Abstract
This study compared the joint angles measured during the execution of uchimata (inner thigh throw) among judokas with varying skill levels. It also derived practical insights for technical instruction. The study participants included 20 male judokas belonging to a university judo club, 10 of whom had participated in national tournaments (hereafter referred to as “skilled”) and 10 of whom had not participated in national tournaments (hereafter referred to as “unskilled”) . Movements were recorded using Mac3D (frequency 250 Hz) , an optical 3D movement analysis system. Ground reaction forces acting on the judoka’s feet during the movements were measured using a force plate (frequency 1000 Hz) . The results showed that the skilled group had a greater maximum trunk tilt angle than the unskilled group, and this maximum angle occurred significantly earlier. Additionally, there was a tendency for the maximum value of Tsurite to be smaller, whereas the maximum value of Hikite was larger. This led to skilled judokas effectively pulling the opponent forward and possibly using the principles of leverage for the throw. Therefore, it was suggested that to enhance the uchimata technique, using both Tsurite and Hikite to collapse the uke during the Turning phase would stabilize the posture of the tori during the Throwing phase, even when standing on only one pivot foot, and would enable the tori to quickly lift the opponent.
