Jenny Meadows's participation in the London 2012 Olympics is in doubt after she was ruled out of this weekend's trials in Birmingham. The 800m runner has
been struggling with a knee injury and was unable to run at the weekend.

The 27-year-old, who won the 800m at the World Championships in Moscow last year, was due to run in the heats of the women's 800m on Saturday.

But she was unable to run after