Amplitude / blog / education / New Prosthetic Ankle Adapts to Rough Terrain and Stairs

New Prosthetic Ankle Adapts to Rough Terrain and Stairs

Sasser tests the prosthetic ankle.

Photograph courtesy of Vanderbilt University.

Vanderbilt University lab of Michael Goldfarb, PhD, has completed
testing of a smart prosthetic ankle that can respond to varying terrain
and stairs. The ankle’s motor, actuator, sensors, and chip work together
to either conform to the surface the foot is contacting or remain
stationary, depending on the user’s needs. The team hopes to
commercialize the ankle within about two years.

“Our prosthetic
ankle is intelligent, so you can wear a dress shoe, a running shoe, a
flat—whatever you’d like—and the ankle adapts,” said Goldfarb, the H.
Fort Flowers Professor of Mechanical Engineering; professor of
electrical engineering and physical medicine and rehabilitation; and
co-director of the Center for Rehabilitation Engineering and Assistive
Technology at Vanderbilt. “You can walk up slopes, down slopes, up
stairs and down stairs, and the device figures out what you’re doing and
functions the way it should.”

Most prosthetic ankles lack smooth roll over when walking, causing the user to swing the prosthesis outward.

tried hydraulic ankles that had no sort of microprocessors, and they’ve
been clunky, heavy, and unforgiving for an active person,” said Mike
Sasser, who has a transtibial amputation and tested the device over
several years at Goldfarb’s engineering laboratory. “This isn’t that. It
actually lifts the toe for you.

Harrison Bartlett, a doctoral
student in Goldfarb’s lab, gathered feedback from the sensors and made
adjustments based on the data and Sasser’s user experience. Bartlett
also interviewed nearly 100 potential users to understand what would
make the ankle a success.

“I talked to one person whose favorite
restaurant was at the top of a long flight of stairs, so they haven’t
eaten there in ten years,” he said. “Another sat on benches throughout
an amusement park while their family enjoyed the rides because they
couldn’t be sure about navigating that with their prosthetic. We want to
return people to any of the life activities they want to do.”

This story was adapted from materials provided by Vanderbilt University.