According to the Global Burden of Disease study, low back pain is the leading cause of years lived with disability worldwide, associated with huge direct and indirect costs. Most persons complaining of low back pain present pain or discomfort between the lower ribs and the gluteal folds, with or without leg pain, that is not caused by an identifiable disease or problem (such as fracture, cancer, infection, nerve root pain, etc). This is now classified as “non-specific low back pain (NSLBP).” NSLBP is defined as “acute” when it lasts less than 6 weeks and as “subacute” when it lasts less than 12 weeks. Persons with NSLBP are a clinically heterogeneous group, and there is widespread agreement that their management should be individually tailored.

One treatment known by its tailored design is the McKenzie method, which uses history-taking and symptomatic and mechanical responses to spinal loading strategies in order to classify people into one of three McKenzie syndromes (derangement, dysfunction, or postural syndrome); those whose symptoms are caused by a serious disease or trauma, or who present a chronic pain syndrome, are classified as “other” and are referred elsewhere. After classification, a customized treatment is applied, including specific exercises that resemble the loading strategies used during assessment, along with postural advice and education on self-management.

Given these premises, Almeida and other authors have just published a Cochrane Systematic Review to investigate whether the McKenzie method is an effective and safe treatment for (sub)acute NSLBP. The authors searched for trials aimed at adults with (sub)acute NSLBP (less than 12 weeks) that were randomly assigned either to the McKenzie treatment (considering only studies representing the principles of the original method) or to other interventions. They included trials comparing changes in the short-term (closest to two weeks) and intermediate-term (closest to three months) in NSLBP-related pain and disability. They found five studies (three in the U.S., one in Australia, and one in Scotland), with 536 participants overall. Two of the studies compared the McKenzie method to minimal intervention (e.g., educational booklet), three to manual therapy (one to chiropractic manipulation; one to joint mobilization and one to spinal thrust manipulation), and one to other interventions (back massage and advice). All trials were at high risk of bias, and none measured adverse events; thus, no evidence was found on the safety of the method.

Compared to minimal interventions, the authors found low-certainty evidence that the McKenzie method may result in a slight reduction in pain in the short term, but not in the intermediate term, while it may not reduce disability in either the short or the intermediate term. Compared to manual therapy, they found low-certainty evidence that the McKenzie method may not reduce pain in the short term, while it may actually result in a slight increase in pain in the intermediate term.  As to disability, there is low-certainty evidence that the McKenzie method may not reduce disability, either in the short or intermediate term. Finally, compared to massage and advice, there is very low-certainty evidence that the McKenzie method may not reduce disability either in the short or medium term. The authors conclude, based on low- to very low-certainty evidence, that the treatment effects for pain and disability found in their review were not clinically important, and that the McKenzie method is not an effective treatment for (sub)acute NSLBP. Further, while the inclusion of trials not adequately implementing the McKenzie method was a major source of criticism of another review on this topic, here the authors specifically selected only trials that applied the original McKenzie method. Considering also that all included trials were at high risk of bias in favor of the intervention, and yet they did not demonstrate a clinically important benefit, they believe it unlikely that future studies will show different results. In conclusion, despite the widespread belief that customized exercise programs enable better outcomes for people with NSLBP, the customization based on the McKenzie classification did not provide evidence of improving either pain or disability in (sub)acute NSLBP. 

Summary by Francesca Cecchi