Responses to Backward Walking Training Post-Stroke (BRAVE)

Approximately 15,000 Veterans are hospitalized for stroke each year with new cases costing an estimated $111 million for acute inpatient, $75 million for post-acute inpatient, and $88 million for follow-up care over 6 months post-stroke. The investigators have previously established the effectiveness of a backward walking training program to improve gait and balance in post-stroke Veterans. To best serve Veterans in this era of personalized medicine, there is a current need to determine the appropriate training dose as well as which post-stroke Veterans would most benefit. This study addresses both needs as it will 1) test responses to two different doses (18 vs. 27 sessions) of backward walking training and 2) assess brain activity, measured by magnetic resonance imaging, before and after training intervention to determine its ability to predict rehabilitation response as well as brain mechanisms of behavioral change.

This prospective, single-blind, randomized controlled trial will enroll individuals between 2- and 4-months post-stroke and is designed to address the study's three Specific Aims (See Figure below). The study will be approved by an ethics review board and all participants will provide written informed consent. Baseline pre-intervention assessment (Assessment A) will consist of clinical gait and balance assessments and resting state Functional Connectivity MRI and functional MRI. Brain imaging at Assessment A will test the hypotheses that rs-FC and fMRI can predict BWTraining intervention response (Specific Aim 2). Following Assessment A, participants will be randomized to receive 1) 18 sessions or 2) 27-sessions of BWTraining 3x/week for six or nine weeks respectively. Participants in the 18-session group will wait 3 weeks following randomization to begin training such that Assessment B will take place at approximately the same time post-stroke for all participants. This will assure that all participants have had the same duration of time post-stroke after study enrollment to experience spontaneous recovery. Gait and balance measures at Assessment B will be compared to Assessment A to test Specific Aim #1. MRI brain measurements at Assessment B will be compared to those at Assessment A to test the hypotheses of exploratory Aim #3. Assessment C, at six weeks post-intervention will evaluate short-term and Assessment D, at 6-months post-intervention will evaluate long-term retention gains in gait and balance. The investigators will recruit 54 individuals post-stroke to allow up to a 10% attrition rate and still provide a sufficient participant pool (n=48) to address the Specific Aims.

Rehabilitation, Gait, Physical Therapy Modalities, Magnetic Resonance Imaging, Postural Balance, Accidental Falls

Participants will be randomized to receive either: 1) 27 sessions of backward walking training or 2) 18 sessions of backward walking training

Outcome Assessors will be masked to group assignment. Outcome Assessors will not deliver the intervention and will not be present in the building when the intervention is being delivered. Participants will be instructed to not reveal their group assignment to the outcome assessor.

Participants will receive 27 sessions of backward walking training. Each session wil consist of 20 minutes of gait training on a treadmill and 20 minutes of gait training over ground.

Participants will receive 18 sessions of backward walking training. Each session wil consist of 20 minutes of gait training on a treadmill and 20 minutes of gait training over ground.

Gait speed will be measured with the 10-Meter Walk Test. Individuals will be given a 3 meter warm-up distance for walking, preceding the 10 meter distance and 3 meters beyond the 10 meters to continue walking. The time that it takes to traverse the 10 meters at the subject's usual pace will be recorded.

BW Speed will be assessed with the 3-Meter Backward Walk test (3MBWT). The test consists of a 1 meter warm-up distance, a timed 3 meter distance, followed by an additional 1 meter to continue walking. An average of two trials will be recorded.

A 10-item clinical gait and balance test of dynamic activities. Reported scores range from 0 to 30 with a larger number representing a better score.

This 16-item self-report measure is used to assess perceived efficacy (self-reported confidence) in maintaining balance while performing a number of activities common in community-dwelling older adults. This scale is reported as an average of the 16 items from 0% to 100% with a larger number representing a better score.

This tool consists of 14 items that assesses static and dynamic standing balance, ability to sit, stand up and transfer. The range of this scale is 0-56 with a larger number representing a better score.

Gait speed will be measured with the 10-Meter Walk Test. Individuals will be given a 3 meter warm-up distance for walking, preceding the 10 meter distance and 3 meters beyond the 10 meters to continue walking. The time that it takes to traverse the 10 meters at the subject's usual pace will be recorded.

BW Speed will be assessed with the 3-Meter Backward Walk test (3MBWT). The test consists of a 1 meter warm-up distance, a timed 3 meter distance, followed by an additional 1 meter to continue walking. An average of two trials will be recorded.

A 10-item clinical gait and balance test of dynamic activities. Reported scores range from 0 to 30 with a larger number representing a better score.

This 16-item self-report measure is used to assess perceived efficacy (self-reported confidence) in maintaining balance while performing a number of activities common in community-dwelling older adults. This scale is reported as an average of the 16 items from 0% to 100% with a larger number representing a better score.

This tool consists of 14 items that assesses static and dynamic standing balance, ability to sit, stand up and transfer. The range of this scale is 0-56 with a larger number representing a better score.

Inclusion Criteria: Berg Balance Scale < 42 Self-selected 10 meter gait speed < 0.8 m/s Diagnosis of unilateral stroke > 2 months < 4 months post-stroke Able to ambulate at least 10 feet with maximum 1 person assist Medically stable Exclusion Criteria: Presence of neurological condition other than stroke Serious cardiac conditions (hospitalization for myocardial infarction or heart surgery within 3 months, history of congestive heart failure, documented serious and unstable cardiac arrhythmias, hypertrophic cardiomyopathy, severe aortic stenosis, angina or dyspnea at rest or during activities of daily living) Anyone meeting New York Heart Association criteria for Class 3 or Class 4 heart disease will be excluded Severe arthritis or orthopedic problems that limit passive ranges of motion of lower extremity (knee flexion contracture of -10 degrees, knee flexion ROM < 90 degrees, hip flexion contracture > 25 degrees, and ankle plantar flexion contracture > 15 degrees) Severe hypertension with systolic greater than 200 mmHg and diastolic greater than 110 mmHg at rest Pain upon ambulation Receiving physical therapy services for mobility and/or gait Living in a skilled nursing facility Any MRI contraindication, including but not limited to the presence of metal, MR sensitive implanted medical devices, or claustrophobia