1. Department of Surgery, Aspetar Orthopaedic and Sports Medicine Hospital, Doha, Qatar.
2. Department of Orthopaedics, Institute of Clinical Sciences, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden.
3. Football Research Group, Linköping University, Linköping, Sweden.
4. Unit of Physiotherapy, Department of Health, Medicine and Caring Sciences, Linköping University, Linköping, Sweden.
5. Unit of Community Medicine, Department of Health, Medicine and Caring Sciences, Linköping University, Linköping, Sweden.
6. Department of Orthopaedics, Hässleholm-Kristianstad Hospitals, Hässleholm, Sweden.
7. Department of Orthopaedics, Sahlgrenska University Hospital, Mölndal, Sweden.