Jump jockey Aidan Coleman has welcomed a security review at Southwell Racecourse after he was allegedly punched by racegoers on Tuesday.
Coleman, 27, suffered minor injuries including two chipped teeth, when two people burst into the riders' changing room after the day's last race.
Four people were arrested and later released on bail, Nottinghamshire Police said on Wednesday.
Southwell is to "review and enhance" its security arrangements.
The Professional Jockeys' Association said the incident was "deeply concerning", and called on other racecourses to review their security.
Coleman, who rode at Chepstow on Wednesday, said: "I'm absolutely fine, us jump jockeys are a tough bunch.
"The only comment I would make is to question why they were still on the racecourse in the state they were. Southwell has announced that it is beefing up security so from my perspective it's over."
Two men and one woman were arrested on suspicion of assault and damage, and another woman for obstructing police.