C leg for amputees

7/25/2007 5:00 AM

By: Marcie Fraser

There are 15,000 amputees worldwide wearing a C leg. This computerized leg allows people overcome their disability and return to the life they lived before.

Sparky Gallagher said, "I was 28 and had bone cancer. It's a tumor that starts inside your femur and breaks through and they don't have much choice but to amputate. You go through chemotherapy and fitting up a leg after that."

Before his amputation, Sparky Gallagher was an active young man. Over the years, he's been fitted with several prosthetics, some not so successful and he fell a lot.
He said, "No one knows how to fall unless you are an ice skater or something like that. You have to learn all those things."

Walking with a prosthetic, especially down hills or stairs, takes practice and he fell every day, but not anymore. He's wearing a C leg, a computerized prosthetic knee joint with a microprocessor on board.

Clinical Prosthetics Orthotics Owner David Misener said, "Essentially they all work together for the computer that's on board. It knows when the heel is touching the ground. It knows when the toe is coming off the ground. So the computer is responding to the amputee walking."
The computerized leg reads and controls valves 50 times a second, adjusting to how a person is walking. His gait, flexing and heel-toe load is adjusted using a lap top. This prosthetic is most appropriate for active amputees.

Misener said, "You need to be able to walk at variable cadence. You need to be able to walk at different speeds so the technology on board is actually useful."

It's not uncommon for any of us to trip, stumble, even take a fall, but when a person with a C leg stumbles, there is a computer that senses it, adjusts and goes into a safe mode.
So if Sparky trips, the leg automatically adjusts causing some of the hydraulics to stiffen which gives a person a second to catch their balance.

He said, "It gives you that little bit of time then you got the time to make a hop with your other leg, and if you know you are going to fall it gives you time to get your arm out. Sometimes you've got time to grab a counter or a rail."

Misener said, "You can certainly golf. You can downhill ski. You can run. You can jog. You can bike. You can stand all day. Certainly it gets you back doing what you would like to do throughout the day."