New Purdue Health and Kinesiology head an expert in biomechanics, balance in older adults

Li-Shan Chou is the new head of the Purdue University Department of Health and Kinesiology. His research “applies engineering theories to synthesize underlying mechanisms governing human locomotion.”(Tim Brouk)

Written by: Tim Brouk, tbrouk@purdue.edu

Early in his academic research, a young Li-Shan Chou was interested in making bipedal robots and perfecting their movements in the mechanical engineering field. During his studies, however, he became more interested in the source material — actual humans and their body movements.

Decades, degrees and tenure-track faculty positions later, Chou is a leading expert on how adult humans move and maintain balance. The researcher and professor was named the head of the Purdue University Department of Health and Kinesiology (HK) this summer and has brought in a wealth of research, technical know-how, and cutting-edge hardware and software that tracks human movement.

A recent focus of Chou’s work has been looking at balance and gait of older adults. The work, he finds, is extremely important.

“There is a societal need in this area of fall prevention because one out of four adults over the age of 65 have fallen at least once a year and many of them never fully recover,” Chou said. “I want try to enhance our quality of life down the road.”

While bipedal robot research has exploded since he shifted to human movement, Chou has no regrets in the change.

“I became fascinated by the human body system, but another reason is more selfish — I mean, I want to have a golden life in my older years,” he said with a smile.

AI in HK

Chou’s latest work has been aided by new motion-capture technology. Gone are the ping pong ball-like sensors placed over the clothing to pick up movements. Inertial Measurement Units (IMUs) that fit on the subject’s skin now collect and broadcast clear data to the researcher. Then there are the cameras and software that can focus on “landmark points” on the body like shoulders, elbows and knees. The software uses AI to “learn” and “construct” a digital skeleton of the study participant’s body.

“The cameras can identify a skeleton with certain length and certain width scaled to fit the contour of your body shape.” Chou explained. “The bone movement is what we try to detect, not your soft tissue movement.”

The new IMU sensors can even vibrate to alert the subject for to indicate movements that can be improved or adjusted for easier tolls on the body. They can help the participant move more efficiently while exerting less effort and avoiding overcompensation for other body parts during the movement analysis.

“Not only can they detect your body movement, they can also generate haptic feedback,” Chou said. “The sensors actually can generate some kind of vibrations or pattern of signals onto the body, and hopefully the individuals can understand and comprehend this additional augmented signal and then react for the correction.”

An example would be correcting a participant’s posture during walking. The sensors would alert problem areas during the movement, telling the subject and researchers what parts of the body can be engaged more or less during the movement.

This is your brain on movement

Chou plans to pair these next-generation sensors with functional near-infrared spectroscopy (fNIRS) and EEG. A study participant would don the integrated fNIRS/EEG cap while hooked up to motion capture sensors, and Chou and his colleagues can examine brain activity by detecting changes in blood oxygenation while performing physical activities.

“That’s an indicator of how much your brain is engaged,” Chou said. “We are interested in how the brain interacts with the motor function. There are also a lot of diseases, like dementia, associated with cognitive degeneration in our society.”

“If you are engaged in multitasking, how does your brain handle all this?” Chou asked. “This methodology could record the brain’s activity when an individual is multitasking. What happens to the brain when they encounter a large object while walking? Does the subject walk around or step over? Which task takes priority? For patients with Parkinson’s disease or other cognitive degenerative diseases, learning what kind of brain activity is used in such situations could prevent falls, which are extremely dangerous for older adults.”

Giant leap in Purdue kinesiology research

This technology and work are still being set up in West Lafayette as Chou transitions his research from Iowa State, but Chou’s expertise will boost HK’s biomechanics focus. Professor Shirley Rietdyk, a Purdue HK researcher for more than 20 years, said Chou’s arrival will bolster an already strong body of research in her Human Motor Behavior Group.

“A lot of the work that I do is parallel to what Li-Shan has been doing,” she added. “It’s just wonderful to have Li-Shan here to be able to brainstorm, collaborate and bounce ideas off of each other.”

Rietdyk said Chou’s technological process can help with studies outside of the lab. The untethered sensors can feed into the computer from the subject’s home instead of the lab setting where participants are often less relaxed. Chou, Rietdyk and their colleagues could study how an older person navigates their own home, how they can reduce hazards to their walking and what improvements they can make that could very well save their lives.

“We will get more realistic environments and more realistic distractions,” Rietdyk explained. “People fall quite often when they’re doing something else at the same time, such as talking to someone, which is a very realistic task. I’d like to explore more about how they pay attention to the environment, how they notice the hazards and how to respond appropriately.”