horse hoof anatomy
Anecdotally veterinarians and farriers know hoof anatomy influences horse soundness and movement.

“Variations in hoof anatomy may alter stress distribution, this predisposing horses to pathologies and lameness,” said Babak Faramarzi, DVM, CVA, MSc, PhD, an associate professor at the Western University of Health Sciences College of Veterinary Medicine, in Pomona, California.

However, studies exploring the relationship between hoof conformation, biomechanics, and potential injuries are limited.

So Faramarzi and colleagues conducted a study on the topic, and he shared the results at the 2018 American Association of Equine Practitioners Convention, held Dec. 1-5 in San Francisco, California.

The researchers studied nine clinically sound sport horses of the same breed; the horses all had the same job, living conditions, and farrier. Faramarzi said each horse walked across a pressure plate, and the team recorded the force (F), contact pressure (CP, that which the hoof exerts on the pressure plate), and contact area (CA, the actual portion of the hoof that contacts the pressure plate). Then, they took radiographs and photos of the horses’ hooves and examined 55 internal and external measurements.

Some of the key findings, he said, include:

  • Toe angle was negatively correlated with contact area; this could suggest that the smaller the toe angle, the more extensive the hoof contact with the ground; steep toe angles are often associated with club feet, while a more shallow toe angle is generally associated with long toes;
  • Several heel-height measurements were negatively correlated with dorsal force, meaning it’s possible that the lower the heel height, the more force that’s exerted on the front of (dorsal part of) the hoof;
  • Hoof wall length was negatively correlated with palmar contact area; this might suggest that taller heels could result in less ground contact area in the back half of the hoof;
  • Larger medial wall angles (the angle the hoof wall facing the other hoof makes with the ground) were correlated with higher F, CP, and CA; this could mean that the larger the medial wall angle, the more force and pressure that’s exerted on that side of the hoof;
  • Dorsal hoof wall thickness and coffin bone length and width were correlated with F and CP; so it’s possible that a thicker front hoof wall is associated with more force and contact pressure with the ground; and
  • Coffin bone height was negatively correlated with CA—taller coffin bones might be associated with a smaller ground contact area.

So what does this all mean?

“Patterns of correlation between hoof anatomy and biomechanics confirmed the significance of hoof anatomy,” Faramarzi said. “These findings provide valuable information on the significance of changing the hoof anatomy, such as therapeutic trimming and shoeing in addressing hoof pathologies (disease or damage).”