Printing play: A path forward for children with prosthetics

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Quentin Sanders

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A child who uses a lower-limb prosthesis faces unique challenges when it comes to activities most children take for granted, such as running and being active. Without access to a prosthetic device designed to support these movements, children may miss out not only on the simple joys of play, but also on critical opportunities for physical development during key stages of growth.

Quentin Sanders. Photo by Ron Aira/Office of University Branding

George Mason University researcherQuentin Sandersis part of a collaborative research team working to make high-performance prosthetic limbs more affordable, accessible, and better tailored to the needs of active children. Sanders, along with Jonathon Schofield, an associate professor at the University of California, Davis, and Garrett Melenka, an associate professor at York University, received a three-year, $500K grant from the National Science Foundation to support the project, which began in September 2025.

Most standard foot or leg prostheses are built for basic walking, not for the kind of active movement that helps children develop strength, balance, and coordination, the benefits that come from running and jumping with friends.

"This limitation can be especially challenging for children," said Sanders, who has a joint appointment in the Department of Bioengineering and the Department of Mechanical Engineering. "Kids want to run and play. When they can't, they're more likely to avoid physical activities, such as sports, or even stop using their prosthesis altogether."

A 3D-printed running blade prototype, created using the technique Sanders and his colleagues are developing. Photo provided

Often seen in competitive events such as the Paralympic Games, running blades are curved, spring-like prosthetic feet made from carbon fiber that mimic the energy return of a biological foot. While these devices offer an alternative option to standard leg prostheses and can enable children to run, they are expensive and often inaccessible. A single running blade can cost several thousand to tens of thousands of dollars and is typically not covered by insurance because it is considered nonessential, rather than medically necessary.

Some charitable organizations help families access these devices, but demand far exceeds supply, and for growing children, one blade is rarely enough. "Kids grow quickly," said Sanders. "As they get taller, they outgrow their prostheses, which means going through multiple blades over time."

The research team has several goals, starting with identifying what children truly need from an activity-enabling prosthesis. The researchers are examining how motivation to be active, physical growth, and different types of movement influence prosthetic performance in everyday settings. "What do you use it for? What don't you use it for? What do you wish you could do?" said Sanders.

The team is also analyzing how children move while using their current running blades, studying activities such as running, jumping, and changing direction to better understand the biomechanics and physical demands involved.

Finally, the team will take a close look at how today's running blades perform under real-world demands. "We want to understand how stiff they are, how much load they can handle, and when they might fail," said Sanders. "We can then combine that information with what kids tell us they want to do and use it to guide our 3D printing process-creating blades that are better suited for active play."

Sanders and his collaborators are using an advanced additive manufacturing approach known as continuous-fiber 3D printing, in which carbon fibers are embedded within the printed plastic to reinforce the prosthetic structure. This method enables the creation of strong, lightweight devices that can be tailored to a child's size, growth, and activity needs.

"By combining manufacturing, composite materials, prosthetics, design, and biomechanics, this project provides an innovative and holistic solution," said Melenka.

The technique is already used to produce strong, lightweight components in the aerospace and automotive industries, but it has seen limited adoption in prosthetic design. This project represents one of the first efforts to apply it systematically to activity-enabling prostheses for children.

"What's most exciting about this project is the collaboration across institutes, disciplines, and areas of expertise," said Schofield. "We are bringing together researchers in movement mechanics, advanced materials manufacturing, and pediatric lower-limb prosthetic care. We are also incorporating the lived experience of children and families, along with clinicians who work with these patients every day."

The work also has the potential for industry disruption, according to Sanders. "If we can show that a child's physical measurements and movement needs can be translated into a digital model and then used to 3D print a customized prosthesis, existing prosthetic manufacturers would begin to integrate this approach into their production pipelines."

For Sanders, the motivation goes beyond technical innovation. "I've always been interested in translating new technologies into real-world solutions," he said. "Helping people with disabilities and impairments is why I got into this field in the first place."