Relationship Between Lower Body Performance Testing Metrics And Pelvis Energy Flow In Collegiate Baseball Hitting

ABSTRACT BACKGROUND: The baseball swing is a complex sequence of coordinated movements in which pelvis energy flow plays a central role in driving swing efficiency and performance. However, the relationship between lower-body performance testing metrics and mechanical energy flow during the swing is not well understood. PURPOSE: The purpose of this study was to examine the relationship between lower-body performance metrics and energy flow during baseball hitting. METHODS: Eleven collegiate hitters (age: 20.7 ± 1.4 years) first underwent a battery of performance tests, including the countermovement jump (CMJ), isometric mid-thigh pull (IMTP), hip abduction and adduction isometric strength, and passive hip range of motion (ROM), following a hitting assessment utilizing a 3-D motion capture system. Independent variables included peak power, jump height, rate of force development (RFD), peak vertical force, impulse, modified reactive strength index (mRSI), average hip strength, and hip internal/external ROM. Dependent variables included energy absorption at the stride hip, energy generation at the drive hip, and energy transfer through the L5S1 joint. RESULTS: Multiple regression analysis showed that CMJ and IMTP metrics significantly predicted drive-hip energy generation (R2 = 0.982, p < .05), with jump height, peak power, concentric impulse, and RFD emerging as significant predictors. Stride-hip absorption (R2 = 0.680) and L5S1 transfer (R2 = 0.871) explained a substantial proportion of variance in the models, but no individual predictors reached significance.CONCLUSION: Explosive neuromuscular outputs, particularly jump height, peak power, concentric impulse, and RFD, are critical for initiating rotational energy at the drive hip, while absorption and trunk transfer could depend more on swing-specific mechanics and timing. These findings highlight the value of CMJ and IMTP testing for identifying physical qualities that contribute to swing efficiency and support the development of training programs emphasizing explosive lower-body outputs to enhance hitting performance.