1. Department of Physical Medicine and Rehabilitation, Harvard Medical School, Boston, Massachusetts, USA.
2. MassGeneral Hospital for Children Sports Concussion Program, Waltham, Massachusetts, USA.
3. Department of Physical Medicine and Rehabilitation, Spaulding Rehabilitation Hospital, Charlestown, Massachusetts, USA.
4. College of Osteopathic Medicine, University of New England, Biddeford, Maine, USA.
5. Schoen Adams Research Institute, Spaulding Rehabilitation Hospital, Charlestown, Massachusetts, USA.