A Novel Strategy to Decrease Fall Incidence Post-Stroke
Phase: NA
Conditions: Stroke
Sponsor: VA Office of Research and Development

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Title: A Novel Strategy to Decrease Fall Incidence Post-Stroke 
NCT: 02688777 
Date: 12/21/22 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 

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Protocol 
1. Project Title: A Novel Strategy to Decrease Fall Incidence Post-Stroke 
 
2. Investigator(s):    Dorian Rose, PhD, PT 
 
 
 
 
David Clark, ScD 
 
 
 
 
 
3. Abstract:  
Background/Purpose: Falls are a common and costly complication following stroke. While residual 
walking and balance deficits contribute substantially to long-term disability, of greater concern for 
this population is the incidence of falls. Between 40% and 70% of individuals fall within their first 
year post-stroke. Individuals who fall have increased incidence of serious adverse outcomes, 
including fractures, depression, and mortality. A primary goal of stroke rehabilitation is to improve 
mobility in the presence of motor, balance, and visual-spatial 
deficits. The conundrum all stakeholders must face is that increased mobility may increase risk 
for falls, whereas limiting walking and general mobility will lead to a multitude of deficits 
associated with inactivity, including recurrent stroke. Because of these serious consequences, 
there is an urgent need in the rehabilitation of Veterans with stroke to both identify those who 
are at fall risk and develop intervention strategies that will reduce fall incidence while increasing 
mobility. Backward walking has recently emerged as both a potential predictor of fall incidence 
as well as an intervention modality to prevent future falls. However, it has not yet been 
assessed under the rigors of a controlled trial. We will conduct a randomized controlled trial 
with three specific aims to examine 1) the effectiveness of Backward Walking Training 
(BWTraining) early poststroke in decreasing falls, 2) the timing of BWTraining delivery to 
increase Backward Walking speed (BWSpeed), and 3) the relationship between BWSpeed and 
prospective fall incidence.  
Subjects: One-hundred twenty-eight individuals, 2 months post-stroke, will participate. 
Additional study criteria include: 1) ambulatory with gait speed < 0.8 m/s; 2) community-
dwelling; 3) Berg Balance Scale < 42; 4) absence of other neurological conditions; 5) 
discharged from physical therapy services; 6) stable cardiac status; 7) absence of lower 
extremity orthopedic impairments or pain that limits gait ability.  
Methods: Following baseline assessment, participants will be randomized to BWTraining at 2 
months (Immediate group) or 1-year post-stroke (Delayed group). The intervention consists of 
18 sessions (3X/week for 6 weeks) of BWTraining: 20–30 minutes of step training using a Body 
Weight Support and Treadmill system (BWST) followed by 15 minutes of overground gait 
training delivered by a physical therapist-led team. Participants will walk backward overground 
with assistance as warranted to transfer stepping skills from the BWST environment to 
overground. The Immediate group will be followed prospectively for 1-year and compared to the 
Delayed group to determine the effectiveness of BWTraining in decreasing falls (Specific 
Aim#1). BWSpeed post-intervention will be compared between groups to assess the timing 
effect of BWTraining (Specific Aim #2). The Delayed group will be followed prospectively for 1-
year prior to BWTraining, to determine if BWSpeed at 2-months is a predictor of fall incidence in 
the first year post-stroke (Specific Aim #3).  

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Outcome Measures: Fall incidence 2-months to 1-year post-stroke is our primary outcome 
measure. Secondary measures include forward and backward walking gait speed, dynamic 
balance measured by the Functional Gait Assessment, fall self-efficacy measured by the 
Activities-Balance Confidence Scale and gait kinematics.  
Data Analysis Plan: The total number of falls per patient month for the immediate and delayed 
intervention groups will be calculated, and using a nonparametric ratio estimate, point and 
interval estimates for the average hazard for each group will be determined. The ratio of the two 
individual group estimates, 95% confidence limits and P-values will be obtained. Forward 
stepwise ordinal logistic regression will be used to determine the independent relationship 
between BWSpeed at 2-months post-stroke and 1-year fall incidence of those in the Delayed 
intervention group. 
4.  Background: 
Falls are a Common and Serious Complication after Stroke. 
Stroke is the leading cause of chronic disability world-wide1  and in the United States more 
than 795,000 persons experience a new or recurrent stroke each year.2 Impairments of 
motor control and the subsequent functional limitations in ambulation ability are the most 
common manifestations of stroke. Falls among community-dwelling individuals with stroke 
are widely reported in the literature, with incidence of falls reported to be 40% and 70%.3, 4 
When tracked over a period of four to six months, community-dwelling individuals with 
stroke were two times more likely to fall than the average elderly population.5, 6 Individuals 
post-stroke have a higher fall risk secondary to persisting neurological impairments such as 
motor,7, 8 sensory9 and vision10 deficits. These deficits can directly affect balance and 
mobility, thereby increasing fall risk. 
 
