A Novel Mechanics-based Intervention to Improve Post-stroke Stability

Sponsor
VA Office of Research and Development (U.S. Fed)
Overall Status
Completed
CT.gov ID
NCT02964039
Collaborator
(none)
54
1
3
36
1.5

Study Details

Study Description

Brief Summary

The purpose of this study is to determine whether a novel treadmill training intervention can improve the gait stabilization strategy used by individuals who have experienced a stroke.

Condition or Disease Intervention/Treatment Phase
  • Behavioral: Error reduction
  • Behavioral: Error augmentation
  • Behavioral: Activity matched control
N/A

Detailed Description

Every year, approximately 15,000 American Veterans experience a stroke, with an estimated cost of acute and follow-up care in the hundreds of millions of dollars. Following a stroke, the restoration or improvement of walking is a high-ranking goal among patients, but only about half of the population is able to return to typical levels of community ambulation. The resultant decrease in independent mobility is strongly associated with a decline in quality of life. Gait instability is a common contributor to limited mobility through either an increased fall-risk or fear of falling, but current interventions to address post-stroke gait instability have had limited success. This project will conduct initial testing of a novel elastic force-field designed to improve post-stroke gait stability through targeted motor learning. The results of these experiments will serve as the basis for the development of novel gait rehabilitation techniques, which have the potential to increase the quality of life of thousands of Veterans and save millions of dollars.

Study Design

Study Type:
Interventional
Actual Enrollment :
54 participants
Allocation:
Randomized
Intervention Model:
Parallel Assignment
Masking:
Double (Participant, Outcomes Assessor)
Primary Purpose:
Treatment
Official Title:
A Novel Mechanics-based Intervention to Improve Post-stroke Gait Stability
Actual Study Start Date :
Apr 1, 2017
Actual Primary Completion Date :
Mar 31, 2020
Actual Study Completion Date :
Mar 31, 2020

Arms and Interventions

Arm Intervention/Treatment
Experimental: Error reduction

Participants will complete a 12-week training program, in which they practice walking on a treadmill for 30-minutes during twice-weekly training sessions. During these sessions, participants will interface with a custom-built force-field able to exert mediolateral forces on the legs, which will be in "error reduction" mode. This training period will be followed by a 12-week follow-up period. Five assessment sessions will be interspersed throughout this total 24-week period.

Behavioral: Error reduction
During training sessions, a custom-built force-field will exert forces on the legs while participants walk. These forces will push the legs toward mechanically-appropriate mediolateral locations, having the effect of reducing the errors in foot placement that are often present among individuals who have experienced a stroke.

Experimental: Error augmentation

Participants will complete a 12-week training program, in which they practice walking on a treadmill for 30-minutes during twice-weekly training sessions. During these sessions, participants will interface with a custom-built force-field able to exert mediolateral forces on the legs, which will be in "error augmentation" mode. This training period will be followed by a 12-week follow-up period. Five assessment sessions will be interspersed throughout this total 24-week period.

Behavioral: Error augmentation
During training sessions, a custom-built force-field will exert forces on the legs while participants walk. These forces will push the legs away from mechanically-appropriate mediolateral locations, having the effect of amplifying the errors in foot placement that are often present among individuals who have experienced a stroke.

Sham Comparator: Activity matched control

Participants will complete a 12-week training program, in which they practice walking on a treadmill for 30-minutes during twice-weekly training sessions. During these sessions, participants will interface with a custom-built force-field able to exert mediolateral forces on the legs, which will be in "transparent" mode. This training period will be followed by a 12-week follow-up period. Five assessment sessions will be interspersed throughout this total 24-week period.

Behavioral: Activity matched control
During training sessions, participants will interface with a custom-built force-field while they walk. The force-field will essentially get out of the way, producing minimal forces on the legs, and having no direct effect on the errors in foot placement that are often present among individuals who have experienced a stroke.

Outcome Measures

Primary Outcome Measures

  1. Partial Correlation Between Pelvis Displacement and Paretic Step Width During Gait (Change From Baseline) [baseline, 4-weeks, 8-weeks, 12-weeks, 24-weeks]

    A custom measure that quantifies the strength of the relationship between body mechanics and foot placement. This measure falls within a relatively narrow range among neurologically intact controls, but is substantially reduced in some individuals who have experienced a stroke, indicating a reduced ability to stabilize their gait pattern. This measure relates the mechanical state of the body at the start of each step (mediolateral pelvis displacement and velocity of the pelvis relative to the stance foot) to the step width at the end of the step. Specifically, the partial linear correlation between pelvis displacement and step width was calculated, accounting for variation in pelvis velocity. The change in this measure relative to baseline is calculated at four time points (after 4, 8, 12, and 24 weeks).

Secondary Outcome Measures

  1. Functional Gait Assessment (Change From Baseline) [baseline, 4-weeks, 8-weeks, 12-weeks, 24-weeks]

    A commonly-used clinical test to quantify balance and stability during various walking tasks. The minimum value is 0, the maximum value is 30, and higher scores indicate better outcomes. The total maximum value of 30 is calculated as the sum of 10 subscores, each of which has a scoring range of 0-3 and represents a distinct walking task. The change in this measure relative to baseline is calculated at four time points (after 4, 8, 12, and 24 weeks).

