The Assessment of Chronic Low Back Pain by Surface Electromyography

ABSTRACT

OBJECTIVE: We studied the clinical utility of surface electromyography (SEMG) for the assessment of chronic low back pain (CLBP). METHOD: We compared electrical activity from electrodes placed on the 16 lumbar paraspinal areas between 25 CLBP patients and 25 control subjects in static neutral standing posture and dynamic flexion-reextension state. The CLBP patients and the control subjects were matched for age, gender, and body mass index (BMI) to adjust for any confounding effects. We analyzed amplitudes and areas of electrical activity on lumbar paraspinal muscles in neutral standing posture and dynamic flexion-reextension state. RESULTS: In the static neutral posture, there are increased amplitudes of electrical activity in CLBP compared with controls (p<0.01). In the dynamic flexion-reextension state, area ratio of electrical acitivity during the extension state to electrical acitivity during flexion state are significantly decreased in CLBP compared with controls (p<0.01). The presence of lumbar radiculopathy or the severity of LBP is not well correlated with the electrical acitivity on SEMG. The sensitivity and the specificity of SEMG are 72% and 80% respectively. CONCLUSION: These results indicate that SEMG is a useful method for the assessment of CLBP.