Context: Bridge exercises are extensively used in trunk-strengthening programs. The aim of this study was to investigate the effect of bridging duration on lateral abdominal muscle thickness and gluteus maximus activation.
Design: Cross-sectional.
Methods: Twenty-five young males participated in this study. Transversus abdominal (TrA), external and internal oblique ultrasound thickness, gluteus maximus electromyographic activation, and sacral tilt angle were simultaneously measured for every second during 30-second bridging exercise. The contraction thickness ratio and root mean squared signal (normalized to maximum isometric contraction signal) during 6 exercise durations (from 0 to 5, 10, 15, 20, 25, and 30 s) were also calculated and compared using analysis of variance designs.
Results: TrA and internal oblique contraction thickness ratio and gluteus maximus root mean squared increased during the first 8 to 10 seconds and remained elevated until the end of the 30-second exercise (P < .05). External oblique contraction thickness ratio declined during exercise (P < .05). Five-second bridging showed less TrA thickness and anteroposterior and mediolateral sacral tilt angle and a lower anteroposterior tilt variability compared with bridges, which lasted more than 10 seconds (P < .05).
Conclusions: Bridge exercises longer than 10 seconds may be better for promoting TrA recruitment than bridges of shorter duration. Clinicians and exercise specialists could adjust the duration of bridge exercise based on the aims of the exercise program.
Keywords: diagnostic ultrasound; electromyography; muscle recruitment; trunk/core.