  2. Activities-specific Balance Confidence Scale (Change From Baseline) [baseline, 4-weeks, 8-weeks, 12-weeks, 24-weeks]

    A commonly-used clinical scale that quantifies an individual's confidence in performing various tasks requiring balance. The minimum value is 0, the maximum value is 100, and higher scores indicate a better outcome. The overall score is calculated as the mean of 16 subscores, each of which can range of 0 to 100 and represents self-efficacy at a distinct movement task. The change in this measure relative to baseline is calculated at four time points (after 4, 8, 12, and 24 weeks).

  3. 10-meter Walk Test (Change From Baseline) [baseline, 4-weeks, 8-weeks, 12-weeks, 24-weeks]

    A commonly-used clinical test to quantify general gait function. Walking speed is measured during the middle 6-meter portion of a 10-meter straight line path. The change in this measure relative to baseline is calculated at four time points (after 4, 8, 12, and 24 weeks).

  4. Fall Incidence [6 months (during 12 week follow-up period)]

    Self-report history of fall occurrence, quantified by the average number of falls per participant in each group during the 12-week period that followed completion of the study's intervention component

  5. Fear of Falling [6 months (at completion of 12-week Follow-up period)]

    Self-report statement of whether a participant has a fear of falling

Eligibility Criteria

Criteria

Ages Eligible for Study:
21 Years and Older
Sexes Eligible for Study:
All
Accepts Healthy Volunteers:
No
Inclusion Criteria:
  • At least 21 years old

  • Experience of a stroke 6 months prior to participation

  • Preferred overground gait speed of at least 0.2 m/s

  • Ability to walk at self-selected speed for 3 minutes without a cane or walker

  • Provision of informed consent.

Exclusion Criteria:
  • Resting heart rate above 110 beats/min

  • Resting blood pressure higher than 200/110 mm Hg

  • History of congestive heart failure, unstable cardiac arrhythmias, hypertrophic cardiomyopathy, severe aortic stenosis, angina or dyspnea at rest or during activities of daily living

  • Preexisting neurological disorders or dementia

  • History of major head trauma

  • Legal blindness or severe visual impairment

  • Life expectancy <1 yr; 8)

  • History of deep vein thrombosis or pulmonary embolism within 6 months

  • Uncontrolled diabetes with recent weight loss, diabetic coma, or frequent insulin reactions

  • Orthopedic injuries or conditions (e.g. joint replacements) in the lower extremities with the potential to alter the gait pattern.

Contacts and Locations

Locations

Site City State Country Postal Code
1 Ralph H. Johnson VA Medical Center, Charleston, SC Charleston South Carolina United States 29401-5799

Sponsors and Collaborators

  • VA Office of Research and Development

Investigators

  • Principal Investigator: Jesse C. Dean, PhD, Ralph H. Johnson VA Medical Center, Charleston, SC

Study Documents (Full-Text)

More Information

Publications

None provided.
Responsible Party:
VA Office of Research and Development
ClinicalTrials.gov Identifier:
NCT02964039
Other Study ID Numbers:
  • N2256-R
  • RX002256
First Posted:
Nov 15, 2016
Last Update Posted:
Dec 2, 2021
Last Verified:
Dec 1, 2021
Individual Participant Data (IPD) Sharing Statement:
Yes
Plan to Share IPD:
Yes
Studies a U.S. FDA-regulated Drug Product:
No
Studies a U.S. FDA-regulated Device Product:
No
Product Manufactured in and Exported from the U.S.:
No
Keywords provided by VA Office of Research and Development
Additional relevant MeSH terms:

Study Results

Participant Flow

Recruitment Details Participants were recruited and enrolled between February 2017 and October 2019 from a database housed at the Medical University of South Carolina. Individuals in this database had previously experienced a stroke, and had agreed to be contacted for participation in research studies.
Pre-assignment Detail Of the 93 participants who were assessed for eligibility, 54 met the study's inclusion criteria and were interested in participating in the intervention. These 54 participants were randomized to one of the three study arms.
Arm/Group Title Error Reduction Error Augmentation Activity Matched Control
Arm/Group Description Participants will complete a 12-week training program, in which they practice walking on a treadmill for 30-minutes during twice-weekly training sessions. During these sessions, participants will interface with a custom-built force-field able to exert mediolateral forces on the legs, which will be in "error reduction" mode. This training period will be followed by a 12-week follow-up period. Five assessment sessions will be interspersed throughout this total 24-week period. Error reduction: During training sessions, a custom-built force-field will exert forces on the legs while participants walk. These forces will push the legs toward mechanically-appropriate mediolateral locations, having the effect of reducing the errors in foot placement that are often present among individuals who have experienced a stroke. Participants will complete a 12-week training program, in which they practice walking on a treadmill for 30-minutes during twice-weekly training sessions. During these sessions, participants will interface with a custom-built force-field able to exert mediolateral forces on the legs, which will be in "error augmentation" mode. This training period will be followed by a 12-week follow-up period. Five assessment sessions will be interspersed throughout this total 24-week period. Error augmentation: During training sessions, a custom-built force-field will exert forces on the legs while participants walk. These forces will push the legs away from mechanically-appropriate mediolateral locations, having the effect of amplifying the errors in foot placement that are often present among individuals who have experienced a stroke. Participants will complete a 12-week training program, in which they practice walking on a treadmill for 30-minutes during twice-weekly training sessions. During these sessions, participants will interface with a custom-built force-field able to exert mediolateral forces on the legs, which will be in "transparent" mode. This training period will be followed by a 12-week follow-up period. Five assessment sessions will be interspersed throughout this total 24-week period. Activity matched control: During training sessions, participants will interface with a custom-built force-field while they walk. The force-field will essentially get out of the way, producing minimal forces on the legs, and having no direct effect on the errors in foot placement that are often present among individuals who have experienced a stroke.
Period Title: Overall Study
STARTED 18 18 18
Received Allocated Intervention 15 17 14
COMPLETED 14 17 13
NOT COMPLETED 4 1 5

Baseline Characteristics

Arm/Group Title Error Reduction Error Augmentation Activity Matched Control Total
Arm/Group Description Participants will complete a 12-week training program, in which they practice walking on a treadmill for 30-minutes during twice-weekly training sessions. During these sessions, participants will interface with a custom-built force-field able to exert mediolateral forces on the legs, which will be in "error reduction" mode. This training period will be followed by a 12-week follow-up period. Five assessment sessions will be interspersed throughout this total 24-week period. Error reduction: During training sessions, a custom-built force-field will exert forces on the legs while participants walk. These forces will push the legs toward mechanically-appropriate mediolateral locations, having the effect of reducing the errors in foot placement that are often present among individuals who have experienced a stroke. Participants will complete a 12-week training program, in which they practice walking on a treadmill for 30-minutes during twice-weekly training sessions. During these sessions, participants will interface with a custom-built force-field able to exert mediolateral forces on the legs, which will be in "error augmentation" mode. This training period will be followed by a 12-week follow-up period. Five assessment sessions will be interspersed throughout this total 24-week period. Error augmentation: During training sessions, a custom-built force-field will exert forces on the legs while participants walk. These forces will push the legs away from mechanically-appropriate mediolateral locations, having the effect of amplifying the errors in foot placement that are often present among individuals who have experienced a stroke. Participants will complete a 12-week training program, in which they practice walking on a treadmill for 30-minutes during twice-weekly training sessions. During these sessions, participants will interface with a custom-built force-field able to exert mediolateral forces on the legs, which will be in "transparent" mode. This training period will be followed by a 12-week follow-up period. Five assessment sessions will be interspersed throughout this total 24-week period. Activity matched control: During training sessions, participants will interface with a custom-built force-field while they walk. The force-field will essentially get out of the way, producing minimal forces on the legs, and having no direct effect on the errors in foot placement that are often present among individuals who have experienced a stroke. Total of all reporting groups
Overall Participants 18 18 18 54
Age (years) [Mean (Standard Deviation) ]
Mean (Standard Deviation) [years]
64
(13)
57
(13)
57
(14)
59
(14)
Sex: Female, Male (Count of Participants)
Female
9
50%
6
33.3%
9
50%
24
44.4%
Male
9
50%
12
66.7%
9
50%
30
55.6%
Ethnicity (NIH/OMB) (Count of Participants)
Hispanic or Latino
0
0%
0
0%
0
0%
0
0%
Not Hispanic or Latino
18
100%
18
100%
18
100%
54
100%
Unknown or Not Reported
0
0%
0
0%
0
0%
0
0%
Race (NIH/OMB) (Count of Participants)
American Indian or Alaska Native
0
0%
1
5.6%
0
0%
1
1.9%
Asian
0
0%
0
0%
0
0%
0
0%
Native Hawaiian or Other Pacific Islander
0
0%
0
0%
0
0%
0
0%
Black or African American
6
33.3%
7
38.9%
8
44.4%
21
38.9%
White
12
66.7%
10
55.6%
10
55.6%
32
59.3%
More than one race
0
0%
0
0%
0
0%
0
0%
Unknown or Not Reported
0
0%
0
0%
0
0%
0
0%
Affected leg (Count of Participants)
Left leg
10
55.6%
9
50%
10
55.6%
29
53.7%
Right leg
8
44.4%
9
50%
8
44.4%
25
46.3%
Time since stroke (months) [Mean (Standard Deviation) ]
Mean (Standard Deviation) [months]
53
(48)
53
(46)
56
(57)
54
(50)
Height (inches) [Mean (Standard Deviation) ]
Mean (Standard Deviation) [inches]
66
(4)
68
(4)
67
(4)
67
(4)
Weight (pounds) [Mean (Standard Deviation) ]
Mean (Standard Deviation) [pounds]
187
(49)
189
(44)
181
(39)
186
(43)
Partial Correlation Between Pelvis Displacement and Paretic Step Width During Gait (Correlation Coefficient) [Mean (Standard Deviation) ]
Mean (Standard Deviation) [Correlation Coefficient]
0.44
(0.10)
0.34
(0.19)
0.51
(0.10)
0.43
(0.16)
Functional Gait Assessment (Score on a scale) [Mean (Standard Deviation) ]
Mean (Standard Deviation) [Score on a scale]
15.5
(3.2)
13.8
(5.2)
13.5
(5.0)
14.3
(4.6)
Activities-specific Balance Confidence scale (Score on a scale) [Mean (Standard Deviation) ]
Mean (Standard Deviation) [Score on a scale]
65.7
(22.2)
69.8
(12.4)
69.3
(15.3)
68.3
(16.6)
Walking speed (10-meter walk test) (meters per second) [Mean (Standard Deviation) ]
Mean (Standard Deviation) [meters per second]
0.84
(0.21)
0.73
(0.31)
0.78
(0.31)
0.78
(0.28)
Fall incidence (self reported over previous year) (Count of Participants)
Count of Participants [Participants]
6
33.3%
7
38.9%
7
38.9%
20
37%
Fear of falling (self-reported) (Count of Participants)
Count of Participants [Participants]
5
27.8%
7
38.9%
4
22.2%
16
29.6%

