Oscar Pistorius is faster on two prosthetic legs than many athletes are on two intact legs, which makes some people believe those legs give the South African runner an advantage.
Controversy has been simmering about the curved Cheetah carbon fiber legs for some time, and a new study comparing various aspects of his athletic performance with that of able-bodied runners aimed to clarify the prostheses' benefits -- or lack thereof. Ultimately, it might make things muddier.
Pistorius had competed (and won medals) for years in the Paralympics, but in 2007 he ran in an international competition against able-bodied runners. Later that year, the International Assn. of Athletics Federations banned technical devices incorporating springs, wheels or other elements that could give a benefit to the user, although it denied the ban was linked to Pistorius.
Subsequently, scientists determined that the prosthetics did give Pistorius certain advantages, and in 2008 the athletic association decided he couldn't run in competitions against able-bodied runners. However, that ruling was overturned by the Court of Arbitration for Sport (a Swiss-based international arbitration organization that decides sports-related disputes) later that year, saying there wasn't enough evidence supporting the claims that the prosthetics gave Pistorius an edge. (Pistorius wanted to compete in the 2008 Olympics in either the 400 meters or the 4 x 400 relay, but did not qualify.)
What the Court of Arbitration saw was a study conducted by several researchers and done at the Locomotion Laboratory at Rice University in Houston. The results -- published in the June issue of the Journal of Applied Physiology -- did not conclusively say whether Pistorius' prosthetics gave him an advantage.
Three things were tested: how much energy Pistorius expended during running, how resistant he was to fatigue, and his sprinting mechanics. His results were compared with competitive male runners with intact limbs.
Pistorius runs slightly more economically than able-bodied runners, but the results were not statistically different, says Peter Weyand, associate professor of applied physiology and biomechanics at Southern Methodist University in Dallas and lead author of the study. However, Pistorius uses 17% less energy than sprinters. "That was exactly what I expected," he said. "He has 20% less limb musculature. Other athletes use their calf muscles to generate force, but he doesn't have that."