The consequences of falls can have a negative physical and psychosocial impact for 
individuals post-stroke. Physical injuries following a fall for those post-stroke include both 
fractures7, 11 and soft tissue injuries3, 11 with overall injury incidence reported to be 15%-
50%.3, 7, 9, 11 Hip fractures are the most common fractures reported; a 2.1% rate of hip 
fractures has been reported to occur in individuals with stroke after a fall.7 There is a two-to 
four-fold increase in the risk of hip fractures in individuals with stroke than in those without. 
12-14 Negative psychosocial impact of falls on individuals with stroke include fear of falling, 
reduced mobility, greater disability, depression, increased stress experienced by the 
caregiver, and social isolation.3, 4, 6 Fear of falling often leads to activity restriction as 
reported by Mackintosh et al.,11 who determined that 44% of individuals post-stroke 
restricted their activities due to fear of falling. Belgen reported that individuals with stroke 
who fell were 5.6 times more likely to be afraid of falling.15 This fear of falling leads to 
reduced falls-related self-efficacy, resulting in a loss of functional independence.15 
Community-dwelling individuals with stroke who have fallen have also been found to be less 
socially active and more depressed.3 Depression and reduction in social activity can result 
in further deconditioning and reduction in physical activity, further increasing the risk of falls 
in these individuals.14 Given this devastating cascade of events that can occur following a 
fall in this population and the enormous health-care dollars associated with a fall and its 
potential sequelae, there is an urgent need to develop rehabilitation strategies that will 
decrease fall incidence in individuals post-stroke. Specific Aim 1 will examine the efficacy of 
BWTraining to decrease fall incidence in the first year post-stroke.  

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Backward Walking Training is an Emerging Intervention for Post-Stroke Gait. 
BWTraining has been used as a strategy in the rehabilitation of orthopedic conditions as it 
produces less mechanical strain on the knee joint16 and it is an effective means for increasing 
the strength and power of the quadriceps.17 BWTraining is also an option to improve aerobic 
capacity as backward walking can increase energy expenditure to levels high enough to 
maintain cardiorespiratory fitness.18 BWTraining to improve gait and dynamic balance post-
stroke is a more recent application of this modality. Yang et al.,19  demonstrated in people 5-7 
months post-stroke that the addition of a  30-minute BWTraining to each conventional care 
session delivered 3x/week for three weeks resulted in a significant improved forward walking 
speed, stride length, and gait symmetry when compared to conventional training alone. 
However, with the lack of an active control group it is not known if these benefits were simply 
due to the additional therapy. In high-functioning stroke survivors who were able to ambulate 
without an assistive device or orthotic, Weng and colleagues20 reported that walking speed as 
well as balance and lower extremity motor function was significantly more improved for those in 
a BWTraining compared to those who received dose-matched conventional therapy. Although 
total training time was matched, these results need to be interpreted cautiously as the amount of 
gait training in the conventional therapy group was not standardized nor matched to the amount 
of backward gait training.  The foundation for this current proposal resulted from our case-
series with individuals post-stroke21 and our recently conducted pilot RCT that compared 
BWTraining to standard balance training in subsequent balance and gait ability22, 23 
Individuals in the BWTraining group demonstrated larger improvements in forward and 
backward gait speed, balance confidence and balance ability compared to those in dose-
matched balance training group. Despite the limitations of these small prior studies, they 
provide enticing evidence that BWTraining may be a post-stroke gait rehabilitation strategy 
superior to current approaches. A current gap in the investigation of this novel rehabilitation 
strategy is its efficacy in reducing future fall-incidence. Secondary to the relationship 
between BWSpeed and fall incidence in the elderly, we hypothesize that a BWTraining 
would be an effective modality in decreasing falls. Specific Aim 1 will test this hypothesis. 
BWTraining has been assessed in both the acute and chronic post-stroke population but the 
effects of timing of this intervention to increase BWSpeed have not been compared directly 
under the rigors of a randomized controlled trial. Specific Aim 2 will test the effects of 
intervention timing and will provide important information regarding when BWTraining may 
be most beneficial for those post-stroke in increasing BWSpeed, an indicator for fall-risk. 
Identification of Fall Risk is Necessary to reduce Future Falls. 
Identification of individuals at risk for falling is an important aspect of post-stroke 
rehabilitation in order to implement pro-active measures both intrinsically (related to the 
individual) and extrinsically (associated with their environment). Clinical tests of walking 
speed and postural balance to predict fall risk after stroke have been reported previously.24-
26 Gait speed has been reported to predict fall risk both in community-dwelling elderly27-29 
and in individuals post-stroke.30 A recent, intriguing finding, worthy of further exploration is 
that backward, more so than forward walking identified, in a cohort of community-dwelling 
elderly, those that had fallen in the previous 6 months.31 Walking backward at a speed less 
than 0.6 m/s identified 100% of fallers and those who walked backward at a speed less than 
0.4 m/s had a 3.2 times greater likelihood of being a faller than those who walked faster. In 
comparison, forward walking velocity at a cut off of 1.0 m/s only identified 83% of fallers. If 
BWSpeed is a more reliable predictor of falls than forward walking speed in the post-stroke 