Outcome Measures

1. Primary Outcome
Title Partial Correlation Between Pelvis Displacement and Paretic Step Width During Gait (Change From Baseline)
Description A custom measure that quantifies the strength of the relationship between body mechanics and foot placement. This measure falls within a relatively narrow range among neurologically intact controls, but is substantially reduced in some individuals who have experienced a stroke, indicating a reduced ability to stabilize their gait pattern. This measure relates the mechanical state of the body at the start of each step (mediolateral pelvis displacement and velocity of the pelvis relative to the stance foot) to the step width at the end of the step. Specifically, the partial linear correlation between pelvis displacement and step width was calculated, accounting for variation in pelvis velocity. The change in this measure relative to baseline is calculated at four time points (after 4, 8, 12, and 24 weeks).
Time Frame baseline, 4-weeks, 8-weeks, 12-weeks, 24-weeks

Outcome Measure Data

Analysis Population Description
The total of 44 participants analyzed corresponds to the participants who completed the intervention and follow-up assessment.
Arm/Group Title Error Reduction Error Augmentation Activity Matched Control
Arm/Group Description Participants will complete a 12-week training program, in which they practice walking on a treadmill for 30-minutes during twice-weekly training sessions. During these sessions, participants will interface with a custom-built force-field able to exert mediolateral forces on the legs, which will be in "error reduction" mode. This training period will be followed by a 12-week follow-up period. Five assessment sessions will be interspersed throughout this total 24-week period. Error reduction: During training sessions, a custom-built force-field will exert forces on the legs while participants walk. These forces will push the legs toward mechanically-appropriate mediolateral locations, having the effect of reducing the errors in foot placement that are often present among individuals who have experienced a stroke. Participants will complete a 12-week training program, in which they practice walking on a treadmill for 30-minutes during twice-weekly training sessions. During these sessions, participants will interface with a custom-built force-field able to exert mediolateral forces on the legs, which will be in "error augmentation" mode. This training period will be followed by a 12-week follow-up period. Five assessment sessions will be interspersed throughout this total 24-week period. Error augmentation: During training sessions, a custom-built force-field will exert forces on the legs while participants walk. These forces will push the legs away from mechanically-appropriate mediolateral locations, having the effect of amplifying the errors in foot placement that are often present among individuals who have experienced a stroke. Participants will complete a 12-week training program, in which they practice walking on a treadmill for 30-minutes during twice-weekly training sessions. During these sessions, participants will interface with a custom-built force-field able to exert mediolateral forces on the legs, which will be in "transparent" mode. This training period will be followed by a 12-week follow-up period. Five assessment sessions will be interspersed throughout this total 24-week period. Activity matched control: During training sessions, participants will interface with a custom-built force-field while they walk. The force-field will essentially get out of the way, producing minimal forces on the legs, and having no direct effect on the errors in foot placement that are often present among individuals who have experienced a stroke.
Measure Participants 14 17 13
4-week assessment
-0.02
(0.22)
0.12
(0.20)
-0.04
(0.14)
8-week assessment
0.05
(0.15)
0.11
(0.20)
-0.02
(0.16)
12-week assessment
0
(0.08)
0.08
(0.18)
0.01
(0.12)
Follow-up assessment (after 12 weeks)
-0.01
(0.16)
0.11
(0.18)
0
(0.14)
Statistical Analysis 1
Statistical Analysis Overview Comparison Group Selection Error Reduction, Error Augmentation, Activity Matched Control
Comments
Type of Statistical Test Superiority
Comments
Statistical Test of Hypothesis p-Value 0.047
Comments A priori threshold: 0.05
Method ANOVA
Comments 0.047 is the main effect of group from a 2-way ANOVA that also included time (p=0.77) as a within-subjects factor.
2. Secondary Outcome
Title Functional Gait Assessment (Change From Baseline)
Description A commonly-used clinical test to quantify balance and stability during various walking tasks. The minimum value is 0, the maximum value is 30, and higher scores indicate better outcomes. The total maximum value of 30 is calculated as the sum of 10 subscores, each of which has a scoring range of 0-3 and represents a distinct walking task. The change in this measure relative to baseline is calculated at four time points (after 4, 8, 12, and 24 weeks).
Time Frame baseline, 4-weeks, 8-weeks, 12-weeks, 24-weeks

