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