Robot exoskeleton for stroke - Rehabilitation Institute of Chicago

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Effect of Mobility Training Using Robotic Exoskeletons on Stroke Survivors

Project Overview

RIC's Matthew Knowlton, DPT, explains how exoskeletons work.

Project R2

Objective: Evaluate a clinical training strategy that uses a robotic exoskeleton in individuals who have experienced severe stroke.


Up to 80% of stroke survivors experience considerable gait deficits, including reduced walking speeds and asymmetrical walking patterns, which limit their capacity for community ambulation.

Although various treadmill-based motorized (robotic) devices have been developed to facilitate stepping practice in highly disabled populations, current devices only allow walking at a constant speed, and do not impose the balance and postural demands necessary for walking over ground.

This project will test and evaluate a new generation of exoskeletons (designed by Ekso Bionics) that may provide the benefits of over-ground stepping practice, including limb loading and balance and posture control, while simultaneously reducing the need for therapist assistance.

Clinical Significance

Stroke is the leading cause of adult-onset disability, and there are more than 6.4 million non-institutionalized stroke survivors in the United States.

Currently, stroke survivors are classified based on their self-selected walking speeds as either:

  • unable to walk (non-ambulators)
  • limited household ambulators (walking speed <0.4m/s)
  • limited community ambulators (0.4–0.8m/s)
  • community ambulators (>0.8m/s)

These walking speeds are significantly lower than those of healthy controls (1.3-1.5 m/s).

Recent statistics show that 40% of all stroke survivors experience moderate to severe impairments that require special care while an additional 10% are admitted to skilled nursing or long term care facilities and categorized as non-ambulatory (wheelchair-bound) or limited household ambulators. These individuals are unlikely to walk again. Thus, there is a compelling need to develop mobility-training strategies for survivors of severe stroke.

Target Population

Individuals who have experienced a severe stroke and are unable or have a limited ability (i.e., self-selected walking speed <0.4m/s) to walk.

Call for Research Participants

The Max Nader Center for Rehabilitation and Outcomes Research is conducting a study involving chronic stroke patients. The purpose of this study is to develop safe and effective training techniques for walking using a robotic exoskeleton. Participants will take part in 90-minute sessions (2-3 times per week) for 10 weeks.

Participants must meet the following criteria:

  • 6 months or more post stroke
  • Weight under 220 pounds
  • Be able to tolerate upright standing for a minimum of 30 minutes
  • No contractures
  • No severe osteoporosis
  • Age 18-85 years

For additional information, please contact:

Raquel Minarsch, DPT at (312) 238-2080 or

Read more about the study here.



We will update this page periodically with project news and related interviews.


From Bench to Bedside: The Long Walk for Robotic Exoskeletons (Wyss Institute, Harvard University)


"The Effects of Mobility Training Using Robotic Exoskeletons on Functional Recovery in Individuals with Severe Stroke." (2014 RESNA Conference Presentation, updated PDF version)

Project Staff

Arun JayaramanArun Jayaraman, PhD, Principal Investigator. Dr. Jayaraman is director of the Max Nader Center for Rehabilitation Technologies & Outcomes within the Center for Bionic Medicine at the Rehabilitation Institute of Chicago, and an assistant professor in the departments of Physical Medicine & Rehabilitation and Medical Social Sciences at Northwestern University. His research focuses on developing and executing both industry-sponsored and investigator-initiated research in rehabilitation robotics, prosthetics, and other assistive and adaptive technologies to treat physical disability. He specifically focuses on using quantitative outcome measures to improve the real-world use of rehabilitation technology. Dr. Jayaraman received his PhD in Rehabilitation Sciences from the University of Florida.

Dr. RymerWilliam Zev Rymer, MD, PhD, Co-Investigator. Dr. Rymer is Director of the Sensory Motor Performance Program (SMPP) at the Rehabilitation Institute of Chicago, as well as a professor of biomedical engineering at the McCormick School of Engineering, and a professor of physiology at Northwestern's Feinberg School of Medicine. He received his PhD from Monash University in Australia and his MD from the University of Melbourne. Dr. Rymer's research interests include regulation of movement in normal and neurologically disordered human subjects; physiological effects of spinal cord injury; sources of altered motoneuronal and inter-neuronal responses in spinal segments below a partial or complete spinal cord transaction using electro-physiological; pharmacological and biomechanical techniques; and rehabilitation robotics.

Chaithanya Mummidisetty, MS

Chaithanya Mummidisetty, MS, Engineering Project Leader.
Mr. Mummidisetty is a research engineer at the Center for Bionic Medicine within the Rehabilitation Institute of Chicago. He earned his bachelor's degree in biomedical engineering from Osmania University in India and an MS in biomedical engineering from the University of Miami. His research interests include gait rehabilitation for Stroke & Spinal Cord Injury patients, signal processing, new technology development, and outcomes research.

Matthew Knowlton, PT, DPT Matthew Knowlton, PT, DPT.
Mr. Knowlton is a research physical therapist in the Max Nader Rehabilitation Technologies & Outcomes Lab at the Rehabilitation Institute of Chicago. He received a BS degree in biology from Western Illinois University and a doctorate of physical therapy from Andrews University. His research interests include robotic exoskeletons used for rehabilitation or personal mobility, gait training for stroke and spinal cord injured subjects, and outcome measures research.

Additional staff members: Susan Deems-Dluhy, PT, DPT, NCS; Kate Scanlan, PT.

This research is supported by the U.S. Department of Education, National Institute on Disability and Rehabilitation Research, grant number H133E130020.