Long before Oscar Pistorius was convicted of murder, he was in court for the right to run alongside non-disabled athletes. He prevailed despite fears that his carbon-fiber prosthetic legs gave him an unfair advantage, becoming the first runner with prosthetic limbs to compete internationally against runners without disabilities.
Pistorius’s situation raised questions about the implications of using technology to help achieve athletic greatness. Those can apply to other disabled athletes, too, and now engineers are proposing new guidelines to keep prosthetic leg users honest.
Bryce Dyer heads up research at Bournemouth University’s design and engineering department. A prize-winning prosthetics designer, he set out to determine a way to analyze the use of lower-limb running prostheses (LLRPs) in competitions for disabled athletes.
He knew it wouldn’t be easy. “It’s an impossible problem to deal with,” he admits, “but you can’t ignore it either.” Because the field of prosthetics is advancing so rapidly, he says, it’s hard to quantify what’s even out there, much less regulate it. Only in recent years has prosthetic design evolved past mere comfort.
Dyer opted for a more-is-better approach. First, he looked at performance data from the men’s 100 meter sprint event at Paralympic games between 1976 and 2012 as a way of establishing how far prosthetic technology has come. When he compared that data to data from the same distance event at the Olympic Games, he found consistent performance improvements on the part of disabled athletes.
Next, Dyer tried to come up with a consensus on how prosthetics should be used by disabled runners. He recruited an expert panel that included spectators of disability sports, individuals who design, fit or service prosthetics, governing bodies' members, academics and disabled athletes themselves and asked them what they thought about prosthetics in competition. The process resulted in guidelines that could regulate future use of prosthetic limbs, primarily by addressing how such limbs should compare to athletes’ biological lower limbs. The measure is restored, not enhanced, functionality.
Armed with those proposed guidelines, Dyer began watching footage of Paralympic games, analyzing the gait of winning sprinters and showing that even those who crossed the finish line first still exhibited some randomized asymmetry in their stride.
All that analysis -- about the perceptions and realities of runners with prosthetic limbs -- led to Dyer proposing a way to evaluate prostheses through drop jumps.
Officials, he says, could require athletes to jump down from a platform, land on their (prosthetic) foot or feet and immediately jump vertically or horizontally -- the same method used to assess the sprinting capability of runners without disabilities. It's nearly impossible to cheat on such a test: With or without prosthetic limbs, runners have no way of manipulating the effect of gravity. But drop jumps could help officials evaluate prosthetic limbs’ performance with statistical reliability.
“Medals could be won or lost based purely on the kind of limbs [an athlete is] using,” Dyer says. “A lot of these philosophical arguments about fairness are going to come into question again in a few months time” when the Olympics return.
There’s no telling what is next in the world of super-powered athletic prosthetics, in his view. He thinks we’re in a golden age of prosthetic technology -- with everything from elective amputations to genetic athletic modification closer than you might think.
Prosthetics, which are usually custom-made for elite athletes, are far more complicated than a pair of running shoes. And that’s precisely the point, he says. Because the equipment used by elite runners with disabilities is so specialized, “things could change really quickly.” That’s even more reason to pause and look ahead to the next Pistorius-like controversy, even as disabled athletes sprint toward their next great achievements.