1 WHO Collaborating Center for Public Health Aspects of Musculoskeletal Health and Ageing, University of Liège, Liège, Belgium. olivier.bruyere@uliege.be.
2 Physical and Rehabilitation Medicine & Sports Traumatology, FIFA Medical Centre of Excellence, IOC Research Centre for Prevention of Injury and Protection of Athlete Health, FIMS Collaborative Center of Sports Medicine, University and University Hospital of Liège, Liège, Belgium.