Augmenting Upper Limb Function and Functional Neuroplasticity Using Epidural Stimulation of the Cervical Spinal Cord

Inclusion Criteria:

* Confirmed stable medical condition for participation by study physician.
* Male or female aged 22 - 70 years old.
* Must provide documentation from personal primary treating physician that reports stable medical condition.
* Able to passively range bilateral upper extremities within normal mobility parameters as defined by study protocol
* Maintain current oral anti-spasticity regimen/dosage as approved by study physician with no change in regular use that may affect study outcomes.
* Six (6) months to 20 years post spinal cord injury.
* Non-progressive spinal cord injury.
* Chronic spinal cord injury classified as ASIA Impairment Scale (AIS) grade A, B, or C.
* Neurological level of injury above T2.
* Eligible for fMRI per safety questionnaire.
* Women of childbearing potential must agree to the use of an effective means of avoiding pregnancy for the duration of the study

Exclusion Criteria:

* Currently involved in another rehabilitation training study.
* Lower motor neuron injury revealed in the upper limbs.
* Stabilization hardware in the cervical spine, preventing implantation of ESS system.
* Active pressure sores, wounds, unhealed bone fractures, peripheral neuropathies, or painful musculoskeletal dysfunction (including contractures in the upper and lower extremities).
* Any ongoing medical condition which would preclude participant from regular physical activity (including but not limited to: ventilator dependence, cardiopulmonary disease, uncontrollable autonomic dysreflexia or orthostatic hypotension, or active urinary tract infections).
* Intrathecal baclofen pump therapy for spasticity.
* Botox injections to primary upper extremity and trunk musculature within the past 3 months which would result in absence of muscle tone and thus preclude response to electrical stimulation therapy.
* Current or history of neuromuscular conditions (including but not limited to: unhealed ligament of muscle tears in the upper or lower extremities, pain in weight bearing positions for upper and lower extremities).
* Current or history of seizures or cerebral lesions.
* Clinically significant depression, psychiatric disorders, or ongoing drug abuse.
* Currently taking tricyclic anti-depressants, selective serotonin reuptake inhibitors (SSRIs), serotonin nor-epinephrine reuptake inhibitors (SNRI), or bupropion (Wellbutrin).
* Any reason the PI or treating physician may deem as harmful to the participant or inappropriate for the participant to enroll or continue in the study.
* Body Mass Index (BMI) over 30.
* Pregnancy or nursing.