Kinesiology Study Will Seek Interventions to Help Older Adults Maintain Mobility

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Katherine Boyer (left) and Jane Kent

Kinesiology researchers Katherine Boyer and Jane Kent have received a five-year, $3.4 million grant from the National Institutes of Health (NIH) to zero in on what’s happening in an older adult’s body when it starts requiring more energy to walk, even as pace slows down.

The ultimate goal is to use their findings to create interventions—such as targeted activity guidelines—to keep older adults as mobile and healthy as possible, for as long as possible.

Some critical signs of aging include slower steps that also require more energy to take—and that one-two punch can foreshadow reduced mobility and ultimately trigger a cascading decline in health.

“Your walking speed remains constant for most of your life, and then after about the age of 65 it starts getting slower,” says biomechanist Katherine Boyer, professor of kinesiology and an expert in gait mechanics.

Boyer and physiologist Jane Kent, Distinguished Professor Emerita of Kinesiology who specializes in the biochemistry of muscle, are bringing together their years of complementary research to advance understanding of the processes that lead to diminished mobility as we age.

At about the same time as walking speed begins to slow, the energy it takes to walk a given distance—called the “energy cost of walking”—starts to increase. “So, you’re using more energy to travel the same distance as a young person,” Boyer says. In addition, Kent explains, the older adults’ muscles grow smaller and weaker, which can make completing everyday tasks more challenging. 

Boyer and Kent were the first and senior authors, respectively, of a white paper, “Age-related changes in gait biomechanics and their impact on the metabolic cost of walking,” published in Experimental Gerontology in 2023, which grew out of a National Institute on Aging workshop and led to this new funding area.

“We will look at a combination of how people move, or their gait strategy, and the bioenergetics and the muscle contractile function, or how your muscles work, as possible reasons that this energy cost goes up,” Kent says.

An older adult’s slower walking that requires more energy can lead to fatigue and a decrease in performance, which can increase the risk of falling. Real-world examples: Making it across the street at a pedestrian crosswalk before the traffic light changes, or getting tired more quickly and easily from housework, like sweeping or vacuuming. 

In early 2026, Kent and Boyer and their team will begin recruiting adults for their research. They will be looking for 30 younger adults (ages 25-40), and 60 older adults (ages 65-85) to participate in the study. The group will be balanced among men and women to assess sex as a biological variable. Each of the participants will wear an accelerometer to measure their routine physical activity. 

“We don’t just want to study individuals who are highly active and high functioning in the community,” Boyer says. “We would like to study those individuals who are having a hard time.”

At the UMass Institute for Applied Sciences (IALS) Human Magnetic Resonance Center and other labs on campus, the research team will use electromyography, gait analysis, dynamometry, MRI and magnetic resonance spectroscopy to examine neural and mechanical demand, as well as metabolic economy, in the major muscle groups activated during walking. Those muscle groups are the quadriceps, which extend the knee; the plantar flexor muscles, commonly known as the calf muscles; and the hip extensors, commonly known as the glutes.

“Most of the literature has focused just on the knee extensors,” Boyer says, “but when we’re walking, the calf muscles and the glutes are the muscle groups producing most of the work, or most of the force, in order to move you forward. We know lots about the quadriceps, and we know a lot less about the plantar flexors, and we know very, very little about the glutes, and how those change with age.”

Kent adds, “We are going to try to understand how these muscle groups change in terms of their morphology, or their size, and the amount of fat deposited in these muscles with age. How does their strength and ability to produce energy change with age?”

The study’s advanced imaging is “technically innovative,” Boyer says. “We’re currently building these devices so that people can do contractions of the individual muscle groups while they’re lying in the MRI machine.”

Then the researchers will analyze how the resulting measurements of real-time energy production during muscle contractions relate to the energy cost of walking.