Electromyographic analysis of muscle activation during pull-up variations

This study sought to identify any differences in peak muscle activation (EMGPEAK) or average rectified variable muscle activation (EMGARV) during supinated grip, pronated grip, neutral grip and rope pull-up exercises. Nineteen strength trained males (24.9 ± 5 y; 1.78 ± 0.74 m; 81.3 ± 11.3 kg; 22.7 ± 2.5 kg m−2) volunteered to participate in the study. Surface electromyography (EMG) was collected from eight shoulder-arm-forearm complex muscles. All muscle activation was expressed as a percentage of maximum voluntary isometric contraction (%MVIC). Over a full repetition, the pronated grip resulted in significantly greater EMGPEAK (60.1 ± 22.5 vs. 37.1 ± 13.1%MVIC; P = 0.004; Effect Size [ES; Cohen's d] = 1.19) and EMGARV (48.0 ± 21.2 vs. 27.4 ± 10.7%MVIC; P = 0.001; ES = 1.29) of the middle trapezius when compared to the neutral grip pull-up. The concentric phases of each pull-up variation resulted in significantly greater EMGARV of the brachioradialis, biceps brachii, and pectoralis major in comparison to the eccentric phases (P = <0.01). Results indicate that EMGPEAK and EMGARV of the shoulder-arm-forearm complex during complete repetitions of pull-up variants are similar despite varying hand orientations; however, differences exist between concentric and eccentric phases of each pull-up.