Imagine a therapeutic device that children with cerebral palsy could wear at home to strengthen their legs and increase their mobility, eventually allowing them to walk without assistance.  Now imagine the device was low-tech and affordable, making it accessible to children around the globe who have limited or no access to expensive therapies that require robotics, supervision by a trained clinician, or invasive surgeries. PlayGaitTM, a device being developed by the Ability & Innovation lab at the University of Washington, is applying new exotendon technology to bring this device to market.

Photo of PlayGait research team
Left: Dr. Kristie F. Bjornson; Center: Dr. Katherine Steele; Right: Jessica Zistasis
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Leading this effort are Kristie Bjornson, a UW assistant professor in pediatrics working with Seattle Children’s Research Institute, Katherine Steele, a UW assistant professor of mechanical engineering, and Jessica Zistatsis, a research assistant in mechanical engineering.  

Their labs were awarded this year’s $30,000 Global WACh-W.H. Coulter Foundation pilot grant for engineering solutions to improve the health of women, adolescents and children.  The team will use the award to help test the device on children with cerebral palsy to determine whether the pediatric exoskeleton increases mobility, and to better understand perceptions of usability including comfort, fit, and aesthetics. The device will be reimbursable by most insurance companies, making it easily accessible to everyone, and the researchers are beginning discussions with therapists in low resource settings to identify how they can adapt their design to best serve kids in those environments. Funds will enable collection of critical pilot data for PlayGait and bring their team one step closer to putting this innovative technology into the hands of families who need it most.

Cerebral palsy is the most common motor disability, affecting about 1 in every 300 children in the United States, and even more children globally.  Cerebral palsy affects muscle development and can cause muscle and joint tightness or stiffness that inhibits a child’s ability to learn to walk and to walk efficiently once they do walk. Early intervention with therapies like PlayGait may have positive long-term impacts on a child’s ability to move freely and independently throughout their lifetime and reduce the burden on caregivers who support them.

PlayGait is designed to leverage exotenden technology, a mechanism that uses an elaborate series of cables and springs that simulate tendons connecting multiple joints, to achieve improvement in motor function. Similar technology has shown promise for improving walking for adult stroke survivors by a Seattle-area start-up, Cadence Biomedical. The PlayGait research team is currently optimizing the prototype device and measuring its effect on children’s movements as they use it to strengthen their leg muscles and improve their ability to walk on their own.

“The currently available assistive devices for home use include walkers, crutches, and ankle foot orthoses, but none of these train kids to walk unassisted,” says graduate researcher Jessica Zistatsis.  Children will be able to wear PlayGait at home, at school, and around the community to learn a proper walking pattern.

Zistatsis continued, "Ultimately, we hope this will allow kids to outgrow the need for assistive devices."


The University of Washington’s Global Center for Integrated Health of Women, Adolescents and Children (Global WACh) envisions a world in which communities recognize the value of women, children, and youth by assuring them access to quality health services and the educational, social and economic opportunities necessary to achieve health and well-being. Global WACh is a cooperative effort, providing expertise from the UW Departments of Global Health, Pediatrics, and Obstetrics and Gynecology required to approach maternal child health from a lifecycle perspective.

Awards through the Global WACh-W.H. Coulter Foundation collaboration support the development of technologies that address unmet clinical needs and have strong potential to improve the health and wellbeing of women, adolescents and children in low-resource settings in the United States and abroad.

For more information on PlayGait and the Global WACh-W.H. Coulter Foundation pilot award please email