Non-Invasive Cervical Electrical Stimulation for SCI

Most spinal cord injuries are anatomically incomplete - some nerve circuits remain intact, even if the individual cannot feel or control them. Activating spared nerve circuits may improve functional recovery. With this goal, the Investigators have developed a form of electrical stimulation over the cervical spinal cord that can activate muscles in both hands simultaneously and comfortably. This technique, called cervical electrical stimulation (CES), works at the skin surface - no surgery or other invasive procedures are required. The long-term goal is to use CES to strengthen residual circuits to hand muscles after SCI. Regaining control over hand function represents the top priority for individuals with cervical SCI. In the current study, the Investigators first need to better understand how CES works. In the first half of this study, the Investigators will take a systematic approach to determining how CES interacts with other circuits in the spinal cord and the brain. In the second half of the study, the Investigators will test combinations of CES with active hand and wrist movements to find ways to enhance physical movement with CES. These experiments will improve understanding of electrical stimulation in SCI, and may set the table for future treatments to prolong any short-term benefits observed in this study.