투구 시 보폭에 따른 공의 구속과 운동학적, 운동역학적 차이 = Ball Speed and Kinematic, Kinetic Differences According to Stride Length During Pitching

다국어 초록 (Multilingual Abstract)

PURPOSE This study analyzed differences in ball speed and kinematic, kinetic characteristics according to stride length. METHODS Forty participants recruited for the study were divided into two groups based on stride length: an over stride group (overstride, OS) and an under stride group (understride, US). Independent sample t-tests were conducted to analyze differences in pelvis and trunk kinematics, ground reaction forces (GRF), and timing of pitch between groups. RESULTS Significant differences were found between groups in drive leg GRF impulse, pelvis, trunk closed angle and pelvic angular velocity (p<.05). Furthermore, the OS had statistically later pitching timings than the US at stride foot contact, maximal external rotation, and ball release phases (p<.05). CONCLUSIONS The maximized drive leg GRF impulse created a wider stride, significantly increasing the pelvis and trunk’s opening angles. Additionally, the OS displayed characteristics of later pitching timings compared to the US. However, since no significant differences in ball speed were observed between groups based on stride length, perhaps stride length does not contribute directly to ball speed. Future research should investigate optimal stride length tailored to individual flexibility and physical characteristics.