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population is not known. Given the difficulty post-stroke of combining hip extension with 
knee flexion, necessary to take a backward step, we hypothesize this BWSpeed-fall 
incidence relationship exists post-stroke as well. Specific Aim 3 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. 
Backwards walking challenges postural stability in a controlled and safe environment 
with a dynamic task similar to the type known to induce falls. 
Most falls leading to injuries occur while walking and of these falls the majority occurs in the 
sideways or backwards directions.32 This is not surprising as there are greater postural 
demands in backward compared to forward walking.33 Many everyday walking activities, such 
as opening a door to enter a room, approaching a chair to sit down, or opening the refrigerator 
require stepping backwards. Compensatory stepping in all directions is an important strategy 
necessary for preserving stability.34 Because stepping responses are necessary for fall 
prevention, the difficulties in taking several consecutive large and rapid steps backward might 
be a factor contributing to fall incidence post-stroke. A decreased ability to take rapid 
compensatory steps has been shown to be closely related to measures of balance and fall 
risk.35  Straube and colleagues36 trained individuals post-stroke in variable stepping contexts 
(sideways, backwards) and reported subsequent improvements in dynamic balance activities. 
While we recognize that falls post-stroke are multifactorial7, the inability to combine hip 
extension with knee flexion required for backward stepping may be a contributor to the 
prevalence of falls in this population. Repetitive practice of this movement combination in a 
controlled environment may facilitate its expression when necessary to prevent a fall. We 
hypothesize that BWTraining will improve balance and falls self-efficacy and decrease fall 
incidence in the first year post-stroke. 
Backwards walking effectively engages cerebral pathways damaged by stroke.  
In addition to the increased challenge to postural stability BWTraining affords, there are 
additional benefits to this rehabilitation strategy. Compared with forward, backward walking is 
more effective at inducing cerebral activation.33, 37 Examination of cortical activity during 
backward walking revealed an increased oxygenated hemoglobin (oxyHb) response compared 
to forward, suggestive of increased cortical processing, in the Supplementary Motor Area 
(SMA), Primary Motor Cortex (PMC), and Superior Parietal Lobule.33 This outcome is similar to 
that of an animal model study that demonstrated more intense activity in the medial motor 
cortices during backward compared to forward walking.38 This greater cortical activation may 
promote cortical neural plasticity by more intensely engaging the circuits damaged by stroke. 
Backward walking also provides a means for high repetition of practice, which is known to be a 
prerequisite to induce cortical reorganization.39   
Backwards walking allows patients to practice coordinated locomotion independent from 
the abnormal patterns that are characteristic of forward walking after stroke. 
In humans, evidence suggests that the neural control of forward and backward walking may 
largely originate from the same basic neural circuitry.40, 41 Hoogemaker et al.,42 has postulated a 
conceptual framework suggesting pattern generating circuits in the spinal cord provide the basic 
rhythms of the respective gait pattern, but that the details of the pattern are dictated both by 
spinal and supraspinal circuits. Kinematic analysis of leg movements has supported this idea, 
especially for the proximal joints.16, 40, 41, 43, 44 Due to the many similarities in the kinematics and 
kinetics of forward and backward walking, when a video of an individual walking backward is 
reversed, the differences with this same individual walking forward are barely noticeable.45 
Many authors have suggested that these two forms of locomotion are generated by the same 
basic neural mechanisms.43, 44, 46, 47 Hip extension is more active in backward walking due to the 
concentric contraction of knee flexors during early swing phase16, 44 which may be beneficial at 

