This study uses direct measurements of limb ground reaction forces (GRFs) to analyze the galloping of ridden Thoroughbred racehorses. It finds that the force exerted by each limb during the motion is roughly equal and varies with speed, which provides insight into locomotion mechanics and potential factors influencing injury risk.

Understanding Ground Reaction Forces (GRFs)

• Ground reaction forces (GRFs) are the forces exerted by the ground on a body in contact with it. In the context of this study, this refers to the forces exerted on the horse’s limbs as they make contact with the ground during a gallop.
• Direct measurements of GRFs in galloping horses are sparse. This research is significant because it provides objective and direct measurements of these forces.

Method and Findings

• The study collected GRFs data from multiple limbs of seven Thoroughbred racehorses using force plates.
• The research found that the observed peak vertical GRFs values were approximately equally distributed among the horse’s limbs.
• Specifically, the values recorded were 13.6 N kg for the non-lead hindlimb, 12.3 N kg for the lead hindlimb, 14.0 N kg for the non-lead forelimb, and 13.6 N kg for the lead forelimb at a speed of 11.4 m s.
• This even distribution of forces is not common in fast-moving four-legged creatures, who typically have a 60:40 distribution.

Implications of the Research

• An even distribution of load on all limbs during galloping might be useful in reducing the accumulation of fatigue in the limbs of the animals, thus lowering the risk of injury.
• The study also found that horses apply a net accelerative impulse with the hindlimbs and a net decelerative impulse with the forelimbs.
• This knowledge of GRFs in horses enhances our understanding of the mechanics of galloping in fast-moving species and could be useful in optimizing athletic performance or in designing more effective injury prevention strategies.