A horse rider left paralysed after being thrown from her horse is suing the motorcyclist she says caused the animal to bolt.

Shelley Brown, of Portland Road, Hove, broke her back in the fall when startled horse Tommy tried to jump a fence.

Ms Brown, 46, has filed a High Court writ seeking damages of more than £300,000 from trail bike rider Ian Surry, of Sandown Road, Southwick, claiming the noise from his engine spooked the horse.

Ms Brown was riding Tommy with friend Mark Denyer on Mill Hill, Shoreham, when the accident happened in March 2006. The injury to her back has left Ms Brown paraplegic.

According to Ms Brown’s High Court writ, Mr Surry was riding his 250cc trail bike towards her. The claimant was an experienced horse rider and Tommy is sound in traffic, her solicitor Scott Rigby has told the High Court.

The defendant’s bike, being a trail bike, was designed to be ridden off-road. As a trail bike, it generated a comparable decibel noise level higher than bikes designed for road use only.

Ms Brown said she and her companion tried to wave at the biker to warn him to slow down. He failed to slow down but continued down Mill Hill at speed before turning in front of the riders into the car park, said the writ.

Tommy became frightened, spooked and bolted into the entrance to the bridleway opposite, where he attempted to jump a gate in that entrance. He hit the top of the gate and fell causing catastrophic injuries to the claimant.

Ms Brown is claiming Mr Surry was negligent because he did not look out for horseriders, continued at speed when he ought to have seen her and slowed down.

She is also suing the Motor Insurers Bureau, a body set up by insurance companies for claims against uninsured drivers, believing Mr Surry did not have insurance at the time of the accident.

Mr Surry was unavailable for comment.