Fall-recovery Training for Those With Chronic Stroke and Low Falls Self-efficacy
Phase: NA
Conditions: Stroke
Sponsor: University of Delaware

NCT04112173 
Fall-recovery training for those with chronic stroke and low falls self-efficacy 
Study Protocol and Statistical Analysis Plan 
9/18/2019 

1.  Protection of Human Subjects 
 
 
a. Human Subjects Involvement, Characteristics, and Design 
 
This feasibility study has a single-arm, repeated measures design in which a non-active 
control period is followed by an intervention period.  In other words, there are three 
assessment visits (baseline, assessment after non-active control period, and assessment 
after experimental intervention). 
 
A total of five participants with chronic stroke (i.e. 6 or more months after stroke) are 
expected to qualify for this study. All participants must have low balance self-efficacy, as 
determined by an Activities-Specific Balance Scale (ABC) score less than 68. We plan to 
enroll an additional two participants, anticipating that these participants will not be eligible 
to continue in the study after the initial DXA and physical therapist screening. 
 
All in-person activities will occur at the University of Delaware. 
 
b. Study Procedures, Material, and Potential Risks 
 
Proposed involvement of human subjects will include the following: 
1. Study participation requires nine laboratory visits. Assessment visits will take up to four 
hours. Training visits will take one to two hours. 
2. Upon enrollment, the Fugl-Meyer Lower Extremity assessment and the Stroke Impact 
Scale will be administered to characterize participant impairment. 
3. We will record the height, mass, and age of all participants. 
4. Study staff will provide an initial screening to ensure that potential participants meet 
the inclusion and exclusion criteria. 
5. If the participant is over the age of 50 years, his or her bone mineral density will be 
measured from dual-energy X-ray absorptiometry (DXA; Delphi W; Hologic, Inc.). 
Subjects will not be allowed to continue with the study if they have a total hip or 
femoral neck bone mineral density t-score < -2.5. The left hip will be evaluated unless 
the subject has had a left hip replacement. If both hips have been replaced, then the 
participant will not continue in the study. DXA scans will be performed by a State of 
Delaware certified radiation technician. 
6. Falls self-efficacy will be determined by administering the Activities-Specific Balance 
Confidence (ABC) scale and the Falls Efficacy Scale – International (FES-I).  Because 
the ABC scale dictates group assignment in our study design, this measure also 
serves as a screening tool. 
7. We will administer the following surveys: 
a. Physical Activity Scale for Individuals with Physical Disabilities 
b. Center for Epidemiologic Studies Depression Scale (CES-D) 
c. A survey on the family and friend support for exercise habits 
d. Barriers to Physical Activity and Disability Survey 
8. We will administer the following clinical evaluations: 
a. Berg-Balance Scale 
b. Abbreviated Balance Evaluation Systems Test (Mini-BESTest) 
c. Functional Gait Assessment 
d. Timed Up-and-Go test 
e. 10 m walk test 
f. Six-minute walk test 
9. Reactive postural control will be quantified from anterior, posterior, and lateral single-
stepping thresholds. Participants will be outfitted with a safety harness attached to an 
overhead rail. As they stand on a computer-controlled treadmill (ActiveStep®, Simbex, 
Lebanon, NH), participants will be instructed to “try not to step” in response to rapid 

