Muscle activity in bilateral and unilateralbody weight squat : An electromyographic study
Abstract: Hegnelius, M. - Background. It would be beneficial to the society to bring more awareness about the health benefits that comes with physical activity. Resistance training is a form of physical activity that has positive health benefits for athletes as well as for the average person. Squat is a resistance training exercise that can be performed on one (unilateral) or two (bilateral) legs. Both bilateral and unilateral squat are exercises that are similar to a wide range of different athletic as well as everyday movements. Aim. The aim of this study was to investigate if there is a difference in muscle activity, with electromyography (EMG), in gluteus maximus, gluteus medius, rectus femoris and biceps femoris between bilateral and unilateral body weight squat. Method. Fifteen healthy students (8 women and 7 men) volunteered to participate in the study. EMG signals were collected using surface electrodes with a collection frequency of 1000Hz. EMG data was processed through average root mean square. The values were normalized to maximum voluntary isometric contraction (MVIC) and expressed as percent (% MVIC). Result. The result of the present study showed that there was statistically significantly higher muscle activity in unilateral compared to the bilateral body weight squat in gluteus medius and rectus femoris (p<0.05), together with a trend for higher muscle activity in unilateral body weight squat in gluteus maximus and biceps femoris (p=0.07). The present study also showed that the highest muscle activity during a bilateral squat was found in rectus femoris which had significantly higher muscle activation compared to the other three muscles. Furthermore, for the unilateral squat, rectus femoris and gluteus medius had the highest muscle activity and had significantly higher muscle activity compared to gluteus maximus and biceps femoris. Conclusion. Practical implications from this study was that more muscle activity was required when performing unilateral body weight squat although the bilateral body weight squat is a more stable exercise. Further practical implication is that gluteus medius works significantly higher in unilateral compared to bilateral body weight squat which strengthen GM and by this develops a more stable lower body.
AT THIS PAGE YOU CAN DOWNLOAD THE WHOLE ESSAY. (follow the link to the next page)