James Nall grimaces in pain as his motor and sensory function is tested while performing an ISNCSCI exam (International Standards for Neurological Classification of Spinal Cord Injury) at the Colorado Neurological Institute in Englewood, CO August 05, 2013. Nall had volunteered to help demonstrate the exam during a training session. He said he doesn’t mind being used as a Guinea pig, “Craig Hospital has done so much for me, anyway I can give back, I’ll do it.” (Photo By Craig F. Walker / The Denver Post)