Outcome Measure Data

Analysis Population Description
The total of 44 participants analyzed corresponds to the participants who completed the intervention and follow-up assessment.
Arm/Group Title Error Reduction Error Augmentation Activity Matched Control
Arm/Group Description Participants will complete a 12-week training program, in which they practice walking on a treadmill for 30-minutes during twice-weekly training sessions. During these sessions, participants will interface with a custom-built force-field able to exert mediolateral forces on the legs, which will be in "error reduction" mode. This training period will be followed by a 12-week follow-up period. Five assessment sessions will be interspersed throughout this total 24-week period. Error reduction: During training sessions, a custom-built force-field will exert forces on the legs while participants walk. These forces will push the legs toward mechanically-appropriate mediolateral locations, having the effect of reducing the errors in foot placement that are often present among individuals who have experienced a stroke. Participants will complete a 12-week training program, in which they practice walking on a treadmill for 30-minutes during twice-weekly training sessions. During these sessions, participants will interface with a custom-built force-field able to exert mediolateral forces on the legs, which will be in "error augmentation" mode. This training period will be followed by a 12-week follow-up period. Five assessment sessions will be interspersed throughout this total 24-week period. Error augmentation: During training sessions, a custom-built force-field will exert forces on the legs while participants walk. These forces will push the legs away from mechanically-appropriate mediolateral locations, having the effect of amplifying the errors in foot placement that are often present among individuals who have experienced a stroke. Participants will complete a 12-week training program, in which they practice walking on a treadmill for 30-minutes during twice-weekly training sessions. During these sessions, participants will interface with a custom-built force-field able to exert mediolateral forces on the legs, which will be in "transparent" mode. This training period will be followed by a 12-week follow-up period. Five assessment sessions will be interspersed throughout this total 24-week period. Activity matched control: During training sessions, participants will interface with a custom-built force-field while they walk. The force-field will essentially get out of the way, producing minimal forces on the legs, and having no direct effect on the errors in foot placement that are often present among individuals who have experienced a stroke.
Measure Participants 14 17 13
4-week assessment
0.1
(1.8)
1.5
(2.3)
1.6
(2.1)
8-week assessment
0.8
(2.3)
1.9
(2.7)
2.5
(2.8)
12-week assessment
1.5
(2.5)
2.9
(1.9)
2.1
(1.8)
Follow-up assessment (after 12 weeks)
1.0
(2.5)
2.2
(2.5)
1.9
(3.5)
Statistical Analysis 1
Statistical Analysis Overview Comparison Group Selection Error Reduction, Error Augmentation, Activity Matched Control
Comments
Type of Statistical Test Superiority
Comments
Statistical Test of Hypothesis p-Value 0.16
Comments A priori threshold: 0.05
Method ANOVA
Comments 0.16 is the main effect of group from a 2-way ANOVA that also included time (p=0.023) as a within-subjects factor.
3. Secondary Outcome
Title Activities-specific Balance Confidence Scale (Change From Baseline)
Description A commonly-used clinical scale that quantifies an individual's confidence in performing various tasks requiring balance. The minimum value is 0, the maximum value is 100, and higher scores indicate a better outcome. The overall score is calculated as the mean of 16 subscores, each of which can range of 0 to 100 and represents self-efficacy at a distinct movement task. The change in this measure relative to baseline is calculated at four time points (after 4, 8, 12, and 24 weeks).
Time Frame baseline, 4-weeks, 8-weeks, 12-weeks, 24-weeks

