New Rehabilitative Device Combines Form And Function For Children With Mobility Impairments

Prone standers allow children with mobility impairments to stand upright. Proper weight-bearing on long bones helps prevent osteoporosis, while improving circulation, muscle tone and functioning of internal organs.

Although important tools, prone standers can be quite intimidating from a child's point of view: Most are cold and sterile-looking. To help children keep a positive attitude, Mary Lou Tierney, a master's graduate of Georgia Tech's industrial design program, has created a user-friendly prone stander.

Prone standers traditionally have been designed to work at the therapist's level — meaning that children are elevated to adult height. "It's easier for the therapist, but isolates the child," said Tierney, explaining that the height can be frightening to small children and prevents them from interacting with others. Many impaired children spend three or four hours a day in a prone stander, and that is a long time to be separated from playmates.

By positioning children just a few inches off the ground, Tierney's "peer-level" prone stander allows them to interact with peers, use a computer or work on a project on the removable plastic tray. Giving children more control lowers emotional barriers to therapy, said Tierney, who has named her device "The Buddy System" to reflect its user-friendly focus.

With its bright red pod and yellow confetti frame, The Buddy System "looks more like a whimsical space-age toy rather than some kind of institutional cage," said Julius T. Corkran, an industrial designer at Georgia Tech's Center for Rehabilitation Technology (CRT), a research center that deals with physical disabilities. Corkran, who helped Tierney with mechanical issues and construction of the prototype, added: "Although playful, aesthetics are also practical. For example, the multicolor flecks on the polycarbonate tubing help hide scuff marks and food stains."

Placement is another departure from the norm. "Many prone standers provide too much support, and the child ends up being hung by his armpits," said Alan Harp, another CRT industrial designer who worked on the project. When this happens, weight is not really applied, and strapping can cause pressure sores. In contrast, The Buddy System uses wider straps and unique cushioning that supports the body, but still allows weight to be transferred. "It doesn't hold you as much as it aligns and positions you," Harp explained.

Instead of traditional foam padding, cushioning at the torso, knees and hips is comprised of an inch-thick gel. Covered with Darlexx (a soft, hypoallergenic fabric used for wheelchairs and wetsuits), the gel conforms better with a child's body and allows pressure to dissipate, preventing irritation.

Tierney began experimenting with prone standers as a senior thesis project in January 1997. "Besides gaining more experience with human factor design, I wanted to do something with social merit and recognized there was a need. Products for the disabled and elderly tend to be very utilitarian in design," said Tierney, now an industrial designer at Motorola in Plantation, Fla.

One of Tierney's biggest challenges was designing the system for a broad range of users. Generally, children with cerebral palsy have excessive muscle tone and require a prone stander that can withstand a lot of force. At the other end of the spectrum, children with Down's syndrome have little muscle tone and need a lot of support to remain upright.

Accommodating children from 25 to 40 inches tall, the system is easy for therapists to position children in place. Yet there are few removable parts, which is important in clinical settings where pieces can be easily lost.

The Buddy System also adapts easily to the home environment. ItÕs easy to operate and narrow enough to fit through standard doorways. "Parents don't need an extensive manual to use it," Tierney said. Aesthetics are another plus, she added: "Parents are often concerned about buying products that label their child as special, but The Buddy System blends in with toys the child or his siblings might have."

A patent application has been filed for the prone stander, and the Georgia Tech Research Corporation (GTRC), which assists in commercialization of research, has begun searching for licensees.

The Buddy System comes with a full set of CAD drawings, a bill of materials outlining specific parts and their costs, and a pre-production prototype — rare for a university project. "Typically, inventions that come out of universities are embryonic," said Orman Simpson, a technology licensing associate at GTRC. "By carrying it to this level of development, Mary Lou has significantly lowered production engineering costs."

The Buddy System also has potential to evolve into other assistive products. By removing its central pod and adding interchangeable parts, the prone stander can be transformed into an alternative walker or a gait trainer (for children who have advanced beyond the prone stander).

For the past six months, The Buddy System has been "road-tested" at the Elaine Clark Center, an early intervention program in Atlanta. "The reaction has been nothing but positive," said Nancy Morrissey, the center's educational program coordinator. "It doesn't look like a piece of equipment — children see it as friendly, not scary. Even children without ambulatory problems want to ride in it."