Nov. 1, 2010
Contact:
Claire Miller, 404-413-8118
College of Education
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| Mark Geil, associate professor of biomechanics, demonstrates to 6-year-old Jayden House the articulating knee in House’s new prosthetic leg. |
Like most 6-year-olds, Jayden House loves to play his video games, but he loves to play soccer and swim, too. He excelled in his preschool tumbling class and easily keeps up with his friends on the playground.
Jayden’s athleticism may not at first seem remarkable, but it is considering he was born without most of his right leg and has been using a prosthetic limb since he was a year old.
One of the most intricate parts of Jayden’s artificial leg is the articulating knee – a hinge-like joint that can bend when he walks, runs or does other activities.
Most children in Jayden’s situation don’t receive an articulating knee as early as he did, but that could change in the coming years thanks to a collaboration between the orthotics and prosthetics experts at Children’s Healthcare of Atlanta and Mark Geil, associate professor of biomechanics in the Department of Kinesiology and Health in the College of Education.
“For many of these children, living without a limb has been a part of their lives as long as they can remember,” Geil said. “It’s the job of the allied health care team – the orthopedic doctors, prosthetists and physical therapists – to try to work with these children to develop a prosthetic solution that can help them function as well as possible.”
And the earlier the better, as Jayden’s mother, Jessica Nalbandian, will attest. “With the bendable knee, he was able to crawl around pretty easily and he started walking when he was about a year and a half old,” Nalbandian said. “It didn’t take him long to learn how to walk. He’s a very active child.”
Taking a Chance
Geil began focusing his research on prosthetic knees in children in 1998, when prosthetists and physical therapists at Children’s hypothesized that children could be fitted with articulating knees sooner. They asked Geil to look into the possibility, and a partnership between the children’s hospital and the Department of Kinesiology and Health was born.
“For years, the conventional wisdom in prosthetics has been that you can’t put an articulating prosthetic knee on a kid until they’re three to five years old – until they’ve developed the ability to independently stand and walk,” Geil explained. “A few enterprising and observant prosthetists have challenged that and thought that maybe people aren’t giving kids enough credit.”
At the same time, prosthetics manufacturers began making smaller knees that could fit younger children – a crucial development that enabled Geil and his colleagues at Children’s to conduct the necessary research.
In his laboratory at Georgia State University, Geil conducted a study with five children who had just learned to crawl to test the differences between prosthetic limbs with an articulating knee and traditional limbs with knees that must be locked straight during movement or that don’t have a knee joint at all.
In Geil’s lab test, the five children wore tiny spherical markers on their legs and crawled around the lab with an articulating knee. As they crawled, several cameras set up at different angles recorded their movement. Then the children were outfitted with locked knees and were recorded again as they maneuvered around the room.
The result? The children had an easier time crawling around the room with the articulating knee than with the locked knee. They were able to maneuver around with a locked knee, but the cameras captured stark differences between the two crawling patterns.
“That’s where I really understood what the clinicians at Children’s Healthcare of Atlanta were sharing with me because I’d see kids who had been crawling very happily with the articulating knee 10 minutes before start crawling with the locked knee, and they would stop and look at their leg. And you could see them thinking, ‘Something’s not right here,’” Geil said. “It was fascinating to me to see them stop and process what had changed. It’s not like you or I picking up a big hammer or a little hammer and saying that one hammer is different than the other. It’s a kid saying, ‘My leg is different.’ Any they didn’t like it.”
With an internal grant from Georgia State, Geil was able to bring those same children back to the lab a few years later to study how they walked with articulating and non-articulating prosthetic limbs, and the conclusions were the same: Children walk more easily with a knee that bends.
Geil hopes to show others in the medical field that articulating knees not only make crawling, walking and other movements more natural, but they also ensure that children with prosthetic limbs don’t miss out on an important part of their development.
“We looked at how normal muscle development can happen and what kinds of activities promote that. Walking is one of them, but the precursors to that are important, too – crawling, pulling oneself to a standing position and kneeling,” Geil said. “Those are things that kids do naturally and if you take them away, a kid is missing a very vital stage of development in terms of muscle strength and the brain’s ability to control muscles.”
The repercussions of this delayed development go beyond just the physical, Geil noted. “If a child cannot keep up with his or her peers, quality of life and social development are affected, as well. There’s an important link between biomechanics and overall well-being.”
Inspiring Change
Geil and his colleagues have published research on articulating knees incrementally and hope to have another article published soon on the benefits of prescribing articulating knees earlier in a child’s life.
In the meantime, Geil has started to see his research make waves in the medical field on a case-by-case basis.
“I have a colleague at Children’s Memorial Hospital in Chicago who was trying to convince a clinician to prescribe an articulating knee to a very young child,” he said. “The clinician initially said no, but after my colleague showed him my research findings, he gave that kid a knee. That thrills me.”
Geil was also excited to see Jayden’s progress during a recent trip to Children’s, where Jayden was fitted for a new prosthetic leg. Jayden’s easy gait through the hallways of the hospital even inspired another child with a prosthetic limb to try walking without his crutches.
“They want to keep up with and play with other children,” Geil said. “What we have established with this research is that kids can move well with an articulating knee in their very first prosthesis. And now there’s hope that they can participate with their peers.”