The effect of McKenzie therapy as compared with that of intensive strengthening training for the treatment of patients with subacute or chronic low back pain: A randomized controlled trial.

STUDY DESIGN: A randomized controlled comparative trial with an 8-month follow-up period was conducted. OBJECTIVE: To compare the effect of the McKenzie treatment method with that of intensive dynamic strengthening training in patients with subacute or chronic low back pain. SUMMARY OF BACKGROUND DATA: Randomized studies indicate that the efficacy of the McKenzie method in the treatment of patients with acute or subacute low back pain is debatable. Currently, no randomized studies examining the effects of this method for patients with chronic low back pain have been published. METHODS: For this study, 260 consecutive patients with low back pain and at least 8 weeks duration of symptoms (85% of the patients had more than 3 months duration of symptoms) were randomized into two groups: Group A was treated with the McKenzie method (n = 132), and Group B was treated with intensive dynamic strengthening training (n = 128). The treatment period for both groups was 8 weeks at an outpatient clinic, followed by 2 months of self-training at home. Treatment results were recorded at the end of the treatment period at the clinic, then 2 and 8 months after. In both groups, 30% of the patients were lost to follow-up evaluation. An intention-to-treat analysis of the main effect variables, disability, and pain was performed for all the patients included in the study. A supplementary analysis of the 180 patients who completed the full treatment program also was undertaken. RESULTS: Intention-to-treat analysis showed a tendency toward a difference in reduction of disability in favor of the McKenzie group at the 2-month follow-up assessment (P = 0.04), but no differences at the end of treatment and at the 8-month follow-up evaluation. No differences in reduction of pain were observed at any time between the groups. The supplementary analysis of the patients who had completed the full intervention showed a tendency toward a difference in favor of the McKenzie method in reduction of pain at the end of treatment (P = 0.02). This difference reached statistical significance at the 2-month follow-up assessment (P = 0.01), but no difference was found after 8 months. The supplementary analysis showed no differences between the groups with regard to reduction of disability. CONCLUSION: The McKenzie method and intensive dynamic strengthening training seem to be equally effective in the treatment of patients with subacute or chronic low back pain.