It comes suddenly — it may be weakness in an arm, trouble seeing, slurred speech. Stroke.

“We think it only happens to old people, but it also happens to young people,” Jennifer Semrau said.

She remembers how shocked she was when the 36-year-old stroke patient with 2-year-old twins came into the clinic where she was working as a postdoctoral fellow a few years ago at the University of Calgary. Semrau became fascinated with the science behind motor control — the complex sensing and signaling that regulates our every move — and became driven to find scientific answers to help stroke survivors recover.

Now an assistant professor of kinesiology and applied physiology at UD, Semrau is delving deeper into a sense that’s critical to movement, but you may not have heard much about it: proprioception. When you’re asked to close your eyes and touch your nose (go on, give it a try), proprioception is the so-called “sixth sense” in play — that awareness of where your different body parts are.

“People recovering from a stroke have a lot of difficulty with it,” Semrau said.

With a recent $748,231 grant from the National Science Foundation, she’s working to help stroke survivors with upper limb issues regain that sense to improve their movement. The project will conduct human subject experiments, develop novel computational models, and use machine learning methods to enhance the design of personalized, subject-adaptive robotic interventions that are optimized for each individual’s specific profile of impairment.

“A patient may have weakness, an inability to use an arm,” Semrau said. She recalled a story a colleague told her about a man in his late 60s who was a farrier — he made his living shoeing horses, and then he had a stroke. As he was recovering, he felt as though he could move normally, but he would have to look at his hands to actually know where they were in relation to each other, making his work that much more difficult.

“We want to help these stroke survivors gain that control back — both the control of the limb and the actual sensation of the limb,” Semrau said.

In her lab, Semrau is using an interactive robot called the Kinarm (for Kinesiological Instrument for Normal and Altered Reaching Movement) to help with post-stroke assessments. Less than 20 of these devices are in use around the world with individuals with stroke.

The Kinarm resembles a comfy theater seat in which the person sits, with independently movable platforms for each arm, and a small virtual reality ‘movie screen’ for viewing straight ahead.

Semrau and doctoral student Duncan Tulimieri evaluate a stroke survivor doing such tasks as taking the paddler test, where the individual is asked to hit a red ball that’s virtually coming right at him, while his arms and hands are hidden from view. The arms, able to move independently in their movable platforms, are equipped with sensors for measuring motor function through movement accuracy, speed, timing and eye tracking.

Tulimieri can adjust the robot so that study participants can move their arms in a frictionless environment.

“Often, stroke survivors can’t lift their arms against gravity,” he explained.

Conversely, as the individual regains strength in a physical therapy program personalized to their specific condition, the team can increase the resistance to make an arm work harder.

Overall, the data collected helps the researchers design treatment protocols that are truly tailored to the stroke survivor on the road to recovery. The information also contributes to the lab’s ongoing work to better understand the underlying impairments.

Tulimieri, who is now in the second year of his doctoral research in UD’s Biomechanics and Movement Sciences program, says he’s putting his background in exercise science and robotic task programming to good use. In the new year, thanks to a grant from the University of Delaware Research Foundation (UDRF), Tulimieri will have the unique opportunity to work directly with Kinarm’s software developers and programmers to develop custom programs for the robot.

“I love the clinical aspect of this research, working with stroke survivors, and I like to work with robots,” Tulimieri said. “I’m excited about the work ahead.”

The UDRF grant will advance use of robotic tools to identify behavioral biomarkers of proprioceptive impairment that may impact motor skill recovery after stroke. Semrau plans to use the pilot data collected to develop a proposal to the National Institutes of Health for a full-blown study.

“I always want my research to be purposeful and to help people,” Semrau said. “It comes down to: What can we do to improve someone’s quality of life?”