1. Recruit male and female volunteers with spastic paresis due to incomplete SCI with impaired hand function, and randomize subjects into 1 of 3 groups, each of which receives 6 weeks of upper extremity training for 3 sessions/week, as follows: a) somatosensory stimulation of the median, ulnar and radial nerves at the level of the wrist (2 hours/session); SS group b) somatosensory stimulation of the median, ulnar and radial nerves at the wrist (2 hours/session) followed by an activity-based upper extremity training program (1 hour/session); SS+ABT group and c) sham somatosensory stimulation of the median, ulnar and radial nerves at the wrist (2 hours/session) followed by an activity-based upper extremity training program (1 hour/session); ABT group then carry out training in the 3 subject groups simultaneously, each group consisting of 2 subjects at a time, with 2 sets of subjects/year over a 2-year period, yielding a target sample of 36 subjects.