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improving lower limb coordination after stroke. Training under conditions with a greater demand 
for muscle activation may facilitate activity in muscles weakened secondary to stroke. An 
advantage of BWTraining in individuals post-stroke is that a backwards step requires hip 
extension with simultaneous knee flexion to bring the lower extremity posterior to the trunk.  
This movement combination is often difficult after stroke due to the re-emergence of the 
predominant flexion synergy48  that often occurs following CNS damage. Repetitive movement 
that requires activation of hip extensors with knee flexors, out of the predominant flexor synergy 
pattern, as required in backward walking, may improve muscle activation and subsequent motor 
control to transfer to improved muscle activation and appropriate kinematics during forward 
walking. Although causes of falls are multifactorial, it is important to note that a primary physical 
contributing factor to a fall is the difficulty and/or inability to take a backward step to maintain 
balance.49 Training in backward stepping may be an effective strategy to regain coordinated hip 
extension with knee flexion needed to efficiently take a backward step to maintain balance, 
remain upright and prevent a fall. 
5. 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. 
6. Research Plan: 
This prospective, single-blind, RCT enrolling individuals at 2-months post-stroke is designed 
to address the study’s three Specific Aims (See Figure below).  Participants will be 
randomized to either Immediate (2-months post-stroke) or Delayed (1-year post-stroke) 
BWTraining. The primary endpoint for SA#1 and SA#3 will be Assessment D at 1-year post-
stroke. The primary endpoint for SA#2 will be Assessment E at approximately14-months 
post-stroke. Secondary assessment time points (Assessments B and C) will allow us to 
examine potential mechanisms of recovery contributing to our primary results. Individual 
treatment allocations will be in sealed envelopes. Envelopes will be opened only on 
enrollment of the next eligible participant. We will recruit 142 individuals post-stroke. This 
will permit up to a 10% attrition rate and still provide a sufficient participant pool to address 
our Specific Aims.  
 

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Figure. Participants will be randomized into an Immediate (BWTraining at 2-months post-stroke) or a 
Delayed (BWTraining at 1-year post-stroke) group. Primary assessment points are A (2-months post-
stroke), D (1-year post-stroke) and E. Secondary assessment points are B and C (6-months post-stroke). 
 
Participant Recruitment and Screening. Priority for participation in this study will be given to 
volunteers who are Veterans. To optimize our capability to recruit Veterans we will conduct 
the study’s assessments and intervention at two locations: 1) The Malcom Randall VA 
Medical Center in Gainesville FL, and 2) Brooks Rehabilitation in Jacksonville, FL. Utilizing 
these two recruitment sites will assure us of reaching our planned recruitment of 142.  
Individuals post-stroke will be recruited from: 1) VA BRRC site: a. Database (IRB#457-
1999) of the Malcom Randall VA BRRC, a VA RR&D Center of Excellence. The database 
contains over 400 individuals with stroke who have been screened by a neurologist and 
interdisciplinary team to gather preliminary information about medical, motor and cognitive 
status. All individuals in the database have signed informed consent and agreed to be 
contacted for research participation. b. VA Informatics and Computing Infrastructure (VINCI) 
is an initiative to improve researchers’ access to VA data and to facilitate the analysis of 
those data while ensuring Veterans’ privacy and data security. c. Clinician referrals from 
Select Rehabilitation – potential participants will be provided an IRB-approved study flier 
and if interested will provide signed authorization to be contacted by study personnel. 2) 
Brooks site: a. Brooks Active Research Registry: Brooks Rehabilitation in Jacksonville, FL is 

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one of the nation’s largest inpatient rehabilitation hospitals and stroke is their largest 
diagnostic category, with approximately 600 stroke admissions per year. Research studies 
within this entity are conducted under the auspices of their Clinical Research Center. 
Brooks Rehabilitation Clinical Research Center maintains an IRB-approved registry of 
individuals who have experienced a neurological injury, approximately 640 individuals with a 
stroke diagnosis who have signed HIPAA Authorization and can be contacted regarding 
research trial participation. Potential participants will be contacted via phone and a phone 
screen will be conducted. The phone screen script is provided in a separate document. If 
individuals pass the phone screen, they will be invited and scheduled for an in-person 
screen. Information obtained from the phone screen will only be shared with study 
personnel and will be stored in a locked cabinet in a locked room. b. Individuals who 
respond to an IRB-approved advertisement. They will undergo phone screen as above. c. 
Individuals who signed a Brooks Notice of Privacy Practices upon Brooks admission (which 
indicates their information may be used for research) will have their medical records 
reviewed by study personnel and if appropriate will be provided an IRB-approved study flier. 
If interested, they will have the opportunity to sign the Screening Informed Consent and 
complete the Screening Assessment while they are an inpatient. If they prefer to wait until 
they are discharged from inpatient rehabilitation,they will be contacted at six-weeks post-
stroke to determine their continued interest and confirm eligibility. Women and members of 
diverse ethnic and racial groups will be actively recruited.  
 
Inclusion criteria: 1) Diagnosis of unilateral stroke, 2) > 2 months < 4 months post-stroke, 3) 
Berg Balance Scale < 42, 4) Self-selected 10 meter gait speed < 0.8 m/s, 5) Able to 
ambulate at least 10 feet with maximum 1 person assist, 6) Medically stable, 7) 18-95 years 
of age, 8) living in the community, 9) Unilateral lower extremity paresis confirmed by a score of 
< 32 on the Fugl-Meyer Motor Assessment50, 10) Physician approval for patient participation. 
 
