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.
Nakai et al. (2026) studied this question.