Model-informed Patient-specific Rehabilitation Using Robotics and Neuromuscular Modeling

Stroke is the third leading cause of death and the primary cause of long-term disability in the United States, affecting approximately 795,000 people each year. Hemiparesis, or unilateral weakness, is common after stroke and responsible for changes in muscle activation and movement patterns as well as declines in walking speed. It has been shown that increased walking speed directly corresponds to a higher quality of life in older adults and therefore, is often the goal of motor rehabilitation after stroke. However, there is no consensus on the best method for improving walking function after stroke and the results of post-stroke gait studies vary widely across sites and studies. Walking is one of the human's most important functions that serve survival, progress, and interaction. The force between the foot and the walking surface is very important. Although there have been many studies trying to understand this, there is a need for the development of a system that can advance research and provide new functionality. In this work, we will conduct a series of studies that attempt to analyze human gait and adaptations from different perspectives.

Study Overview

• Status: Recruiting
• Conditions: Stroke
• Intervention / Treatment: Behavioral: Belt Accelerations; Behavioral: Belt accelerations combined with an exoskeleton; Behavioral: Variable Stiffness treadmill

• Study Type: Interventional
• Enrollment (Estimated): 72
• Phase: Not Applicable

Contacts and Locations

Study Locations

• United States
  • Delaware
    • Newark, Delaware, United States, 19716
      • Recruiting
      • University of Delaware
      • Contact: Panagiotis Artemiadis, Ph.D.; Phone Number: 302-831-8546; Email: partem@udel.edu
      • Principal Investigator: Panagiotis Artemiadis, Ph.D.

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: Yes

Description

Inclusion Criteria:

Two groups of subjects will be included in the study.

Group A: Individuals must be between the ages of 18 and 80 years, be in general good health, and be proficient in English. The subjects' physical fitness for participation in the research procedures will be documented via the Physical Readiness Questionnaire (PAR-Q). Their answers to the PAR-Q will be evaluated by the study team to determine if they are suitable for the study. Individuals should not have significant musculoskeletal conditions (osteoarthritis, joint replacement etc). The subjects' resting heart rate must be between 60-100 beats per minute, while their resting blood pressure between 90/60 to 140/90. The subjects should weigh under 250 pounds (lbs).

Group B: Individuals must be between the ages of 18 and 80 years, speak English, have a single, unilateral, chronic stroke (>6 months post-stroke), confirmed by Magnetic Resonance Imaging (MRI) or Computed Tomography (CT) scan. They should be able to walk at a self-selected speed for at least 15 minutes without assistance from another person. They should be able to respond to questions during screening, provide informed consent and fully follow instructions. The subjects' resting heart rate must be between 60-100 beats per minute, while their resting blood pressure between 90/60 to 160/90. The subjects should weigh under 250 pounds (lbs).

Exclusion Criteria:

• Any neurological conditions (applicable to Group A - healthy subjects) or other neurological conditions in addition to stroke (applicable to Group B - stroke survivors);
• Inability to walk outside the home before the stroke (applicable to Group B - stroke survivors);
• Coronary artery bypass graft in the past 3 months, myocardial infarction in the past 3 months, uncontrolled or untreated atrial fibrillation, severe or painful peripheral vascular disease, diagnosis of heart failure, or unstable or untreated angina;
• Expressive aphasia
• Reported musculoskeletal pain or conditions that limit walking (such as tendonitis, arthritis, osteoporosis, spinal stenosis, or any orthopedic surgery or fracture to the legs or spine in the last 6 months);
• Inability to communicate with investigators (e.g., due to severe aphasia or other cognitive impairment);
• Severe respiratory problems such as chronic obstructive pulmonary disease (COPD);
• Unexplained dizziness;
• Weight greater than 250 pounds (lbs).
• Inability to ascend and descend 4 steps with handrails using another person's assistance (if desired)

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Basic Science
• Allocation: N/A
• Interventional Model: Single Group Assignment
• Masking: None (Open Label)

Number of Arms

1

Arms and Interventions

Participant Group / Arm

Intervention / Treatment

Experimental: All subjects; All subjects (healthy and stroke survivors) participating in the study

