Animal Welfare group Paw Justice is calling for a ban on bareback rodeo riding, saying the sport invariably leads to animal suffering.
The group is basing its claim on a slow-motion analysis of modern bareback rodeo - where the rider lies flat on the horse with their feet above the horse's neck and shoulders.
"At normal speed the rider looks like he's holding on for dear life," says Paw Justice Co-founder Craig Dunn.
"When you slow it down you can see he's deliberately and forcibly slamming his spurs down on to the horse's neck and shoulders to make the horse buck more and thereby receive higher marks from the judges."
Elsa Flint, a behavioural veterinarian with 26 years' experience, said the action would create mental and physical trauma for the horse.