Scientists study cause of canine knee ailments
By GREG KLINE
© 2005 THE NEWS-GAZETTE
Published Online August 20, 2005
Elizabeth Hsiao-Wecksler has studied older practitioners of Tai Chi, pregnant women and trick skaters to find out how human movements change with age, exercise and acute physical changes like pregnancy.
“We’re looking at balance and the control system people have,” said the director of the University of Illinois Human Dynamics and Controls Lab. “We’re looking at how people respond to disruptions in their balance.”
But the UI mechanical and industrial engineering professor, who uses a motion-capture system similar to those used to produce hit movies, such as “The Polar Express,” is looking at a decidedly different kind of subject these days.
They have four feet for one thing.
Hsiao-Wecksler, who’s collaborated with UI kinesiology and anthropology colleagues previously, is helping Dominique Griffon, a professor in the College of Veterinary Medicine, with a study of Labrador retrievers.
Specifically, Griffon is trying to find out what makes Labs and some other dog breeds prone to cranial cruciate ligament deficiency – in layman’s terms, knee problems.
It’s the kind of injury that might sideline your favorite running back. But the dogs don’t get it from a wicked hit by a linebacker.
In canine patients, the problem where the cruciate ligament is supposed to hold the femur and the tibia, the upper and lower leg bones, in proper relation to each other seems to happen naturally. It may start when a dog is a few years old, then gradually degenerates over the years into major hind-limb lameness.
“We don’t know all the factors involved in this,” said Griffon, who’s also a veterinary surgeon. “That’s the purpose of the study.”
The hope is that by uncovering the root causes, the research will lead to ways of identifying the problem even before it starts and of overcoming it.
If the cause has to do with the way the dogs’ knees are constructed, for example, corrective surgery techniques might be developed, Griffon said.
Likewise, if something such as an imbalance in muscle strength in various locations around the knee is the issue, a therapy program might be used to pump up the muscles that need to be in order to restore the proper balance.
Griffon is studying the problem using a variety of methods, including computed tomography, commonly referred to as a CAT scan.
Some reading she was doing about the kind of thing Hsiao-Wecksler does prompted Griffon to contact her UI colleague.
“It’s never been done with dogs,” Griffon said.
Hsiao-Wecksler’s lab uses a system of six cameras to follow subjects, whether two- or four-footed, as they walk or otherwise move along a 32-foot track.
The cameras collect video, but they also include infrared sensors that pick up reflections from marble-sized balls glued to various key points on the subject’s body. It’s the same kind of system employed, say, to capture actor Tom Hanks’ movements and turn them into an animation, as was done for “The Polar Express.”
At the UI, the data is used to create a computerized 3-D model of subjects’ movements.
Combined with data from an instrumented force platform in the track that measures how hard the dogs bear down as they move across it, the system allows the UI researchers to get a highly detailed picture of which muscles are doing what during the animals’ gait and the forces being exerted on their knees, among other things.
Griffon is looking at both healthy dogs and dogs that have developed cranial cruciate ligament deficiency to study differences between the two.
The researchers still need several healthy pure-bred Labrador retrievers that are approximately eight years old and a few Labs with lameness problems. The dogs get a free dental cleaning for participating.
Interested Labrador retriever owners can call Carrie Bubb, veterinary technician, at (217) 265-5533.