Falls are a concern for people living with spinal cord injury (SCI) or stroke. Falls may result in injury and a fear of falling, which often cause people to restrict their mobility and daily activities. Despite its importance, fall prevention for people with SCI or stroke has not been studied in detail, and as a result, there is a lack of treatments to address their high fall risk.

Functional electrical stimulation (FES) is the application of a mild electrical stimulus to a muscle that helps it move better. In this study, the MyndSearch device will be used to deliver FES. The visual feedback balance training (VFBT) is similar to playing a video game on a balance board while following visual cues on a screen.

The purpose of this study is to evaluate an intervention that combines FES and VFBT to improve balance and lead to the recovery of safe mobility in individuals living with neurological disease or injury (e.g., spinal cord injury, stroke).

Falls are an "emerging public health crisis" that cost the Canadian health care system billions of dollars each year. Moreover falls have a significant, detrimental impact on the lives of those who fall. In addition to physical injury and hospital admission, individuals may experience a post-fall syndrome characterized by dependence, depression, and reduced mobility and participation. Individuals living with the effects of neurological disease or injury are at a particularly high risk of falling. For example, 69-78% of individuals with spinal cord injury or disease (SCI/D) and 73% of individuals post-stroke fall at least once per year. Despite this high fall risk, evidence-based initiatives to prevent falls among those with SCI/D or stroke are lacking in neurorehabilitation. Furthermore, little time is dedicated to improving balance during inpatient neurorehabilitation. For example, ambulatory inpatients with SCI/D spend, on average, a mere 2.0±2.0 hours on balance training over the course of their entire inpatient stay. Our team is developing effective solutions to the "high-volume, high-risk and high-cost challenge" of falls. Our long-term objective is to develop an intervention that improves balance in a clinically meaningful and feasible way, facilitating the recovery of safe upright mobility and addressing the current health crisis of falls in individuals living with neurological disease or injury. The intervention will be developed with a focus on neurological populations, as these patient groups have a critical need for balance training; however, the intervention will be transferrable to other populations at risk of falls, such as older able-bodied adults.

A probable solution to the gap in balance interventions is functional electrical stimulation (FES), whereby an electrical current is applied to peripheral nerves to facilitate muscle contractions. By applying the appropriate amount of electrical stimulation at the appropriate time during movement execution, the central nervous system can be re-educated, facilitating motor and functional improvements. The investigators developed a closed-loop FES system whose controller mimics the physiological control system. By combining this system with visual feedback balance training (VFBT), the investigators developed a prototype system of FES and VFBT (FES+VFBT). This intervention involves standing on a force plate with one's centre of pressure (COP) presented on a monitor. As the user moves his/her COP in response to a game, FES is delivered to the plantarflexor and dorsiflexor muscles through the device, MyndSearch.

Our primary objective is to evaluate the efficacy of the FES+VFBT system in a pilot study with individuals with lived experience, namely individuals with SCI/D or individuals living with stroke.

Inclusion Criteria:

1. Individuals with a non-progressive, motor incomplete SCI/D (i.e. American Spinal Injury Association Impairment Scale (AIS) C or D) or a middle cerebral artery (MCA) stroke
2. chronic stage of recovery (i.e. >1 year post-SCI/D or stroke), when natural recovery has plateaued
3. ≥18 years old
4. able to stand independently for 60 seconds
5. moderate level of trunk control as evidenced by the ability to reach forward >2 inches in standing (i.e. score of 1-3 on the Berg Balance Scale Reaching Forward task);
6. free of any other condition besides SCI/D or stroke that significantly affects walking or balance (e.g., no vestibular disorder, significant vision loss)
7. able to understand spoken English

Exclusion Criteria:

1. a prior lower extremity fragility fracture
2. an injection of botulinum toxin to leg muscles in the past two weeks or injection planned during treatment period
3. peripheral nerve damage in the legs
4. contraindications for FES (i.e. implanted electronic device, active cancer or radiation in past six months, uncontrolled epilepsy, skin rash/wound at an electrode site, pregnancy, active deep vein thrombosis)31
5. contraindications for TMS (i.e. history of epilepsy and/or seizures)

Performance on clinical measures will be evaluated by a physical therapist who is blind to the study purpose, design, and intervention.