Yesterday, I wrote about an athlete named Blake Leeper, who I stumbled across recently. Leeper, who was born without legs below the knee, will be sprinting in next month's Paralympic World Championships in Lyon, France with the aid of the kind of high-tech prosthetic "blades" used by South African sprinter Oscar Pistorius.
Despite being born without lower legs, Leeper played basketball and ran cross country throughout high school. Leeper thought his athletic career was over when he graduated from high school -- right up until he saw Pistorius and others running in the 2008 Paralympic Games with prosthetic blades.
He promptly raised the $15,000 to get a set of blades for himself. It took him three months to get comfortable with the new prosthetics. In his first race in 2009, he qualified for a spot on the U.S. Paralympic team.
Last July in Canada, he tied Pistorius' 100-meter paralympic world record with a time of 10.91 seconds. Like Pistorius, Leeper is hoping to compete in the Olympics as an able-bodied athlete.
The blades were developed by a medical engineer named Van Phillips, who figured out how to build prosthetics that store kinetic energy like a spring, which allows athletes to run and jump effectively.
The blades are constructed of a reinforced carbon fiber -- a strong, light-weight material that's now used in an array of settings from athletic gear to bicycles, sailboats and nearly any equipment where high strength-to-weight ratio is important.
The manufacturing process involves layering together 30 to 90 carbon fiber sheets, which is then autoclaved to remove bubbles and fuse the sheets into a solid plate. Once the plate has cooled, it's cut into the now-familiar blade shape, which is then bolted to a carbon fiber socket that's custom fit to Leeper's legs.
Spikes, developed by Nike research, are mounted to the bottom of the blade, which aid in traction and help athletes such as Leeper sprint at maximum speed.
The blades are slightly longer than a runner's biological leg and foot would be. The curve replaces the ankle hinge with a compression that bends and releases with every stride. When a runner is standing still, he looks like he's standing on tiptoe because there's very little compression of the ankle curve. And oh yeah, no running backward -- the blades have no heel and are designed for forward motion only. Wearers report that the blades almost seem to have a mind of their own. It's nearly impossible to stand still and it's even difficult to move slowly in them. It takes strength and training to control them.
The prosthetics do a remarkable job of restoring a person to a performance level near his biological potential. In a study done to determine whether Pistorius was gaining an unfair advantage competing in the able-bodied Olympics, researchers found that biological legs had an elastic energy return of 93-95 percent. The return from carbon fiber blades: 92 percent.
While the technology is fascinating, the real story is the dedication and hard work of athletes like Blake Leeper, who are stretching the boundaries of what's possible for people with disabilities.