Page 22 - Mobility Management, September 2018

Pediatric Series
The Measure of a Child
Body Structures Are Different for
Babies & Children
The Automotive Medicine Study — conducted to review how children’s bodies differed from adults’ bodies in the context
of automobile safety design — noted that a newborn typically weighs about 5 percent of what he/she will weigh as an adult. For the first nine months of life, a baby’s body fat increases rapidly. “After this period of high incremental change,” the study said, “there is a period of less rapid growth, so that by 5 years of age, the thickness of the subcutaneous layer is about half the thick- ness of the 9-month-old infant.”
Automotive manufacturers and companies that design chil- dren’s car seats need to know this information so they position safety restraints most effectively: “Loading of the body by strap- type restraints must occur in areas where the body is strongest, i.e., on solid skeletal elements,” the study said. Likewise, seating and mobility manufacturers need to understand the specific anatomy of children to design optimal systems.
Gabriel Romero, VP of Sales & Marketing for Stealth Products, remembered the considerations that went into designing the company’s Niño system years ago.
“It was really important to create a product that was designed specifically for kids and early intervention, when it came to pads and the way they curved, how laterals fit,” he said. “We had to shrink everything down, but we also had to change some function on it. The swingaway didn’t swing away the way it needed to; the way it needed to swing away would be a different angle for a child.”
It’s a fact that Romero said has carried over to Stealth’s components, as well.
“I used to call it the Willy Wonka Machine,” he said. “Everybody wants to put the product through and just shrink
it, and they think that’s enough. But it’s not, in cushions and especially positioning products. We encountered it in our belt line, since we have both adult sizes and pediatric sizes. We saw the cuts, the thicknesses of padding, all these differences. The padding is in a different place, and also the thickness of padding is different. You start looking at how the pelvis is different from an adult to a child and where the joints are, and it’s all different.”
As an example, he showed off an ADI backrest (pictured)
To maintain the appropriate contour in this ADI pediatric back, engineers had to consider the placement and thickness of the foam.
20 SEPTEMBER 2018 | MOBILITY MANAGEMENT
specially created for a young child to use on a self-propelled chair. “It had a contour, and I’m thinking I could cradle a baby with this back in my arms, as small as it is. But we didn’t only shrink it down. We had to shrink the contour, we had to design the foam differently — because if [the foam] was too thick, you wouldn’t have the contour.
“The point of contour is different because of the location of their arms. The last thing you want is to not consider where that drop in contour needs to be on a back, and how it could expand the child’s arms out so they’re really not getting a full push.”
Pediatric Growth Is Different
Josh Tucker, the new National Sales Manager for Leggero, pointed out that while kids and adults can both “grow,” the nature of the changes in size is different.
“The most important reason for a pediatric-specific design is going to be growth,” he said. “The [adult] body eventually stops growing in height. We can get wider, but our bone size stays the same. It doesn’t matter if I’m 6'2" and 300 lbs. or 6'2" and 170 lbs.; my skeletal structure is exactly the same. Children are not the same. Their hands and feet are growing, their legs are getting longer, their weight is getting higher. So when you take an adult version and just make it smaller, you’re not taking into account that the pediatric body is going to eventually grow out of that chair in every dimension.”
The means of everyday mobility can also impact a person’s body over time, Romero noted.
“If someone’s been in a wheelchair up to the age of 25, there are extreme differences between him and someone who was injured at 25 and then started using a wheelchair,” he said.
Camber for Kids
One area in which manual, self-propelled pediatric chairs can have a real-world advantage over their grownup counterparts is camber.
Camber can improve stability and maneuverability in both adult and pediatric manual chairs. But adding negative camber — i.e., angling the tops of the rear wheels towards the user’s body — also results in splaying the bottoms of the rear wheels outward. In an adult wheelchair, camber can therefore result in a chair that’s too wide to get through tight doorways, aisles and other small spaces.
On a kid’s chair that’s much narrower to begin with, adding camber and creating a greater width poses less of an accessibility problem. At the same time, angling the tops of the rear wheels toward a pediatric user can help kids reach, grab and push the wheel or pushrim more effectively, so they get more distance from each stroke.
And that’s important because in addition to children’s arms being shorter, they also have less strength than adults do. “Taking into account the endurance of the child is also
important,” Tucker said. “Children fade fast throughout the day, so we have to make sure pediatric equipment has push handles or handlebars, something for Mom and Dad to use.”
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