The McKenzie method in assessing, classifying and treating non-specific low back pain in adults with special reference to the centralization phenomenon

Kilpikoski, Sinikka The McKenzie method in assessing, classifying and treating non-specific low back pain in adults with special reference to the centralization phenomenon. Jyvaskyla: University of Jyvaskyla, 2010, 90 p. (Studies in Sport, Physical Education and Health, ISSN 0356-1070; 158) ISBN 978-951-39-4120-8 (PDF), 978-951-39-4050-8 (nid.) Finnish summary. Diss. In the McKenzie method of mechanical diagnosis and therapy clinical presentations are classified into mechanical syndromes based on patients’ symptom response to standardized loading strategies. Pain centralization is a specific finding as a response to the loading when assessing patients with low back pain (LBP). The aims of this study among Finnish adults (mean age 42 years, N= 173) with non-specific LBP were: (1) to assess inter-examiner agreement and reliability in classifying the subjects according to the McKenzie method with variability expressed by the kappa coefficient, and observed agreement; (2) to estimate utilizing magnetic resonance imaging (MRI) the association, expressed by sensitivity, specificity, positive and negative predictive values, likelihood ratios and diagnostic confidence value between pain centralization and lumbar disc morphology; (3) to compare treatment outcomes in subjects allocated randomly into orthopaedic manual therapy (OMT), McKenzie or “advice only” interventions with oneyear follow-up; (4) to compare those with centralizing LBP treated by OMT, McKenzie or “advice only”; and (5) to investigate if centralization defined on the initial visit predicts treatment outcomes. The inclusion criteria of the randomized controlled trial were: male or female age 18 to 65 years, acute (more than seven days from onset) to chronic non-specific LBP with or without radiation to the lower limb(s). Exclusion criteria were pregnancy, serious pathology (“red flags”) and back surgery within the past two months. Back and leg pain were assessed by the Visual Analogue Scale, disability with the Roland-Morris questionnaire and functional status with 7 daily activities on a 0-to 4-point scale at baseline, immediately after a treatment period, and at follow-up points of 3, 6 and 12 months. Intention-to-treat analysis was used. Inter-examiner reliability in sub-grouping patients according to the McKenzie classification was good. MRI showed that pain centralization was associated with abnormalities of lumbar discs. OMT and McKenzie seemed to be only marginally more effective in treating non-specific LBP compared to the one-session “advice only” treatment. However, those with centralizing LBP treated by McKenzie showed better and longer lasting recovery of symptoms compared with centralizers in the “advice only”-group. Furthermore, adults with centralizing LBP on the initial visit showed a tendency to better recovery of symptoms than those without, independently of the treatment used. To conclude, promising results were obtained for the McKenzie method in the pre-treatment assessment, classification and treatment of nonspecific LBP in working-age adults. However, only tendency was found for better and longer lasting recovery among the sub-group of centralizers treated by the McKenzie method.