Two previous systematic reviews have analyzed the effects of the McKenzie method9,10 in patients
with acute, subacute, and chronic low back pain. The review by Clare et al9 demonstrated that the McKenzie method showed better results in short-term pain relief and improvement of disability compared with active interventions such as physical exercise. The review by
Machado et al10 showed that the McKenzie method reduced pain and disability in the short term when compared with passive therapy for acute low back pain. For chronic low back pain, the 2 reviews were unable to draw conclusions about the effectiveness of the McKenzie method due to the lack of appropriate trials. The randomized controlled trials that have investigated the McKenzie method in patients with chronic low back pain13–17 compared the method with other interventions such as resistance training,17 the Williams method,14 unsupervised exercises,16
trunk strengthening,15 and stabilization exercises.13 Better results in reducing pain intensity were obtained with the McKenzie method compared with resistance training,17 the Williams method,14 and supervised exercise.16 However, the methodological quality of these trials13–17
is suboptimal.