Movement System Impairment-Based Classification Versus General Exercise for Chronic Low Back Pain: Protocol of a Randomized Controlled Trial

Background. Low back pain (LBP) is an important health problem in all developed countries and is associated with high levels of disability. Evidence-based clinical practice guidelines usually recommend different physical therapy interventions to manage this condition. However, those interventions usually result in small to moderate clinical effects. Recent studies suggest that interventions based on subgroup classifications may improve the effect sizes compared with rehabilitation programs where the same interventions were applied to all patients. Objective. This study will investigate the efficacy of treatment based on a Movement System Impairment (MSI)-based classification model for patients with chronic LBP compared with general exercise. The primary outcomes will be pain intensity and disability at 2 months after randomization. Design. The study is a 2-arm, prospectively registered, randomized controlled trial with a blinded assessor. Setting. The study setting will be a university physical therapy clinic in Brazil. Participants. A total of 148 individuals with chronic LBP will participate in the study. Intervention. Included individuals will be randomly allocated to participate in an 8-week treatment program based on the MSI-based classification or a general exercise program of stretching and strengthening exercises. Measurements. Pain intensity, disability, and global impression of recovery will be assessed by a blinded assessor at baseline and at follow-up appointments after treatment (2 months) and 4 and 6 months after randomization. Limitations. Therapists will not be blinded. Conclusions. The results of this study may contribute to a better understanding of the efficacy of treatments based on classification of participants with chronic LBP into subgroups.