Ultrasound-Based Morphofunctional Assessment of the Transversus Abdominis and Urinary Incontinence in Female Rugby Players

Abstract

Background: Female rugby players are exposed to repeated contact, impact, acceleration, deceleration, and trunk-stabilization demands that may challenge lumbopelvic control and intra-abdominal pressure regulation. Rehabilitative ultrasound imaging can characterize transversus abdominis (TrA) thickness changes during standardized tasks, although these measures should not be interpreted as direct indicators of neuromuscular activation or sport-specific trunk function. This study aimed to characterize ultrasound-derived TrA thickness and thickness change in nulliparous female rugby players and to explore whether these measures, immediate visual feedback, sport-related variables, and body mass index were associated with urinary leakage. Methods: A cross-sectional observational study was conducted with 34 nulliparous female rugby players recruited from two competitive rugby clubs. Urinary leakage was assessed using the validated Spanish version of the International Consultation on Incontinence Questionnaire-Short Form (ICIQ-UI SF), with current urinary leakage defined as leakage reported within the four-week recall period. TrA thickness was measured bilaterally using rehabilitative ultrasound imaging at rest, during the abdominal drawing-in maneuver (ADIM), and during ADIM with real-time ultrasound-based visual feedback. Exploratory analyses were conducted to examine associations between current urinary leakage and ultrasound-derived TrA measures, sport-related variables, and body mass index. Results: Overall, 41.2% of participants reported having experienced urinary leakage at some point, while 20.6% reported current urinary leakage. Among participants reporting leakage type, stress urinary incontinence was the most frequent pattern, and perceived impact on daily life was low. TrA thickness increased bilaterally during ADIM compared with rest. Immediate visual feedback did not produce a statistically significant additional increase in TrA thickness. No significant associations were observed between current urinary leakage and TrA thickness measures, side-to-side differences, weekly training hours, years of rugby practice, or body mass index. Conclusions: In this exploratory sample, ultrasound-derived TrA thickness measures during controlled ADIM tasks were not significantly associated with current urinary leakage. Future studies should include larger samples, direct pelvic floor muscle assessment, respiratory monitoring, body composition measures, and dynamic rugby-specific tasks.