1. From the Department of Physical Therapy (T.G.H.), University of Illinois at Chicago; the Sensory Motor Performance Program (T.G.H., D.D.C., J.H.K., T.D., J.L.M., H.R.R.), Rehabilitation Institute of Chicago, Ill; and the Department of Physical Medicine and Rehabilitation (T.G.H.), Northwestern University Feinberg School of Medicine, Chicago, Ill.