The dynamic course of musculoskeletal disorders in an assembly line factory

To describe the course of employee-individual clinical status with respect to upper limb musculoskeletal disorders (UL-MSDs), epidemiological surveillance of UL-MSDs was implemented for three consecutive years at a household appliance assembly company.

A standardized clinical examination guide was used to survey UL-MSDs of employees seen in annual consultation. Recorded data included eight specific UL-MSDs as well as the main sociodemographic characteristics of employees. Univariate and multivariate analysis were performed. Significance was defined as P<0.05. All statistical analysis were performed with Statgraphics (version 5.1) software.

During three consecutive years, 459 employees were seen in the occupational medicine consultation. The annual prevalence of UL-MSD cases was 20.2% in 2000, 21.7% in 2001 and 24.0% in 2002. In fact, this relative stability conceals significant renewal of the population suffering from UL-MSDs with time, illustrated by both a high rate of annual incidence of cases (9.8 and 13.5% in 2001 and 2002, respectively) and a high rate of annual recoveries (37.0 and 44.3% in 2001 and 2002, respectively).

Factors governing variation in individual clinical status of employees with respect to UL-MSDs and their interactions remain little known and open up interesting research prospects.