Exclusion criteria: 1) Presence of neurological condition other than stroke, 2) 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, 3) Severe arthritis or orthopedic problems that limit 
passive ranges of motion of lower extremity (knee flexion contracture of  -10°, knee flexion 
ROM < 90°, hip flexion contracture > 25°, and ankle plantar flexion contracture  > 15°), 4) 
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. 
5) Pain upon ambulation, , 6) Unable to ambulate at least 150 feet prior to stroke, or 
experienced intermittent claudication while walking less than 200 meters, 7) Living in a 
skilled nursing facility, 8) History of serious chronic obstructive pulmonary disease or 
oxygen dependence, 9) Non-healing ulcers on the lower extremity, 10) Uncontrollable 
diabetes with recent weight loss, diabetic coma or frequent insulin reactions, 11) On renal 
dialysis or presence of end stage liver disease, 12) Pulmonary embolism within previous 6 
months, 13) History of major head trauma, 14) History of sustained alcoholism or drug 
abuse in the last six months, 15) Current enrollment in a clinical trial to enhance stroke 
motor recovery, 16) Intracranial hemorrhage related to aneurysmal rupture or an 
arteriovenous malformation, 17) Injection of lower extremity muscle relaxant in the past 6 
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Inclusion and Exclusion criteria will initially be determined by medical record review.  If following 
the medical record review a potential participant remains eligible, they will be scheduled for an 
in-person screen to determine if they meet the criteria listed below.  Potential participants will 
sign the screening Informed Consent Form and then the following screening assessments will 
be administered:  
 
1. Berg Balance Scale51: This tool consists of 14 items that assesses static and dynamic 
standing balance, ability to sit, stand up and transfer. 
2. 10 Meter Walk Test: Participants, wearing a gait belt and guarded by a licensed 
physical therapist, will traverse a total distance of 14 meters, two times at their self-
selected walking pace. The time to traverse the middle 10 meters will be recorded 
with a stop watch. 
3. Lower Extremity Fugl-Meyer Motor Assessment: The participant’s ability to move their 
paretic lower limb will be assessed in the supine, sitting and standing position. 
4. Range of Motion:  Range of Motion of the hips, knees and ankles of both lower limbs will 
be assessed. This assessment will take place in the supine and sitting positions. 
5. Three-Meter Backward WalkTest. The test consists of a 1 meter warm-up distance, 
a timed 3 meter distance, followed by an additional 1 meter to continue walking. 
Participants will walk this distance two times and the speed will be averaged. 
 
Participants who meet eligibility criteria following the screening assessment will be invited to 
sign Part 2 Consent, the Intervention Informed Consent Form. Intervention Informed Consent 
allows for baseline testing and study participation.  
 
Following baseline assessment (Assessment A) participants will be randomized to either the 
Immediate Group (initiate BWTraining within 1-week of Assessment A) or the Delayed Group 
(initiate BWTraining at 1-year post-stroke).  
 
BWTraining Intervention. The intervention consists of 18-21 sessions, 3x/week for 6 weeks. 
BWTraining will occur both on a treadmill and overground. BW training will consist of 20–30 
minutes of step training with a BWST system, manual assistance provided by trainers, with rest 
periods provided as warranted followed by 15 minutes of overground gait training. A 20–30 min 
period of actual stepping on the treadmill is the goal with rest periods as needed. Each training 
session may last up to 1 hour and 30 minutes including time for warm-up, stretching, and cool 
down. Participants will be fitted with a harness around their hips and torso, which will be 
attached to an overhead support system directly above the treadmill. From a stationary 
position, the treadmill belt will gradually be increased in speed with intervention trainers 
assisting participant to step backward with their paretic leg, their non-paretic leg (if needed) 
and at the hips for weight-shift. 
Training targets: The overall goal is to enable the participant, by the end of training, to walk 
independently for a total of 20 minutes in four, 5 minute bouts at 0% BWS with good stepping 
kinematics. Progression of training will be accomplished by: (1) gradually decreasing BWS from 
40% to 0%, (2) initiating treadmill speed just below participant’s overground backward walking 
speed, increasing as able and as tolerated, and (3) providing manual assistance initially when 
the participant is unable to independently step or control upright posture, and decreasing 
manual assistance to afford skill and control progression by the participant.  
 

