A Pain that I'm Used to. Disentangling Stable from Temporary Components of Musculoskeletal Disorders and Their Work-Related Antecedents

Despite the impact of psychosocial risks on musculoskeletal disorders (MSDs) is well-known, past longitudinal studies have mainly treated these factors as stable traits, assuming MSDs and their causes remain constant throughout employees' work experience. However, symptom fluctuations are a key aspect of living with musculoskeletal conditions. Thus, to better understand the development and persistence of MSDs, it is crucial to disentangle their stable and temporary components and examine the role of work-related antecedents at both levels. In the current study (a) we investigate the degree of stability and changeability over time of MSDs and their work-related antecedents (workload, control, support from colleagues and psychological health), and (b) examine the association among these variables at the two levels. A shortitudinal design with three measurement points over three months was conducted with 795 Italian employees, using Doubly Latent Multilevel Structural Equation Modelling. We found that around two-thirds of the reliable variance in MSDs and their work-related factors was explained by the trait-like components; nevertheless, significant within-person changes were observed across all variables. Psychosocial risks and psychological health had notable, situation-dependent effects on MSDs, although chronic stressful conditions (e.g., consistently high workload) had a stronger impact on MSDs through reduced psychological health than situational variations (e.g., higher-than-usual workload). Control and support emerged as protective factors only when ensured on a permanent basis. Overall, the present study highlights the need for comprehensive occupational health interventions addressing both situational and chronic work factors to reduce the risk of MSDs.