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

• ClinicalTrials.gov Identifier: NCT02964039
• Recruitment Status: Completed
• First Posted: November 15, 2016
• Results First Posted: July 28, 2021
• Last Update Posted: December 2, 2021
• Sponsor: VA Office of Research and Development
• Information provided by (Responsible Party): VA Office of Research and Development

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
Stroke	Behavioral: Error reduction; Behavioral: Error augmentation; Behavioral: Activity matched control	Not Applicable

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 (Clinical Trial)
• 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: April 1, 2017
• Actual Primary Completion Date: March 31, 2020
• Actual Study Completion Date: March 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) [ Time Frame: 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) [ Time Frame: 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) [ Time Frame: 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) [ Time Frame: 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 [ Time Frame: 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 [ Time Frame: 6 months (at completion of 12-week Follow-up period) ]
   Self-report statement of whether a participant has a fear of falling

Eligibility Criteria

• Ages Eligible for Study: 21 Years and older (Adult, Older Adult)
• Sexes Eligible for Study: All
• Accepts Healthy Volunteers: No

Criteria

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

United States, South Carolina

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)

Documents provided by VA Office of Research and Development:

Study Protocol and Statistical Analysis Plan  [PDF] January 30, 2020

More Information

• Responsible Party: VA Office of Research and Development
• ClinicalTrials.gov Identifier: NCT02964039
• Other Study ID Numbers: N2256-R; RX002256 ( Other Grant/Funding Number: VA ORD )
• First Posted: November 15, 2016
• Results First Posted: July 28, 2021
• Last Update Posted: December 2, 2021
• Last Verified: December 2021

Individual Participant Data (IPD) Sharing Statement:

• Plan to Share IPD: Yes
• Plan Description: De-identified, anonymized data sets will be available to other investigators or members of the public upon request. These data sets will be made available upon completion of data collection, processing, and initial statistical analyses. The data sets will include physiological measures related to functional mobility, as well as the results of clinical tests.

• 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:

stroke; rehabilitation; gait

Additional relevant MeSH terms:

Stroke; Cerebrovascular Disorders; Brain Diseases; Central Nervous System Diseases; Nervous System Diseases; Vascular Diseases; Cardiovascular Diseases