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"Leg Up" -- The Discovery Files

The Discovery Files
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A new prosthetic ankle, developed by Vanderbilt University scientists, aids its users by adjusting to terrain that would typically present a challenge. It works by using a tiny motor, actuator, chip and sensors that work together to either conform to the surface the foot is contacting or remain stationary, depending on what the user needs.

Credit: NSF/Karson Productions

Audio Transcript:

"Smart" ankle.

I'm Bob Karson with the Discovery Files, new advances in science and engineering from the National Science Foundation.

Prosthetic legs have much improved, but to users there's still a major (pun intended) stumbling block: Terrain. Every hill, stair, ramp or uneven patch of ground slows movement because of uncertain balance and stability. Prosthetic ankles don't adjust the feet for different terrains. They don't naturally roll through the motion of walking.

But a team at Vanderbilt University is looking at the problem from a new angle. They've developed a prosthetic "smart" ankle that moves with the user. It's packed with a tiny motor, sensors, a chip and an actuator that simulates leg muscles.

All work together to sense and react to changing terrain -- conforming to the surface the foot is contacting or remaining stationary. The developers say it "figures out what you're doing and then does what it should." It allows the user to wear any kind of shoe: running, dress, flats -- the device adjusts automatically.

Part of what gives it it's natural, very human feel is that the team reached out to nearly a hundred potential users to understand what would make the ankle a success. The idea is for people to be able to do more of the activities they want to. (Sound effect: runner passes) I'd say this is a (pun intended) major stride.

"The discovery files" covers projects funded by the government's National Science Foundation. Federally sponsored research -- brought to you, by you! Learn more at or on our podcast.

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