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Outcome Measures. Participants’ assessments will be stored in a secured study database, 
password protected, accessible only to study employees. Each participant will be given a study 
ID with assessments recorded and stored under the study ID. Hard copy folders will be stored in 
a locked filing cabinet in a locked room with access only available to study personnel. 
Participants in both groups will be assessed in parallel throughout the study timeline. 
Assessments will be conducted five times according to the study design above: 
1. Assessment A (baseline, prior to randomization)  
2. Assessment B 6 weeks following randomization 
3. Assessment C 6-months post-stroke  
4. Assessment D 1-year post-stroke 
5. Assessment E 6 weeks following Assessment D.  
The assessment battery will be conducted in a 1.5 hour appointment. Assessments are 
similar to those encountered in physical rehabilitation and should not result in undue fatigue, 
but participants will be able to rest as needed. All outcome measures will be conducted by 
licensed physical therapists, blinded to group assignment. The physical therapist will be 
beside the participant during all physical assessments of gait and balance. All therapists will 
receive standardized training and will be required to pass a competency exam to ensure 
standardization of the outcome measure protocol across assessors. Assessments are: 
 
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. 
Participants will walk this distance two times and the speed will be averaged. 
Three-Meter Backward WalkTest. We will use this test to collect our variable of interest, 
BWSpeed. The test consists of a 1 meter warm-up distance, a timed 3 meter distance, 
followed by an additional 1 meter to continue walking. Participants will walk this distance 
two times and the speed will be averaged. 
Functional Gait Assessment (FGA),52 a 10-item clinical gait and balance test during which 
participants perform the following activities: walk at normal speeds, at fast and slow speeds, 
with vertical and horizontal head turns, with eyes closed, over obstacles, in tandem, backward 
and while ascending and descending stairs. Excellent test-retest53 and intra- and inter-rater 
reliability54 has been established patients post-stroke.    
Activities-Specific Balance Confidence Scale (ABC): 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.  
Berg Balance Scale (BBS):51 This tool consists of 14 items that assesses static and 
dynamic standing balance, ability to sit, stand up and transfer. From our previous work 
characterizing and identifying risk factors for falls post-stroke55, BBS scores < 42/56 was the 
single best predictor of multiple/injurious falls. This assessment is ubiquitously used in 
stroke rehabilitation and will aide in describing our study cohort. This has been tested in a 
stroke population and has well-established reliability and validity.  
Lower-Extremity Fugl-Meyer Motor Score:56 This tool consists of 17 items that assess motor 
control of the lower extremity as participants move their hip, knee and ankle in lying, sitting 
and standing is probably the most widely known scale of motor and sensory recovery after 
stroke. This assessment will provide a description of lower extremity impairment and aide in 
describing our study cohort. 
Four-Step Square Test:57 This clinical test of dynamic standing balance examines the ability 
to step over small objects, change direction and includes taking a backwards step. In a 

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study that confirmed the feasibility and validity of this assessment for individuals post-
stroke, those who reported a fall scored > 15 sec to complete the assessment.58 
Timed Up and Go Test: This clinical assessment of gait and balance consists of a participant 
standing up from a chair, walking three feet straight ahead, turning around and returning to the 
chair to sit down. 
Modified Falls Efficacy Scale (MFES)59 is a 14-item questionnaire based on the Falls Efficacy 
Scale (FES),60 modified for people with chronic stroke. It includes the 10 items from the FES 
plus 4 items considered complex for people with stroke and is designed to measure self-
perceived fear of falling during task performance. Significant differences in MFES scores 
between patients in a Falls and Balance Clinic and healthy older adults (p < 0.05) attests to the 
scales’ validity.59 
Modified Rankin Scale (mRS): This 0-5 scale is a functional outcome measure of stroke that 
reflects the overall level of disability. The clinician assessor scores the participant based on their 
impression and observation of the participant over the course of the evaluation process. 
Kinesiologic assessment of walking: To more explicitly describe changes in participants’ gait 
as a result of the intervention, secondary outcome measures will include:  
1) Assessment of kinematics using a passive motion-capture system:Hip, knee and ankle 
angle data from the LE’s will be acquired by placing reflective markers on the 
participant using a modified Helen Hayes marker set with rigid clusters on the pelvis 
and each thigh, shank and foot segments and recording the movement of these 
markers at 100 Hz using a 12 camera motion capture system (Vicon Motion Capture 
Systems, Oxford, UK). Data will be processed using Visual 3D (C-Motion, Inc., 
Germantown, MD). Intersegmental joint moments (normalized to body mass) will be 
calculated using standard 3D inverse dynamics techniques.  
2) Assessment of kinetics and spatio-temporal movement characteristics:Three-
dimensional ground reaction forces will be acquired under each foot as participants 
walk across force plates. The force plates are flush with the floor and are not an obstacle 
or tripping hazard.  The participant will be asked to stand or walk in a specific location 
corresponding with the force plates embedded in the floor.  This will be done while they 
also are wearing the EMGs and reflective markers so that all data are captured 
simultaneously.  GRF data will be normalized to body weight. Sagittal plane hip, knee 
and ankle joint moment impulses and the vertical GRF will be calculated. 
3) Spatial-Temporal gait variables of stride time, stride length, step time, step length 
and step width will be captured during forward and backward walking across a 
GAITRite instrumented walkway (CIR Systems Inc, Havertown, PA). Additionally, the 
participant will be asked to walk over a 12’ instrumented walkway.  The walkway appears 
like a basic carpet with embedded switches to record foot falls and placement.  The edges 
of the carpet walkway will be taped down to minimize the possibility of tripping on the edge 
of the carpet.  Participants will be guarded by the physical or occupational therapist at all 
times and/or an overhead harness may be used.  The instrumented walkway (carpet) will 
provide quantitative data regarding the spatial and temporal characteristics of standing 
and walking.   
4) Assessment of muscle activation using surface electromyography (EMG) By analyzing 
the electrical activity generated during muscle contraction or limb movement, EMG allows 
us to develop a better understanding of how the nervous system’s control of movement is 
disrupted following stroke and whether this control is affected by the intervention. Using 
standard surface preparation (cleaning the skin with water or alcohol pad, shaving of 
excess hair) and electrode placement, surface EMGs will be collected from lower 
extremity and trunk muscles using surface EMG electrodes. EMG sensors will be attached 

