Analysis of the Force Characteristics of Seoi-nage based on the Performance Height of Elite Male Judo Athletes

Abstract

Seoi-nage is a representative technique frequently used in judo. Therefore, it is essential to identify how seoi-nage force characteristics change under various conditions. This study aimed to determine the differences in the force characteristics at different performance heights of elite male judo athletes. Twenty elite male judo athletes participated in the study. They were asked to perform seoi-nage at different heights (80 cm and 60 cm) using a rubber band as a practice situation. Data were collected by a force-measurement device with a rubber band connected to the device. The time variables, force value magnitude, force value rate, and force value angle in the vertical/horizontal planes were calculated and compared at 80 cm and 60 cm. There were significant differences in the force magnitude and the force vector vertical angle at 80 cm and 60 cm (p<.05). The force magnitude was greater at 60 cm than at 80 cm height. The force vector vertical angle was greater at 60 cm than at 80 cm height. In conclusion, seoi-nage at 80 cm height requires less force than at 60 cm; hence, judo players should perform the seoi-nage throw placing their center of mass lower than that of an opponent. Practicing seoi-nage repeatedly at 60 cm height under the training conditions is recommended. Seoi-nage at 60 cm height can be considered an effective training method for increasing the ability to handle difficult opponents.