When the Paralympic Games begin in Tokyo on Aug. 24, more than a dozen athletes—sprinters, long-distance runners, cyclists, long-jumpers, table tennis players—will compete wearing prosthetics made by Össur, a company itself founded by an amputee.

Started 50 years ago in Reykjavik, Össur manufactures braces, everyday prosthetics, and other kinds of orthopedic devices; in 2020, its sales totaled $630 million. But Össur also makes specialized prosthetic legs for competitive athletes, of the kind that have become so familiar to viewers everywhere since the success of the South African sprinter Oscar Pistorius: sleek, curved, carbon-fiber blades that look like they’ve arrived from the future.