Post-stroke Perturbation Training

Proactive and Reactive Perturbation Training to Reduce Falls and Improve Gait Stability in People With Chronic Stroke

Following a stroke, many individuals have a high risk of falls, which can negatively influence quality of life. Unfortunately, current treatments have not effectively addressed this problem. This study investigates whether two methods of delivering mechanical perturbations during walking have the potential to improve post-stroke walking balance and reduce real-world fall incidence.

Study Overview

• Status: Completed
• Conditions: Stroke
• Intervention / Treatment: Behavioral: Reactive Perturbations; Behavioral: Proactive Perturbations

• Study Type: Interventional
• Enrollment (Actual): 86
• Phase: Not Applicable

Contacts and Locations

Study Locations

• United States
  • South Carolina
    • Charleston, South Carolina, United States, 29425
      • Medical University of South Carolina

Participation Criteria

Eligibility Criteria

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

Description

Inclusion Criteria:

• Experience of a stroke at least 6 months prior to participation
• Self-reported experience of a fall in the previous year, and/or a fear of falling
• Gait speed of at least 0.2 m/s
• Ability to walk on a treadmill without a cane or walker
• Provision of informed consent

Exclusion Criteria:

• Evidence of cerebellar damage
• Resting blood pressure higher than 220/110 mm Hg
• History of unstable cardiac arrhythmias, hypertrophic cardiomyopathy, severe aortic stenosis, angina or dyspnea at rest or during activities of daily living
• Preexisting neurological disorders or dementia
• Legal blindness or severe visual impairment
• History of DVT 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

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Single

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Reactive Perturbations	Behavioral: Reactive Perturbations; A novel device will be used to apply controlled mediolateral perturbations to participants' trunk as they walk on a treadmill, requiring reactive responses to avoid a loss of balance. All perturbations will have a duration of 200 ms, and will be applied immediately after onset of the swing phase with either the paretic or non-paretic leg. If in a given training session, a participant does not experience any losses of balance, the perturbation magnitude will be increased in the next training session. Perturbations will begin at 3% body weight (BW), and will progress in increments of 3% BW up to a maximum of 15% BW. The structure of the Reactive perturbation session will be identical to that used for Proactive perturbation training sessions, including overground trials, treadmill trials without perturbations, and Perturbed and Catch trials in which Perturbations are delivered.
Experimental: Proactive Perturbations	Behavioral: Proactive Perturbations; A novel device will be used to perturb the relationship between pelvis motion and step width by applying mediolateral forces to participants' legs. Participants will first perform a 3-minute overground walking trial at their self-selected speed, in which they do not interact with the perturbation device. Participants will then perform a 3-minute treadmill walking trial at their self-selected speed, in which they again do not interact with the perturbation device. Participants will then perform a series of alternating 3-minute Perturbed and Catch trials, all at their self-selected speed. For the Perturbed trials, perturbations will be delivered in each step throughout the trial. For the Catch trials, perturbations will cease for the final minute of walking. A total of 5 Perturbed and 5 Catch trials will be performed. Finally, participants will perform a 3-minute overground walking trial at their self-selected speed, in which they do not interact with the perturbation device.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Fall incidence	A fall will be defined as an event in which a participant loses their balance and comes to rest on the ground, floor, or lower level. Falls will be measured during the 12-week periods preceding and following the intervention, using 2-week calendars on postcards to be sent to the investigators.	32 weeks (12-week period pre-intervention; 12-week period post-intervention)

