The effect of speed and gradient on hyperextension of the equine carpus.

This study discusses how the speed and gradient of a moving horse affect the hyperextension of the equine carpus, or wrist joint. The researchers tested five thoroughbred horses running at different speeds on a treadmill set at different gradients, and found that hyperextension increased with speed and was greater on an incline.

Background

• The research focuses on the equine carpus, the equivalent of the human wrist. It’s recognized for having a clear limit to joint extension, estimated to be about 180 degrees.
• According to the researchers, during the horse’s movement, the carpus tends to hyperextend, particularly during the stance phase – where the horse’s hoof impacts the ground and carries weight.
• The hyperextension is typically resisted by the carpal bones and ligaments. It’s suggested that the large increase in hyperextension might be related to certain stress levels in the carpus, which could potentially lead to injury.

Methods of Study

• Fives Thoroughbred horses were utilized in the study. They were exercised on a treadmill at different speeds, ranging from 1.8m/s to 10m/s, and at different gradients of 0% and +7.5%.
• Data used for their research was obtained using a method known as optical motion capture. Generally, it records the movement of objects or people and is widely used in biomechanical analysis of human and animal locomotion.

Results and Findings

• The study found that the peak hyperextension of the carpus (PCE) increased linearly with speed during horse movement.
• Faster speeds and running on an incline led to more significant hyperextension. More specifically, the study found a greater rate of increase when the treadmill was set at a +7.5% gradient.
• The validity of the regression equations was considerably boosted by subtracting the standing carpal angle (the angle when a horse is standing still) from the PCE when the horse was in motion.

Significance of Study

• Understanding how speed and gradient affect the hyperextension of the equine carpus may help in the understanding and prevention of potential horse injuries related to locomotion.
• This study may highlight the potential need for considering different factors such as speed and gradient in training regimes for performance horses to maintain their physical health.