David Knight: 'It's a hugely frustrating and disappointing situation to be in for many reasons, not least because I'd had a great pre-season and was coming into the world championships feeling really good. Things had gone well as far as my training, testing and racing before Spain and I was really looking forward to the defending my E3 title. I hate not racing especially as my team and all my sponsors have, like myself, put a huge amount of work in over the last few months. The other thing that's really frustrating is that it's one of those injuries that's fine 95 per cent of the time, not like a broken bone that when it's broken is broken. It's hard to explain simply what the problem is, but it's basically the same thing that put me out of the first day of the last round of the '11 world championship, in France. My hip will only rotate so far, mechanically, before it stops. The problem I have is that there's some additional bone on the top of the ball on my femur, and on the inside of the joint. When my hip rotates as far as it can I have bone hitting bone, which is what's causing the problem. If I catch my foot, like I did in Spain, it kind of pulls the hip joint apart. That pulls the muscles and ligaments, but also damages the cartilage. And when you damage cartilage you get a build up of fluid, which makes things worse. I had scans on my hip earlier this week but for now I want to try and get back racing. I can walk ok, and if I can ride with my feet on the pegs most of the time I'm hoping things won't be too bad. I'll not know how things are until I start the first day, but with some painkillers I'm hoping I'll be able to manage the pain and do my best.'