Associations of lumbopelvic control angle with upper-extremity explosive power, closed-chain performance, and dynamic balance in recreational tennis players: a cross-sectional study

Lumbopelvic control may contribute to kinetic-chain function during upper-extremity activities, but whether it is similarly associated with different performance domains in tennis players remains unclear. This study examined associations between lumbopelvic control and upper-extremity explosive power, closed-chain functional performance, and dynamic balance in recreational tennis players. Eighty-four recreational tennis players (40 women, 44 men; mean age 32.1 ± 9.7 years) completed a pressure-biofeedback assessment of lumbopelvic control, the Closed Kinetic Chain Upper Extremity Stability Test, Seated Medicine Ball Throw, and Upper Quarter Y-Balance Test. Lower angles during the leg-lowering task indicated better task-specific lumbopelvic control. Associations were examined using Pearson correlations, sex-adjusted partial correlations, and multivariable linear regression adjusted for sex, weekly tennis training, and tennis experience. Lower lumbopelvic control angles were associated with higher Closed Kinetic Chain Upper Extremity Stability Test scores ( r = − 0.484, p < 0.001) and greater Seated Medicine Ball Throw distance ( r = − 0.731, p < 0.001), but not with right- or left-side Upper Quarter Y-Balance Test composite scores (both p > 0.05). After adjustment for sex, weekly tennis training, and tennis experience, lumbopelvic control angle remained associated with Seated Medicine Ball Throw distance (B = − 5.74 cm/°, 95% CI − 8.43 to − 3.05; β = −0.352; p < 0.001), whereas its association with Closed Kinetic Chain Upper Extremity Stability Test performance was not statistically significant (B = − 0.10 touches/°, 95% CI − 0.26 to 0.05; p = 0.195). Performance on the pressure-biofeedback bilateral leg-lowering task was associated with seated medicine-ball throwing distance after adjustment for the measured covariates. In contrast, the adjusted association with closed-chain functional performance and the observed associations with upper-quarter dynamic balance were not statistically significant. These findings are specific to the assessments employed and do not establish causal relationships or improvements in tennis-specific performance. Domain-specific assessments remain necessary when evaluating upper-extremity performance in recreational tennis players.