The objective of this study is to advance personalized, portable, and non-invasive hand-grasp neuro-orthoses that restore naturalistic grasp functions for those with tetraplegia due to spinal cord injury (SCI), designed around their needs and preferences.

Battelle has developed a novel wearable sleeve that can reanimate a paralyzed limb via Functional Electrical Stimulation (FES) that is controlled non-invasively by the user. Previous work has shown the ability of this sleeve and FES technology to significantly enhance independence and quality of life when controlled by an implanted brain-computer interface, thus now investigators plan to trial use of the high-definition FES system with simpler, non-invasive control mechanisms to expedite translation of this technology into real-world settings. Each participant will complete up to 10 research sessions (~1.5hrs each) in their residence or at an alternative location. The study location is restricted to Columbus Ohio and surrounding areas. Participants will be compensated for their time.

In Aim 1, investigators will evaluate the ability of a non-invasive, user-controlled FES system to increase functional hand use in the homes of individuals with SCI. The research team will train participants to use the FES system for different functional hand movements and activities they identify as important to them, then measure FES system effectiveness using standardized assessments.

In Aim 2, investigators will assess the viability of using the sleeve technology to non-invasively record muscle activity as the participant attempts different functional movements.

In Aim 3, human-centric design methodology and contextual inquiry interviews will be employed to understand study participants' needs and preferences for a FES assistive device. This information will determine actions to improve usability and optimize the system for unsupervised home use.

Inclusion Criteria:

• ≥ 18 years old
• ≥ 12 months post-SCI and medically/neurologically stable
• Cervical spinal cord injury (C1-C8); any etiology except neurodegenerative conditions
• Unable to grasp objects independently with both hands (tetraplegia)
• Manual muscle testing (MMT) scores ≥4/5 for elbow flexion and ≥2/5 for wrist extension
• Willing to participate in sessions at home or able to travel to alternate site for study sessions

Exclusion Criteria:

• Ventilator-dependent (dependent upon mechanical life support due to inability to breathe effectively)
• Poorly controlled autonomic dysreflexia (more than one episode in 3 months prior to enrollment)
• Moderate to severe spasticity (Modified Ashworth Scale (MAS) >1+) in the hand, wrist, or forearm
• Received a localized injection (e.g. Botox) to hand, wrist, or forearm muscles within past 12 months
• Currently participating in physical rehabilitation for upper extremity impairments
• Individuals having or requiring any of the following: implanted pacemaker, life supporting/sustaining equipment, or critical non-removable implantable electronic devices such as an insulin pump or neurostimulator.
• Presence of any other clinically significant medical comorbidity and/or neurological condition for which participation in the study may pose a safety risk and/or influence results
• Presence of the following medical conditions: uncontrolled seizure disorder, active malignancy in the upper extremities, or open wounds/infections in the upper extremities
• Individuals whose forearm is determined to be too small or too large to fit the electrode sleeve being investigated
• Individuals who are pregnant or plan to get pregnant during the course of the study