Outcome Measure Data

Analysis Population Description
The total of 44 participants analyzed corresponds to the participants who completed the intervention and follow-up assessment.
Arm/Group Title Error Reduction Error Augmentation Activity Matched Control
Arm/Group Description Participants will complete a 12-week training program, in which they practice walking on a treadmill for 30-minutes during twice-weekly training sessions. During these sessions, participants will interface with a custom-built force-field able to exert mediolateral forces on the legs, which will be in "error reduction" mode. This training period will be followed by a 12-week follow-up period. Five assessment sessions will be interspersed throughout this total 24-week period. Error reduction: During training sessions, a custom-built force-field will exert forces on the legs while participants walk. These forces will push the legs toward mechanically-appropriate mediolateral locations, having the effect of reducing the errors in foot placement that are often present among individuals who have experienced a stroke. Participants will complete a 12-week training program, in which they practice walking on a treadmill for 30-minutes during twice-weekly training sessions. During these sessions, participants will interface with a custom-built force-field able to exert mediolateral forces on the legs, which will be in "error augmentation" mode. This training period will be followed by a 12-week follow-up period. Five assessment sessions will be interspersed throughout this total 24-week period. Error augmentation: During training sessions, a custom-built force-field will exert forces on the legs while participants walk. These forces will push the legs away from mechanically-appropriate mediolateral locations, having the effect of amplifying the errors in foot placement that are often present among individuals who have experienced a stroke. Participants will complete a 12-week training program, in which they practice walking on a treadmill for 30-minutes during twice-weekly training sessions. During these sessions, participants will interface with a custom-built force-field able to exert mediolateral forces on the legs, which will be in "transparent" mode. This training period will be followed by a 12-week follow-up period. Five assessment sessions will be interspersed throughout this total 24-week period. Activity matched control: During training sessions, participants will interface with a custom-built force-field while they walk. The force-field will essentially get out of the way, producing minimal forces on the legs, and having no direct effect on the errors in foot placement that are often present among individuals who have experienced a stroke.
Measure Participants 14 17 13
4-week assessment
2.2
(11.2)
-0.6
(6.9)
3.7
(10.3)
8-week assessment
2.5
(12.9)
-1.2
(4.9)
4.1
(16.2)
12-week assessment
6.1
(16.4)
2.8
(6.8)
5.4
(12.5)
Follow-up assessment (after 12 weeks)
8.1
(14.7)
4.6
(7.9)
3.7
(22.8)
Statistical Analysis 1
Statistical Analysis Overview Comparison Group Selection Error Reduction, Error Augmentation, Activity Matched Control
Comments
Type of Statistical Test Superiority
Comments
Statistical Test of Hypothesis p-Value 0.64
Comments A priori threshold: 0.05
Method ANOVA
Comments 0.64 is the main effect of group from a 2-way ANOVA that also included time (p=0.024) as a within-subjects factor.
4. Secondary Outcome
Title 10-meter Walk Test (Change From Baseline)
Description A commonly-used clinical test to quantify general gait function. Walking speed is measured during the middle 6-meter portion of a 10-meter straight line path. The change in this measure relative to baseline is calculated at four time points (after 4, 8, 12, and 24 weeks).
Time Frame baseline, 4-weeks, 8-weeks, 12-weeks, 24-weeks

Outcome Measure Data

Analysis Population Description
The total of 44 participants analyzed corresponds to the participants who completed the intervention and follow-up assessment.
Arm/Group Title Error Reduction Error Augmentation Activity Matched Control
Arm/Group Description Participants will complete a 12-week training program, in which they practice walking on a treadmill for 30-minutes during twice-weekly training sessions. During these sessions, participants will interface with a custom-built force-field able to exert mediolateral forces on the legs, which will be in "error reduction" mode. This training period will be followed by a 12-week follow-up period. Five assessment sessions will be interspersed throughout this total 24-week period. Error reduction: During training sessions, a custom-built force-field will exert forces on the legs while participants walk. These forces will push the legs toward mechanically-appropriate mediolateral locations, having the effect of reducing the errors in foot placement that are often present among individuals who have experienced a stroke. Participants will complete a 12-week training program, in which they practice walking on a treadmill for 30-minutes during twice-weekly training sessions. During these sessions, participants will interface with a custom-built force-field able to exert mediolateral forces on the legs, which will be in "error augmentation" mode. This training period will be followed by a 12-week follow-up period. Five assessment sessions will be interspersed throughout this total 24-week period. Error augmentation: During training sessions, a custom-built force-field will exert forces on the legs while participants walk. These forces will push the legs away from mechanically-appropriate mediolateral locations, having the effect of amplifying the errors in foot placement that are often present among individuals who have experienced a stroke. Participants will complete a 12-week training program, in which they practice walking on a treadmill for 30-minutes during twice-weekly training sessions. During these sessions, participants will interface with a custom-built force-field able to exert mediolateral forces on the legs, which will be in "transparent" mode. This training period will be followed by a 12-week follow-up period. Five assessment sessions will be interspersed throughout this total 24-week period. Activity matched control: During training sessions, participants will interface with a custom-built force-field while they walk. The force-field will essentially get out of the way, producing minimal forces on the legs, and having no direct effect on the errors in foot placement that are often present among individuals who have experienced a stroke.
Measure Participants 14 17 13
4-week assessment
0.01
(0.08)
0.03
(0.08)
0.03
(0.08)
8-week assessment
0.02
(0.10)
0.04
(0.07)
0.04
(0.10)
12-week assessment
0.05
(0.14)
0.02
(0.08)
0.06
(0.10)
Follow-up assessment (after 12 weeks
0.01
(0.15)
0.01
(0.11)
0.01
(0.11)
Statistical Analysis 1
Statistical Analysis Overview Comparison Group Selection Error Reduction, Error Augmentation, Activity Matched Control
Comments
Type of Statistical Test Superiority
Comments
Statistical Test of Hypothesis p-Value 0.92
Comments A priori threshold: 0.92
Method ANOVA
Comments 0.92 is the main effect of group from a 2-way ANOVA that also included time (p=0.076) as a within-subjects factor.
5. Secondary Outcome
Title Fall Incidence
Description Self-report history of fall occurrence, quantified by the average number of falls per participant in each group during the 12-week period that followed completion of the study's intervention component
Time Frame 6 months (during 12 week follow-up period)

