Electromyography analysis of lower extremity muscles during squat and stoop movement

Abstract

There are different styles of lifting objects of the ground, and each style gives out different percentage of contribution of each muscle. The purpose of this study is to investigate the muscle activity between stooping and squatting to avoid low back pain and how the muscle activities differ from a correct technique of squatting, and an incorrect one. The Rectus Abdominis, Erector Spinae, Quadriceps and Hamstrings muscle were chosen to be monitored for differences in this study. Selected subjects were two healthy males, with the same height and age, one subject has no experience in doing squats - define as amateur, and the other subject know the basic method of squat-ting - define as non-amateur. In order to capture and analyze the activity of the muscles, Myon EMG and ProEMG software were used. Participants performed, stooping and squatting movement for 12 repetitions with 5 minutes' rest in between. The muscle activation strength was obtained by calculating the Root Mean Square of the EMG data. Results shows that the non-amateur gave out greater RMS difference in muscle activation for the Erector Spinae and Rectus Abdominis among other muscles compared to amateur for both stooping and squatting. Another finding was that, the results of a non-amateur were more balanced between both left and right muscles activation compared to the amateur subject. These observations raised the need of mind muscle connection and muscle coordination in order to lift efficiently in order to avoid low back injury.