The Effect of Supplementary Shouting Technique on Muscle Activity to Rectus Abdominis and External Oblique During Crunch Exercise in Healthy Subjects

Abstract

Purpose: The purpose of this study was to examine the effects of a supplementary shouting technique on abdominal muscle activationto the rectus abdominis (RA) and external oblique (EO) muscles during performance of crunch exercise in healthy subjects. Methods: Sixty-four subjects were randomly allocated to two groups, crunch exercise with shouting group (SG) and crunch exercisewith non-shouting group (NSG), with 32 subjects in each group, respectively. The interventions were conducted over three trials in eachgroup, and measurements were performed on each subject by one examiner in three trials. Muscle activation of RA and EO was evaluatedusing electromyography (EMG) during performance of crunch exercise with or without shouting. Results: Our results showed a significantly greater increase in the EMG patterns of the RA and EO muscles during performance of crunchexercise in the SG compared to the NSG (p<0.01). Conclusion: These findings suggest that addition of the shouting technique during performance of crunch exercise, at the same time,would suggest positive evidence for improving activation of abdominal muscles.