As it gets more difficult to squeeze even one finger under the noseband, pressure on the horse increases exponentially. | Photo: iStock

Nobody knows where the “two-finger rule” for fitting bridle nosebands came from. But according to results of the latest study on noseband tightness, it makes sense.

When a rider can easily slip two fingers between a horse’s front nasal bones and the noseband, pressure levels around the horse’s face are generally acceptable. But as it gets more difficult to squeeze even one finger under the noseband at that same place, pressure on the horse increases exponentially, reaching heights that are technically inhumane, a leading equitation scientist said.

“Our pressure readings at half-finger and zero-finger tightness literally went off the screen, and we thought our system was malfunctioning,” said Orla Doherty, MVB, MSc, PhD, MRCVS, of the University of Limerick, in Ireland, and hon. president of the International Society for Equitation Scientist (ISES)