Amy Palmiero-Winters has done what eluded South African sprinter Oscar Pistorius, the double amputee who tried to qualify for the 2008 Summer Olympics. “It’s sort of like Jackie Robinson breaking the racial barrier in professional baseball,” says Roy Pirrung, president of the American Ultrarunning Association and the U.S. team leader for worlds. “I think it’s that high of an impact.” Pistorius’ attempt was clouded by debate over whether his carbon-fiber