Department of Orthopaedic Surgery, University of Iowa, Iowa City, 52242, USA. john-glaser@uiowa.edu

A prospective, randomized, double-blind, placebo-controlled clinical trial was performed to investigate the efficacy of electrical muscle stimulation when combined with a therapist-guided, standardized exercise therapy program in the treatment of nonacute low back pain. Eighty patients with low back pain of at least 6 weeks' duration were randomized into the following 2 groups: standardized exercise therapy with functional electrical muscle stimulation or standardized exercise therapy with placebo electrical stimulation. Subjects were evaluated at baseline, 2 months, and 6 months with a standardized back pain questionnaire and objective measurements of lumbar spine function. Exercise therapy was continued for 6 months, but electrical stimulation was discontinued at the 2-month interval. Of the 80 patients initially enrolled, 42 discontinued or withdrew before completing the entire study protocol. At the 2-month follow-up interval, subjects in the treatment group had statistically significantly improved lumbar spine function compared with the control subjects. This effect continued during the last 4 months of the study after electrical stimulation had been discontinued. This suggests that electrical muscle stimulation can be an effective adjunctive treatment modality for nonacute low back pain. The effects of this combined therapy seem to last beyond the duration of electrical stimulation treatment.