Comparison between healthy subjects and low back pain patients based on surface electromyography features

Abstract

The aim of this study was to compare quantitatively the difference in Surface Electromyography (sEMG) features between healthy subjects and low back pain (LBP) patients. We recruited thirty LBP patients and thirty healthy subjects. They performed maximum voluntary flexion (MVF), while sEMG data were collected from the multifidus, external oblique and transverse abdominal muscles. We used Integrated EMG (IEMG), Mean Power Frequency (MPF) of sEMG signals, and Median Frequency (MF) of sEMG signals as a base for analysis. Results showed that there were significant differences between the LBP group and the healthy group in all variables. For all explored muscles, there was a significant difference between the healthy group and the LBP group on IEMG (p<0.05). Furthermore, the mean IEMG values of the LBP group were lower than those of the healthy group. MPF and MF of the LBP group were higher than those of the healthy group. Meantime, MPF and MF of multifidus muscles of LBP individual were higher than those of healthy individual. The lower IEMG values in the LBP patients indicate that the discharge of the explored muscles in the LBP patients were lower than those in the healthy group. The higher MPF and MF could be explained by the fact that the lumbar muscles in LBP patients get fatigued and stiff easily, and the multifius muscles were more easily get fatigued than other explored muscles. Our study indicated that IEMG, MPF, MF of sEMG signals captured from the lumbar muscles could serve as a predictor of the risk of LBP patients.