Sign in. Thanks for reading Scientific American. Create your free account or Sign in to continue. See Subscription Options. Go Paperless with Digital. Get smart. Sign up for our email newsletter. Sign Up. Support science journalism. Knowledge awaits. See Subscription Options Already a subscriber? Create Account See Subscription Options. Continue reading with a Scientific American subscription. Woodhall, at 18, already has run Roger Buhrley, who coached Woodhall earlier in his career, was at a track clinic a couple of years ago at the Olympic Oval in Salt Lake City when he was approached by an expert in biomechanics who had studied Woodhall.
Cruz believes a generation of top double-amputee sprinters is on the rise, the legacy of Pistorius before he was found guilty of murdering his girlfriend, and that means the issue of fairness likely will be raised again. At the U. To compete at the international level, they would have to run the in the range of seconds. Pressure is building for conclusive results. Markus Rehm, a Paralympic long jumper from Germany who wears a prosthetic on his right jumping leg, attempted to enter last summer's Olympic Games but was denied by the IAAF.
His best jump of 8. As a high school track coach for almost 30 years, I believe that is true only to an extent. I believe it all evens out at about meters, and after that a runner on blades has a tremendous advantage over able-bodied sprinters. A comparative analysis of elite performers shows that you can determine a sprinter's best meter time simply by doubling his meter time. The formula is remarkably accurate for the state's top able-bodied prep sprinters this spring.
The variance between the second half of the meter race and the first half for Landon Maxfield and William Prettyman was -. Dallin Draper ran the second half of the race. Dominic Bentil had the best variance, running the second half of the race.
By comparison, Woodhall's variance was a whopping. If he ran the first half of the in Even if he ran a faster opening that particular day, it wouldn't be enough to account for such a huge variance. In the world championships, Usain Bolt set the world record for the in 9.
Do the math: 9. His world record for the , set in the same meet, was In the era of political correctness and "inclusiveness, it is reasonable to wonder if scientists and sports officials can reach an objective conclusion. The obvious question is would Woodhall be this fast if he had his natural legs? Buhrley says no, but for reasons that are different than you might think.
Start your day with the top stories you missed while you were sleeping. Cookie banner We use cookies and other tracking technologies to improve your browsing experience on our site, show personalized content and targeted ads, analyze site traffic, and understand where our audiences come from.
The trio, and other experts, measured Pistorius's oxygen consumption, his leg movements, the forces he exerted on the ground and his endurance.
They also looked at leg-repositioning time—the amount of time it takes Pistorius to swing his leg from the back to the front. After several months the team concluded in a paper for The Journal of Applied Physiology that Pistorius was "physiologically similar but mechanically dissimilar" to someone running with intact legs. He uses oxygen the same way natural-legged sprinters do, but he moves his body differently.
The results of the Rice University study—physiologically similar, mechanically different—were presented to the Court of Arbitration for Sport CAS in Switzerland in , which decided that Pistorius should be allowed to run, revoking the IAAF's decision.
He missed qualifying for the Beijing Olympics by 0. But then scientific controversy arose. Members of the team that had published the paper began to express very different ideas about what, exactly, "mechanically different" meant. One group said that Pistorius's differences leave him on a level running field with all the other athletes. The other said that Pistorius is mechanically different in a way that confers a serious competitive advantage.
Weyand, the scientist with the treadmills, believes that Pistorius's prosthetics allow him to move in a way that no non-prosthetics wearer could, giving him an advantage. Kram, the biomechanics expert, believes that the Blade Runner's blades hinder him just as much as they help. One of the biggest points of contention is limb-repositioning time. The average elite male sprinter moves his leg from back to front in 0.
The five most recent world record holders in the meter dash averaged 0. Pistorius swings his leg in 0. Pistorius's rivals are swinging a lower leg that weighs about 5. Kram and his researchers countered with a paper claiming to have measured Walter Dix, a meter sprinter, swinging his leg faster than Pistorius. But they used television footage of Dix rather than the standard, high-speed research video generally used to make such measurements. High-speed footage for Dix from that same season does exist, Weyand says, and it shows the runner clearly repositioning his limbs at around the same rate as the average Olympic sprinter.
Swing time is important because it affects some central factors that determine how fast a person can run. Repositioning his legs faster means Pistorius can keep his foot on the ground longer than everyone else. It's a bit counterintuitive, but Weyand argues that a runner's speed is largely determined by how long he can keep his feet on the ground, rather than in the air.
The longer a foot remains on the ground, the more time the person has to generate force that will propel him forward. More force generally means more speed. Kram argues, however, that because the Cheetahs are made of carbon fiber, and are lighter, they can't transmit nearly as much force to the ground as a human leg can, creating less forward propulsion. So Pistorius has to push down harder than most people to get the same amount of force against the ground.
Weyand counters that Pistorius simply doesn't need to push as hard to run just as fast. Of course, other researchers have other theories about a possible advantage. Because Pistorius's Cheetah's don't tire, his lower leg stays springy throughout the entire race.
0コメント