A Wearable System Aims to Change How Osteoarthritis Progresses—One Step at a Time
By Michelle Fiscus, Senior VP & Chief Communications Officer
More than 2 million people in North Carolina are living with osteoarthritis, and for many, it doesn’t begin with a clear diagnosis—it begins over the years, with small, repeated strain that builds until walking, climbing stairs, or even standing still starts to hurt. By the time the pain shows up, the damage is often already underway, setting people on a path that can end in joint replacement and a steady loss of independence.
At the University of North Carolina at Chapel Hill, Drs. Jason Franz and Brian Pietrosimone have spent the last decade focused on a part of that problem most patients—and most clinics—never see. Their work centers on the forces moving through the joint during something as routine as walking. “Over the past 10 years, our research has consistently pointed to one key factor: the compressive forces acting on the joint during walking,” he explains.
Those forces add up. People take thousands of steps each day, and even subtle shifts in how weight moves through the knee or hip can compound over time. “Because we take thousands of steps each day, even small changes in how forces move through the joint can have a big impact over months and years,” Franz says. Yet today, those forces are almost never measured in real-world care. Clinics rely on symptoms or imaging—tools that often reflect damage after it’s already occurred.
Franz’s team is building something different: a wearable system designed to measure those forces in real time and help people change them. The system uses small sensors paired with advanced algorithms to estimate how a person is loading their joints as they walk. Then it responds with simple cues—visual or auditory—so they can adjust their movement immediately. “The goal is to make each step you take work for your joint health instead of against it,” Pietrosimone says.
The concept is straightforward. The execution hasn’t been—until now. Moving from a controlled research environment into everyday clinical use is where most technologies stall. That’s the point NCInnovation is stepping into.
With NCInnovation’s non-dilutive funding, Franz’s team is shifting from a validated prototype to something that can function inside physical therapy clinics. That means refining the hardware, building a usable interface, and testing how both therapists and patients interact with it in real care settings. It’s a transition from “we know this works” to “this can be used, adopted, and trusted.”
Without that step, Franz is direct about what happens: “The technology risks staying in the lab rather than reaching the patients and providers who could benefit from it.”
If the system works as intended, it changes the role patients play in managing their condition. Today, care often revolves around managing symptoms or strengthening surrounding muscles. This approach introduces something that doesn’t currently exist in most clinics: a way to directly measure and adjust the forces contributing to joint damage. “This technology would give [clinicians] that capability along with a clear, objective target to guide treatment,” Franz says.
For patients, that translates into something more immediate and actionable—guidance in the moment, while they’re moving, instead of waiting for pain to signal a problem. Over time, that could mean maintaining mobility longer, staying active, and potentially delaying or avoiding joint replacement surgery altogether.
The scale of that impact matters in North Carolina. Osteoarthritis affects people across age groups—from older adults to younger individuals recovering from joint injuries—and places a growing burden on both families and the healthcare system. With more than 500 physical therapy clinics across the state, the infrastructure for care already exists. What’s been missing is a tool that can translate complex biomechanics into something usable, day-to-day.
Franz and Pietrosimone see the next five years as the turning point: a clinically validated system, integrated into therapy settings, with evidence that it improves outcomes and fits into how care is actually delivered. Success isn’t theoretical—it’s whether this becomes part of routine treatment.
“What keeps us motivated is the combination of scientific evidence and real patient need,” they say.