Mental Practice Impact on Gait and Cortical Organization in Spinal Cord Injury (SCI)

Inclusion Criteria: * age \> 18 years old; * incomplete SCI (ASIA Grade C or D), experienced \> 1 year prior to enrollment; * motor grade of \> 1 \< 3 in the quads, hamstrings, and hip flexors, and ability to ambulate with at least a maximal assist; * range of motion in the lower limbs within functional limits; * motor function in at least half of ASIA key lower extremity muscles with strength \< or \> 3/5; * able to ambulate at least 10 meters with 1 person assistance and/or assistive device; * medically stable (ie, no bladder infection; decubiti); (8) stable dosage of antispasticity medications for duration of study Exclusion Criteria: * excessive spasticity in the lower limbs as measured by a score of \> 3 on the Modified Ashworth Spasticity Scale; * excessive pain in the lower limbs as measured by a score of \> 5 on a Visual Analog Scale or \> 8/10 with a clarified scaled picture graph; * moderate to severe osteoporosis, as indicated by the patient's physician; * heterotropic ossification, as indicated by the patient's physician; * psychological conditions that would contraindicate participation in the program and no abnormalities of attention, with minimum cognitive capacity present sufficient to participate in MP; * fracture or fracture history in the lower limbs (individuals with a remote history of fractures may be included at discretion of the study physical therapists at each site); * enrolled in any form of rehabilitation; * for subjects to be administered fMRI, implant containing electrical circuitry, generating electrical signals, or having moving metal parts, metal pins or plates above the waist, orthodontic braces, or other positives on a standard checklist of MRI exclusion criteria used by the Radiology Department; * pregnant; * DSM-IV Major Depressive Episode symptom criteria of \> 5/9 as exclusion threshold instead of CESD;