The purpose of the current study is to evaluate whether a home-based, telehealth-supported intervention combining Blood Flow Restricted Exercise (BES) and Transspinal Stimulation (TS) will improve motor and functional abilities greater than BES+sham TS in persons with chronic, incomplete tetraplegia.

Cervical spinal cord injury (cSCI) results in physical impairment and limited mobility, with the most severe cSCI necessitating wheelchair use for ambulation and impaired upper extremity function resulting in subsequent chronic comorbidities. These comorbidities may include psychosocial, cardiovascular, metabolic and respiratory consequences, as well as a significant socioeconomic burden. The economic burdens for persons with cSCI, their families, and society are increasing at an alarming rate, especially with decreasing mortality due to advances in medical interventions. Restoring some degree of upper extremity and hand function would improve overall functional ability and quality of life. Through physical rehabilitation, upper extremity function can improve, but gains are limited for people with the most severe, motor-complete cSCI. Attempts have been made to restore and improve upper extremity and hand function using implanted epidural stimulation of the cervical spinal cord, but alternatives to this invasive therapy are warranted to maximize the amount of people who may benefit from enhanced motor activation.

The total study duration is 30 weeks. The first 4 weeks will start and end with baseline assessments (Baseline 1 &2). The rest of this 4-week period will consist of 2 sessions/week of education and optimization provided to the participant and a caregiver, to instruct them to use the TS device and blood pressure machine and carry out massed practice training for both groups. The first two weeks of this 4-week phase will occur onsite in the laboratory, and the second two weeks of this 4-week phase will occur at home via telehealth to familiarize participants and companions with the telehealth platform - however, if the participant and companion desire more on-site instruction, they may come into the lab to do this during this time as well. Following the first 4-week phase, 16 weeks of 3 sessions/week of BES+TS or BES+sham TS training at home with supervision from the research team via telehealth will occur.

In the week following completion of the intervention, post-intervention outcome measures assessments will take place. There will then be an 8-week washout period where participants will receive no training. Following the 8-week washout, participants will be asked to come back to the lab for one more follow-up assessment of outcome measures to test any long-term effects of the intervention.

Inclusion Criteria:

1. A written clearance from the study medical doctor to ensure that the participant is safely able to engage in the study.
2. Participants must have a companion that will be able to help him/her throughout the study.
3. Greater than 1-year post SCI, neurologic level of C8 or above.
4. American Spinal Injury Association Impairment Scale (AIS) scores of B, C, or D indicating presence of an incomplete SCI.
5. Visible muscle contraction response to NMES wrist extensors, bilaterally.
6. Agreement to use telehealth services for delivery of research exercise training by study staff. Possesses appropriate technology to engage in telehealth including a personal web camera, computer, microphone, speakers, and high-speed broadband internet connection, valid email address (needed to obtain VA issued video conferencing software), and telephone number used to obtain login credentials for the In-Home Video Software - Cisco Jabber Video for Telepresence Software.
7. Response of muscle contraction of wrist extensors bilaterally to neuromuscular electrical stimulation.

Exclusion Criteria:

1. Unhealed fracture in upper or lower extremities.

2. Severe scoliosis, severe upper extremity contractures, or other musculoskeletal issues that would impede participation in a BES + TS intervention or valid evaluation of outcome measures.

3. High resting blood pressure greater than 140/80 mmHg.

4. Taking anti-coagulants or anti-platelet agents, including aspirin if unable to be off this medication for medical reasons.

5. Pregnancy (female participants). A home pregnancy test will be conducted to role out any pregnancy before the study at the McGuire VAMC. The test will be repeated every month during the course of the study.

6. Implanted pacemakers and/or implanted defibrillator devices.

7. Other exclusion criteria may include the presence of implanted electrical device, cancer, thrombosis, pacemaker, defibrillator, or seizures. Patients who are currently on or receive anti-platelet or anticoagulant medications will be excluded from the trial.

8. Any condition that, in the judgment of the principal investigator or medical provider, precludes safe participation in the study.

9. Other exclusion criteria at the discretion of the medical team may include:

   1. Uncontrolled autonomic dysreflexia (AD), refers to episodes of AD that do not respond to medications to ensure stable blood pressure in persons with SCI
   2. Concurrent severe neurological injuries other than SCI: MS, CP, severe TBI, and stroke.
   3. Unresolved deep vein thrombosis.
   4. Psychiatric or cognitive impairments that preclude adherence to the intervention.
   5. Known cardiac pathology that precludes safe participation.
   6. Metabolic conditions such as cardiovascular disease, uncontrolled type II diabetes mellitus, uncontrolled hypertension, and those on insulin.
   7. Presence of pressure sores stage three or greater.
   8. Presence of a symptomatic urinary tract infection.
   9. Severe spasticity as assessed by the Modified Ashworth Scale.
   10. Changing neurologic status due to conditions such as progressive posttraumatic syringomyelia.