The Effect of Stretch-Shortening Cycle on the Joint Power of the Jireugi in the Taekwondo Juchumseogi Stance

Abstract

The purpose of this study was to investigate the muscle mechanical properties of the pelvic axial pre-rotational movement for the Jireugi in the Taekwondo Juchumseogi stance. Eleven elite Taekwondo Poomsae athletes participated. Each participant performed 5 right hand Jireugi in Juchumseogi stance as fast and strong as possible while their motion was recorded by a 3D motion analysis system and the ground reaction forces by two force plates. The power and work of the muscular group surrounding the waist were analyzed to verify the effect of the stretch-shortening cycle (SSC) theory. The cause of the greater power seems to be the application of the SSC by the muscles surrounding the waist during the preparation phase of the pre-rotation group. For the none pre-rotation group, they only used the concentric contraction of the muscles surrounding the waist. Because the pre-rotation group used the SSC theory, they had the effect of shortening of the range of movement, creating a fast and more powerful rotation, thus anticipating the increase the magnitude of impact.

The Effects of Upper Limb, Trunk, and Pelvis Movements on Apkubi Momtong Baro Jireugi Velocity in Taekwondo

“…The angular velocities and acceleration of the trunk and pelvis about the vertical axis had a similar pattern as that observed in a study by Lee and Park (2015). This result was consistent with studies by Choi (2013aChoi ( , 2013b, and Choi et al (2014), who emphasized that the movement of the waist about the vertical axis was responsible for left rotation acceleration, in the direction opposite punching, at maximum punching speed. The power of the waist was positive, and became negative over time.…”

“…Similar to the results of studies by Choi (2013aChoi ( , 2013b and Choi et al (2014), which emphasized the importance of the trunk, pelvis, and waist movements about the vertical axis during the execution of Jireugi, the movements of the trunk and waist in this study also appeared to have a positive influence on the punching speed.…”

“…The waist angle, which is the angle of the trunk relative to the pelvis, rotated to the right by 52°. Choi (2013aChoi ( , 2013bChoi ( , 2013c, Choi et al (2014), and Yoo (2015b) observed similar twisting patterns of the waist. At E1, the waist twisted in the direction opposite the punching arm, at the moment of reaching maximum punching speed (E2), it twisted in the direction of the punching arm.…”

A Study of Motor Expertise about Kinematic and Kinetic Characteristics of Lower Extremity in the Seokmun Ilwol Martial Art Yin-yang Bo Gait Pattern

“…KI: knee internal rotation peak frame; KE; knee external rotation peak frame; HI: hip internal rotation peak frame; HE: hip external rotation peak frame; PE: pelvic external rotation peak frame; PTr: pelvic transfer frame; KAbM: knee abduction Moment peak frame. (Kang et al, 2007), 태권도 주춤 서 지르기에서 골반과 상체를 동시에 회전시키는 집단에 비해 골반을 먼저 회전시킨 후 상체를 회전시키는 집단이 '골반 종축 선 회전 동작'을 통해 파워 를 발휘하고 있음을 확인하였다 (Choi et al, 2014 (Winter, 1990). X자로 교차하며 허리의 비틀림을 이 용하는 음양보법 보행 패턴을 통해 축적되는 에너지의 숙 련자 집단과 미숙련자 집단 간 차이를 확인하기 위해 골 반 분절에서의 위치 에너지를 비교하였다.…”