1. Department of Physical Medicine and Sports Traumatology, University Hospital of Liège, Liège, Belgium;
2. Physiotherapy Service, Department of Motility Sciences, University of Liège, Liège, Belgium;
3. Department of Public Health, Biostatistics, University of Liège, Liège, Belgium;
4. Department of Public Health, Epidemiology and Health Economics, University of Liège, Liège, Belgium