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Fear of falling	Participants will be asked if they have a fear of falling (yes/no).	8 weeks (pre-intervention; post-intervention)
Functional Gait Assessment	A common clinical measure of gait balance	8 weeks (pre-intervention; post-intervention)
Activities-specific Balance Confidence scale	A common clinical measure of balance self-efficacy	8 weeks (pre-intervention; post-intervention)
Walking speed	Participants will be instructed to walk overground along a 10-meter path at the speed they would normally use around their house of the store. Speed will be measured for the middle 6-meters of the path.	8 weeks (pre-intervention; post-intervention)
Foot placement stabilization strategy (mechanics)	We will calculate the partial correlation between the pelvis displacement at the start of each step, and step width at the end of the step, accounting for pelvis velocity.	8 weeks (pre-intervention; post-intervention)
Foot placement stabilization strategy (gluteus medius activity)	We will calculate the partial correlation between the pelvis displacement at the start of each step, and the mean magnitude of gluteus medius activity during the first half of the swing phase, accounting for pelvis velocity.	8 weeks (pre-intervention; post-intervention)
Center of pressure shift stabilization strategy (mechanics)	We will calculate the partial correlation between the pelvis velocity at the start of each step, and the magnitude of the change in mediolateral center of pressure location under the stance foot during the step, accounting for pelvis displacement.	8 weeks (pre-intervention; post-intervention)
Center of pressure shift stabilization strategy (peroneus longus activity)	We will calculate the partial correlation between the pelvis velocity at the start of each step, and the mean magnitude of peroneus longus muscle activity during the single support stance phase of this step, accounting for pelvis displacement.	8 weeks (pre-intervention; post-intervention)
Push-off stabilization strategy (mechanics)	We will calculate the partial correlation between the pelvis displacement at the start of each step, and the time integral of the total ground reaction force under the trail leg during the double support phase preceding this step, accounting for pelvis velocity.	8 weeks (pre-intervention; post-intervention)
Push-off stabilization strategy (medial gastrocnemius activity)	We will calculate the partial correlation between the pelvis displacement at the start of each step, and the mean magnitude of medial gastrocnemius activity during the double support phase preceding this step, accounting for pelvis velocity.	8 weeks (pre-intervention; post-intervention)
Largest rejected perturbation (trained perturbations) Largest rejected perturbation (trunk)	We will identify the largest mediolateral magnitude perturbation that participants can experience without a loss of balance.	8 weeks (pre-intervention; post-intervention)
Largest rejected perturbation (untrained perturbations) Largest rejected perturbation (trunk)	We will identify the largest mediolateral magnitude perturbation that participants can experience without a loss of balance.	8 weeks (pre-intervention; post-intervention)
Angular momentum modulation (trained perturbations) Largest rejected perturbation (trunk)	We will calculate the absolute difference in the range of frontal plane angular momentum during a step, relative to an unperturbed step. This will be calculated for the perturbed step and the subsequent recovery step.	8 weeks (pre-intervention; post-intervention)
Angular momentum modulation (untrained perturbations) Largest rejected perturbation (trunk)	We will calculate the absolute difference in the range of frontal plane angular momentum during a step, relative to an unperturbed step. This will be calculated for the perturbed step and the subsequent recovery step.	8 weeks (pre-intervention; post-intervention)

Collaborators and Investigators

• Sponsor: Medical University of South Carolina
• Collaborators: Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD)
• Investigators: Principal Investigator: Jesse Dean, Medical University of South Carolina

Study record dates

Study Major Dates

• Study Start (Actual): October 6, 2021
• Primary Completion (Actual): December 5, 2025
• Study Completion (Actual): December 5, 2025

Study Registration Dates

• First Submitted: April 17, 2021
• First Submitted That Met QC Criteria: April 17, 2021
• First Posted (Actual): April 22, 2021

Study Record Updates

• Last Update Posted (Estimated): December 17, 2025
• Last Update Submitted That Met QC Criteria: December 12, 2025
• Last Verified: December 1, 2025

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Cerebrovascular Disorders; Brain Diseases; Central Nervous System Diseases; Nervous System Diseases; Vascular Diseases; Cardiovascular Diseases; Stroke
• Other Study ID Numbers: 00101810; 1R01HD103923-01 (U.S. NIH Grant/Contract)

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: YES
• IPD Plan Description: De-identified participant data consisting of the clinical assessments and biomechanical walking data collected in this study will be shared through the IPCSR website.
• IPD Sharing Time Frame: The data will be shared once the primary publication generated from this study has been published.
• IPD Sharing Access Criteria: No restrictions will be placed on the use of the data to be shared.
• IPD Sharing Supporting Information Type: STUDY_PROTOCOL; SAP; ICF

Drug and device information, study documents

• 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