Muscle Coordination-Based Feedback for Stroke Rehabilitation

The purpose of this study is to compare two interventions currently used to improve gait and lower limb function in individuals with chronic stroke (i.e., high-intensity gait training and high-intensity gait training with functional electrical stimulation (FES)) with novel interventions based on the coordinated activity of multiple muscles, known as muscle synergies. To this end, the researchers will recruit chronic stroke patients to participate in training protocols according to the currently used rehabilitation programs as well as novel rehabilitation programs that provide real time feedback of muscle synergies using multichannel FES and visual feedback.

The researchers will determine if using muscle synergies to drive interventions provides greater rehabilitation outcomes than the interventions that are currently used in therapy. Then, the researchers aim to investigate which modality of feedback (somatosensory vs visual) on muscle synergies may result in the greatest improvements. Therefore, we will have two aims. The main objective of Aim 1 of this study is to compare 1) conventional high-intensity gait training, 2) standard FES gait training, and 3) a novel muscle synergy-based multichannel FES (MFES) gait training for the purpose of improving lower limb function (i.e., gait) in individuals with chronic stroke. The main objective of Aim 2 of this study is to compare 1) muscle synergy-based MFES gait training, 2) muscle synergy visual biofeedback gait training, and 3) a combination of synergy-based MFES and muscle synergy visual biofeedback gait training to determine the key modality to driving neuroplastic change in the organization of muscle synergies during gait training. To this end, the researchers will randomly enroll 15 patients with chronic stroke to one of the three rehabilitation programs/groups listed above in each aim and assess the efficacy of each program to improve the following patient outcomes throughout and following rehabilitation:

1. Changes in functional impairment measured by clinical assessments.
2. Changes in gait biomechanics.
3. Electrophysiological changes in motor control.
4. Feasibility of clinical use of novel interventions and the perceived usefulness by patients.

This will provide information about the potential advantages of using the novel synergy-based biofeedback systems in a chronic stroke population and may be the foundation for a larger clinical trial and extension of this rehabilitation technology to the subacute stroke population as well as other neurologically impaired populations.

Eligibility Criteria:
Healthy participants:

Inclusion Criteria:

* Age 18-80 years, inclusive
* Normal hearing and vision, can be corrected
* Able to understand and give informed consent
* Able to understand and speak English

Exclusion Criteria:

* Reduced cognitive function or inability to perform study tasks
* Any neurological disorder or history of neurological injuries (e.g., Parkinson's disease or other neurodegenerative disorder, dementia, brain injury, spinal cord injury, multiple sclerosis, peripheral nerve injury, or cancer of the central nervous system)
* Presence of pathology that could cause abnormal movements of extremities (e.g., epilepsy, marked arthritis, chronic pain, musculoskeletal injuries)
* Recent fracture or osteoporosis (as reported by subject)
* Lesions or wounds on the legs
* Medical (cardiac, renal, hepatic, or oncological) or psychiatric disease that would interfere with study procedures
* Pregnancy
* Prisoners

Patients:

Inclusion Criteria:

* Age 18-80 years, inclusive
* Normal hearing and vision, can be corrected
* History of a single unilateral, supratentorial ischemic or hemorrhagic stroke at least six months prior
* Reduced ambulation but able to walk \>10m independently on level ground (with assistive device if needed)
* Medical clearance from medical team (signed Medical Clearance form)
* Able to understand and give informed consent
* Able to understand and speak English
* Able to passively move all joints (i.e., hip, knee, ankle) through the range of motion of a typical gait cycle

Exclusion Criteria:

* Reduced cognitive function and inability to perform study tasks
* Severe aphasia
* Co-existence of other neurological diseases (e.g., Parkinson's disease or other neurodegenerative disorder, dementia, brain injury, spinal cord injury, multiple sclerosis, or cancer of the central nervous system)
* History of peripheral nerve injury
* Severe hip, knee, or ankle arthritis
* Recent fracture or osteoporosis (as reported by subject)
* Medical (cardiac, renal, hepatic, or oncological) or psychiatric disease that would interfere with study procedures
* Significant spasticity or contracture in the lower limbs (Modified Ashworth Scale score of 3 or higher)
* Use of pacemakers, defibrillators, electrical implants, or metallic implants
* Lesions or wounds on the paretic leg
* Botox (botulinum toxin) injection to lower limbs within the prior 3 months, or planned injection during study period
* Pregnancy
* Prisoners
* Concurrent or planned participation in surgeries, significant medical treatments, other lower limb research studies, or physical therapy during the study timeline

Therapists:

Inclusion Criteria:

* Licensed physical therapist at SRALab
* At least 1 year of experience as a physical therapist
* Regularly treats people with stroke, at minimum once per week
* Able to give informed consent
* Active CITI training certification, or willing to complete this online CITI training

Exclusion Criteria:

* Inability to interact safety with the technologies
* Unwillingness to try to use the technologies
* Unable to complete at least 1 competency session and deliver at least 6 intervention sessions