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to the skin with double-sided hypoallergenic medical tape.  Before the data collection, 
functional tests will be performed while each EMG channel is examined to assure clear 
signals and to check for crosstalk.  
. 
Fall Incidence. In addition to the assessments described above that will be conducted at the 
5 specific time points, fall incidence will be monitored throughout the study for each 
participant using the international standards for defining and reporting falls,61 including the 
following definition for a fall: “A person has a fall if they end up on the ground or floor when 
they did not expect to. Most often a fall starts while a person is on their feet, but a fall could 
also start from a chair or bed. If a person ends up on the ground, either on their knees, their 
belly, their side, their bottom, or their back, they have had a fall.” This explanation will be 
provided to participants and caregivers and printed on monthly calendars issued at 
randomization. Participants and/or caregivers will place an “X” on the corresponding date if 
a fall occurs, and submit to their study site each month (even if no falls occurred). If a 
calendar is not received within one week of its expected return, study personnel will contact 
participants. Participants will be contacted to follow-up on reported falls using the Fall 
Characterization Questionnaire. Information collected for each fall will include presence and 
nature of any injury, location of the fall, and ability to get up independently after the fall. 
Three categories will be used to characterize falls outcome poststroke: multiple or injurious 
(M/I); single, noninjurious (S/NI); and nonfallers. Injurious falls will be defined as those 
resulting in serious injury: fracture, loss of consciousness, or hospital admission. This 
information will be collected in-person for those currently receiving the study intervention 
and via phone for participants who have either completed or have yet to begin BWTraining. 
 
Monitoring Delayed BWTraining. Participants randomized to  Delayed BWTraining (Usual 
Care) will be assessed at the same time points as the Immediate BWTraining Group, at 
Baseline (Assessment A), at 6-weeks post-enrollment (Assessment B) and at 6-months 
post-stroke (Assessment C). In addition to these on-site assessments, this group (as well as 
the Immediate BWTraining Group) will be monitored throughout the first year post-stroke for 
1) Any usual and customary rehabilitation services and 2) Fall incidence.  
1. Usual and Customary Rehabilitation services: Throughout study participation, for ethical 
reasons, subjects will be permitted to engage in usual and customary clinical rehabilitation 
services. Any rehabilitation services received outside of the study intervention will be 
tracked and described in written logs. All subjects will be provided a health utilization log 
and will complete a daily checklist to report the type (PT, OT, Speech) and the length (0.5 
hr.; 0.75 hr.; 1.0 hr.). These logs will be returned (via post mail or email) on a monthly basis. 
Participants will receive a reminder email or phone call three days prior to the submission 
date. This monthly contact with those randomized to Delayed BWTraining will facilitate 
participant retention. Upon receipt of the intervention logs the study coordinator will call the 
participant to thank them. There will be no restrictions on the type of clinical rehabilitation 
service except that participants will be required to abstain from any that involve backward 
walking either over ground or on a treadmill. 
2. Falls: As described above participants will be provided Monthly fall calendars upon 
enrollment, and asked to submit the monthly calendar (via post mail or email) whether they 
have fallen or not. Participants will receive a reminder email or phone call three days prior to 
the submission date. Upon receipt of the fall calendar, the study coordinator will call the 
participant to either: 1) thank them for returning the calendar, and/or 2) conduct a 
standardized questionnaire regarding fall specifics. Participants will have email and phone 

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access to the Study Coordinator and the Principal Investigator whom they will be instructed 
to contact with questions at any time. 
 
