Musculoskeletal health in Swiss bus drivers: findings from the TRAPHEAC study

Professional bus drivers are exposed to occupational hazards leading to chronic disease, including musculoskeletal disorders and joint pain. Here, we investigated factors associated with joint pain among Swiss bus drivers. We used data from the Transport Personnel Health Cohort (TRAPHEAC-N=549), a Swiss bus driver cohort, and the Swiss Health Study (SHeS-N=1,364), a population-based study. Joint pain was assessed using the Nordic questionnaire. Exposures included vibrations, ergonomics, work organization, stress, BMI, smoking, and physical activity. Associations were analyzed using logistic regression and random forest models. Joint pain was prevalent in TRAPHEAC, especially in the neck (67%), lower-back (59%), shoulders (54%), and upper-back (45%). Comparatively, back pain prevalence in SHeS was 11% (odds-ratios comparing TRAPHEAC with SHeS: 1.89). Logistic regression showed associations between seat and floor vibrations with neck, upper-back, and elbows (odds-ratios 1.1-1.5), while stress was associated with joint pain across all regions. BMI and ergonomics were associated with selected pain locations. Random forest models, using permutation importance, identified stress (shoulder, upper-back, lower-back, and knee pain) with seat vibrations and ergonomics (neck and ankle pain), as the most influential predictors of joint pain. Despite modern infrastructure, joint pain remains prevalent among Swiss bus drivers, supporting prevention targeting biomechanical and psychosocial factors.