Development of a Device Adjusting Ground Reaction Force and Manipulating Pelvic Rotation to Support for Improving Sprint Running Skills

Abstract

Recently, an approach for sports that attempts to support improving skills by measuring and analyzing human motions using motion capture and sensors and then feeding back the data to athletes has been generally applied. It is difficult to construct ideal motions in sprinting for track-and-field because the motions are instantaneous and complex. So, in the method using data, skill acquisition depends on the athlete’s ability. And the researches on supporting the acquisition of skills directly is still developing. Therefore, the authors focused on the effective use of the elastic function of muscle-tendon complexes and the rotation of the pelvis to promote the external rotation of the hip joint in sprinting and developed a device that provides clues to construct these motions. This experimental device promotes the effective use of the elastic function of the muscle-tendon complexes by giving elastic force in the vertical direction of the body to adjust the ground reaction force. In addition, this device manipulates the rotation of the pelvis by giving a torque in the direction of pelvic rotation to present the timing of pelvic rotation. The authors investigated acceleration when running and the relationship between the central axis of the body and the position of the feet with the device. The results suggested the tendency to increase average acceleration and run with contacting the ground on each of right and left axis.