Abstract
BACKGROUND: Pelvic control and pelvic-trunk coordination are essential for efficient energy transfer during a baseball pitch. Proper pelvis control ensures the smooth transmission of forces from the lower extremities through the trunk to the upper body. Although the importance of pelvic control has been acknowledged in baseball mechanics, its specific role during pitching remains underexplored. PURPOSE/HYPOTHESIS: The purpose of this study was to examine the relationship between pelvic control, pelvic-trunk coordination, and pitching velocity in baseball pitchers. It was hypothesized that better pelvic control and coordination would significantly correlate with higher pitching velocity. STUDY DESIGN: Descriptive laboratory study. METHODS: A total of 34 asymptomatic male baseball pitchers were recruited from high school and collegiate teams. Pelvic control was assessed using inertial measurement units during a single-leg balance with movement test and the pitching motion. Pelvic-trunk coordination, assessed from foot contact to maximal external rotation and from maximal external rotation to maximal internal rotation, was analyzed using angle-angle plots of pelvic and trunk rotation. Coupling angles are categorized as in-phase (same direction) and anti-phase (opposite direction) coordination, with percentages calculated for each phase. Pitching velocity was measured using a radar gun. RESULTS: Significant correlations were found between pelvic control in the axial plane in the single-leg stance test condition and pitching velocity (stride leg: r = -0.76, P < .01; drive leg: r = -0.65, P < .01). During pitching, pelvic angle variation in the axial plane also had a strong negative correlation with velocity (r = -0.78, P < .01). In addition, pelvic control showed distinct coordination patterns at different phases of the pitching motion. A higher percentage of anti-phase coordination from foot contact to maximal external rotation was positively correlated with pitching velocity (r = 0.74, P < .01), while a higher percentage of in-phase coordination from maximal external rotation to maximal internal rotation showed a positive correlation with pitching velocity (r = 0.58, P < .01). CONCLUSION: This study highlights the role of pelvic control and pelvic-trunk coordination in achieving higher pitching velocities, particularly in the axial plane. The findings highlight the significance of these factors in maximizing pitching velocity. CLINICAL RELEVANCE: These findings highlight the importance of incorporating specific pelvic control and coordination exercises into training regimens for baseball pitchers to optimize pitching velocity.Registered at ClinicalTrials.gov (NCT05644704).