The association of physical activity and sedentary behaviour with low back pain disability trajectories: A prospective cohort study

Background: Multiple factors influence the recovery process of low back pain (LBP). The identification and increased knowledge of risk factors might contribute to a better understanding of the course of LBP. Objectives: To investigate the association of habitual physical activity (PA) and sedentary behaviour (SB), measured at baseline, with disability trajectories in adults with LBP. Methods: A prospective cohort study where habitual PA levels were measured using the Short QUestionnaire to ASsess Health enhancing physical activity (SQUASH), SB was calculated as average sedentary hours per day, and LBP disability using the Oswestry Disability Index (ODI). Participants completed the questionnaires at one and a half, three, six, and twelve months. Linear mixed models were estimated to describe the association of habitual PA levels SB measured at baseline with disability trajectories. Other predictors were gender, education level, age, pain, number of previous episodes of LBP, and duration of LBP. Results: Habitual SB measured at baseline in adults (n = 347) with LBP were not associated with disability trajectories. For PA, participants with one metabolic equivalent of task (MET) hour per day above average recovered 0.04 [95% CI 0.004 to 0.076] points on the ODI per month faster than participants with an average amount of MET hours per day. Conclusions: Habitual SB was not associated with LBP disability trajectories over a one-year follow-up. High levels of habitual PA at baseline were associated with improved recovery in LBP disability trajectory, but the finding is not clinically relevant.