In our prior work, members of our study team found that residual, sub-movement threshold EMG signals can be measured reliably from the forearm of chronically paralyzed individuals with spinal cord injury (SCI) using the NeuroLife EMG-FES System, and that EMG can be used to discriminate multiple attempted hand movements to drive continuous control of functional electrical stimulation (FES). Briefly, the NeuroLife EMG-FES System is a completely non-invasive system (surface electrodes only, no implantable components) worn on the forearm of participants and has up to 160 electrodes that can record electromyography (EMG), or muscle activity, and also electrically stimulate (FES) muscles. This allows users to attempt a movement and, even in the absence of physical movement, the system can detect what they are trying to do and electrically stimulate the muscles they are attempting to use. We hypothesize that this ability to control the system with participant's own muscle signals will assist in improving and restoring hand function of SCI survivors with tetraplegia. Furthermore, preliminary studies have suggested the potential for motor-intention driven FES to promote functional recovery after system use. With the dual-purpose use as a functional orthosis and as a rehabilitation tool for restoration of hand function, the NeuroLife EMG-FES System is poised to transform the state of care for those with hand impairment due to SCI.

The overarching goal of this proposal is to investigate the safety, feasibility, and early efficacy of the NeuroLife EMG-FES system on upper extremity outcomes in chronic SCI survivors with tetraplegia. A pilot clinical trial will allow us to test the following aims: Aim 1. Determine the early efficacy of using the NeuroLife EMG-FES System as a functional orthosis to complete functional activities after 12 weeks of task practice using the system. Aim 2. Determine the early efficacy of using the NeuroLife EMG-FES System as a rehabilitation tool to improve sensorimotor function after 12 weeks of task practice using the system. Aim 3. Develop and establish EMG-based biomarkers of neuroplasticity and recovery after chronic SCI.

We plan to conduct a pilot clinical trial investigating the NeuroLife EMG-FES Sleeve System in adults (n=12) with chronic (\>12 months) tetraplegia due to spinal cord injury. Briefly, the NeuroLife EMG-FES System is a completely non-invasive system (surface electrodes only, no implantable components) worn on the forearm of participants and has up to 160 electrodes that can record electromyography (EMG), or muscle activity, and also electrically stimulate (FES) muscles. Using this combined, closed-loop technology participants will complete a 12-week protocol with a study therapist practicing functional activities using their hand/forearm while wearing the NeuroLife EMG-FES Sleeve System. We will assess functional outcomes using standardized clinical measures at 6 timepoints (double baseline, 4 weeks, 8 weeks, post-intervention, and 4 weeks post-intervention). At these timepoints we will also collect high-definition EMG data using the NeuroLife EMG-only system to investigate the ability to use EMG as a biomarker of recovery over time in chronic SCI participants undergoing rehabilitation.