1 Rehabilitation Engineering Lab, Department of Kinesiology and Community Health, University of Illinois at Urbana-Champaign, Champaign, IL, United States.
2 Departments of Physical Medicine and Rehabilitation and Biomedical Engineering, Northwestern University, Chicago, IL, United States.
3 Jesse Brown VA Medical Center, Chicago, IL, United States.
4 Beijing Advanced Innovation Center for Biomedical Engineering, School of Biological Science and Medical Engineering, Beihang University, Beijing, China.
5 Rehabilitation Engineering and Applied Research Laboratory, The George W. Woodruff School of Mechanical Engineering, Georgia Institute of Technology, Atlanta, GA, United States.