Electromyography Comparison of Sex Differences During the Back Squat

Abstract Mehls, K, Grubbs, B, Jin, Y, and Coons, J. Electromyography comparison of sex differences during the back squat. J Strength Cond Res 36(2): 310–313, 2022—Currently, there is limited information regarding the muscle activity differences between men and women during the traditional back squat. The back squat is a widely used exercise which stimulates lower-body musculature; thus, information regarding the muscle activity patterns during this exercise is pertinent when prescribing resistance training. This study evaluated muscle activity differences (using surface electromyography) in men and women during the traditional back squat with a load prescribed to elicit strength gains. Resistance-trained men ( n = 14) and women ( n = 14) performed 3 sets of 4 repetitions in the traditional back squat using 85% of their pretest 1 repetition maximum. Muscle activity data were collected for 6 muscles including the vastus lateralis, vastus medialis, rectus femoris, gluteus maximus, semitendinosus, and biceps femoris (BF). Independent sample t tests revealed a significantly higher normalized muscle activity in men in the BF muscle during the descending phase of the back squat. No other muscle activity differences were present between men and women. These results indicate that men activate the BF muscle during the traditional back squat to a greater extent than women. For women, it may be necessary to consider other exercises to optimally stimulate and strengthen the BF muscle during resistance training.