Abstract
Physical activity (PA) is recommended to prevent chronic diseases; However, its precise benefit remains unclear. Orthopedic research tracking patients' activity primarily focuses on surgical outcomes, leaving a gap in understanding PA as a risk factor for musculoskeletal conditions. This study uses All of Us Research Program data to investigate the association between PA and musculoskeletal pain development. Adults who shared their Fitbit and electronic health record (EHR) data with at least 6 months of Fitbit tracking before their first documented pain episode in the EHR were included. Daily step counts and three activity levels (light, moderate, and vigorous) were analyzed using time-dependent Cox models to examine associations between PA and incident neck, low back, hip, and knee pain. Hazard ratios (HRs) were estimated by comparing the 75th to the 25th percentile of each PA measure (i.e., interquartile range increase), adjusting for age, sex, Body mass index (BMI), and educational level. Among 14,754 participants (median age 51.3 [IQR 25.7], 72% female), 796, 144, 1362, and 1754 developed back, neck, hip, and knee pain, respectively. Higher daily steps were associated with reduced risk of both low-back (HR 0.89 [0.8-0.98]) and neck pain (HR 0.69 [0.54-0.9]). Greater "moderate activity" was associated with a lower risk of low-back (HR 0.82 [0.72,0.95]) and hip pain (HR 0.87 [0.78,0.97]). In contrast, "vigorous activity" was associated with lower risk of neck (HR 0.53 [0.38-0.73]), low-back (HR 0.72 [0.62-0.84]), and hip pain (HR 0.93 [0.87-0.99]). PA was not related to knee pain. To our knowledge, this is the largest study on PA as a risk factor for musculoskeletal pain. Higher PA levels were associated with reduced risk of developing neck, low-back, and hip pain, with no association with knee pain. PERSPECTIVE: This is the largest study to our knowledge that highlights the association between objectively measured physical activity and reduced risk of developing neck, low-back, and hip pain. These findings support integrating activity recommendations into musculoskeletal health strategies, providing insight into how different activity levels influence pain risk.