Effects of rotational box jump training on the movement timeof the Judo Technique “uchimata” in university judo players

The present study examined the effects of rotational box jump training on the movement time of the Judo Technique “uchimata” in male university judo players（ n = 18） . The participants were classified into three groups: a rotational box jump training group（ RBJ group, n = 6） , a box jump training group（ BJ group, n = 6） , and a notraining group（ CON group, n = 6） . The RBJ group was instructed to rotate their hips in the same direction when getting on the box as they did when performing the Judo Technique “Uchimura” workout they performed in normal practice, and when descending from the box to the tatami, they were instructed to return using the same direction. For example, if the participants got on the box by rotating their hips to the left, they were instructed to rotate their hips to the right when they got off the box. The training was conducted three days a week three sets of ten times for four weeks, for a total of 12 sessions. As a result, the training of the RBJ group shortened the movement time from the “Kuzushi” to “Tsukuri” phase. Moreover, the rebound jump index was significantly improved. These results suggest that rotational box jump training improved the ability of Stretch-Shortening Cycle （SSC） and shortened the movement time of the Judo Technique “uchimata” in university judo players.