In This Issue
It's All About Balance
Falling is often the start of the end for seniors, says U of G kinesiologist
BY ANDREW VOWLES
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| By learning more about how people control balance and posture in walking, Prof. John Zettel hopes to help prevent falls among older adults. Photo by Martin Schwalbe |
Both of his toddlers began walking early. But Prof. John Zettel saw both boys Alex, now three, and Lucas, 19 months tumble as often as any children finding their feet. For Zettel, who joined the Department of Human Health and Nutritional Sciences (HHNS) last year, watching them walk and often fall down was a mixture of parental angst and academic interest.
The kinesiologist studies control of balance and posture in walking, particularly in older adults. By learning more about how these systems keep us upright, Zettel hopes to help prevent falls among seniors that may lead to injury, confinement and even death.
Falls are the second leading cause (after car accidents) of injury-related hospitalizations for all ages, accounting for 29 per cent of injury admissions, according to a 2004 report by the Canadian Institute for Health Information. Four out of 10 of all injury hospitalizations involve seniors aged 65 and over, the largest proportion of all such cases.
Besides those problems, falling can cause seniors to lose confidence and restrict their activities. That can lead in turn to declining health and function, increasing the possibility of more serious falls.
It's a big deal for older adults, says Zettel. That's often the start of the end.
Studying this phenomenon involves a bit of a paradox. He'll deliberately perturb people, not enough to make them fall over or hurt themselves but enough to prompt a balance reaction that he can measure and analyze.
To do that, he hopes to acquire a special moving platform for his lab in the Animal Science and Nutrition Building. About the size of his office and equipped with motors under computer control, the walled platform will move in unexpected ways, like a bus or subway car jolting underfoot.
The idea is to simulate what you might encounter in daily life, says Zettel. The key is to make it as unpredictable as possible.
Subjects wearing a safety harness hooked to the ceiling won't fall over, but they'll have to catch themselves to keep their balance or to avoid obstacles set up on the platform.
Zettel will use cameras and other monitors to capture their movements. Unlike setups elsewhere, his system will include eye trackers to see where people look as they navigate this uncertain experimental world. Fed into the computer, that information will show him how the body responds to gentle perturbations.
That's a step toward helping to devise ways to prevent falls and injuries.
He's also planning to look at what happens when adults older and younger are preoccupied with another task and then forced to maintain their balance.
In the past, researchers believed that maintaining balance happened automatically. Now, many think that keeping the body upright and moving properly requires concentrated brainpower even if we're not aware of what's going on in our head. That would explain poorer performance on secondary tasks when subjects are forced to keep their balance.
We never really think about standing up and keeping our balance, says Zettel. It runs in the background.
The problem is probably more acute in older adults, who often have to dedicate more cognitive resources to certain tasks, he says.
He also hopes to work with stroke patients with balance problems. He figures they may help researchers zero in on affected areas of the brain responsible for vision, the vestibular system and locomotion and especially where information from those different systems comes together.
Consider the near-infinite number of movements you make every day, never mind the contortions some people put their bodies through on the sports field, the dance floor or anywhere else.
A lot of times, we have no idea how we're pulling that off, says Zettel, who regularly flings his body around playing basketball and Ultimate Frisbee. It's an enormously complex system.
He became interested in biomechanics and particularly in the complexities of human movement while studying kinesiology at the University of Waterloo. He completed graduate degrees at the University of Toronto before doing a post-doc at York University's Centre for Vision Research, where he added vision tracking to his research toolkit.
In Toronto, he also worked at the Centre for Studies in Aging at Sunnybrook Health Sciences Centre.
Zettel came to U of G to join a growing biomechanics group in HHNS. In his department, Prof. Leah Bent studies individual neurons involved in posture and balance. Prof. Lori Vallis works with gait analysis and studies how seniors avoid obstacles while walking.
Two days a week, he heads for the University of Guelph-Humber, where he teaches math/biophysics and biomechanics in a new program that leads to a B.A.Sc. in kinesiology and a diploma in fitness and health promotion.
Zettel lives in Guelph with his wife, Paulina a naturopath and also an Ultimate competitor as well as those two precocious walkers.