I made the mistakes not because I'm tired.

Out of the tens of thousands of prosthetic legs they've made, there's never been any 400-meter athletes run under 50 seconds. So, if this was such a technologically advanced prosthetic leg, then how come not everyone's qualifying, or coming close to the qualification time, then?

I wasn't happy with my performance at the World Championships in Daegu. I had an unbelievable race in the heats, but misjudged the semi and finished last.

Thank you to everyone that has made me the athlete I am! God, family and friends, my competitors and supporters! You have all had a hand!

When you're competing, you don't have the choice of what the weather will be like. It really doesn't affect me. I ran one of my fastest times in the New York Diamond League meeting last year. It was raining pretty hard then.

There is a big difference between being good and being great.

I grew up not really thinking I had a disability. I grew up thinking I had different shoes.