How much of an advantage could a double-amputee like Pistorius get from use of artificial feet? Engineer Kevin Harney, business development manager of the lower extremities division of international prosthetics giant Otto Bock HealthCare GmbH, points out that a unilateral amputee is faster out of the blocks in the acceleration phase of a sprint but starts to fatigue on his sound side during the stabilization and terminal phases, making it more and more difficult to keep loading the prosthesis efficiently.
For double amputees, however, the situation is reversed. "Once bilateral amputees reach their natural frequency response"--the optimal balance of stride length and frequency "all the athlete need to do is ensure that he applies the necessary forces to maintain that frequency. This means they are faster in the terminal phase, and "this is typically where they win the race," says Harney. This point was obviously not lost on Pistorius, who had a sudden "growth spurt"--he lengthened his prostheses-- between May 2004, when Frasure fitted him with his first pair of top-notch sprinting feet, and September, when he showed up for the Paralympics. "Oscar was at least two inches taller in Athens than the height I set him up at in North Carolina," Frasure confirmed by e-mail.
All three of these experts hasten to point out that there is a limit. "You cannot run on stilts. You may be taller, but you are not more efficient," in Gailey's words. Miriam Wilkens, the IPC's communications director, agrees that too much height creates instability. Indeed, when Pistorius won the 200 in Athens, he was running so tall he nearly fell over at the end of his race.
True. But he also broke the world record.
At a September meeting in Rio de Janeiro of the International Wheelchair and Amputee Sports Federation (IWAS), the rules-making body for disability athletics, regulators addressed the question of how tall is too tall. A previous attempt a decade ago to fix a maximum allowable length of prostheses for double amputees failed, IWAS Executive Director Maura Strange explained before the meeting, because experts "were unable to define a credible anatomical formula, due to variability in arm and torso lengths in relation to leg lengths." Besides, the experts concluded, any gain in stride length would be outweighed by the loss in balance and stability.
This time, following a complaint from the United States, IWAS reversed itself and is now in favor of instituting one of two anatomical formulas to determine "natural" height for double amputees. The first, called the "demi-span" measure, said IWAS athletics director Jan Bockweg, is a variant of the rule of thumb that a person's "wingspan"--the horizontal measure of one's outstretched arms--is equal to his or her height, within five percent. The second formula is based on the distance from the midpoint of the elbow to the prominent bone of the waist.
But both these proposals are subject to challenge and have been rejected in the past. "Using just one criterion could give inaccurate results," says Frasure. "I can speak from experience--I am 6-foot-0 but my wingspan is 6-foot-4." Whatever their shortcomings, both IWAS proposals are wending their way through a complicated approval process, and one or possibly the average of both will almost certainly be put in place in time for the Beijing Games in 2008, where Pistorius hopes to make history as the first amputee to run in the Olympics.
In the end , the IAAF and International Olympic Committee will have to decide whether to let Oscar and Marlon, or other amputee athletes yet to emerge, join the club of the world's most elite runners. That decision may not be the same for each of them, and Pistorius may wind up having to trim an inch or two off his running feet. For Scott Sabolich, owner and clinical director of an eponymous prosthetics clinic and research center in Oklahoma City, that, indeed, is the solution. "Pistorius should be able to compete only if he is found to be within two percent of normal height as measured by the length of his arms at full weight bearing," he wrote in an e-mail exchange, adding that he had protested Pistorius's victory in Athens for precisely this reason. As a unilateral amputee, however, Marlon Shirley (with whom Sabolich has worked extensively) "should be able to compete because his height is not affected, even on one side," Sabolich thinks.
But ultimately the real question is not one of science but of humanity and of fairness: should Oscar be allowed to run even if he gains some measure of advantage as a sprinter from his misfortune as a human being? And how does that advantage--if there is one--compare with the good fortune of a Carl Lewis or a Michael Johnson, members of what Gailey calls "the lucky sperm club" of athletes literally built to run because of their unnaturally long legs?
A strong argument could be made that cutting a bilateral athlete such as Pistorius down to size, so to speak, is in fact a means of preventing him from ever running as fast or faster than his able-bodied colleagues. The underlying and unspoken prejudice may be that if a disabled sprinter is able to match the times of the world's best able-bodied runners, then, almost by definition, he must somehow have an "unnatural" advantage.
Indeed, "the usual complaint about prostheses in competition is that they are not 'natural,'" says Silvers, the ethicist at San Francisco State University. "But this complaint abandons consistency, because a lot of prostheses are used in competitive sports, including the Olympics, with no complaint--prosthetic skin swimwear, for example." Pistorius using a prosthetic, surely, is not the same thing as Ben Johnson taking growth hormones, or a baseball player using a corked bat. Enhancing what is already nearly perfect and repairing what is seriously damaged are qualitatively different undertakings.
Which is why, unlike Sabolich, Gailey is more inclined to let the young South African find his own perfect altitude. "If at a given moment a human being can line up and cover a given distance faster than anyone else, he should get the gold. The fact that he is using something to compensate for a missing limb should not disqualify him," Gaily says. But, he adds, "I don't think the world is ready to see an amputee win an Olympic event."
About the Author
MARLOWE HOOD (firstname.lastname@example.org) is a journalist based in Paris. He first wrote about Oscar Pistorius in "Running Against the Wind" in the June 2005 issue of IEEE Spectrum.