 Pistorius has been using the same Össur blades since 2004.He was born without fibulae and with malformed feet, and his legs were amputated about halfway between knee and ankle so he could wear prosthetic legs.He wears socks and pads which are visible above the sockets to reduce chafing and to prevent blisters, and the sockets have straps in the front that can be tightened to make the prosthesis fit more snugly.