Effectiveness of Spinal Manipulation for Chronic Low Back Pain

Acute or sub-acute low back pain patients have been the target of the preponderance of past randomized clinical trials of spinal manipulation.  Fewer studies have used chronic pain patients.  A study published on May 27, 2011 from Northwestern Health Science University randomly assigned 301 chronic low back pain patients to one of three treatment arms consisting of spinal manipulation, home exercise, or supervised exercise.  The study found that there was no significant difference in the three groups with respect to pain and several other outcomes.  Patients that received the supervised trunk exercises “were most satisfied with care and experienced the greatest gains in trunk muscle endurance and strength”.  For a chiropractor who is not engaged in research there would be many questions about this study.

This type of research is extremely challenging and costly.  Underlying all such studies are numerous methodological problems and, at times, some arbitrary decisions.  In this case all patients were treated with short lever, high velocity, low amplitude manipulations.  The treatments were on average 1 to 2 per week.  Limited adjunctive therapy was available consisting of ice, heat, and massage.  This is not typical of most practices where other forms of manipulation, flexion-distraction, traction, ultrasound, exercise, nutrition and many other interventions are used (based upon the recent Practice Analysis of Chiropractic published by the NBCE).  The same could be said for the other two arms of the study where both the home exercise and supervised exercise may not have been using procedures and doses to optimize the outcomes.  The point is not that this study was poorly done but rather why it is so complex to conduct this type of clinical research.  The profession needs much more of this high quality research.

A 2011 Cochrane review of chiropractic treatment of chronic low back pain concluded “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 chronic low-back pain.”  These studies do not suggest that chiropractic is less effective than other therapies for reducing low back pain but rather it is no better than the other therapies that do reduce pain.