Study shows that aging adults with mild cognitive impairment may have trouble learning new walking patterns

Research underway at the University of Delaware seeks to better understand how the brain controls movement and how motor skills are learned in health and disease.

“Our initial findings show that older adults with MCI (mild cognitive impairment) are not learning as much or as rapidly about the new movement patterns that we’re trying to teach them,” said Susanne Morton, an associate professor of physical therapy (PT) in the University of Delaware’s College of Health Sciences.

Morton’s research is propelled by a $50,000 award from the donor-created Maggie E. Neumann Health Sciences Research Fund, which targets research and innovation aimed at improving the lives of people with disabilities.

People with MCI function independently but are at a higher risk of developing Alzheimer’s dementia. 

Morton is running older adults, some with MCI, through various locomotor tasks to gauge their balance and walking systems and their ability to learn new walking patterns. The Neumann-funded pilot study in Morton’s Neuromotor Behavior Lab on STAR Campus yielded surprising results.

“Certain forms of motor learning are implicit, meaning they happen automatically and subconsciously. People with MCI, who function independently, shouldn’t have any trouble with the type of motor learning, but we’re finding they do.” 

For one test, study participants walk on a split-belt treadmill, which engages two belts at varying speeds, forcing one leg to move twice as fast.

“Learning to walk on a split-belt treadmill is very implicit; people can’t consciously explain how they make their walking patterns symmetric even though belt speeds are symmetric,” Morton said. “However, people with MCI were quite impaired with this task. It looks like they’re limping because they can’t restore their symmetric stepping.”

The findings are significant and could change the practice of physical therapy in people with cognitive impairment. 

“Most neurological rehabilitation is based on repeating actions until they’ve been mastered; implicit motor learning approaches are necessary for recovery and rehabilitation,” Morton said. “If patients with MCI have trouble with that type of motor learning, it could result in longer hospital stays, reduced gains from therapy, and ultimately, worse outcomes.”

This piques the interest of biomechanics and movement science doctoral student Soumya Bhat. The physical therapist’s dissertation work centers on moving the practice of PT in the right direction.  

“PT relies on successfully teaching new patterns or restoring patterns,” Bhat said. “If people come in after a stroke, the goal is to get them walking again.”

This kind of physical activity is crucial to prevent further complications or injuries. 

“Making people more active decreases heart conditions and the progression of neurological diagnoses. All that activity relies on being able to move, and we’re still trying to understand how different therapies help our patients,” Bhat said. “We have very little understanding of how to treat someone with cognitive deficits or how to improve outcomes in persons with stroke or Parkinson’s.” 

Early findings from Morton’s and Bhat’s research also indicate that people with MCI do worse the more instructions they’re given. 

“The cognitive load may be too much,” Morton explained. “Trying to solve the problem on their own is all their brain can process, then if they try to process instructions, it’s dual tasking.” 

It’s like walking while texting, and then you trip. 

“From a rehabilitation perspective, as PTs, we give patients a lot of verbal instructions,” Morton said. “So, now, if someone has a cognitive impairment, we’re realizing it may be better to say nothing at all.”

A single command could prove more beneficial than detailed instructions for patients with cognitive impairment.

“Just say, ‘Step to the target,’ and have a line on the floor,” Morton said. 

Morton and Bhat presented their findings at the Combined Sections Meeting of the American Physical Therapy Association in Boston in February. 

The Neumann Award has allowed Morton and Bhat to gather enough meaningful data to serve as a launching pad to seek significant funding from the National Institutes of Health to study why people with MCI have trouble learning new balance and walking patterns. 

“They don’t have major physical mobility problems, weakness or loss of strength, and no neurologic issues — other than their cognition — that put them at risk for falls,” Morton said. “But people with MCI look just as bad, if not worse, than patients with lesions to major motor learning regions of the brain like the cerebellum. It’s very striking to see the overlaps in how they look.

“It suggests that balance and walking measures like ours may be better biomarkers or early detectors of MCI or Alzheimer’s disease.”

About the fund

Maggie E. Neumann Health Sciences Research Fund was established in 2020 to support research designed to improve health and quality of life outcomes for children and adults with physical and developmental disabilities. While the fund resides at the College of Health Sciences, the intent is to support interdisciplinary research across all UD colleges.

The research fund was created with a gift from Donald J. Puglisi and Marichu C. Valencia in honor of their granddaughter, Maggie E. Neumann. Puglisi is a member of UD’s Board of Trustees, and they both serve on the President’s Leadership Council.