Robotic Leg Has Natural Gait: Scientists Help Amputees with New Artificial Limb

Walking isn't as easy as you might think. Balance and coordination need to be taken into account, especially when creating artificial limbs. For years, researchers have attempted to great an artificial leg with a natural gait--no easy task. Now, though, scientists may have taken a giant step toward success.

So how are the researchers accomplishing this feat? The scientists are focusing on one specific part of the foot: the ankle. More specifically, they're working on a microprocessor-controlled ankle-foot prosthesis that comes close to achieving the innate range of motion of this highly complex joint. In fact, these computerized artificial legs have pressure-sensitive sensors on the bottom of the foot that detect how the amputee is walking, which sends signals to a microprocessor which, in turn, adjusts the prosthesis to make the walking more natural.

The microprocessor-controlled prostheses that are currently on the market can move an artificial foot only in one direction, toe up and toe down. "But in reality, we never walk in a straight line for any length of time," said Mo Rastgaar, one of the researchers, in a news release. "When you walk and reach an obstacle, you have to turn, and there's always something in our way."

That's why the new effort revolves around an ankle-foot that can move on two axes. It can both incorporate the side-to-side roll as well as raising the toe up and down. In tests, the prosthetic ankle-foot was able to copy the angles of a human ankle walking in a straight line and turning.

Currently, the researchers hope to refine the prosthesis. They eventually want to make it available to amputees, especially wounded soldiers.

"Artificial limbs tend to evolve from wars, because of the increased awareness of the problems faced by amputees," said Kenton Kaufman, one of the researchers, in a news release. "Amputees have lots of problems with falling; 64 percent of above-the-knee amputees fall every year, compared to 33 percent of older adults."

The findings could help amputees achieve a more natural gait with artificial limbs. As the scientists continue to hone their model, they could eventually achieve a limb that can move and act like a real one.

Want to see the prosthesis for yourself? Check out the video below, courtesy of YouTube.