Are small effects for back pain interventions really surprising?

The widely reported small effects of physical therapy interventions for LBP need to be understood and interpreted in the context of the natural course of LBP and the inherent limitations of clinical trials, especially for complex health conditions. The findings should motivate physical therapists to reconsider their role as primary health care professionals, with much more to offer than highly effective interventions. Researchers should be challenged to better understand the causes of LBP and the mechanisms by which treatments work so that more effective and individualized treatments can be developed in the future.