Kent Stephenson lies down during voluntary training while Katelyn Gurley tracks his level of muscle activity and force at the Human Locomotion Research Center laboratory, Frazier Rehab Institute, as ... more 
Kent Stephenson lies down during voluntary training while Katelyn Gurley tracks his level of muscle activity and force at the Human Locomotion Research Center laboratory, Frazier Rehab Institute, as part of the University of Louisville's Kentucky Spinal Cord Injury Research Center, in Louisville Kentucky, as pictured in this handout photo courtesy of University of Louisville. REUTERS/University of Louisville/Handout via Reuters less 
1 / 20
Reuters | Photo By HANDOUT / Reuters
Tue, Apr 8, 2014 12:13 AM EDT