Relationship of Lumbar Multifidus Activity, Disability, and Pain During Standing in People With Chronic Low Back Pain: Cross-Sectional Study From a Randomized Controlled Trial

Abstract

Objective

The purpose of this study was to determine the relationship between pain, disability, and lumbar multifidus activity in people with chronic low back pain while standing.

Methods

This cross-sectional study included baseline analysis of a randomized controlled trial of 150 patients with chronic low back pain. Pain intensity during standing, disability, and lumbar multifidus activity was assessed using a visual analog scale, the Oswestry Disability Index questionnaire, and surface electromyography, respectively. Multiple linear regression was used to analyze the association between lumbar multifidus activity, pain during standing, and disability.

Results

Lumbar multifidus (LM) activity on the right side did not significantly correlate with pain intensity during standing, except for the left-side percent maximum voluntary contraction of the LM, which showed a significant positive correlation with pain intensity (r = 0.328, P < .001). There was a positive correlation of functional disability with right-side LM activity (r = 0.180, p < .05) and left-side LM activity (r = 0.351, p < .001).

Conclusion

An increase in lumbar multifidus activity is correlated with increased pain during standing and disability.