1. Department of Physical Medicine and Rehabilitation, Orthopaedic Hospital, Lausanne University Hospital, Lausanne, Switzerland
2. Institute for Research in Rehabilitation, Clinique Romande de Réadaptation, Sion, Switzerland
3. Institute of Social and Preventive Medicine, Lausanne University Hospital, Lausanne, Switzerland
4. Department for Musculoskeletal Rehabilitation, Clinique Romande de Réadaptation, Sion, Switzerland