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.
PURPOSE This study aimed to analyze the differences in ground reaction forces (GRF) and pelvis and trunk kinematic patterns between groups based on ball speed during pitching. METHODS Twenty-nine males were recruited for this study. Participants were categorized based on ball speed into high (HG), medium (MG), and low (LG) ball speed groups. Statistical analysis was performed using one-dimensional statistical parametric mapping (SPM1D) one-way analysis of variance to compare GRF and pelvis and trunk kinematic patterns, followed by Bonferroni post-hoc tests. RESULTS Drive leg anterior and resultant GRF were greater in the HG than in the LG (p<0.001). The posterior GRF of the stride leg in the HG was greater than in the LG (p<0.008). Additionally, the vertical GRF of the stride leg was greater in the HG than in the LG (p<0.003), as was the resultant GRF of the stride leg (p<0.003). CONCLUSIONS The GRF of the drive and stride legs was significantly related to ball speed, indicating that a pitching strategy to maximize the GRF of the drive and stride legs is required.
