Oscar Pistorius was only 11 months old when his legs were amputated(切断する)below the knee. Now, the 21-year-old South African, nicknamed the "Blade Runner," runs on specially adapted carbon-fiber blades that have seen him win Paralympic titles and challenge records set by able-bodied athletes. On Monday, the International Association of Athletics Federations ruled that Pistorius's prosthetics(義足、義眼等の人口補充物)give him an unfair advantage over other athletes and that he will not be allowed to compete in the Olympic Games. Their investigation revealed that the prosthetic "Cheetah" blades enable Pistorius to run "at the same speed as the able bodied sprinters with about 25% less energy expenditure."