著者

久保田 浩史 渡辺 直勇 渡辺 涼子 佐藤 武尊 山本 浩貴

出版者

日本武道学会

雑誌

武道学研究 (ISSN:02879700)

巻号頁・発行日

vol.46, no.2, pp.99-104, 2014-01-31 (Released:2015-01-31)

参考文献数

18

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It is possible that quick reaction of the whole body is delayed during exerting muscle strength, and this effect is larger when exerting larger muscle strength. This study aimed to examine the defensive motion reaction time in judo competitors, while exerting different handgrip strengths. Subjects were 46 young males (mean age, 19.7 ± 1.3 years; mean height, 172.5 ± 4.6 cm; and mean weight, 79.0 ± 13.9 kg) with black belt in judo. They performed the defensive motion reaction time test exerting handgrip strength. They placed only one leg on a mat with a device measuring the whole body reaction time, grasped a grip strength device with one hand, and reacted to a light stimulus under each condition (different grip strength levels): 0%, 20-30%, 50-60%, or >80% of their maximal handgrip strength. One way analysis of variance was used to evaluate the significant differences among the means of the defensive motion reaction time values for each condition. On statistical analysis, the reaction time was significantly longer in the 20-30%, 50-60%, and the >80% conditions than in the 0% condition, and significantly longer in the >80% condition than in the 20-30% condition. The size of difference (effect size) between the 0% and the 20-30% conditions was small, and that between the 0% and the 50-60% conditions were moderate, and that between the 0% and the >80% conditions were moderate, and it tended to be larger with increasing handgrip strength exertion. Moreover, as the handgrip strength became larger, also the reaction time was significantly delayed (Y=9.6X+332.6). In conclusion, the defensive motion reaction time in judo competitors is delayed with handgrip exertion, and the delay is larger when larger strength is exerted.