Error Based Learning for Restoring Gait Symmetry Post-Stroke

Many of the 780,000 people affected by stroke each year are left with slow, asymmetric walking patterns. The proposed project will evaluate the effectiveness of two competing motor learning approaches to restore symmetric gait for faster, more efficient, and safer walking.

Study Overview

• Status: Completed
• Conditions: Stroke
• Intervention / Treatment: Other: Same Belt Speeds; Other: Different Belt Speeds

Detailed Description

Walking after stroke is characterized by reduced gait speed and the presence of interlimb spatiotemporal asymmetry. These step length and stance time asymmetries can be energy inefficient, challenge balance control, increase the risk of falls and injury, and limit functional mobility. Current rehabilitation to improve gait is based on one of two competing motor learning strategies: minimizing or augmenting symmetry errors during training. Conventional rehabilitation often involves walking on a treadmill while therapists attempt to minimize symmetry errors during training. Although this approach can successfully improve gait speed, it does not produce long-term changes in symmetry. Conversely, augmenting or amplifying symmetry errors has been produced by walking on a split belt treadmill with the belts set at different fixed speeds. While this approach produced an 'after-effect' resulting in step length symmetry for short periods of time, with some evidence of long term learning in people with stroke, it had no influence on stance time asymmetry. The investigators propose that patients need real-time proprioceptive feedback of symmetry errors so that they are actively engaged in the learning process. For this project, the investigators developed and validated a novel, responsive, 'closed loop' control system, using a split-belt instrumented treadmill that continuously adjusts the difference in belt speeds to be proportional to the patient's current asymmetry. Using this system, the investigators can either augment or minimize asymmetry on a step-by-step basis to determine which motor learning strategy produces the largest improvement in overground spatiotemporal symmetry.

• Study Type: Interventional
• Enrollment (Actual): 48
• Phase: Not Applicable

Contacts and Locations

Study Locations

• United States
  • North Carolina
    • Chapel Hill, North Carolina, United States, 27599
      • University of North Carolina at Chapel Hill

Participation Criteria

Eligibility Criteria

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

Description

Inclusion Criteria:

• ability to walk >10 m overground without physical assistance
• overground comfortable gait speed (CGS) < 1.0 m/s (using assistive devices and bracing below the knee as needed)
• able to walk independently on the treadmill at >80% CGS
• exhibits stance time and/or step length asymmetry during CGS

Exclusion Criteria:

• cerebellar lesion
• uncontrolled cardiorespiratory/metabolic disease (cardiac arrhythmia, uncontrolled hypertension or diabetes, orthostatic hypertension, chronic emphysema)or other neurological or orthopedic disorders that may affect gait training
• botulinum toxin to the lower limb in the past 6 months
• a history of balance deficits or unexplained falls not related to the stroke
• uncontrolled seizures
• concurrent physical therapy
• Mini-Mental Status Exam (MMSE) < 24
• communication impairments which could impede understanding of the purpose or procedures of the study or an inability to comply with experimental procedures

Study Plan

How is the study designed?

Design Details

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

Number of Arms

3

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Active Comparator: Control; Symmetric Gait. Dual-belted treadmill belts moving at the same belt speeds during training	Other: Same Belt Speeds; 18 sessions of training (3X/week). 20 minutes/session on treadmill; 10 minutes/session overground 70-75%HRmax. Control-Dual-belted treadmill belts respond to encourage symmetric gait
Experimental: Gait Asymmetry; Error Augmentation. Belts of a dual-belted treadmill may move at different belt speeds to amplify spatiotemporal gait asymmetry during training	Other: Different Belt Speeds; 18 sessions of training (3X/week). 20 minutes/session on treadmill; 10 minutes/session overground 70-75%HRmax. Treadmill belts of dual-belted treadmill respond either to amplify asymmetric gait or encourage symmetric gait.
Experimental: Gait Symmetry; Error Minimization. Belts of a dual-belted treadmill may move at different belt speeds to encourage spatiotemporal gait symmetry during training	Other: Different Belt Speeds; 18 sessions of training (3X/week). 20 minutes/session on treadmill; 10 minutes/session overground 70-75%HRmax. Treadmill belts of dual-belted treadmill respond either to amplify asymmetric gait or encourage symmetric gait.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Change from baseline in spatiotemporal gait symmetry after 6 weeks of training	Spatiotemporal gait symmetry is calculated as a ratio of paretic to non-paretic measures after walking over a pressure sensitive mat.	participants will be followed for the duration of their training, expected to be about 6 weeks

