"Blade Runner" Oscar Pistorius will be running at the World Championships, but some people think his blades give him an unfair advantage.
The South African runner was missing some bones in his legs when he was born - and has prosthetic blades fitted instead.
He's qualified for this month's World Championship and hopes to make the team for the 2012 Olympics.
But some people think his blades actually give him an advantage. Oscar says his speed is all down to intense training and is trying to prove he doesn't have an unfair edge.