 Methodological development: indicators and profiles for longitudinal musculoskeletal disorders monitoring 
The aim of this article is to illustrate the development of an analysis method for the longitudinal follow-up of musculoskeletal symptoms (WMSD) based on the identification of indicators and profiles. The overall approach to developing these indicators entailed complementary approaches (qualitative and quantitative) and sequential analyses of body maps completed by 16 seasonal workers at the start and end of each work shift for two work seasons (135,000 pain scores). The indicators comprised, among other elements, WMSD chronicity, specificity (profiles of diffuse and/or specific pains), temporal trajectories, anatomical location and number of anatomical locations. More specifically, these indicators and the overall approach of this methodological development made it possible to characterize the evolution and to analyse, in different ways, the variability of the fluctuating character of WMSDs over time. Studying the evolution of pain longitudinally could also be usefully integrated into an evaluative framework for ergonomic intervention studies conducted in the workplace.