Trunk muscle thickness and sprint, agility, and jump performance in competitive football players

BACKGROUND: Trunk musculature is increasingly recognized for its role in athletic performance, yet remains less studied than lower limb muscles. This study aimed to examine the associations between trunk muscle thickness and sprint, agility, and jump performance in competitive male football players. METHODS: Fifteen male football players (tier 3; mean age: 19. 73 ± 1. 75 years; training experience: 8. 06 ± 1. 57 years) participated. Thickness of five trunk muscles was measured at rest using B-mode ultrasound. Sprint (20-m), agility (Pro-Agility), and countermovement jump (CMJ) tests were conducted. To control for type I error across 15 comparisons, Bonferroni correction was applied (αₐdj = 0. 0033). Significant associations were further examined using linear regression. RESULTS: After adjustment for multiple testing, transversus abdominis and internal oblique thickness were significantly associated with 20 m sprint time (r = - 0. 739 to - 0. 746, p ≤ 0. 002). These muscles were also significantly associated with agility performance (r = - 0. 704 to - 0. 746, p 0. 05; d < 0. 2). CONCLUSION: Greater thickness of specific deep anterior trunk muscles appears to be associated with sprint and agility performance in competitive football players. These findings suggest that deep trunk morphology may be associated with sprint and change-of-direction performance, although causal relationships cannot be inferred due to the cross-sectional design.