1. Department of Physical Medicine & Rehabilitation, University of Utah, Salt Lake City, Utah;
2. Department of Orthopaedics, University of Utah, Salt Lake City, Utah;
3. Department of Family and Community Health, Division of Sports Medicine, Duke University, Durham, North Carolina;
4. Department of Orthopedics, Division of Sports Medicine, Duke University, Durham, North Carolina;
5. Department of Internal Medicine, University of Utah, Salt Lake City, Utah;
6. School of Medicine, University of Utah, Salt Lake City, Utah;
7. Department of Physical Medicine and Rehabilitation, Spaulding Rehabilitation Hospital, Harvard Medical School, Boston, Massachusetts; and
8. Department of Physiotherapy, Trinity College Dublin, Dublin, Ireland.