1. Department of Physical Medicine and Rehabilitation at the Rehabilitation Institute of Michigan in the Detroit Medical Center, Wayne State University, Detroit, MI, USA
2. Department of Physical Medicine and Rehabilitation at the University of Texas Southwestern Medical Center, Dallas, TX, USA
3. Department of Orthopaedic Surgery, Medical College of Wisconsin, Milwaukee, WI, USA
4. Marianjoy Rehabilitation Hospital, Wheaton, IL, USA
5. Department of Physical Medicine and Rehabilitation at the Rehabilitation Institute of Chicago, Feinberg School of Medicine, Chicago, IL, USA