ABSTRACT
OBJECTIVE: To determine the effectiveness of the McKenzie Method compared to any conservative interventions on pain and disability in patients with chronic low back pain (LBP) with directional preference (DP). METHODS: We searched six electronic databases up to September 2022. Eligible randomized controlled trials were those assessing the McKenzie Method delivered by credentialed therapists for chronic LBP with DP. Two reviewers independently selected studies, extracted data, assessed risk of bias with the revised Cochrane Risk of Bias 2.0 tool and certainty of evidence with the Grading of Recommendations Assessment, Development and Evaluation (GRADE) framework. RESULTS: Five trials (n = 743) were included. There was low-certainty evidence that the McKenzie Method, compared to all other interventions combined, produced clinically important reductions in short-term pain (mean difference [MD] -1.11 points on a 10-point scale; 95% CI -1.83 to -0.40) and in intermediate-term disability (standardized mean difference [SMD] -0.53; 95% CI -0.97 to -0.09). Low-to-moderate certainty evidence showed that the McKenzie Method also resulted in clinically important improvements in short-term pain (MD -1.53; 95% CI -2.51 to -0.54) and disability (SMD -0.50; 95% CI -0.74 to -0.25) when compared specifically to other exercise approaches, and in intermediate-term pain (MD -2.10; 95% CI -2.94 to -1.26) and disability (SMD -1.01; 95% CI -1.58 to -0.43) as well as long-term disability (SMD -0,59; 95% CI -1.14 to -0.03) when compared to minimal intervention. Low-certainty evidence showed usually small, clinically unimportant effects in comparison to manual therapy. CONCLUSION: We found low-to-moderate certainty evidence that the McKenzie Method was superior to all other interventions combined for up to 6 months for pain and up to 12 months for disability, with clinically important differences versus exercise in the short term and versus minimal interventions in the intermediate term. The only clinically important long-term effect was on disability compared to minimal intervention.