Videorecording. For participants who signed the video recording consent, we will periodically 
videorecord training sessions. This will allow the intervention therapists to view the participant’s 
training and strategize on how to progress the intervention. Videorecordings will also provide the 
therapists feedback on how they can best assist the participant. Assessment sessions will also 
be periodically recorded. This will provide assessment therapists feedback on their 
implementation of the assessments. Videorecordings may also be used in scientific 
presentations. Participants will be informed when videotaping is occurring  
 
Data Analysis Plan: For Specific Aim #1 (primary outcome for entire study is the average fall 
rate per year), we will calculate the total number of falls per patient year for the Immediate 
intervention and Delayed intervention (control) groups, and use the actuarial method 
described below to estimate the average hazard rate in each group, and the overall hazard 
ratio. We will compare the Immediate and Delayed groups’ fall rate at Assessment D, 1-year 
post-stroke. The analysis takes repeated falls within the same subject into account.  
Consider the number of falls, Yij for the j-th patient on treatment i (i=1,2) in the year, and Tij , 
the time at risk for the subject (usually 1 year, less for withdrawals before then). The 
estimated average fall hazard for treatment i is the ratio estimator Hi= ΣYij / ΣTij. Under 
nonparametric considerations, if the true average hazard over subjects and time for 
treatment i is ϴi , then by the delta method, Log(Hi)- log(ϴi ) (Log=natural log) is 
asymptotically normal with mean zero and variance Vi , i=1,2 defined by  
   
Vi=[{ Var(Yij)/(Mean Yij)2} +{ Var(Tij)/(Mean Tij)2} -{2 Cov (Yij , Tij )/(Mean Yij )/(Mean Tij )}]/Ni 
 
with the means, variances, and covariance, the sample moments, and Ni is the sample size 
for treatment i. The log of the estimated average hazard ratio Log(H2/H1) is asymptotically 
normally distributed with mean Log(ϴ2 /ϴ1)=Log(ϴ2 )- Log(ϴ1 ) and asymptotic variance 
(V1+V2). This enables us to obtain a two-sided P-value and after taking natural anti-logs, a 
point estimate and 95% confidence interval for the true average hazard ratio. 
 
Power analysis: The study is powered around Specific Aim 1, comparison of fall incidence 
at 1-year post-stroke for those in the Immediate versus the Delayed BWTraining groups. 
Although the analysis is valid for any within patient distribution of the number of falls and 
time at risk, we must make additional assumptions to calculate power.  Dean and 
colleagues62, in a study of post-stroke fall incidence reported an average of 1.5 falls per 
patient year, and hence we will plan for a 33% reduction from 1.8 falls per year to 1.2 falls 
per year, with 80% power at p=0.05.  Using a Poisson rate of 1.8 vs. 1.2 falls per year we 
would require 64 subjects randomized to each group to be followed for one year.  Although 
all data for withdrawals will be used up to the time of withdrawal, we shall recruit an 
additional 14 subjects (142 total) to assure we observe 128 patient years. We expect the 
actual distribution of falls to be more compact (less variable) then the Poisson, which allows 
unlimited falls for a patient.  This suggests the real variance within a group will be lower 
than that suggested in the Poisson, making power a bit higher than stated here.  We cannot 
quantify this, however.  Power was derived via large sample approximations, and verified 
via 10,000 simulations. 

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All hard copy records will be stored in a locked filing cabinet in a locked office accessible only to 
study personnel. All electronic data will be stored on a VA secured server. Hard copy data 
collected at Brooks Clinical Research Center will be transported to the Gainesville VA BRRC via 
the Principal Investigator in a locked briefcase. 
7. Possible Discomforts and Risks: 
The risks undertaken in the walking therapy programs of the study are no greater than those in 
everyday physical therapy clinics where persons who have had a stroke are challenged daily to 
exercise, train, practice and improve beyond their current abilities. Safety in therapy is 
mandatory. Research personnel will walk beside participants during all aspects of the exercise 
intervention and all aspects of the assessment that assess gait and balance. Participants may 
experience some fatigue while being tested or during the therapy sessions. Should they become 
tired, they will be allowed to rest. Participants may experience temporary muscle soreness as 
they increase the use of their trunk and limbs during the walking intervention. There is a risk of 
falling during walking activities, but guarding by research personnel will minimize the risk. Stroke 
patients, including those in this study, are at risk for another stroke, coronary heart disease 
related event and cardiac related death, regardless of intervention. 
8. Possible Benefits: 
Subjects participating in this study may see improvements in their walking speed, balance, 
and/or the amount of walking that they are able to do. They may become more confident in their 
balance and walking ability.    
9. Conflict of Interest: 
There are no conflicts of interest apparent for any of the investigators. 
 
 
 
 
 
 
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