Ossur’s “Power Knee” prosthetic leg allows amputees to walk longer while experiencing less physical toll.

It uses sensors located on the artificial knee and on the insole of the other leg, which sends information about their position at high speed. Gyroscopes on the artificial knee and on the ankle also send information about the tilt of the limbs. All of this information flows to a microprocessor in the knee, which sends instructions to the motor to provide the power to offer realistic quadriceps and hamstring motion.

Only about 25 people worldwide have it so far.