Movements of the horse’s mouth in relation to horse-rider kinematic variables.

This study investigated how horses react behaviorally to rein contact and the movement of riders’ hands. It found that these actions resulted in responses like movement of the horse’s lips and mouth, changes in ear position, head tilt and tail movement. It also noted that mouth movements were associated with the trot’s suspension phase, and that the distance between the rider’s hand and the horse’s mouth, as well as the rein tension, had an effect on these mouth movements.

Research Objective and Hypothesis

• The primary objective of this research was to analyze the behavior of horses in reaction to the movement of rein and the riders’ hand. The study sought to understand how the horse responds to rein tension and hand movements, especially in two different riding positions — when ridden ‘on the bit’ (a more controlled position) or unrestrained.
• The hypothesis set forward was that riders’ hand movements and rein tension would elicit noticeable behavioral responses from the horses, and these reactions would be more pronounced when ridden ‘on the bit’ compared to when ridden without restraint.

Methodology

• The study involved seven dressage horses and their riders, performing a sitting trot on a high-speed treadmill. Data were collected through a 12-camera, infrared-based optoelectronic system.
• A rein tension meter was fitted on three horses to measure the rein tension while behavioral observations were noted from video recordings.
• The behavioural responses recorded included lip movement, mouth movement, open mouth, change in ear position, head tilt, and tail movement. Particular attention was given to mouth movements, which were found to associate with the suspension phase of the trot.

Findings

• The position of the horse’s head and neck was found to be non-significant in the final models, suggesting that the position does not play a major role in influencing the horse’s behavioral responses.
• Instead, mouth movements in horses were found to be related to rein tension and the distance between the rider’s hand and the horse’s mouth. This indicates that the horse’s mouth movements are more likely triggered by this distance and tension, rather than its head and neck’s position.

Conclusion

• The study concluded that the interactions between horses and riders are complex and highly variable, which could be affected by various factors such as the rein tension and the distance between the rider’s hand and the horse’s mouth, rather than the position of the horse’s head and neck.