Efficacy of the McKenzie method in patients with chronic nonspecific low back pain: A protocol of randomized placebo-controlled trial

Background The McKenzie method is widely used as an active intervention in the treatment of patients with nonspecific low back pain. Although the McKenzie method has been compared with several other interventions, it is not yet known whether this method is superior to placebo in patients with chronic low back pain.

Objective The purpose of this trial is to assess the efficacy of the McKenzie method in patients with chronic nonspecific low back pain.

Design An assessor-blinded, 2-arm, randomized placebo-controlled trial will be conducted.

Setting This study will be conducted in physical therapy clinics in São Paulo, Brazil.

Participants The participants will be 148 patients seeking care for chronic nonspecific low back pain.

Intervention Participants will be randomly allocated to 1 of 2 treatment groups: (1) McKenzie method or (2) placebo therapy (detuned ultrasound and shortwave therapy). Each group will receive 10 sessions of 30 minutes each (2 sessions per week over 5 weeks).

Measurements The clinical outcomes will be obtained at the completion of treatment (5 weeks) and at 3, 6, and 12 months after randomization. The primary outcomes will be pain intensity (measured with the Pain Numerical Rating Scale) and disability (measured with the Roland-Morris Disability Questionnaire) at the completion of treatment. The secondary outcomes will be pain intensity; disability and function; kinesiophobia and global perceived effect at 3, 6, and 12 months after randomization; and kinesiophobia and global perceived effect at completion of treatment. The data will be collected by a blinded assessor.

Limitations Therapists will not be blinded.

Conclusions This will be the first trial to compare the McKenzie method with placebo therapy in patients with chronic nonspecific low back pain. The results of this study will contribute to better management of this population.