OpenSim User Profile: Jill Higginson, PhD
Jill Higginson at the University of Delaware uses OpenSim to study stroke.
Jill Higginson, PhD, assistant professor of mechanical engineering at the University of Delaware, had one of the original subcontracts to the Simbios grant—a pilot project to explore simulating post-stroke hemiparetic (i.e., partially paralyzed) gait using OpenSim. The project showed that OpenSim could be used to study pathological gait and that it shortens the process of creating such simulations to an hour or so, as opposed to days or weeks. “That was huge,” Higginson says.
In 2008, Higginson received a five-year collaborating R01 to take her work on simulating post-stroke hemiparetic gait further. The project adds a static MRI component to look at muscle atrophy on the paralyzed side; an activation component to assess the force generating capacity of a muscle; and electromyographic (EMG) data to estimate the forces produced by a muscle. At this point, just about two years into the grant, Higginson says they’ve collected data from subjects for the EMG, MRI and activation components and can incorporate each piece into the simulations. “Now we’re working to get these parts to function together and get it streamlined into OpenSim.”
Higginson is “anxiously awaiting OpenSim 2.0,” which will have certain features she desires such as a ground contact model and a customized cost function. These features would allow her to iterate through different hypothetical treatment protocols for individual patients—such as what would happen if you strengthen a particular muscle or change a muscle pattern. “Would that let them better bend their knee or take a longer step?” Higginson asks. Right now, that kind of iteration isn’t possible with OpenSim. “We put in experimental contact forces, but it doesn’t allow you to predict what would happen to those forces if you change the experimental conditions. It would be really cool to be able to do that.”
Even while awaiting this added flexibility, Higginson says she uses OpenSim every day. “OpenSim is a huge benefit. I couldn’t do half of the things that I do without it,” she says. “It lets me concentrate on the science rather than the algorithms.”