THE PREDICTIVE RELATIONSHIP BETWEEN CHANGES IN PHYSICAL ACTIVITY AND FUNCTIONAL DISABILITY AT THREE MONTHS IN AN ACUTE LOW BACK PAIN POPULATION

Abstract

Background: Activity advice and prescription are commonly used in the management of low back pain (LBP). However, no research has assessed whether objective measurements of physical activity predict outcome, recovery and course of LBP.

Methods: One hundred and one patients with acute LBP were recruited into a longitudinal cohort study. Each participant completed the Roland Morris Disability Questionnaire (RMDQ), Visual Analogue Scale and a “simple” activity question, detailing whether they had resumed full “normal” activities (Y/N), at baseline (T0) and 3 months (T1); Baecke Physical Activity Questionnaire, Fear-Avoidance Beliefs Questionnaire and the 12-item General Health Questionnaire at T0. Physical activity was measured for 7 days at T0 and T1 with an RT3 accelerometer and the seven day physical activity recall questionnaire (7d-PAR).

Results: The only significant predictor of RMDQ change was RMDQ score at T0 (p < .0001). Physical activity change did not predict RMDQ change in both univariate (p = 0.82) and multivariate analysis (p = 0.84). Paired t-tests found a significant change in RMDQ (p < .0001) and return to full “normal” activities (p < .0001) from T0 to T1, but no significant change in activity levels measured with the RT3 (p = 0.56) or the 7d-PAR (p = 0.43). RMDQ change (OR 1.72, p = 0.01) and RMDQ at T1 (OR 0.65, p = 0.04) predicted return to full “normal” activities at T1.

Conclusions: These results question the role of physical activity in LBP recovery and the assumption that activity levels change as LBP symptoms resolve.

Conflicts of Interest: None

Sources of Funding: This research was supported by a University of Otago Establishment Grant