Psychosocial and Occupational Factors Associated with Multisite Musculoskeletal Pain Among Motorcycle Couriers: A Cross-Sectional Study

Background: Motorcycle couriers face combined biomechanical and psychosocial demands, but the relationship between multisite musculoskeletal pain, perceived stress, and occupational burnout in this workforce remains insufficiently characterized. We aimed to determine the distribution of musculoskeletal pain and identify factors associated with multisite pain in this group. Methods: This cross-sectional study included 100 male motorcycle couriers working in Istanbul, Türkiye. Musculoskeletal symptoms in nine anatomical regions were assessed with the Nordic Musculoskeletal Questionnaire (12-month reference period); multisite pain was defined as pain in ≥3 regions. Perceived stress (14-item Perceived Stress Scale, PSS-14; one-month reference period) and the three Maslach Burnout Inventory dimensions were measured. Analyses comprised group comparisons, Spearman correlations, univariate and adjusted logistic regression—in which the non-linearity of the stress–pain association was modelled explicitly with a quadratic term—and sensitivity analyses (alternative thresholds, count models, education adjustment, and bootstrap validation). Results: Thirty-two percent reported pain in ≥3 regions; the neck (38%) and lower back (35%) were most affected. PSS-14 scores were markedly higher in the multisite pain group (median 45.0 vs. 26.0, p < 0.001) and correlated with the number of painful regions (ρ = 0.47). The stress–pain association was non-linear: the prevalence of multisite pain was 11.5%, 11.1%, 25.9%, and 95.0% across ascending PSS-14 quartiles, and the adjusted odds rose steeply only at high stress levels (highest quartile, PSS-14 ≥ 43). In the primary adjusted model including linear and quadratic PSS-14 terms, perceived stress remained independently associated with multisite pain (quadratic term p = 0.005; optimism-corrected AUC = 0.851; Hosmer–Lemeshow p = 0.43), and the association persisted after additional adjustment for educational level. Reduced Personal Accomplishment and Depersonalization were associated with the outcome only in unadjusted analyses; Emotional Exhaustion showed no detectable association. Conclusions: Multisite musculoskeletal pain affected one-third of motorcycle couriers and was strongly associated with perceived stress, in a threshold-like, non-linear pattern concentrated at high stress levels. Given the cross-sectional design and self-reported measures, longitudinal confirmation is needed; nevertheless, the findings support combining ergonomic measures with strategies addressing psychosocial strain in this workforce.