Mizzou center engineers techniques for therapy

COLUMBIA, Mo. (AP) - In the basement of Clark Hall at the University of Missouri, biomechanical engineers spend their days in the "gait lab" in Room 6. It looks like a typical lab, with its windowless white walls and fluorescent lighting - except for the infrared cameras strategically aimed at four blue tiles in the middle of the floor.

That's where the action happens.

Two computers are ready to track movements, and a monitor behind them is ready to display them, the Columbia Missourian reported.

For Columbia resident Josh Tucker, 15, the monitor helps him pretend he's a video game character, said his mother, Donna Tucker.

But there's a serious side to the technology.

When Josh was in an all-terrain vehicle accident in April 2012, he suffered a traumatic brain injury that left him in a coma for five months. When he regained consciousness, he had to relearn to eat, speak and walk.

While trying to help Josh recover his walking abilities, therapists at the Children's Hospital Therapy Center found the left side of his body was significantly weaker than his right.

They advised Josh to go to the Mizzou Motion Analysis Center, as the gait lab is formally known. At the lab, researchers would be able to see what was going on mathematically in Josh's limbs.

It's all part of the way MU biomechanical engineers have been researching improvements in measuring and maintaining human motion. The Mizzou Motion Analysis Center, which opened in the summer of 2014, combines research in biomechanical engineering, orthopedics and physical therapy.

So while Josh is pretending he's a video game character, the forces acting on his muscles and nerves are being measured in the hopes of providing him with a better, more precise treatment plan.

On a recent day, researchers placed motion markers - small plastic balls with reflective tape - on Josh's muscles and had him walk on the four force plates in the center of the floor, which act like scales when weight is applied. When Josh moved, his multi-colored skeleton on the computer screen also moved. On the display, lines and balls around his limbs indicated the forces on his muscles.

The infrared cameras were focused on the balls, tracking motion and calculating extension angles and muscle flexion. The force plates also tracked the power generated by Josh's joints - especially on his weak left side.

Through imaging called electromyography (also known as EMG), the computers show which muscles are being activated during each movement. Later, the lab also uses computational models that combine such gait measurements with images from Josh's tests at the Children's Hospital Therapy Center.

It was exciting for Josh to watch a different version of himself on the screen, his mother said. For the researchers focused on the "computational side" of physical therapy, it was just another day's work, center director Dr. Trent Guess said.

"It's just fascinating to me how you don't even think about touching your nose," Guess said. "But how we coordinate the motion of all our arms and fingers is a pretty amazing task. And when you think about how our tissues withstand these forces we put on them in a lifetime, there's no man-made material that can do what our cartilage does."

Guess has a background in mechanical engineering, but he first took an interest in biomechanics while studying for his doctorate at the University of Kansas. He decided he wanted to promote wellness and health using computational methods.

"Being immersed in the clinical side, every day I get to see where the problems are," Guess said. "I was at an engineering school for 10 years. It was fine, but it just felt like we were building a lot of tools and not really doing anything with them."

The center has been working on two studies since it opened. One has been in partnership with the University of Missouri women's soccer team. Guess' research team uses computational models to look at the power distribution in the athletes' limbs. The engineers specifically look at the symmetry and rotation of legs during jumps to measure possible indicators of knee injury, specifically to the anterior cruciate ligament, known colloquially as the ACL.

It takes about a year to measure the athletes and sort through the data, Guess said.

But the other study, which explores how knee tissues called menisci absorb shock, has already yielded success. Guess and his researchers found that if menisci become slack over time, this damage can hinder knee movements significantly.

According to the center's research on osteoarthritis, this finding may ultimately impact research on how to prevent joint pain and degeneration.

Such research can benefit patients at the Children's Hospital Therapy center, physical therapist Mary Meyer said.

When Josh was scheduled for a heel lengthening surgery after the weaknesses in his left side became apparent, Meyer recommended going to the gait lab before and after the surgery. That way, Guess' researchers could do a direct comparison to detect changes.

"In Josh, we were seeing a lot of lower extremity weakness," Meyer said. "We wanted to see what kind of motor control he truly has, to dictate what medical therapy is best for him at this time."

Meyer broached the idea of partnering with the gait lab around half a year ago after seeing the success of the James R. Gage Center for Gait and Motion Analysis, which is operated by Gillette Children's Specialty Health Care in St. Paul, Minnesota. Meyer believed that the lab could help the hospital in Columbia make similar strides in treating its patients.

The EMG imagery that MU's gait lab produces can further indicate which muscles a physical therapist should pay attention to, making their jobs easier, Meyer said.

"When working with children, sometimes it's hard to determine and prioritize what the best medical recommendations are," Meyer said. "A lot of our children have multi-system impairments. We've seen how beneficial it is for the pediatric population to make better recommendations."

For now, the hospital is assigning patients to the lab once a month; the goal for the near future is to double that. So far, Guess and his researchers have been able to do computations for six patients, Meyer said. A single appointment is about three hours long.

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