The way we sit a horse and the way we use our reins—intentionally or not—could be giving signals to horses that we weren’t meaning to give.

Recent study results show that horses react to our “rider kinematics”—the way we move—in patterns not previously identified, said Marie Eisersiö, MSc, of the Swedish University of Agricultural Sciences Faculty of Veterinary Medicine and Animal Husbandry.

The kinematic variable of the relationship between the rider's hand and the horse's mouth is "of importance as it yields some information about the rider's ability to follow the movement of the horse with the hand,” Eisersiö said. It's very important, from a horse welfare standpoint, that riders continuously work on improving how they use the hand, she added.

Eisersiö and her fellow researchers studied seven dressage horses ridden by their regular riders at the sitting trot on a treadmill. The researchers focused on the horses’ head, ears, and mouth movements and compared these findings to the riders’ use of the reins and the phase of the trot. They also measured rein tension in three horses