Effects of integrating hip movements into bridge exercises on electromyographic activities of selected trunk muscles in healthy individuals

This study aimed to identify the electromyographic (EMG) effects in selected trunk muscles after incorporating hip movement into bridging exercise. Twenty-six healthy adults (13 men and 13 women) volunteered for this experiment. EMG data (% maximum voluntary isometric contraction) were recorded from the rectus abdominis (RA), obliquus internus (OI), erector spinae (ES), and multifidus (MF) muscles of the dominant side while the subjects performed 3 types of bridging exercise, including bridging alone (Bridging 1), bridging with unilateral hip movements (Bridging 2), and bridging with bilateral hip movements (Bridging 3) in a sling suspension system. The RA and OI showed greater EMG activity during Bridging 2 and 3 compared to Bridging 1, with the greatest OI activity during Bridging 3 (p < 0.05), and the activity of the MF appeared to be greater during Bridging 3 than during Bridging 1 and 2 (p < 0.05). Furthermore, the OI/RA and MF/ES ratios were significantly higher for Bridging 2 (OI/RA = 1.89 ± 1.41; MF/ES = 1.03 ± 0.19) and Bridging 3 (OI/RA = 2.34 ± 1.86; MF/ES = 1.03 ± 0.15) than Bridging 1 (IO/RA = 1.35 ± 0.92; MF/ES = 0.98 ± 0.16). The OI/RA ratio was significantly higher for Bridging 3 than for Bridging 2. Based on these results, adding hip abduction and adduction, particularly bilateral movements, could be a useful method to enhance OI and MF EMG activity and their activities relative to global muscles during bridging exercise.