Multiple Group One-winning jockey Blake Shinn will be out of action for three to six months after suffering fractures to his C1 and C3 vertebrae in a fall at the Randwick barrier trials.

Shinn was taken to hospital for scans after the fall on Monday complaining of a sore neck and with a suspected concussion.

The jockey tweeted from his hospital bed on Monday evening he felt lucky it was not worse.

"Well I've had better days! But must count my lucky stars it's not worse. Fall at the trials this morning resulted in a C1 & C3 vertebrae fracture, so I'm out of action for 3-6 mths. Gutted to miss spring as had some great rides lined up and was feeling ready to take on the world!" Shinn said.

"Will have to put that on hold for the time being, but I'll be back and better than ever for autumn. Thank you all for the enormous outpouring of support, I'm overwhelmed by all your calls and messages. It really means a lot!"

The winner of the 2008 Melbourne Cup on the Bart Cummings-trained Viewed, Shinn finished second to Brenton Avdulla in last season's Sydney premiership.

Earlier on Monday morning, Shinn rode triple Group One winner Happy Clapper to an eye-catching fourth in a 1250m-trial.

Shinn was aboard the Pat Webster-trained Happy Clapper in his three Group One wins last season in the Epsom Handicap, Canterbury Stakes and Doncaster Mile.