1. Division of Community Pediatric and Adolescent Medicine, Department of Pediatric and Adolescent Medicine, Mayo Clinic, Rochester, Minnesota, USA
2. Department of Pediatric Sports Medicine, Scottish Rite for Children, Dallas, Texas, USA
3. Department of Orthopaedic Surgery, Department of Pediatrics, University of Texas Southwestern, Dallas, Texas, USA
4. Department of Urology, University of Arizona, Tucson, Arizona, USA
5. Faculty of Sport Sciences, Waseda University, Tokyo, Japan
6. The Micheli Center for Sports Injury Prevention, Waltham, Massachusetts, USA