Current evidence suggests that enhanced core stability increase lower extremity function and promote postural stability. Thus, the purpose of this study was to investigate relationships between ulrasonographic thickness of transversus abdominis muscle (TrA), which is one of the core muscle, and static and dynamic balance and core endurance in healthy collegiate males.

Healthy collegiate males who had not suffered any orthopedic injury in the past year were enrolled the study. The thickness of TrA was measured at rest and during contraction on both dominant and nondominant side using ultrasound. Also percentage of change in TrA thickness was calculated as [(thickness(contraction)−thickness(rest))/thickness(rest)]×100. The static and dynamic balance parameters were evaluated with a balance system (Korebalance Mobile System). Core endurance (CE) was also assessed using trunk extensor test, bilateral side bridge tests and the core muscle strength and stability test.

Sixty males were assessed during the study. Their mean age was 22.20±1.77 years and mean body mass index was 23.53±2.93kg/m². Dominant side TrA muscle thickness at rest was correlated with dynamic balance (r=−0.319, P=0.013) whereas no correlation for dominant side TrA muscle thickness at contraction. Nondominant side TrA muscle thickness at rest was correlated with core endurance (r=0.350, P=0.006) wheras no correlation for nondominant side TrA muscle thickness at contraction. Percentage of change in dominant side TrA thickness was correlated with dynamic balance (r=0.464, P=0.000). Percentage of change in nondominant side TrA thickness was correlated with core endurance (r=−0.361, P=0.005).

According to our results, muscle thickness of TrA is associated with postural balance and core endurance. Training to increase the muscle mass of the TrA would be useful to improve balance parameters. Further prospective studies are warranted to investigate the effects of the training of TrA and core endurance on postural balance and athletic performance.