belt displacements. For each directionally-opposed pair of thresholds, a progressively 
difficult series of movements will be implemented. Here, thresholds are defined as the 
perturbation magnitudes that consistently elicits one or more steps in a given direction. 
Within each progression of perturbations, the direction and timing of the belt 
movement is pseudo-randomized to limit anticipatory adjustments. The progression of 
perturbations will continue until each opposite-direction threshold is identified, as 
evident by four consecutive failed responses. 
10. Participants will be given a StepWatchTM activity monitor, and will be instructed on how 
to wear the monitor, when to wear the monitor, and how to return the monitor to the 
study team. Before leaving, we will ensure that the participant is able to don and 
remove the monitor strap on their own. Participants will wear the monitor for seven 
days. 
11. After three weeks, participants will repeat all questionnaires, laboratory, and walking 
activity assessments (Steps 7-11). 
12. After this second assessment, participants will undergo six sessions of perturbation-
based fall-recovery training. Each session will consist of the following five-minute 
perturbation series. 
a. Standing perturbations that induce a forward fall, necessitating multiple steps 
to regain balance and remain on the treadmill. Separate series will focus on 
paretic and non-paretic steps. Participants will be instructed to “try not to fall”. 
b. Standing perturbations that induce a backwards fall. Instructions will be to 
recover in a single step. This constraint is added because, unlike the multiple-
step response of trip recoveries, slip recovery is dictated by first-step features. 
Separate series will focus on paretic and non-paretic steps. 
c. We will apply lateral perturbations, delivered as participants stand facing the 
side of the treadmill.  Participants will be instructed to “try not to fall”. We will 
apply left and right perturbations large enough to elicit a step. 
d. In two separate series, we will apply anterior and posterior perturbations as the 
participants walk. Our treadmill is equipped to deliver perturbations timed 
relative to foot strikes during gait. 
e. The training intensity, as determined by the perturbation size and, if applicable, 
gait speed, will be small at first, progressing to more challenging levels 
dependent upon participant performance, safety, and comfort. In other words, 
the size of the intensity will only be increased if the participant has a successful 
response, agrees to progress to the next intensity, and can do so safely, at the 
discretion of the research staff. 
f. For those participant who must use a cane, we will limit training to standing 
perturbations (parts a, b, and c).  We will modify the perturbations to those just 
large enough to elicit a step or adjustment in the cane position. 
g. After each training session, the ABC scale and FES-I scale will be 
administered. 
13. At the end of the six training sessions, participants will repeat all questionnaire, 
laboratory, and walking activity assessments (Steps 7-11).  Participants will also be 
interviewed with open-ended questions and scales to determine the extent to which 
each aspect of the intervention was perceived as beneficial and challenging.  In 
addition, we will record suggested changes and modifications to improve these 
perceptions and adherence. 
 
Eligibility criteria for study participation include the following: 
 
Inclusion criteria 
• 
Participants must be 18 years or older 
• 
Participants must have had a single stroke of non-cerebellar origin, occurring six or 
more months prior to study enrollment. 

• 
An Activities-Specific Balance Confidence (ABC) score less than 68. 
Exclusion criteria (all self-reported) 
• 
More than one stroke 
• 
Acute illness at the time of functional assessment or training 
• 
Body mass greater than 136 kg (300 lbs) to ensure that the treadmill accelerates 
accurately 
• 
Lower extremity joint replacement or shoulder joint replacement within a year prior to 
participation 
• 
Dementia 
• 
Parkinson’s disease 
• 
A history of back surgery 
• 
A history of neck surgery 
• 
More than one occurrence of back or neck pain in the month prior to participation 
• 
Current back or neck pain at the time of participant enrollment 
• 
Bulging vertebral discs 
• 
Spine, hip, or lower extremity fracture within a year prior to participation 
• 
Open lesions on the lower extremity 
• 
Insulin-dependent diabetes  
• 
Use of a pacemaker 
• 
Use of an ostomy pouch 
• 
Pregnancy 
• 
Osteoporosis 
• 
The inability to stand and walk independently or with the assistance of a cane. 
• 
Doctor recommendation to avoid moderate physical activity or exercise 
• 
Any neural, muscular, or skeletal condition or injury that precludes safe participation in 
the training or introduces a confounding factor on the study, at the discretion of the 
clinician or study staff 
 
 
Materials 
 
Data sources will include anthropometric measurements, clinical measures of function, 
balance and mobility, stepping thresholds (a measure of reactive postural control), 
questionnaires about falls self-efficacy, depression, and physical activity, walking activity 
from step counters, and questions from interviews. All data will be acquired solely for 
research purposes.  All materials will be identified by a subject-specific code, the key of 
which will be stored as a password protected file on a secure computer or server and/or 
in locked cabinets within the locked laboratory. 
 
 
 
Potential Risks 
 
It is possible that subjects could fall to the floor during assessments of mobility and balance. 
All participants will wear a harness attached to an overhead rail while on the treadmill. To 
minimize the risks of a fall during other assessments of balance and mobility, all subjects 
will be appropriately guarded using standard clinical judgment of safety procedures (e.g. 
use of a gait belt and/or harness system when needed, proper positioning of the rater 
relative to the subject, etc.).   
 
