Amateur jockey Tom Weston is being detained in intensive care after suffering two punctured lungs in a fall at the Cheltenham Festival on Thursday.
Weston, 28, was airlifted to hospital after falling on Benbane Head in the Fulke Walwyn Kim Muir Chase.
Trainer Martin Keighley said: "The main thing is that his head is OK as the head injury was the main concern.
"He has punctured both lungs so he will be in intensive care for two days just so they can keep a close eye on that."
An official statement from the Injured Jockeys' Fund said Weston was stable in Southmead Hospital, Bristol.
Weston's mount was not badly hurt in the fall, which took place during the sixth race of the day (16:40 GMT), but the 11-year-old has been taken out of Saturday's Betfred Midlands Grand National Chase at Uttoxeter.
Two years ago, jockey JT McNamara was paralysed after a fall in the same race.
The start of the concluding charity race was delayed by about 15 minutes while Weston was being treated on the course.
Weston is an experienced amateur jockey from Worcestershire.
He won the Fox Hunters' Chase on 50-1 chance Silver Adonis at Aintree's Grand National meeting in 2010 for trainer Dr Richard Newland.