We studied the efficacy of surface electromyography(SEMG) and digital infrared thermographic imaging(DITI) in the assessment of low back pain both(LBP) quantitatively and qualitatively.

We compared electromygraphic signals from electrodes placed in the lumbar area and the digital thermographic images in 16 LBP patients and 16 control subjects. The LBP patients and the control subjects were matched for age, gender, and body mass index(BMI) to adjust for any confounding effects.

In the static analyses of SEMG, median value was 198.1 microV for the LBP patients and 161.3 microV for the controls on the right side, and they were 194.2 microV and 180.5 microV on left side respectively. There was a statistically significant difference between the two groups on the right side(p<0.01), but not on the left side. In the dynamic analyses of the SEMG, the median values of the extension per flexion ratio of right side were 1.12 for LBP patients and 1.39 for controls. and those on the left side were 1.08 and 1.21 respectively. There were statistically significant differences in both sides(p<0.05). The sensitivity and specificity were 100% and 81.3% in DITI, 78.6% and 72.2% in SEMG.

These results indicate that SEMG and DITI are useful methods for indirect assessments of LBP, and that DITI is more sensitive and specific than SEMG.