A freak injury has ended Norwich swimmer Anne Bochmann's medley bid for London 2012, forcing her to concentrate on qualifying in the freestyle at this weekend's British trials.

The former Norwich High School for Girls pupil will now focus on the 200m and 400m freestyle after aggravating a back injury while vacuuming at home, forcing her to re-adjust her plans for the Olympics.

'I did some Hoovering in January and it kind of aggravated it again,' she said. 'It was really frustrating that it was something so little that had sparked it up. But it's definitely focused my training onto freestyle.

'It's a shame not to be doing the medley work but hopefully I'll come back to that in the future. But it wasn't worth the risk pushing it and not being able to work at all.

'There's no Hoovering allowed now. I'm not at all upset about that.'

Bochmann will need to finish in the top two at the upcoming trials at London's Aquatic Centre to secure a place in Team GB although she knows she has got her work cut out in a field that also consists of double Olympic champion Rebecca Adlington and two-time world silver medallist Jo Jackson.

However, Bochmann is not putting herself under too much pressure, insisting she will be treating the trials like any other British Championships she has competed at.

'I've done so many, one every year since I was 11, so I'll think of it like that rather than think of it being the Olympic trials for London,' the 18-year-old told BBC Radio Norfolk. 'It's been my dream for so long, but if you put a ridiculous amount of pressure on it doesn't work.'