Accelerometer-determined physical activity and clinical low back pain measures in adolescents with chronic or subacute recurrent low back pain

Study Design: Cross-sectional. Background: Although low back pain (LBP) occurs commonly in adolescence, little is known about the relationship between objectively measured physical activity and chronic LBP. OBJECTIVES: To assess the relationship between an objective physical activity measure (accelerometer) and standard clinical measures (pain intensity, disability, and quality of life) in a sample of adolescents with recurrent or chronic LBP. Methods: The study included a subsample of 143 adolescents, 12 to 18 years of age, from a randomized clinical trial. Pearson correlations (r) and bivariate linear regression were used to assess the relationship between baseline measures of sedentary, light, and moderate-to-vigorous physical activity using accelerometers and clinical measures of LBP (pain intensity, disability, and quality of life). Results: Participants spent an average of 610.5 minutes in sedentary activity, 97.6 minutes in light physical activity, and 35.6 minutes in moderate-to-vigorous physical activity per day. Physical activity was very weakly associated with clinical measures of LBP (r<0.13). None of the assessed correlations were statistically significant, and bivariate regression models showed that physical activity measures explained very little of the variability for clinical measures of LBP (R2<0.02). Conclusion: We found no important relationship between objectively measured physical activity and self-reported LBP intensity, disability, or quality of life in adolescents with recurrent or chronic LBP. The parent randomized clinical trial was registered at ClinicalTrials. gov (NCT01096628).