Behavioral: Belt Accelerations; Intervention used in both healthy and stroke survivors. In this mode, participants are walking on a treadmill with two belts with independent speed control. The speed of each belt will increase with constant acceleration during double support, shortly before push-off of the supported leg.; Behavioral: Belt accelerations combined with an exoskeleton; Intervention used in both healthy and stroke survivors. In this mode, participants are walking on a treadmill with two belts with independent speed control, and using a hip exoskeleton. The velocity of each belt will increase with constant acceleration during double support, shortly before push-off of the supported leg. At the same time, they will be interacting with a wearable motion assistive device (i.e., exoskeleton). The exoskeleton will apply forces to the leg to resist hip extension during accelerations, reducing hip extension relative to the values of that participant at baseline.; Behavioral: Variable Stiffness treadmill; Intervention used in both healthy and stroke survivors. In this mode, participants are walking on a treadmill with two belts with identical speed control. A variable stiffness mechanism under one belt will change the vertical stiffness of one side of the treadmill for one or multiple steps. The walkers will be informed before stepping on the softer surface on one side, which can be either the left or the right side.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Contralateral plantarflexor muscle activation during exposure to belt accelerations	Magnitude of the neural signal (in millivolts (mV) sent to three muscles during push-off, as explained via surface ElectroMyoGraphic signals, measured during exposure to belt accelerations. Three measurements (one from each relevant muscle) will be considered primary outcome measures.	During intervention
Contralateral plantarflexor muscle activation during exposure to combined exposure to belt accelerations and exoskeleton interaction	Magnitude of the neural signal (in millivolts (mV) sent to three muscles during push-off, as explained via surface ElectroMyoGraphic signals, measured during exposure to combined exposure to belt accelerations and exoskeleton interaction. Three measurements (one from each relevant muscle) will be considered primary outcome measures.	During intervention
Contralateral plantarflexor muscle activation during exposure to lowered stiffness step perturbation	Magnitude of the neural signal (in millivolts (mV) sent to three muscles during push-off, as explained via surface ElectroMyoGraphic signals, measured during exposure to lowered stiffness step perturbation. Three measurements (one from each relevant muscle) will be considered primary outcome measures.	During intervention
Hip extension exposure to belt accelerations	Extension of the leg during push-off, measured as hip extension angle in degrees, during exposure to belt accelerations.	During intervention
Hip extension during exposure to combined exposure to belt accelerations and exoskeleton interaction	Extension of the leg during push-off, measured as hip extension angle in degrees, during exposure to combined exposure to belt accelerations and exoskeleton interaction.	During intervention
Hip extension during exposure to lowered stiffness step perturbation	Extension of the leg during push-off, measured as hip extension angle in degrees, during exposure to lowered stiffness step perturbation.	During intervention
Step length symmetry exposure to belt accelerations	Step length symmetry, measured as a percentage of the left leg step length to the right leg step length, during exposure to belt accelerations.	During intervention
Step length symmetry during exposure to combined exposure to belt accelerations and exoskeleton interaction	Step length symmetry, measured as a percentage of the left leg step length to the right leg step length, during exposure to combined exposure to belt accelerations and exoskeleton interaction.	During intervention
Step length symmetry during exposure to lowered stiffness step perturbation	Step length symmetry, measured as a percentage of the left leg step length to the right leg step length, during exposure to lowered stiffness step perturbation.	During intervention

Collaborators and Investigators

• Sponsor: University of Delaware

Publications and helpful links

General Publications

• Chambers V, Artemiadis P. Using robot-assisted stiffness perturbations to evoke aftereffects useful to post-stroke gait rehabilitation. Front Robot AI. 2023 Jan 4;9:1073746. doi: 10.3389/frobt.2022.1073746. eCollection 2022.

Study record dates

Study Major Dates

• Study Start (Actual): September 21, 2022
• Primary Completion (Estimated): June 30, 2026
• Study Completion (Estimated): June 30, 2026

Study Registration Dates

• First Submitted: August 15, 2023
• First Submitted That Met QC Criteria: August 20, 2023
• First Posted (Actual): August 24, 2023

Study Record Updates

• Last Update Posted (Actual): August 24, 2023
• Last Update Submitted That Met QC Criteria: August 20, 2023
• Last Verified: August 1, 2023

More Information

Terms related to this study

• Other Study ID Numbers: R01HD111071 (U.S. NIH Grant/Contract)

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO
• IPD Plan Description: The individual participant data (IPD) will not be shared for confidentiality reasons, as approved by the Institutional Review Board (IRB) of the university.

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No