Outcome Measure Data

Analysis Population Description
The total of 44 participants analyzed corresponds to the participants who completed the intervention and follow-up assessment.
Arm/Group Title Error Reduction Error Augmentation Activity Matched Control
Arm/Group Description Participants will complete a 12-week training program, in which they practice walking on a treadmill for 30-minutes during twice-weekly training sessions. During these sessions, participants will interface with a custom-built force-field able to exert mediolateral forces on the legs, which will be in "error reduction" mode. This training period will be followed by a 12-week follow-up period. Five assessment sessions will be interspersed throughout this total 24-week period. Error reduction: During training sessions, a custom-built force-field will exert forces on the legs while participants walk. These forces will push the legs toward mechanically-appropriate mediolateral locations, having the effect of reducing the errors in foot placement that are often present among individuals who have experienced a stroke. Participants will complete a 12-week training program, in which they practice walking on a treadmill for 30-minutes during twice-weekly training sessions. During these sessions, participants will interface with a custom-built force-field able to exert mediolateral forces on the legs, which will be in "error augmentation" mode. This training period will be followed by a 12-week follow-up period. Five assessment sessions will be interspersed throughout this total 24-week period. Error augmentation: During training sessions, a custom-built force-field will exert forces on the legs while participants walk. These forces will push the legs away from mechanically-appropriate mediolateral locations, having the effect of amplifying the errors in foot placement that are often present among individuals who have experienced a stroke. Participants will complete a 12-week training program, in which they practice walking on a treadmill for 30-minutes during twice-weekly training sessions. During these sessions, participants will interface with a custom-built force-field able to exert mediolateral forces on the legs, which will be in "transparent" mode. This training period will be followed by a 12-week follow-up period. Five assessment sessions will be interspersed throughout this total 24-week period. Activity matched control: During training sessions, participants will interface with a custom-built force-field while they walk. The force-field will essentially get out of the way, producing minimal forces on the legs, and having no direct effect on the errors in foot placement that are often present among individuals who have experienced a stroke.
Measure Participants 14 17 13
Mean (Standard Error) [Falls per participant]
0.50
(0.20)
0.29
(0.14)
0.62
(0.23)
Statistical Analysis 1
Statistical Analysis Overview Comparison Group Selection Error Reduction, Error Augmentation, Activity Matched Control
Comments
Type of Statistical Test Superiority
Comments
Statistical Test of Hypothesis p-Value >=0.22
Comments A priori threshold: 0.05
Method Mixed Models Analysis
Comments We compared incident rates assuming a negative binomial distribution with leas squares means estimates predicted via generalized linear model.
6. Secondary Outcome
Title Fear of Falling
Description Self-report statement of whether a participant has a fear of falling
Time Frame 6 months (at completion of 12-week Follow-up period)

Outcome Measure Data

Analysis Population Description
The total of 44 participants analyzed corresponds to the participants who completed the intervention and follow-up assessment.
Arm/Group Title Error Reduction Error Augmentation Activity Matched Control
Arm/Group Description Participants will complete a 12-week training program, in which they practice walking on a treadmill for 30-minutes during twice-weekly training sessions. During these sessions, participants will interface with a custom-built force-field able to exert mediolateral forces on the legs, which will be in "error reduction" mode. This training period will be followed by a 12-week follow-up period. Five assessment sessions will be interspersed throughout this total 24-week period. Error reduction: During training sessions, a custom-built force-field will exert forces on the legs while participants walk. These forces will push the legs toward mechanically-appropriate mediolateral locations, having the effect of reducing the errors in foot placement that are often present among individuals who have experienced a stroke. Participants will complete a 12-week training program, in which they practice walking on a treadmill for 30-minutes during twice-weekly training sessions. During these sessions, participants will interface with a custom-built force-field able to exert mediolateral forces on the legs, which will be in "error augmentation" mode. This training period will be followed by a 12-week follow-up period. Five assessment sessions will be interspersed throughout this total 24-week period. Error augmentation: During training sessions, a custom-built force-field will exert forces on the legs while participants walk. These forces will push the legs away from mechanically-appropriate mediolateral locations, having the effect of amplifying the errors in foot placement that are often present among individuals who have experienced a stroke. Participants will complete a 12-week training program, in which they practice walking on a treadmill for 30-minutes during twice-weekly training sessions. During these sessions, participants will interface with a custom-built force-field able to exert mediolateral forces on the legs, which will be in "transparent" mode. This training period will be followed by a 12-week follow-up period. Five assessment sessions will be interspersed throughout this total 24-week period. Activity matched control: During training sessions, participants will interface with a custom-built force-field while they walk. The force-field will essentially get out of the way, producing minimal forces on the legs, and having no direct effect on the errors in foot placement that are often present among individuals who have experienced a stroke.
Measure Participants 14 17 13
Count of Participants [Participants]
4
22.2%
5
27.8%
4
22.2%
Statistical Analysis 1
Statistical Analysis Overview Comparison Group Selection Error Reduction, Error Augmentation, Activity Matched Control
Comments
Type of Statistical Test Superiority
Comments
Statistical Test of Hypothesis p-Value 0.99
Comments A priori threshold: 0.05
Method Chi-squared
Comments

