In vitro attenuation of impact shock in equine digits.

The research article studies the role of different structures within a horse’s foot in reducing the shock of impact when the hoof hits the ground. By mounting accelerometers on different parts of a hoof structure taken from a deceased horse, the researchers studied how different components each contribute to the absorption of shock, observing that the interphalangeal joints play a more prominent role than the hoof wall or the soft tissue inside it.

Research Methodology

• The researchers used equine cadaver digits (parts of a horse’s foot structure). To simulate the impact of a horse hoof hitting the ground during a trot, they constructed a specialized test apparatus.
• They attached uni-axial accelerometers at different parts of the foot structure: distolateral and proximolateral hoof wall, the upper surface of the second phalanx (toe bone), and the mid-side of the first phalanx.
• Through these accelerometers, they monitored the deceleration caused by the impact shock when the hoof structure impacted a barrier at different velocities, simulating a trotting horse’s speed ranging from 2.67 m/s to 4.46 m/s.

Findings of the Study

• Based on the deceleration recorded after each simulated impact, the researchers found that the equine foot structure reduces the deceleration in the parts closer to the top of the foot (more proximal).
• Among the components of the foot, the interphalangeal joints (joints between the toe bones) played a larger role in reducing the amplitude of the deceleration – the “shock” of the impact – than either the hoof wall or the soft tissues inside it.
• Regarding the frequency of the deceleration, the researchers observed that the soft tissues inside the hoof acted as what they term a ‘lowpass’ filter, reducing the higher frequencies regarding the deceleration. In contrast, the hoof wall and the interphalangeal joints showed much less frequency reduction.

Conclusion of the Research

• The research provides insight into the role of various structures within a horse’s foot in managing the shock from the hoof’s impact with the ground during locomotion.
• The findings suggest that while all parts play a role, the interphalangeal joints are particularly significant in managing the shock’s amplitude. The soft tissues within the hoof, on the other hand, significantly reduce higher deceleration frequencies.