Activation of the gluteus maximus and multifidus muscles in bridge and hip thrust exercise variations.

BACKGROUND: The gluteus maximus (GM) and multifidus (MF) play important roles in maintaining the stability and mobility of the lumbopelvic-hip complex during various activities. Variations in bridge and hip thrust exercises can affect muscle activity in the GM, MF, and biceps femoris (BF). PURPOSE: To investigate the exercise position that elicited the greatest GM activation, this study examined the muscle activity of the GM, MF, and BF, as well as the GM/BF and GM/MF ratios, across five modified bridge and hip thrust exercise conditions in healthy individuals. METHODS: Twenty healthy male individuals were enrolled in this study. An electromyographic device was used to assess the activity of the GM, MF, and BF muscles. Participants were asked to perform bridge exercises in a randomized order: conventional bridge exercise (BE), bridge exercise with elevated feet (BEEF), conventional hip thrust (HT), hip thrust with the feet placed on a balance cushion (HTFB), and hip thrust with the trunk placed on a balance cushion (HTTB). RESULTS: The muscle activity of the GM showed larger increases in BEEF, HT, HTFB, and HTTB than BE across the five conditions (padj <0.005). Furthermore, larger increases were observed in HT, HTFB, and HTTB than in BEEF, and HTTB showed higher activity than HT (padj <0.005). For the bilateral MF, increases in HT, HTFB, and HTTB were noted compared to BE, and higher muscle activity was observed in HT, HTFB, and HTTB compared to BEEF (padj <0.005). The GM/BF ratio showed a higher muscle activity ratio in HT, HTFB, and HTTB than in BE (padj <0.005). CONCLUSION: HTTB may promote GM activation with relatively lower BF involvement in healthy individuals. Exercise progression may be applied from BE to BEEF, HT, HTFB, and finally HTTB according to functional level.