That's what happened to me around a year ago. It resulted in having to go through an operation, followed by four months of intensive physiotherapy, before I could start to train and practise for my sport properly.
I missed an entire season but I had to take some positives out of the situation.
I had been attempting to change my technique before the injury, which meant specific changes to my training. Once I started to recover from the operation, and was in a position to start training again, I was able to forget about competing and just concentrate on a totally new training regime, working on my core strength and monitoring my progress on a week by week basis.
However, looking back, one of the most important things my time out allowed me to do was to really monitor the progress and results of my key competitors. As they were throwing certain distances, it enabled me to set my targets and standards accordingly. I went to some competitions to see them in action, like last year's BT Paralympic World Cup, meaning that, in a period when I was behind them physically, I could at least be one step ahead of them mentally.
All the hard work that I put in during my rehab phase more than paid off when I become a world champion at the International Paralympic Committee (IPC) Athletics World Championships in January. It was awesome to win a gold – I've been throwing for ten years and I've always been behind the older guys but, for the first time, I felt like I'd caught them up.
At the time, I was just delighted to be out in New Zealand and spending time with the squad but, the longer I was there, the more I was convinced that I had something extra in the tank and could give a winning performance.
Rather than training heavily, most of the month I was in New Zealand was spent having more physio and just working out the little niggles. I'd really started to beat myself up that I might not be able to throw anymore, or that the arm might not be ready, but it turns out all the worrying was totally unnecessary in the end.
It was also great to see so many of my GB team mates take home medals or make real strides in their development. When we went to Beijing, it felt like the GB Paralympic athletes weren't so much of a team.
Peter Eriksson, our head coach, arrived in the post after Beijing and placed a real focus on creating a team environment. From the top Paralympians, like David Weir, right down to the new youngsters, everyone was joining up and encouraging each other in both training and competition in New Zealand. When London 2012 comes around next year, I think this will be the strongest team GB will ever have sent to a Paralympic Games.
Going to the Olympic Park recently was enough to get me motivated and excited about London 2012. The stadium, and park as a whole, look brilliant and all I can think of is how much I want the opening ceremony to arrive and for the Olympics and then Paralympics to kick off. I know there are so many other people out there who are as excited as me.
BT have just launched their search for members of the public to become the Storytellers of the London 2012 Olympic and Paralympic Games. I'll be sharing my story and I hope people see this as a fantastic opportunity to get involved and channel their excitement in a creative way. After all, it's not all about sport – London 2012 will also be a massive cultural event and this campaign will enable people to share their thoughts in a variety of creative ways including writing, social networking, art, photography, film, music and beyond. People can find out more information, and apply to become Storytellers, at www.bt.com/london2012. The closing date is June 2011.
With the 500 Days To Go milestone now passed, there's no doubt that London 2012 is getting so close that it's no longer a dream in the distance, it's becoming incredibly real.
Nathan Stephens, who lost both legs after he was run over by a train when he was nine-years-old, won gold in the javelin event at the Christchurch 2011 IPC World Athletics Championships in January. The 22-year-old Welshman is also a BT ambassador. BT is searching for members of the public to become the Storytellers of the London 2012 Olympic and Paralympic Games. To apply visit www.bt.com/london2012