Effects of heatwrap and exercise in acute low back pain: a multi-arm randomised controlled trial

QuestionIs a heatwrap combined with exercise more effective in improving symptoms and functional outcomes on short- mid- and long-term than either a heatwrap alone or a sham heatwrap in acute low back pain? DesignA multi-arm randomised controlled trial. ParticipantsAdults aged 18 to 65 years with a new episode of low back pain (defined as pain for six weeks or less with no low back pain in the three months preceding the current episode). InterventionParticipants were randomly assigned to one of three groups: heatwrap plus exercise (n=34), heatwrap alone (n=33) or sham heatwrap (n=32). All participants were asked to wear the heatwrap eight hours per day for seven days. The exercise group had to perform exercises 30 minutes per day for five days. All participants received evidence-based advice for the management of their pain. Outcome measuresOur primary outcome was pain-related disability at one week measured with the Oswestry Disability Index. Our secondary outcomes were pain intensity, pain-related fear of movement, self-efficacy, pain catastrophizing and perception of change. Outcomes were measured at baseline and at 1, 4, 12, 26 and 52 weeks. Data analysisWe used linear mixed models (LMMs) to compare intervention efficacy on all outcomes at all time-points with intention-to-treat analyses, testing the Group x Time interaction. ResultsThe analysis included 99 participants. The results for pain-related disability showed no Group x Time interaction (F=0.467; p=0.910), but a statistically significant time effect was observed (F=39.843; p<0.001) as scores decreased for all groups at one week, with an estimated mean difference of -7.8 (95% CI -9.7 to -5.9). All outcomes showed a time effect at all time-points. ConclusionA combination of heatwrap and exercise did not provide a superior effect on symptoms and functional outcomes on short-, mid and long-term when compared to a heatwrap alone and a sham heatwrap in adults with acute low back pain. Future guidelines should consider these results to formulate recommendations for acute LBP. Trial registration: ClinicalTrials.gov Identifier: NCT03986047