A Novel Strategy to Decrease Fall Incidence Post-Stroke

Approximately 15,000 Veterans are hospitalized for stroke each year. Persistent walking and balance deficits contribute to long-term disability and a high incidence of falls. Falls are a common and costly complication of stroke; between 40% and 70% of affected individuals fall within the first year. Falls lead to fear of falling, limitations in self-care and increased dependence. Of greater concern, they lead to serious adverse events, including fractures, depression and mortality. A primary goal of stroke rehabilitation is to improve mobility despite persistent motor, balance and visual-spatial deficits. However, this goal has a down side since it increases fall risks. Here, the investigators propose a novel therapeutic strategy to improve ambulation while decreasing the risk of falls: Backward Walking Training (BWTraining).

The investigators' central hypothesis is that a 6-week BWTraining program at 2-months post-stroke is superior to standard care in reducing falls within the 1st year post-stroke. Identification of those at risk for falling is a necessary component of post-stroke rehabilitation to implement pro-active measures to decrease risk once individuals rejoin community living. Recent research in a cohort of elderly adults determined that maximal Backward Walking Speed (BWSpeed) (not forward) identified individuals that had experienced a fall in the previous six months,6 suggesting that BWSpeed could be a simple, inexpensive screening tool to identify individuals at risk of falling. With a randomized, blinded design, the investigators propose to prospectively assess the value of BWSpeed as a tool to predict future falls.

A notable post-stroke conundrum is that increased mobility may increase fall risk.5 On the other hand, limiting mobility leads to a multitude of inactivity-associated deficits, including recurrent stroke.

To date, no intervention has demonstrated efficacy for improving walking while minimizing fall risk. BWTraining may be a simple and effective intervention to achieve both goals. In the investigators' recent randomized controlled pilot trial (RCT), individuals with sub-acute stroke who participated in a BWTraining demonstrated 3-fold improvement in backward and forward walking speed and fall self-efficacy. Further, BWTraining caused 75% greater improvement in balance versus those in a dose-matched balance training group. At the 3-month follow-up assessment, BWSpeed of the BWTraining group averaged 0.63 m/s, exceeding the threshold for fall risk in elderly adults.

Given the success of the investigators' pilot intervention, a larger and more rigorous trial is needed to demonstrate reduced fall incidence over an extended follow-up period. The investigators designed this RCT to address three specific aims:

Aim #1: Test the hypothesis that 1-year fall incidence is decreased for participants randomized to BWTraining administered at 2-months post-stroke (versus usual care comparison group).

Hypothesis #1a: BWTraining at 2-months post-stroke reduces the number of falls over the next year.

Hypothesis #1b: BWTraining at 2-months post-stroke increases gait speed, improves balance and increases balance confidence over the next year.

Aim #2: Test the hypothesis that BWTraining at 2 months (immediate) vs. 1-year (delayed) post-stroke is more effective at improving BWSpeed.

Hypothesis #2a: BWSpeed improvement from 2- to 14-months post-stroke is greater when BWTraining is delivered at 2 months versus 1 year post-stroke.

Hypothesis #2b: Improvements in forward gait speed, Functional Gait Assessment and Activities-Balance Confidence Scale from 2- to 14-months post-stroke are greater when BWTraining is delivered at 2 months versus 1 year post-stroke.

Aim #3: This exploratory aim will test the hypothesis that BWSpeed at 2-months post-stroke is a significant predictor of fall incidence over the next year 1 year period, after adjusting for other covariates.

Hypothesis #3: BWSpeed at 2-months will be a significant predictor of fall incidence during the first year post-stroke, after adjusting for other covariates.

This study is significant since it concerns a novel strategy to improve ambulation while minimizing the risk of falling after a stroke. BWTraining is highly novel, is easy to administer and exciting preliminary data suggest that is has major potential as a therapeutic tool. In addition, the investigators will determine the potential of BWSpeed (a simple, clinically relevant screening tool) to identify those at risk for future falls.

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
• 18-85 years of age
• Physician approval for patient participation

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
• knee flexion Range Of Motion < 90
• hip flexion contracture > 25
• ankle plantar flexion contracture > 15
• Severe hypertension with systolic greater than 200 mmHg and diastolic greater than 110 mmHg at rest, that cannot be medically controlled into the resting range of 180/100 mmHg
• Pain upon ambulation
• Receiving physical therapy services for mobility and/or gait
• Living in a skilled nursing facility
• Unable to ambulate at least 150 feet prior to stroke, or experienced intermittent claudication while walking less than 200 meters
• History of serious chronic obstructive pulmonary disease or oxygen independence
• Non-healing ulcers on the lower extremity
• Uncontrollable diabetes with recent weight loss, diabetic coma or frequent insulin reactions
• On renal dialysis or presence of end stage liver disease
• Pulmonary embolism within previous 6 months
• History of major head trauma
• History of sustained alcoholism or drug abuse in the last six months
• Intracranial hemorrhage related to aneurysmal rupture or an arteriovenous malformation
• Current enrollment in a clinical trial to enhance stroke motor recovery