Abstract
This study aimed to determine whether bipedal static balance performance, assessed under eyes-open and eyes-closed conditions, contributes to countermovement jump (CMJ) performance when sex-related differences and postural stability parameters are statistically controlled. Sixty-four physically active adults (32 females and 32 males; aged 18–45 years) who regularly engaged in resistance-based exercise participated in the study. Static balance was evaluated in a standardized bipedal stance using the TecnoBody D-Wall system by quantifying center-of-pressure (CoP) ellipse area under eyes-open and eyes-closed conditions. CMJ performance was assessed using the same system, with jump height, flight time, total mechanical work, maximum force, and maximum absolute power recorded. Statistical analyses were performed using IBM SPSS Statistics. Data normality was assessed with the Shapiro–Wilk test. Sex-based differences in anthropometric variables were analyzed using independent samples t-tests or Mann–Whitney U tests, as appropriate. To examine the effect of sex on CMJ performance while controlling for static balance parameters, analysis of covariance (ANCOVA) models were applied, with eyes-open and eyes-closed CoP ellipse areas entered as covariates. ANCOVA results revealed significant main effects of sex on several CMJ outcomes, including flight time, total work, maximum force, and maximum absolute power (p < 0.05), with large effect sizes. Eyes-open static balance did not significantly influence any CMJ parameter. In contrast, the eyes-closed CoP ellipse area demonstrated a borderline significant effect on total mechanical work (p = 0.050), suggesting a limited contribution of proprioceptive-dominant postural control to mechanical work production independent of sex. These findings indicate that bipedal static balance, as quantified by CoP ellipse area, does not substantially explain variability in vertical jump performance beyond sex-related effects. This conclusion is specific to static balance conditions and should not be generalized to dynamic balance or functional stability tasks. Overall, static postural control and explosive jump performance appear to represent largely independent motor capacities, underscoring the importance of task-specific assessment and training strategies in athletic populations. Keywords: Countermovement Jump, Digital Posturography Technologies, Static Balance.
Description
The study examines the relationship between static balance and explosive power in recreational athletes.