Katie Walsh's ride on Wonderful Charm in the Randox Health Grand National on Saturday is in doubt after she was taken to hospital following a fall in the Foxhunters' Chase.
Walsh - who finished third in the 2012 National on Seabass - was unseated from Distime at The Chair, the third fence, and appeared be kicked by another horse as she lay on the ground.
She was stretchered from the course into an ambulance and taken to hospital.
Clerk of the course Andrew Tulloch said: "As far as I know she's been taken straight to hospital."
ITV Racing tweeted: "Katie Walsh has a serious arm injury after a fall at The Chair - her #GrandNational ride on Wonderful Charm is in doubt. Get well, Katie."
