Development of Kyudo Technical Support System by Markerless Motion Capture System

Abstract

We have been studying “Hayake”, one of the Kyudo yips, by investigating motion analysis using inertial sensors and EMG analysis, and found that the Hayake is a phenomenon specific to the left hand during competition. However, the sample size is small because Hayake athletes tend to choose to retire early, and the causes of Hayake have not been fully elucidated. Further, the other reason for the small sample size is that it is complicated to attach measurement devices and reflective markers to the Kyudo player’s body. Therefore, this study aimed to develop a markerless motion capture system using OpenPose, which can estimate shooting motions and provide feedback to an athlete by using a smartphone to easily capture images of the athlete's shooting movements. As a result of this system, it was possible to extract the shooting movement, joint angles, and movement time of six sections of the "Yugamae," "Uchiokoshi," "Daisan," "Kai," "Hanare," and "Zanshin" based on the eight sections of the shooting method, which are a series of shooting movements in Kyudo. This not only provides feedback of helpful information for athletes but also improves the small sample size for research, and the obtained data can be used to develop other studies.