Subjects may experience muscle soreness as a result of participation. Exclusion criteria 
have been determined in an effort to limit discomfort. In the case of acute soreness, the 
current training session will be ended, and subsequent sessions will not resume until 

soreness has subsided. The perturbation magnitude will not be again advanced to the levels 
that initiated soreness. 
 
Occasionally, subjects may feel a heightened level of excitement or nervousness during 
their participation. These feelings are usually due to the anticipation of an oncoming postural 
perturbation (i.e. there is a delay in time from when the subject says they are ready and the 
treadmill belts accelerate). A random delay in the perturbation onset, as well as no indication 
of the upcoming perturbation direction, are maintained in order to improve the ecological 
validity of the protocol (i.e. people are rarely aware of the timing and direction of a fall before 
it is initiated). Should the subject express these feelings, they will be given the option to end 
their participation in the session or study. Furthermore, accommodations such as frequent 
breaks, minimizing the delay before the perturbation, limiting the size of the perturbation, 
and allowing subjects to know the perturbation direction beforehand can be made. If the 
study team member determines that such feelings are unreasonably high, to the point where 
it precludes safe participation in the study, they will end the subject’s participation in that 
aspect of the study. 
 
During assessments and training sessions, we will stop participation if any of the following 
conditions occur: a) ataxia, dizziness, or near syncope, b) any chest pain or angina 
symptoms, c) Signs of poor perfusion cyanosis or pallor, and d) excessive fatigue, 
excessive shortness of breath, leg cramps, claudication. 
 
For subjects who receive it, the DXA scan is accompanied by a negligible effective dose of 
radiation (0.001 mSv; www.radiologyinfo.org). This effective dose is less than 0.1% of the 
dose received from a spine X-ray, and it is comparable to the amount of radiation exposure 
from three hours in natural surroundings. 
 
We consider the risks of our treadmill protocols to be minimal. The risks from these protocols 
are not greater than those encountered with exercise in the free-living environment. A 
harness system arrests the fall before the subject's hands, knees, or head come into contact 
with the treadmill. The subject may experience soreness from the harness support or from 
the required physical activity. The use of a treadmill to deliver perturbations to older adults, 
young adults, individuals with neuromuscular impairment, and individuals with lower-
extremity amputations is well-documented in the literature.  We will be using a commercially 
available, computer-controlled treadmill that is used clinically (CPT Codes: 97750, 97110, 
97112, and 97116) for balance assessments and training (ActiveStep, Simbex, Lebanon, 
NH). Dr. Crenshaw and his laboratory have worked with over 250 individuals, including 
those with chronic stroke, those with lower limb loss, older adults, young adults, typically 
developing children, and children with cerebral palsy, on the ActiveStep with no serious 
adverse events or injuries requiring medical attention. Here, serious adverse events are 
defined as any untoward medical occurrence that results in death, is life threatening, 
requires insubject hospitalization or prolongation of existing hospitalization, or results in 
persistent or significant disability/incapacity. 
 
We expect that those with low falls self-efficacy may frequently rely on a cane to stand and 
walk. Therefore, we have modified our treadmill protocols to be safe and feasible for use 
with a cane. Specifically, we have limited the standing perturbation sizes to those just large 
enough to elicit a step or an adjustment of the cane position.  In addition, we have excluded 
these participants from perturbations delivered as the participant walks on the treadmill. 
 
We see minimal risk of confidentiality—data are coded and no identifying information is 
used in any analyses or publication. We adhere to all HIPAA privacy rules that affect 
research protocols. 
 

 
 
2. Adequacy of Protection against Risks 
 
a. Informed Consent and Assent 
 
For this study we will recruit seven individuals with chronic stroke from Delaware and adjacent 
areas in Maryland, Pennsylvania, and New Jersey. Subjects who complete the Shared Pre-
enrollment Process for Stroke Research Team Studies protocol will be invited to participate in 
this study. The pre-enrollment study is a recruitment arm of the UD Stroke Registry. This 
registry advertises its studies through local media sources, social media, community outreach, 
and word of mouth. 
 
Potential participants will be contacted by phone to explain the study, discuss and confirm 
inclusion and exclusion criteria, answer questions, and invite participation. If an individual is 
interested in participating, they will be invited to STAR Campus for the first study visit. 
 