Adverse Events

Time Frame Adverse event data were collected over a three-year period, corresponding from the time when the first participant was enrolled into the intervention to the time when the overall intervention ended.
Adverse Event Reporting Description We adhered to guidance provided by the Medical University of South Carolina Institutional Review Board; in order for an event to be classified as a reportable adverse event, it cannot be "the expected natural progression of any underlying disease, disorder, or condition of the subject experiencing the adverse event and the subject's predisposing risk factor profile for the adverse event". While we tracked falls, they are thus not included as adverse events.
Arm/Group Title Error Reduction Error Augmentation Activity Matched Control
Arm/Group Description Participants will complete a 12-week training program, in which they practice walking on a treadmill for 30-minutes during twice-weekly training sessions. During these sessions, participants will interface with a custom-built force-field able to exert mediolateral forces on the legs, which will be in "error reduction" mode. This training period will be followed by a 12-week follow-up period. Five assessment sessions will be interspersed throughout this total 24-week period. Error reduction: During training sessions, a custom-built force-field will exert forces on the legs while participants walk. These forces will push the legs toward mechanically-appropriate mediolateral locations, having the effect of reducing the errors in foot placement that are often present among individuals who have experienced a stroke. Participants will complete a 12-week training program, in which they practice walking on a treadmill for 30-minutes during twice-weekly training sessions. During these sessions, participants will interface with a custom-built force-field able to exert mediolateral forces on the legs, which will be in "error augmentation" mode. This training period will be followed by a 12-week follow-up period. Five assessment sessions will be interspersed throughout this total 24-week period. Error augmentation: During training sessions, a custom-built force-field will exert forces on the legs while participants walk. These forces will push the legs away from mechanically-appropriate mediolateral locations, having the effect of amplifying the errors in foot placement that are often present among individuals who have experienced a stroke. Participants will complete a 12-week training program, in which they practice walking on a treadmill for 30-minutes during twice-weekly training sessions. During these sessions, participants will interface with a custom-built force-field able to exert mediolateral forces on the legs, which will be in "transparent" mode. This training period will be followed by a 12-week follow-up period. Five assessment sessions will be interspersed throughout this total 24-week period. Activity matched control: During training sessions, participants will interface with a custom-built force-field while they walk. The force-field will essentially get out of the way, producing minimal forces on the legs, and having no direct effect on the errors in foot placement that are often present among individuals who have experienced a stroke.
All Cause Mortality
Error Reduction Error Augmentation Activity Matched Control
Affected / at Risk (%) # Events Affected / at Risk (%) # Events Affected / at Risk (%) # Events
Total 0/18 (0%) 0/18 (0%) 0/18 (0%)
Serious Adverse Events
Error Reduction Error Augmentation Activity Matched Control
Affected / at Risk (%) # Events Affected / at Risk (%) # Events Affected / at Risk (%) # Events
Total 0/18 (0%) 0/18 (0%) 1/18 (5.6%)
Vascular disorders
Stroke 0/18 (0%) 0 0/18 (0%) 0 1/18 (5.6%) 1
Other (Not Including Serious) Adverse Events
Error Reduction Error Augmentation Activity Matched Control
Affected / at Risk (%) # Events Affected / at Risk (%) # Events Affected / at Risk (%) # Events
Total 0/18 (0%) 0/18 (0%) 0/18 (0%)

Limitations/Caveats

The overall dropout rate of this study was increased by the research shutdown with the coronavirus pandemic.

More Information

Certain Agreements

All Principal Investigators ARE employed by the organization sponsoring the study.

There is NOT an agreement between Principal Investigators and the Sponsor (or its agents) that restricts the PI's rights to discuss or publish trial results after the trial is completed.

Results Point of Contact

Name/Title Jesse Dean
Organization Ralph H. Johnson VAMC / MUSC
Phone 8437929566
Email deaje@musc.edu
Responsible Party:
VA Office of Research and Development
ClinicalTrials.gov Identifier:
NCT02964039
Other Study ID Numbers:
  • N2256-R
  • RX002256
First Posted:
Nov 15, 2016
Last Update Posted:
Dec 2, 2021
Last Verified:
Dec 1, 2021