Objectives: The purpose of this study was to compare the effect of 2 exercise programs combined with electrotherapy on pain intensity and lumbar stabilizer muscles dimensions in patients with nonspecific chronic low back pain.

Methods: A randomized controlled clinical trial was performed with 41 patients with chronic LBP. Participants were randomly allocated into 2 groups: an experimental group (n = 20) received stabilization exercises plus electrotherapy, and a control group (n = 21) received routine exercises plus electrotherapy. Pain intensity, using a visual analog scale, and muscle dimensions of both right and left transverse abdominis and lumbar multifidus muscles, using rehabilitative ultrasonography, were assessed before and immediately after 4 weeks of intervention.

Results: Significant improvement was identified after interventions on pain intensity and muscle size measurements in both groups (P < .01 in all instances). The only exception was the right-side lumbar multifidus cross-sectional area of the control group, which was not statistically significant (P = .081). No significant differences were found between the 2 exercise groups on pain intensity and muscle dimensions (P > .05 in all instances).

Conclusions: The results of this study suggest that a combination of electrotherapy with either routine or stabilization exercise programs may improve pain intensity and muscle dimensions in patients with nonspecific chronic low back pain.