Movement Amplification Gait Training to Enhance Walking Balance Post-Stroke

VA Office of Research and Development

Status: Enrolling

Conditions: Chronic Hemiparetic Stroke

Treatments: Behavioral: High intensity gait training in varying external environments; Behavioral: Treadmill walking in varying external environments

Study type: Interventional

Funder types: Other; Other U.S. Federal agency

Identifiers

NCT06400186

1I21RX004882 (Other Grant/Funding Number)

B4882-P

Details and patient eligibility

About

Stroke is a leading cause of disability in the United States, affecting approximately 795,000 people annually. The Veteran's Health Administration provides over 60,000 outpatient visits for stroke-related care annually at a cost of over $250 million. Among ambulatory people with chronic stroke (PwCS), impaired balance is a common health concern that substantially limits mobility (those with the worst balance walk the least). This project will explore adaptive strategies employed by PwCS in balance challenging environments and if a novel gait training intervention using a robotic device to amplify a person's self-generated movements can improve walking balance. The development of effective interventions to increase walking balance among PwCS will positively impact Veterans' health, quality of life, and ability to participate in walking activities.

Full description

Background: There is a pressing need to develop effective methods to enhance walking balance in people with chronic stroke (PwCS). Interventions that amplify self-generated movements may accelerate motor learning by enhancing a person's perception of movement errors. This method could potentially be applied to help PwCS improve walking balance. To this end, the investigators have developed a cable-driven robot to create a Movement Amplification Environment (MAE) during treadmill walking. The MAE challenges walking balance by applying lateral forces to the pelvis that are proportional in magnitude to real-time lateral center of mass (COM) velocity.

Unlike a popular form of balance training that uses unpredictable perturbations to enhance reactive balance, training in a MAE targets anticipatory balance by developing predictive control mechanisms that are likely to persist when the training environment is removed (after-effects). The investigators believe that supplementing high-intensity gait training (the recommended practice to improve walking speed and distance) with a MAE will substantially enhance walking balance. Thus, the purpose is to evaluate the unique effects of MAE training on walking balance in PwCS and determine feasibility of conducting high-intensity gait training in a MAE.

Specific Aims: Aim 1: To evaluate gait patterns PwCS adapt during and immediately following walking practiced in two balance-challenging training environments: MAE and unpredictable lateral perturbations. Aim 2: To establish feasibility of high intensity gait training in MAE the investigators will evaluate cardiovascular intensity during gait training interventions performed in either a natural unmodified environment or a MAE.

Approach: Aims 1: 15 PwCS will participate in a single-day experiment evaluating gait biomechanics (COM dynamics and stepping patterns) during and immediately following treadmill walking performed in a MAE or while receiving frequent unpredictable lateral perturbations. Outcomes will assess if changes in gait patterns to maintain stability persist immediately following exposure to either of the balance-challenging environments. Aim 2: 15 PwCS will participate in two high-intensity gait training sessions. One session will be performed in a natural unmodified environment, the other in a MAE. The investigators will quantify differences in mean heart rate (HR) between the two sessions and whether mean HR is in the target high-intensity range of 70-85% of maximum HR.

Impact: This project will identify if and how PwCS uniquely adapt locomotor strategies following exposure to balance challenging environments and evaluate feasibility of administering high-intensity gait training in a MAE. Training walking balance of PwCS in a MAE by amplifying their own self-generated movements is a radical departure from current practice and could substantially enhance walking balance. Successful outcomes will motivate a future randomized controlled trial assessing the efficacy of MAE training to enhance walking balance in PwCS.

Enrollment: 30 estimated patients

Sex: All

Ages: 18 to 80 years old

Volunteers: No Healthy Volunteers

Inclusion criteria

• History of chronic stroke (more than 6 months post-stroke) with weakness on one side
• Ability to ambulate over ground for 10 meters with or without a single cane, and/or ankle-foot orthosis
• Ability to tolerate 10 minutes of standing

Exclusion criteria

• Presence of cognitive impairment (score of 22/30 on the Montreal Cognitive Assessment scale (MoCA))
• Presence of aphasia (score of 71/100 on the Mississippi Aphasia Screening Test (MAST))
• Excessive spasticity in lower limbs (score of > 3 on the Modified Ashworth Scale
• Severe cardiovascular and pulmonary disease affecting gait and balance
• History of recurrent fractures or known orthopedic problems in the lower extremities (i.e. heterotopic ossification) affecting gait and balance
• Concomitant central or peripheral neurological injury (i.e. traumatic head injury or peripheral nerve damage in lower limbs) affecting gait and balance
• Evidence of cerebellar ataxia
• Presence of unhealed decubiti or other skin compromise
• Enrollment in concurrent physical therapy or research involving gait or balance training
• Use of braces/orthotics crossing the knee joint
• Known pregnancy

Trial design

Primary purpose: Treatment

Allocation: Non-Randomized

Interventional model: Single Group Assignment

Masking: None (Open label)

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30 participants in 2 patient groups

Biomechanical Response to Balance Challenging Environments

Experimental group

Description:

Aim 1 will determine how people with chronic stroke (PwCS) adapt their gait in response to different balance challenging environments. For Aim 1, the investigators will conduct a single-session cross sectional study to assess gait patterns during and immediately following walking practiced in balance challenging environments. PwCS will perform treadmill walking in a natural unmodified environment, and in two balance-challenging environments that will include a Movement Amplification Environment (MAE), and an unpredictable lateral perturbation environment. All enrolled participants will undergo clinical outcome measure assessments to identify baseline function. In addition, all participants in Aim 1 will undergo biomechanical testing while walking in each of the three environments to assess changes in their walking patterns.

Treatment:

Behavioral: Treadmill walking in varying external environments

Heart Rate Response to Balance Challenging Environments

Experimental group

Description:

Aim 2 is a feasibility study to determine if high intensity gait training can be achieved within a MAE. For Aim 2, the investigators will employ a two-way cross over study design consisting of two gait training sessions (one in a natural unmodified environment and the other in a MAE). The investigators will examine cardiovascular response, perceived exertion, and gait characteristics (speed, number of steps) to quantify if the MAE impacts training intensity. All enrolled participants will undergo clinical outcome measure assessments. In addition, all participants for Aim 2, heart rate (HR), rate of perceived exertion (RPE), number of steps taken during the training sessions, and walking speeds will be recorded.

Treatment:

Behavioral: High intensity gait training in varying external environments