Continuous low-level heatwrap therapy for treating acute nonspecific low back pain

Objective: To evaluate the efficacy of 8 hours of continuous low-level heatwrap therapy for the treatment of acute nonspecific low back pain (LBP). Design: Prospective, randomized, parallel, single-blind (investigator), placebo-controlled, multicenter clinical trial. Setting: Five community-based research facilities. Participants: Two-hundred nineteen subjects, aged 18 to 55 years, with acute nonspecific LBP. Intervention: Subjects were stratified by baseline pain intensity and gender and randomized to one of the following groups: evaluation of efficacy (heatwrap, n=95; oral placebo, n=96) and blinding (oral ibuprofen, n=12; unheated back, wrap n=16). All treatments were administered for 3 consecutive days with 2 days of follow-up. Main Outcome Measures: Primary: day 1 mean pain relief (0- to 5-point verbal response scale). Secondary: muscle stiffness (101-point numeric rating scale), lateral trunk flexibility (fingertip-floor distance), and Roland-Morris Disability Questionnaire over 3 days of treatment and 2 days of follow-up. Results: Heatwrap therapy was shown to provide significant therapeutic benefits when compared with placebo during both the treatment and follow-up period. On day 1, the heatwrap group had greater pain relief (1.76+/-.10 vs 1.05+/-.11, P<.001), less muscle stiffness (43.1 +/- 1.21 vs 47.6 +/- 1.21, P=.008), and increased flexibility (18.6 +/-.44cm vs 16.5 +/-.45cm, P=.001) compared with placebo. Disability was also reduced in the heatwrap group (5.3 vs 7.4, P=.0002). Adverse events were mild and infrequent. Conclusion: Continuous low-level heatwrap therapy was shown to be effective for the treatment of acute, nonspecific LBP.