体育学研究
Online ISSN : 1881-7718
Print ISSN : 0484-6710
ISSN-L : 0484-6710

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半径の小さな曲線走動作における身体の方位変化メカニズム
佐藤 隆彦矢内 利政
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ジャーナル フリー 早期公開

論文ID: 15024

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 The purpose of this study was to determine how runners sprinting along a curved path could rotate their whole-body about the vertical axis to keep facing towards ever-changing movement direction. Ten healthy men were asked to run at 5 m/s along a straight path (RS) and a curved path with a 5-m radius (RC). The running direction in RC was counterclockwise (CCW) as viewed from above. A motion capture system with eight cameras was used to record the three-dimensional coordinates of reflective markers attached to each subject with the sampling frequency set at 240 Hz. The angular momentum of each body segment about the vertical axis passing through the center of mass of the entire body was determined for one complete stride cycle with the method described by Dapena (1978). The average value for the angular momentum of the entire body about the vertical axis was determined for each contact phase and each flight phase. Two-way ANOVA (2 movements×4 phases) was used to test the significance of the main and interaction effects. In addition, the angular momentum was categorized into head and trunk, right leg, left leg, right arm, left arm, both arms and both legs, and the pattern of change in each category during the normalized stride cycle was compared between two movements. Two-way ANOVA demonstrated a significant main effect for both factors with no interaction. In all phases, the average angular momentum in RC was directed more toward CCW as viewed from above than that in RS. Whereas the angular momentum of the head and trunk in RS changed periodically from positive to negative values, that in RC maintained positive values throughout the stride cycle. The angular momentum of the right leg in RC changed periodically in the same phase as in RS, but that of the left leg changed in the reverse phase. The left leg not only moved back and forth in RC, but also moved from side to side, allowing it to undergo circular motion in a direction opposite to the body's rotation in the horizontal plane. Presumably, this circular motion generated reaction effects on the adjacent segments, causing the head and trunk to gain sufficient angular momentum to keep facing toward the running direction.

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© 2015 一般社団法人 日本体育学会
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