Table of Contents
Physiology Journal
Volume 2015 (2015), Article ID 537379, 6 pages
http://dx.doi.org/10.1155/2015/537379
Research Article

The Surface EMG Characteristics between Erector Spinae and Vastus Lateralis during Bending Forward and Squatting Down Tasks

1College of Electronic and Information Engineering, Hebei University, Baoding, Hebei 071000, China
2Healthy Rehabilitation Section, Affiliated Hospital of Hebei University, Baoding, Hebei 071000, China

Received 26 May 2015; Revised 21 September 2015; Accepted 5 October 2015

Academic Editor: Richard H. Bayford

Copyright © 2015 Jinzhuang Xiao et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

Bending forward and squatting down are two common physical tasks in everyday life and at work. This study determined the sEMG characteristics between erector spinae and vastus lateralis during bending forward and squatting down tasks by analyzing the regularity of variation in sEMG frequency domain index-median frequency (MNF) in healthy subjects. The results indicate that sEMG activities in erector spinae are significantly higher than those in the right vastus lateralis during bending forward task. Instead, in squatting down task, sEMG activities in the right vastus lateralis are significantly greater than those in erector spinae. It also shows that the fatigue degree of low back caused by trunk bending is much deeper than that by squatting down. The ratio scope of one-order fitting values of MNF between erector spinae and vastus lateralis ranges from 0.87 to 1.72 among 80% of subjects during bending forward task and ranges from 0.31 to 1.11 during squatting down task. This study provides certain theoretical basis for using the strength of low back in a proper way to avoid getting it hurt in daily physical activities.