment of two-footed landing was found to be the most important factor affecting quick and stable hopping. These results suggest the importance of viewing the developmental characteristics of spatiotemporal body control ability in locomotion, focusing on two-footed synchronism of the continuous twofooted hopping process.