Recent technological advances promise artificial legs that emulate healthy limbs, mechanical engineers at Vanderbilt University in Nashville say.

Lithium-ion batteries that store more electricity, powerful brushless electric motors with rare-Earth magnets, miniaturized sensors built into semiconductor chips, particularly accelerometers and gyroscopes, and low-power computer chips make it possible to create prosthetics that can duplicate the natural movement of human legs, they said.

Prosthetic legs using the technologies will dramatically improve the mobility of lower-limb amputees, allowing them to negotiate stairs and slopes and uneven ground, significantly reducing their risk of falling as well as reducing stress on the rest of their bodies, the researchers wrote in the journal Science Translational Medicine.

Unlike passive artificial legs, robotic legs have the capability of moving independently, so development of a system that integrates the movement of the prosthesis with the movement of the user is "substantially more important with a robotic leg," they wrote.

Vanderbilt's Center for Intelligent Mechatronics has also developed an advanced exoskeleton that allows paraplegics to stand up and walk, and a robotic hand with a dexterity that approaches that of the human hand.