1. Department of Mechanical Engineering and Construction, Universitat Jaume I, Castelló, Spain
2. Department of Biomedical Engineering, Physical Medicine and Rehabilitation, and Physical Therapy and Human Movement Sciences, Northwestern University, Chicago, IL, USA
3. Sensory Motor Performance Program, Rehabilitation Institute of Chicago, Chicago, IL, USA
4. Research Service, Edward Hines, Jr. VA Hospital, Hines, IL, USA