Association between physical activity and pain processing in adults with chronic low back pain compared to pain-free controls

Abstract

BACKGROUND: Pain sensitivity has been negatively associated with physical activity levels. Few studies have examined associations between experimentally induced pain sensitivity and physical activity in adults with chronic low back pain and painfree controls. OBJECTIVE: The objective of this study was to examine associations between physical activity levels and how an individual processes pain using experimentally induced pain stimuli. METHODS: Seventy subjects (CLBP = 49; mean age = 46.8 ± 14.9; Pain-free = 21; mean age = 45.3 ± 18.2, n of females = 46) participated. A self-report questionnaire derived from the International Physical Activity Questionnaire (IPAQ) was used to calculate an activity level index. Pain sensitivity was assessed via quantitative sensory testing (QST) at the right lower extremity. RESULTS: Moderate (U = 688, p < 0.05) and vigorous (U = 649, p < 0.05) physical activity levels were higher in pain-free vs. individuals with CLBP. Activity level was not associated with pain sensitivity (Pain-free: R2 = 0.02, p > 0.05; CLBP: R2 = 0.01, p > 0.05). Both moderate (R2 = 0.49, p < 0.05) and vigorous (R2 = 0.68, p < 0.01) physical activity were associated with pain modulation amongst pain-free individuals. CONCLUSIONS: Findings suggest that physical activity influences pain modulation amongst pain-free individuals, however no relationship exists once CLBP is present. However, future investigation will elucidate the extent to which physical activity level either prevents CLBP or is effective in alleviating CLBP.