University of Vermont

University Communications


Balancing Facts

By Lee Griffin Article published February 4, 2003

Ge Wu
A steady hand for steady feet: Ge Wu of the College of Nursing and Health Sciences is seeking ways to prevent falls in older people. (Photo: Bill DiLillo)

‘Tis the season of slip-sliding away.

Even if you’re still on the receiving side of life’s grace, you’re as much in danger of taking a flyer on the ice as your granny, but the results likely will be remarkably different. Younger people have a better ability to react quickly and right themselves, stumbling more often than falling. And, even falling, they’re more protected by denser bones and stronger connective tissue, sentries ready to resist injury or impatient to heal it.

Older people approach life’s slippery slopes with caution. And with more reasons than just fear for their senior bones. When they fall — and about one in three aged 65-plus does each year (not necessarily on ice) — the consequences can be life altering. For some 10,000 of them, the fall will be fatal. For many more, it will lead to a downward spiraling of mobility and health.

Upright citizen
Ge Wu, associate professor of physical therapy and a biomedical engineer, designs studies to find out why older people fall and what reduces their chances of falling or being injured. Statistics like an aging population and 340,000 broken hips annually suggest it’s a worthy and challenging quest.

“Approximately 30 percent of people aged 65 and older in the United States fall at least once a year,” Wu wrote in a recent review in the American Geriatrics Society journal. Half of those people have multiple falls each year, and the resulting immobility “can lead to severe depression, malnutrition and increased chance of infection.”

Older people lose fast-twitch muscle fibers and no longer react quickly to an imminent fall. Or, Wu says, “they sometimes over-react” and cause a fall. Sensory systems decline, too, slowing feedback to the brain.

Wu says her interest in this problem is long-standing and began with studies on how we maintain balance — “the biomechanics of human movement, gait and postural control.” The work was theoretical, using computer modeling. But Wu wanted “to not just understand but help to improve balance.” In 1994, she received a National Institutes of Health grant for her study that looked at strength training. “But it’s hard to find older folks, especially those most in need of it, to lift weights,” she says. Even those who did try it couldn’t stick to that kind of exercise regimen.

Ancient art, new application
Wu, from China, had studied tai chi there, and she thought that might be a workable alternative. The Chinese martial art promotes slow, continuous movements that gently exercise every body part. Two problems kept the study from taking place locally. Burlington didn't have many experienced tai chi practitioners, and Wu couldn’t find a tai chi master. “I finally did find one, who was teaching faculty and staff at UVM, but a very modified version,” she says. “Westerners can’t handle something with 110 continuous movements,” she laughs. They’re just too busy. So, Wu connected with colleagues in Beijing, and the study proceeded, using retired university faculty for both the study and control groups. The former had practiced tai chi for at least three years; the control group had not. But, in other ways, the two groups were as similar as possible.

The tai chi people topped the control group in two ways. Their balance, tested both with eyes opened and closed, was better, as was their knee strength, gauged by simple extensor, flexor tests. Wu hypothesizes that lower muscle strength helps maintain postural stability, and the strength can develop through long-term practice of tai chi.

In Wu’s Rowell lab, subjects stand on two force plates, atop a simple platform. The plates measure movement like a scale does weight, and also shear forces. No one stands completely still, but older people sway more than younger, particularly with their eyes closed. Wu’s assistants rig each subject with reflective tape markers on various parts of the body and record and observe body sway via cameras with an optical electrical motion analysis system hooked to a computer monitor.

Trying tai chi
Wu’s current study has focused on subjects who have diabetes, some of whom have peripheral neuropathy, damage to peripheral nerves as a result of reduced blood circulation due to diabetes. Those subjects have the added stability problem of reduced sensory input from their feet. Wu hopes to design an exercise regimen for them that might use, for example, hip sensors to compensate for what they can’t feel in their feet.

In a pilot study Wu conducted in Franklin County, with a home health agency, she introduced a modified tai chi regimen to frail, homebound adults who had fallen within the past six months. They were fearful of going out and of trying to do things they’d done before they’d fallen; each needed some health aid assistance.

Wu and her team designed an intervention using videos of about 20 minutes each with simplified tai chi. Participants in that group received a new video weekly for 12 weeks. Another set of home patients was instructed in traditional exercises from a physical therapist. The latter group had a 90 percent drop-out rate, but the tai chi group persevered, and half of them asked to retain the tapes.

Wu says that group also had restored physical confidence and had renewed some physical activities. The researchers also observed “some qualitative change in their physical balance, strength and control,” she says.

In addition to her research and teaching in the three-year master’s program in physical therapy, Wu oversees student projects on various aspects of this problem. She and they are always looking for a few good subjects. If you can admit to being 65 or older, give Wu a call at 656-2556.