A Three-Dimensional Biomechanical Analysis of KOSHIWARI Exercise

摘要

The koshiwari(Sumo Squat)is a traditional exercise used for basic training for sumo wrestling,the national sport of Japan.This study compares and analyzes the kinetics and kinematics of the koshiwari and squat with wide-stance(WSQ)to provide insight related to the mechanical features of the koshiwari.Optical three-dimensional automatic analysis instruments were used to measure movements of 11 men during exercises.A force platform was used to measure floor reactions.Two movements were analyzed:koshiwari and WSQ.The koshiwari and WSQ were compared as analytical objectives,using paired t-tests corresponding to correction joint angles,angular impulse,and joint torques with the level of significance set under 5%.Koshiwari was found to involve markedly greater excursions of abduction(maximum and minimum angle,correction angle to 20%-60%)and external rotation(maximum and minimum angle)at the hip compared with the WSQ,as well as markedly less hip flexion(maximum angle,correction angle 10%-90%)and torso forward tilt(maximum angle,correction angle 30%-100%).Koshiwari also involved greater extension-flexion axis,abduction-adduction axis,external rotation-internal rotation axis angular impulse and flexion(10%-100%),adduction(40%-60%),and external rotation(20%)torques at the hip than WSQ exercises.Results suggest that hip external rotation torque is attributable to hip external rotator muscle activity.The activity can apparently reduce the risk of ACL(Anterior cruciate ligament)injuries and patellofemoral pain syndrome and improve athletic performance.