  The South African track star Oscar Pistorius, whose congenitally anomalous feet were amputated in childhood, uses modern alloy artificial feet that return almost as much energy as the runner's weight loads. Racing officials opposed Pistorius's competing against nondisabled athletes, invoking objections running from fears of his falling on other athletes, through his violating the rules because he has no fleshly foot to touch the starting block, to his very presence corrupting the purity of the sport, and the extravagantly dire prediction that able-bodied athletes would amputate their own fleshly feet to gain advantages derived from prosthetics. Pistorius appears to use about one-fourth less lower leg energy when matched with runners with fleshly feet because his prosthetic ankles are more efficient than fleshly ankles, and initially he was banned from the Olympics due to the claim (subsequently overturned by the International Court of Arbitration for Sport) that his artificial feet gave him an unfair advantage. (See Silvers and Wasserman 2000 for a general discussion of fairness in regard to accommodating people with disabilities in competitive sport and Silvers 2008 in regard to enhanced embodiment.)