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Change from baseline in gait speed after 6 weeks of training	Gait speed is measured in m/sec by having participants walk across a 14' pressure sensitive mat.	participants will be followed for the duration of their training, expected to be about 6 weeks
Change from baseline in balance after 6 weeks of training	Balance will be assessed using the Berg Balance Scale, 4square step test, and the Functional Gait Assessment	participants will be followed for the duration of their training, expected to be about 6 weeks
Change from baseline in endurance after 6 weeks of training	Endurance will be measured as the distance walked (in meters) during the 6 Minute Walk Test	participants will be followed for the duration of their training, expected to be about 6 weeks
Change from baseline in quality of life after 6 weeks of training	Quality of Life will be assessed using the Stroke Impact Scale	participants will be followed for the duration of their training, expected to be about 6 weeks
Change from baseline in metabolic efficiency after 6 weeks of training	Metabolic efficiency is measured as the metabolic cost of transport (MCOT) using a portable metabolic cart to assess cardiorespiratory gas exchange during the 6 Minute Walk Test.	participants will be followed for the duration of their training, expected to be about 6 weeks
Change from baseline in community ambulation after 6 weeks of training	Community ambulation is assessed using Step Watch Monitors (SAMs) which will be worn daily for a minimum of 7 days during waking hours.	participants will be followed for the duration of their training, expected to be about 6 weeks
Change from baseline in gait speed at 1 month follow-up	Gait speed is measured in m/sec by having participants walk across a 14' pressure sensitive mat.	participants will be followed for one month following the duration of their training (expected to be about 6 weeks) for a total of 10 weeks
Change from baseline in balance at 1 month follow up	Balance will be assessed using the Berg Balance Scale, 4square step test, and the Functional Gait Assessment	participants will be followed for one month following the duration of their training (expected to be about 6 weeks) for a total of 10 weeks
Change from baseline in endurance at 1 month follow up	Endurance will be measured as the distance walked (in meters) during the 6 Minute Walk Test	participants will be followed for one month following the duration of their training (expected to be about 6 weeks) for a total of 10 weeks
Change from baseline in quality of life at 1 month follow up	Quality of Life will be assessed using the Stroke Impact Scale	participants will be followed for one month following the duration of their training (expected to be about 6 weeks) for a total of 10 weeks
Change from baseline in metabolic efficiency at 1 month follow up	Metabolic efficiency is measured as the metabolic cost of transport (MCOT) using a portable metabolic cart to assess cardiorespiratory gas exchange during the 6 Minute Walk Test.	participants will be followed for one month following the duration of their training (expected to be about 6 weeks) for a total of 10 weeks
Change from baseline in community ambulation at 1 month follow up	Community ambulation is assessed using Step Watch Monitors (SAMs) which will be worn daily for a minimum of 7 days during waking hours.	participants will be followed for one month following the duration of their training (expected to be about 6 weeks) for a total of 10 weeks
Change from baseline in spatiotemporal gait asymmetry at 1 month follow up	Spatiotemporal gait symmetry is calculated as a ratio of paretic to non-paretic measures after walking over a pressure sensitive mat.	participants will be followed for one month following the duration of their training (expected to be about 6 weeks) for a total of 10 weeks

Collaborators and Investigators

• Sponsor: University of North Carolina, Chapel Hill
• Collaborators: Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD)
• Investigators: Principal Investigator: Michael D Lewek, PT, PhD, University of North Carolina, Chapel Hill

Publications and helpful links

General Publications

• Ryan HP, Husted C, Lewek MD. Improving Spatiotemporal Gait Asymmetry Has Limited Functional Benefit for Individuals Poststroke. J Neurol Phys Ther. 2020 Jul;44(3):197-204. doi: 10.1097/NPT.0000000000000321.

Study record dates

Study Major Dates

• Study Start: January 1, 2012
• Primary Completion (Actual): December 1, 2015
• Study Completion (Actual): December 1, 2015

Study Registration Dates

• First Submitted: May 8, 2012
• First Submitted That Met QC Criteria: May 10, 2012
• First Posted (Estimate): May 15, 2012

Study Record Updates

• Last Update Posted (Actual): February 15, 2019
• Last Update Submitted That Met QC Criteria: February 11, 2019
• Last Verified: April 1, 2016

More Information

Terms related to this study

• Keywords: stroke; Gait; walking
• Additional Relevant MeSH Terms: Cardiovascular Diseases; Vascular Diseases; Cerebrovascular Disorders; Brain Diseases; Central Nervous System Diseases; Nervous System Diseases; Stroke; Physiological Effects of Drugs; Adrenergic Agents; Neurotransmitter Agents; Molecular Mechanisms of Pharmacological Action; Autonomic Agents; Peripheral Nervous System Agents; Neurotransmitter Uptake Inhibitors; Membrane Transport Modulators; Dopamine Agents; Dopamine Uptake Inhibitors; Central Nervous System Stimulants; Sympathomimetics; Adrenergic Uptake Inhibitors; Methamphetamine
• Other Study ID Numbers: 11-1240; R21HD068805 (U.S. NIH Grant/Contract)