Musculoskeletal Disorder Risk in Motorcycle Operators: Development and Validation of a Targeted Screening Scale

Objective: To develop and validate a musculoskeletal disorder screening scale for motorcycle operators. Methods: In a cross-sectional study, 140 Tunisian operators rated pain in nine body regions on a four-point scale. Results: Two factors separated upper-body from lower-body regions and explained 67.5 percent of the variance. Cronbach alpha reached 0.910 and 0.881. The two-factor model outperformed the one-factor model (chi-square difference 67.92, p < 0.001), with loadings from 0.75 to 0.91 and approximation error of 0.103 under ordinal estimation. Engine displacement separated the groups on both subscales (partial eta squared 0.196), age band on the upper body alone (p = 0.007), and riding discipline on neither (p = 0.183). Conclusions: The scale shows a coherent two-factor structure and high internal consistency, with model fit short of the approximation-error threshold.