Jockey Tegan Harrison looks likely to avoid surgery after being injured in a fall at Doomben but could still be sidelined for up to three months.

Harrison was one of four jockeys involved in a chain reaction fall on Monday.

The other three Michael Cahill, Brad Stewart and Jake Bayliss escaped serious injury.

Harrison was riding Nineoneone when the filly fell at the 800m and in the backwash Pintang Prince (Stewart), Missionary Bay (Cahill) and Northern Dragon (Bayliss) dislodged their riders.

Harrison and Bayliss were treated by paramedics for about 20 minutes on the track before both were taken to hospital.

Cahill was examined by the club doctor and cleared to ride in the final race.

"I was very lucky," he said.

Stewart was also examined by the doctor and cleared of any apparent major injury.

Harrison was knocked out as a result of the fall but regained consciousness while being treated.

Later hospital tests showed she had suffered fractures to five vertebrae, two ribs and her sternum.

She also re-injured a collarbone which kept her out of the saddle for several weeks two years ago.

Harrison is not expected to need surgery but her partner, Gold Coast trainer Ben Hull, said at this stage it appeared she could miss several months of riding.

Queensland Jockeys Association boss Glen Prentice said every assistance would be given to Harrison to help her recovery.

"Tegan is very popular and we are all wanting to help in any way we can," he said.

Prentice said at this stage it was not clear how long Harrison would remain in hospital.

Bayliss was initially diagnosed with a sore hip and arm but has been discharged from hospital after being cleared of any breaks.

He will undergo a concussion test later this week but hopes to ride at the weekend.

Chief steward Peter Chadwick said an inquiry into the fall would be adjourned until Harrison was fit to give evidence.