 Stage 1C: Stimulation procedures and standing and stepping interventions Prior to the surgery we will evaluate the research participants for 1 FNPA, 2 nerve conduction study; 3 SEP; 4 sympathetic skin responses SSR, 5 efferent motor activity during standing, 6 efferent motor activity during stepping and 7 reflexes during supine, prone, sitting and standing, 9 bladder function, 10 CV function as described above in the screening. We may repeat these measurements beginning 2 weeks after the surgery both -stimulation for 10 - 14 days. During the two weeks after the surgery, the research participants may be hospitalized at Frazier Rehab Institute to monitor the incision site. The FNPA, NCS, SEP and SSR will be performed while the research participant is lying supine on a mat. The efferent motor assessments will be performed in the body weight support treadmill with the assistance of trainers at the hip and at each leg. 