1 Aspetar Orthopaedic & Sports Medicine Hospital, Doha, Qatar Division of Physiotherapy, Linköping University, Linköping, Sweden.
2 F-MARC (FIFA Medical Assessment and Research Centre), Schulthess Clinic, Zurich, Switzerland.
3 Aspetar Orthopaedic & Sports Medicine Hospital, Doha, Qatar Department of Sports Medicine, Oslo Sports Trauma Research Centre, Norwegian School of Sports Sciences, Oslo, Norway.