2018 Volume 16 Pages 173-179
This study aimed to clarify the rotational acceleration of the head of an uke during tai-otoshi, seoi-nage, osoto-gari, and ouchi-gari when safe ukemi is performed. Eight judo club members of the National Institute of Technology (mean age, 17.5±1.5 years; mean height, 173.0±4.21 cm; mean weight, 72.4±10.57 kg) were subjects who acted as the ukes. A subject with 8 years of experience in judo and qualified to the second dan (age, 20 years; height, 165.0 cm; weight, 70.0 kg) played the role of throwing the uke. A rotational velocity sensor was used to measure the rotational acceleration in the sagittal plane of the uke's head. One-way analysis of variance (Friedman test) was used for the statistical analysis, and when a significant difference was observed, multiple comparison test was performed using the Bonferroni method. The results revealed that of the four throwing techniques, osoto-gari generated maximum rotational acceleration of the uke's head. Furthermore, the maximum rotational acceleration was greater with tai-otoshi than with seoi-nage. Our results suggested that among the four throwing techniques, osoto-gari was most likely to injure the head.