Amputee athletes are reaching the point where they can perform as well as their able-bodied counterparts. Someday soon, they may even surpass them.

Hugh Herr
Even though he'd lost his legs to severe frostbite after a climbing accident when he was 17, all Hugh Herr wanted to do was climb. So he went to work in the machine shop, building new legs with rubber grips to grab rock (below, top and middle image), narrow stubs to wedge into fissures, and spiked feet for climbing ice. Two decades later, Herr, now director of the biomechatronics group at the MIT Media Lab, is still tinkering, building sophisticated prostheses that can match--and may soon outperform--biological limbs. His latest invention? The world's first powered robotic ankle (below, bottom image). Unlike other prostheses, the ankle captures energy generated when the foot hits the ground, using it to propel the wearer forward. Herr says that once the device is optimized, it will make the wearer's gait more efficient than a biological foot would.

Photographed by John Huet at MetroRock, Everett, MA