At this study visit, a member of the study team will guide the potential participant through an 
informed consent document, answering questions that the individual may have. Once written 
consent has been attained, the participant will be enrolled in our study. 
 
 
b. Protection Against Risks 
 
 
If immediate medical treatment is needed for any study related injury or adverse experience, 
the study Physical Therapist will evaluate the participant. If needed, the STAR campus 
emergency response protocol will be activated and first responders will come to the laboratory. 
 
Each participant will be told that he/she has the alternative to not participate in this study, and 
that the choice to end participation will not jeopardize his/her medical care. The honorarium for 
the visit will still be paid. Insurance will not be charged. 
 
All data are coded and no identifying information is used in any analyses or publication. A key 
linking identifiable data to subject codes will be stored as a password protected file on a secure 
computer or server, with physical copies stored in locked cabinets within a locked laboratory. 
We adhere to all HIPAA privacy rules that affect research protocols. 
 
No study staff are qualified to clinically interpret incidental findings from the DXA scan.  At the 
request of the participant, we will provide them with a printed copy of the DXA scan results that 
they can bring to their physician. 
 
 
3. Potential Benefits of the Proposed Research to Human Subjects and Others 
 
The potential benefits associated with the project outweigh the risks of participation. 
Participants may learn more about their capabilities through participation in the assessments. 
Participants who receive a DXA scan may learn more about their bone density.  The general 
knowledge gained by this study may inform hypotheses for subsequent studies to more 
rigorously evaluate the benefits of our exercise intervention on falls self-efficacy and walking 
activity. In addition, the current study will inform modifications to our approach to improve its 
feasibility.  The participant-specific and general knowledge benefits outweigh the risks 
described earlier, including muscle soreness and nervousness/excitement.  These risks are 
experienced in everyday life with the introduction of a new exercise program and when in 

situations where balance may be challenged.  However, in our study, the risks of falling to the 
floor or ground have been reduced by a safety harness and appropriate guarding from study 
staff. 
 
4. Importance of the Knowledge to be Gained 
 
We may develop methods to improve reactive postural control, increase balance self-efficacy, 
and enable walking activity in those with chronic stroke and low falls self-efficacy.  If we are 
able to do so, then we may identify a pathway to enable walking activity, in turn improving the 
quality of life and healthspan of this population. These benefits outweigh the risks of 
participation, which align with risks of starting many other exercise programs (e.g. soreness, 
risk of loss-of-balance, nervousness/excitement). 

Statistical Design and Power 
This feasibility study has a single-arm, repeated measures design in which a non-active control period is followed 
by an intervention period.  In other words, there are three assessment visits (baseline, assessment after non-
active control period, and assessment after experimental intervention). 
 
We expect to enroll seven participants into this study (Figure 1).  Of these participants, we estimate that two 
will not pass initial screening from the physical therapist or DXA scan.  Note that, in order to adhere with IRB 
and Radiation Safety guidelines, we must enroll participants before performing this screening. 
The aim of this study is to demonstrate that fall-recovery training is feasible in stroke survivors with low falls 
self-efficacy. As per feasibility-study guidelines, we will gather evidence of the following: 
• 
Adaptation will be documented by the changes in our protocol relative to our previous applications. 
Although we have proposed a specific training protocol, we anticipate that the need for further adaptation 
may become evident.  Anticipated adaptations include limitations in the protocol duration, perturbation size, 
knowledge of the perturbation direction and timing, frequency and duration of breaks, and availability of 
hand support (handrail, cane, or research staff). By quantifying the number and magnitude of perturbations, 
as well as adherence to the protocol, we will evaluate how this adapted protocol compares to our previous 
version. 
• 
Implementation includes the factors affecting the success and failure of completing the training. We 
anticipate that, despite proposed adaptability, participants may not complete all sessions. We will interview 
and survey participants to ascertain what aspects were perceived as challenging or beneficial, as well as to 
identify aspects that should be removed or changed to improve adherence and perceived benefit. 
• 
Limited Efficacy will be evaluated with effect sizes (Cohen’s d) of changes in self-efficacy and activity. 
 
Given that this is a feasibility study, and not a design using inferential statistics, our sample size is not based 
on a power analysis. The results of this study may inform such analyses that support a subsequent grant 
application.