Effect of maximum expiration with hip adductor contraction during bridge exercise on trunk muscle activity in healthy individual

Objective: To examine the effects of maximum expiration with hip adductor contraction during bridge exercises on trunk muscle activity in healthy individuals. Design: Cross-sectional study Methods: Twenty-seven healthy adults participated. Each participantperformed four types of bridge exercise: normal bridge exercise, bridge exercise with hip adductor contraction, bridge exercise with maximum expiration, and bridge exercise with maximum expiration and hip adductor contraction. Exercises were performed three times for five seconds, with a one-minute rest between trials and a three-minute rest between exercise types. Surface electromyography was used to record the activities of the rectus abdominis, internal oblique, external oblique, and erector spinae muscles. Results: The rectus abdominis had the greatest activation during bridge exercise with maximum expiration and hip adductor contraction compared with the other exercise types (p<0.008). The internal and external oblique muscles also had significant differences in activity among the four exercise types (p<0.008), with activation levels in the following order: bridge exercise with maximum expiration plus hip adductor contraction, bridge exercise with maximum expiration, bridge exercise with hip adductor contraction, and normal bridgeexercise. Erector spinae activity was significantly greater during bridge exercise with hip adductor contraction and bridge exercise with maximum expiration plus hip adductor contraction, compared to the other exercise types (p<0.008). Conclusions: Bridge exercise combined with maximum expiration and hip adductor contraction produced significantly higher activation of key trunk muscles than the other bridge exercise types. These findings suggest that incorporating expiration and adductor contraction during bridge exercise may be an effective strategy for strengthening the trunk of healthy adults.