Upper Extremity Functional Electrical Stimulation (FES) for Restoration of Upper Extremity Function After Spinal Cord Injury (SCI)

Inclusion Criteria: 1\. Neurological Injury: 1. Traumatic spinal cord injury (SCI): neurological level at or above T1 spinal cord level; AIS A, B, C or D impairment grade * Group 1 (Acute SCI): Deemed medically stable by medical practitioner, less than 6 months post-injury. * Group 2 (Chronic SCI): More than 6 months post-injury. or 2. Peripheral nerve injury (PNI), with or without SCI, who are pre- or post- upper extremity (UE) nerve transfer surgery * Group 3 (Acute Pre- or Post-UE nerve transfer surgery): Deemed medically stable and safe/appropriate to participate in MyndMove UE FES therapy intervention by referring neurosurgeon within 6 months pre- or post-UE nerve transfer surgery. * Group 4 (Chronic Post-UE nerve transfer surgery): Deemed medically stable and safe/appropriate to participate in MyndMove UE FES therapy intervention by referring neurosurgeon 6 months or more post-UE nerve transfer surgery. 3\. Has detectable residual connection in upper-limb muscles in at least one of the neurologically affected sides confirmed by a visible contraction when functional electrical stimulation (FES) is applied in at least one upper extremity muscle at baseline. 4\. Has detectable motor function in at least 1 upper extremity muscle on 1 neurologically affected side confirmed by voluntary electromyography (EMG) or detectable motor evoked potential (MEP) at the baseline assessment. 5. (Aim 2 only) Able to commit to intervention and assessment sessions over a maximum duration of 4 months. Exclusion Criteria 1. Traumatic brain injury, stroke, multiple sclerosis, or other disorders that could affect neuromotor function. 2. Severe spasticity that could prevent the study protocol as determined by the investigator. 3. Major executive dysfunction, dementia, depression, neurocognitive impairments, or other major medical co-morbidities. 4. Has contraindications for transcutaneous stimulation using FES such as breakdown of skin in the area that will come into contact with electrodes, thrombosis, or skin disease 5. Poorly managed autonomic dysreflexia that could be triggered by FES. 6. Unhealed upper extremity fracture, contracture, or pressure sore. 7. Implanted neurostimulator (e.g., deep brain stimulation (DBS), epidural/subdural, vagal nerve stimulation (VNS)) 8. Cardiac pacemaker or intracardiac lines. 9. Individuals who require therapy or other care that could interfere with participation in the study. 10. Individuals on investigational drugs or any other intervention known to have a potential impact on neuromotor function. 11. Individuals with substance disorders, including alcoholism and drug abuse. 12. Individuals who are pregnant, breastfeeding, or the desire to become pregnant during the study. 13. In the opinion of the investigators, the study is not safe or appropriate for the participant.