Effect of Grip Width on the Myoelectric Activity of the Prime Movers in the Bench Press

Abstract

The purpose of this study was to determine the effect of grip width on myoelectric activity of the pectoralis major, anterior deltoid, triceps brachii, and biceps brachii during a 1-RM bench press. Grip widths of 100,130,165, and 190% (G1, 2, 3, 4, respectively) of biacromial breadth were used. Mean integrated myoelectric activity for each muscle and at each grip width was determined for the concentric portion of each 1-RM and normalized to percentages of max volitional isometric contractions (%MVIC). Data analysis employed a one-factor (grip width) univariate repeated measures ANOVA. Results indicated significant main effects for both grip width (p = 0.022) and muscles (p = 0.0001). Contrast analyses were conducted on both main effects. Significant differences (p ≤ 0.05) were found between grip widths G4 and both Gl and G2 relative to %MVIC. Significant %MVIC differences on the muscles main effect were also found. All prime movers registered significantly greater %MVICs than the biceps and, in addition, the triceps %MVIC was greater than the pectoralis major.