Effects of Two Different Types of Ankle Foot Orthoses on Gait Outcomes in Patients With Subacute Stroke.

Introduction: Stroke is a leading cause of death and disability in the world today. About
795,000 people are diagnosed with stroke yearly in the United States. The annual cost of
stroke from medical services and disability in our nation is $ 38.6 billion dollars. Gait
rehabilitation is an important aspect of neurorehabilitation with focus on attaining the most
functional and symmetrical gait to prevent falls from faulty gait mechanics, and to prevent
sedentary life styles and associated comorbidities. Ankle foot orthoses (AFOs) are commonly
prescribed in patients with stroke to address ankle and knee instabilities and to restore a
normal and safe walking pattern.The effectiveness of AFOs on various gait parameters has been
reported in patients with stroke, but mostly during the chronic stages of recovery.
Systematic analyses have shown that use of various types of ankle foot orthoses improve
walking impairments and balance, reduce energy costs, and improve knee and ankle kinematics
in people in the chronic stage of stroke recovery, greater than 6 months since the onset of
stroke. It is reported that the majority of the gait improvements occur within the first 6
months following the onset of stroke. However, a limited number of studies have investigated
the effects of AFOs within six months of stroke onset.

Three reported studies have investigated the effects of using an AFO compared to not using an
AFO within 6 months following onset of stroke. Rao et al found that the use of an AFO
significantly improved gait velocity, cadence and step length on the affected and unaffected
side. Hyun et al. found that using an AFO significantly improved VO2 peak and 6 minute walk
test scores . Carse et al showed significant improvement in walking velocity, average step
length and cadence with use of AFO. There is only one reported study which looked at the
effects of using two different types of AFOs during the subacute stage of stroke, less than 6
months following onset. Results of this study showed that gait speed and knee and ankle
control were significantly higher in the Chignon AFO group compared to the polypropylene AFO
group. Additionally, participants in the Chignon AFO group had significantly lower spasticity
than those in the polypropylene AFO group.

In a recent case series report, investigators observed that using a custom Double Adjustable
AFO during the early stages of recovery after stroke resulted in more typical muscle
activation patterns, gait endurance and velocity, and near normal symmetry during gait
without an assistive device or an AFO in three participants. The use of this type of AFO for
gait rehabilitation following stroke in the subacute stages has not been thoroughly studied.

Statement of the Problem Patients with stroke resulting in hemiparesis and foot drop are
affected by gait impairments such as poor symmetry, decreased velocity, and decreased
endurance. AFOs have been shown to be an effective intervention for improving gait parameters
in individuals who are in the chronic stage of stroke recovery. Although, the majority of
gait improvements occur within six months of stroke, the effect of early bracing with
different types of AFOs on gait outcomes has not been investigated thoroughly.

Purpose of the study:

The purpose of this study will be to identify whether patients in the subacute stage of
stroke, who demonstrate foot drop, will have better gait outcomes when using a Double
Adjustable AFO, or a Posterior Leaf Spring AFO. A secondary purpose will be to determine
whether one week of practice significantly changes gait outcomes with either of the AFO
conditions.

Research Hypotheses

The research hypotheses of this study are as follows:

1. There will be a difference in gait endurance measurements, gait symmetry measurements
and gait velocity measurements at baseline when using custom Double Adjustable AFO
compared to a PLS AFO in patients in subacute stage of stroke.

2. There will be a difference in gait endurance measurements, gait symmetry measurements
and gait velocity measurements after one week of practice when using custom Double
Adjustable AFO compared to a PLS AFO in patients in subacute stage of stroke.

3. After a week of practice, there will be a difference in gait endurance measurements,
gait symmetry measurements and gait velocity measurements compared to baseline
measurements, when using either custom Double Adjustable AFO or a PLS AFO in patients in
subacute stage of stroke.

Participants Twenty participants over the age of 18, of any gender and ethnicity, diagnosed
with first time unilateral stroke, 4 - 20 weeks post-stroke onset, resulting in hemiparesis
with foot drop will be recruited. The number of participants was estimated based on
previously reported studies. Hyun et al found significant differences in gait endurance
measured by 6MWT when using AFO compared to using no AFO with 15 participants in a similar
study. In another study by Carse et al, gait velocity and gait symmetry were found to be
significantly better with 8 participants.Therefore, for our study, the potential participant
number was projected as 20.

