Musculoskeletal disorders (MSDs) encompass a range of periarticular conditions affecting the soft tissues (muscles, tendons, nerves, blood vessels, and cartilage) of the limbs and back. Many factors contribute to these conditions, with occupational factors playing a particularly significant role. MSDs are now one of the most pressing occupational health issues, due to their considerable human, social, occupational, and economic costs, as well as their steady increase. In France, prior to the implementation of an epidemiological surveillance program for MSDs by the Department of Occupational Health (DST) of the French Institute for Public Health Surveillance (InVS), little data was available to describe the extent of this problem. Carpal tunnel syndrome (CTS) is one of the most common MSDs of the upper extremities. To improve scientific understanding of this condition and better understand its progression following surgical treatment, the DST of the InVS and the Southern Interregional Epidemiology Unit (Cire) launched a study in the Bouches-du-Rhône department in 2008. (R.A.)