Spinal manipulative therapy (SMT) has significant but very small benefits for patients with chronic low back pain, according to a review article in Spine. "High-quality evidence suggests that there is no clinically relevant difference between SMT and other interventions for reducing pain and improving function in patients with low back pain," according to the study.
The researchers performed a comprehensive review of the medical research literature to identify randomized controlled trials of SMT for adult patients with chronic low back pain. In all studies, patients were randomly assigned to SMT or some other comparison treatment: either an active treatment such as exercise or physical therapy, or an inactive placebo treatment.
In the studies, SMT was most commonly delivered by chiropractors or PTs. The review identified 26 randomized trials including more than 6,000 patients. The studies varied in quality—only 9 of the 26 trials were considered at low risk of bias.
Taken together, the studies provided evidence that SMT has a statistically significant short-term effect in reducing pain and improving function in patients with chronic low back pain. There was also evidence of varying quality that SMT has a short-term effect when added to other treatments.
However, the positive effects of SMT were very small and not likely to be clinically relevant, says Sidney M. Rubinstein, DC, PhD, lead author of the study. The average reduction in pain scores in patients treated with SMT was only about 4 points on a 100-point scale. The benefits seemed to decrease over time, and were no longer significant after one year.
Overall, there was no strong evidence that SMT was more effective than inactive or placebo treatments. Based on the updated review, SMT provides statistically significant improvement for patients with chronic low back pain. However, questions remain as to whether the improvement is clinically relevant, and even whether SMT is more effective than inactive comparison treatments.
"There is evidence that SMT is neither superior nor inferior to other effective treatments for patients with chronic low-back pain," say Rubinstein and colleagues.