Prostheses

Listen to this episode!
RealOne Player required. Download the free RealOne Player

Photo: Athlete Marlon Shirley wearing the Ossur Flex-Foot.

It’s getting easier for people who have lost legs to get around. We’ll see how, today on Engineering Works!

If you read the same stories we did when we were children, you remember what happened to pirates that lost a leg. They walked around on wooden peg legs -- sometimes with a funny-looking crutch.

People who lose legs to accidents or disease these days don’t have to depend on wooden legs. Replacement legs, or prostheses, are getting better all the time. Some are hard to tell from natural legs. Some use hydraulic or pneumatic cylinders to control the way they move. In fact, biomedical engineers are designing prostheses that let the people who wear them run or do other sports.

Let’s look at knees. There are more than a hundred different knee designs in use today. Think about it. An older person who doesn’t get around much needs a knee that’s different from a 25-year-old who runs marathons. Yes, people do run marathons with replacement legs.

Engineers are working on knees that are controlled by microprocessors. They’ll allow the person wearing them to react more quickly – like catching yourself when you stumble. Designers are even looking to the animal kingdom for design ideas. The lower part of a replacement leg used by a young woman who competes in triathlons is flexible and modeled after the rear leg of a cheetah.

It’s time to catch the winners at the finish line. See you later.

Venice
The beautiful piazzas and famous canals of Venice are in trouble. They’ve got more water than they know what to do with.

Concrete Trucks
Concrete is one of the handiest construction materials there is. It’s been around since the Romans.

Explosives
Explosions all go bang, but they’re not all the same. We’ll check into how and why.

Prostheses
Engineers are making replacement legs, or prostheses, better all the time.

Browse or search for more episodes