The interventions include either transcutaneous cervical spinal electrical stimulation combined with physical therapy or physical therapy only. The order of the interventions will be randomized for each subject in a delayed cross-over design. Total duration of the study is 6 months, including 4 weeks baseline measurements, 8 weeks intervention and 12 weeks follow-up. Both immediate and lasting improvements in hand motor and sensory function via transcutaneous cervical spinal stimulation will be evaluated.