Participants will be recruited through a sample of convenience from Baylor Institute of
Rehabilitation locations and through word of mouth. The physical therapists at these
locations will be given a brief description of the proposed study and will be asked to screen
for potential participants. Participants who meet the inclusion criteria and possess none of
the exclusion criteria will be asked to volunteer for the study. Each participant will read
or be read their rights as human subjects and asked to sign the informed consent approved by
the Institutional Review Boards of both Baylor Health Care System and Texas Woman's
University prior to enrollment in this study. A Mini Mental State Examination (MMSE) will be
performed to determine whether the participant has the cognitive ability to sign the informed
consent. Participants will be scheduled to do data collection on the day they receive their
custom double adjustable AFO at Baylor Institute for Rehabilitation, Frisco location.

Procedures:All measurements will be obtained from each participant during three testing
sessions and by only one researcher to avoid inter tester reliability issues. On the first
measurement day, the primary investigator will collect demographic data including age,
height, weight, leg length measurements on each side, and Fugl-Meyer Lower Extremity
Assessment of sensorimotor function. Then the gait outcomes will be measured using one of the
two AFO conditions in random order. The participant will select the order of AFO condition by
drawing out of a hat. Randomization without replacement will be used. Once the order of AFO
wearing has been determined, data will be collected in the randomly selected order.
Participants will be allowed to use any type of assistive device of their choice, but the
same device will be used for all conditions.

First, the 6MWT will be administered with the participant wearing the first randomized AFO.
Participants will be asked to ambulate as far as possible in 6 minutes at a self-selected
walking velocity through a well-lit indoor corridor. A five minute seated resting will be
provided. Next, gait symmetry and gait velocity measurements will be obtained using the
GAITRite system. Participants will be given a practice trial walk prior to beginning of the
testing. Participants will be asked to walk at their comfortable self-selected walking
velocity along the walkway. They will begin walking three meters from the start of the
walkway and will stop walking two meters past the end of the walkway. The beginning and end
of the walking area will be marked with red tape for visibility. The verbal instruction will
be "Please walk from this red line to that red line at your comfortable speed safely". A
second personnel will be walking close to the participant outside of the walkway to ensure
safety. After a five minute sitting break, participant will be asked to walk as fast as they
can safely. The verbal instruction will be "Please walk from this red line to that red line
as fast as you can safely". The GAITRite system will be able to capture both gait symmetry
and gait velocity measurements with the same walk. Three trials will be performed of the
self-selected velocity walk and fast paced velocity walk. The calculated mean of the three
trials will be used for data analysis. After a 10 minute seated rest break, the second AFO
condition will be used and measurements will be repeated in the same order described above.

To assess the effects of practice on the gait measures, AFO's will be randomized for
practice. Participants will be randomized for which AFO they will wear first. Then the
participant will be provided with the selected type of AFO to practice with for the following
week using a prescribed wearing schedule. At the end of the one-week practice time, the
primary investigator will obtain the same measurements obtained at baseline with the
participant wearing the type of AFO that was used to practice the week before. The same
testing conditions and order of testing that were used at baseline will be employed. Once
measurements are completed, the participant will be provided with the second type of AFO and
will be asked to wear for one week using the same prescribed wearing schedule as before.
Final measurements will be taken after completion of the one-week practice using the second
type of AFO with the same testing conditions and orders. At the conclusion of testing each
participant will be asked which AFO they will prefer to use.

Data Analysis : Descriptive statistics will be calculated for all demographic data including
age, height, weight, time since onset Fugl Meyer lower extremity assessment score and AFO
preference. Differences in gait endurance will be analyzed using a 2x2 repeated measures
ANOVA Differences in gait symmetry, and gait velocity between the two AFO conditions and two
practice conditions will be analyzed using two separate 2x2 repeated measures MANOVA. If
assumption of sphericity is not met, Greenhouse-Geisser statistic will be used. An alpha
level of .05 will be used to determine significance of differences, with a Bonferroni
correction applied as needed to protect against Type I error.

Inclusion Criteria:

- Diagnosed with first time unilateral stroke

- 4 - 20 weeks post-stroke onset

- resulting in hemiparesis with foot drop

Exclusion Criteria:

- Inability to receive a double adjustable AFO through their insurance

- unable to follow two steps commands

- unable to ambulate 20 feet with or without assistive device with a minimum level of
assistance of contact guard assistance

- diagnosis of cerebellar stroke

- non ambulatory prior to stroke onset