1. Department of Orthopaedic Surgery; Steadman Philippon Research Institute; The Steadman Clinic; 181 West Meadow Drive, Suite 400 Vail Colorado 8165
2. Department of Orthopaedic Surgery; University of Minnesota; Minneapolis Minnesota
3. Department of Orthopaedic Surgery; Western Michigan University; Kalamazoo Michigan
4. Senter for Idrottskadeforskning; University of Oslo; Oslo Norway