Task-Specific Associations Between Abdominal Pressure and Physical Performance in Adolescent Female Volleyball Players

Assessment of trunk function in sports settings remains challenging, as conventional strength measurements may not reflect integrated trunk stabilization. Abdominal pressure (AP), measured non-invasively using an abdominal cuff device, has been proposed as an indicator of coordinated trunk muscle activity; however, its association with sport-specific performance remains unclear. This study examined the within-session reliability of AP and its task-specific associations with performance measures in adolescent female volleyball players. Twenty-six athletes participated in this cross-sectional study. AP was measured twice within a single session, and reliability was evaluated using intraclass correlation coefficients (ICCs), standard error of measurement, minimal detectable change, and Bland–Altman analysis. Associations between AP and 20 m sprint time, T-test performance, and countermovement jump (CMJ) height were assessed using Pearson’s and partial correlations controlling for normalized trunk and hip flexion strength (N/kg). AP showed high reliability (ICC(3,1) = 0.941; 95% CI: 0.873–0.973). AP was significantly correlated with 20 m sprint time and T-test performance, but not with CMJ height. The association with sprint performance remained after adjustment, whereas that with T-test performance was attenuated. These findings suggest that AP is associated with sprint performance and may reflect task-specific associations, rather than representing a generalized or mechanistic indicator of trunk stabilization. Further longitudinal and interventional studies are needed to clarify causal relationships.