As advanced as prosthetic feet and legs have become, they're frequently lousy with stairs. You usually have to reconfigure your limb to make the climb, even if it's just for a few seconds. That won't be an issue again if the Rehabilitation Institute of Chicago's efforts pay off, however. Its researchers have built a new bionic leg that lets you climb stairs, kneel and otherwise move freely without straining yourself. It revolves around a control system that tells what you're trying to do and adjusts automatically, letting you focus on walking instead of terrain changes. The leg is only in a very limited test run backed by the US Army, but it's expected to become a commercial product that helps amputees of all stripes.

[Image credit: Ann Simon/Rehabilitation Institute of Chicago]