1. The Micheli Center for Sports Injury Prevention, Waltham, Massachusetts
2. Department of Psychology, Colby College, Waterville, Maine
3. Brain Injury Center, Boston Children’s Hospital, Boston, Massachusetts
4. Division of Sports Medicine, Department of Orthopedics, Boston Children’s Hospital, Boston, Massachusetts
5. Department of Pediatrics, Harvard Medical School, Boston, Massachusetts
6. Department of Orthopedics, Harvard Medical School, Boston, Massachusetts