Pelvic Control and Pelvic-Trunk Coordination as Key Determinants of Pitching Velocity in Baseball Pitchers.
Level 4 - case-series / case-control
Cross-sectional descriptive laboratory biomechanics study
PubMed 40727237 · doi:10.1177/23259671251350302
What was done
Researchers evaluated 34 asymptomatic male high school and collegiate baseball pitchers using inertial measurement units (IMUs) during a single-leg balance with movement test and pitching trials. Pelvic control was quantified by angular variation. Pelvic-trunk coordination was assessed via angle-angle plots of rotation to determine percentages of in-phase and anti-phase coupling across two phases: foot contact to maximal external rotation (MER), and MER to maximal internal rotation (MIR). Pitching velocity was measured using a radar gun, and correlation coefficients were calculated.
What was found
Pitch velocity was significantly correlated with pelvic stability and coordination metrics: - Axial-plane pelvic control during single-leg stance correlated negatively with pitch velocity on both the stride leg (r = -0.76, P < .01) and drive leg (r = -0.65, P < .01), indicating less angular variation correlated with higher velocity. - Pelvic angle variation in the axial plane during pitching showed a strong negative correlation with velocity (r = -0.78, P < .01). - Higher anti-phase coordination percentage from foot contact to MER correlated positively with pitch velocity (r = 0.74, P < .01). - Higher in-phase coordination percentage from MER to MIR correlated positively with pitch velocity (r = 0.58, P < .01).
Why it matters
The study identifies specific axial pelvic stability metrics and phase-dependent pelvic-trunk coupling patterns that correlate with pitch velocity, providing biomechanical targets for pitching analysis and training.
Limits
The study is limited by a small sample size (n = 34) restricted to asymptomatic male high school and collegiate pitchers, limiting generalizability to professional or female athletes. The cross-sectional, observational design establishes correlation rather than causation. In-game fatigue, ball-tracking outcomes other than velocity, and injury risk were not assessed.