It is impressive how many different structures of the hoof contribute to shock dissipation and attenuation and vibration damping when the horse’s hoof strikes the ground.
- The sole and the soft tissues in the heel region (frog, digital cushion, hoof cartilages and heel bulbs) dissipate a substantial part of the initial forces generated during ground impact.
- Inertia of the blood in the hoof also contributes to shock dissipation and attenuation and vibration damping. The fluid pressure of blood inside the hoof partially reduces the effect of the impact of initial ground contact.
- As the coffin bone is porous it is capable of containing a large volume of blood. This adds to the total blood volume and increases the shock absorbing and vibration damping ability of the hoof.
- When blood is forced into these blood vessels, the valves in the superficial coronary, subcoronary and heel veins also add to shock absorption. This can be compared to the operating principle of a hydraulic shock absorber.
- The hoof wall acts as a leaf spring. Opening that spring at the back of the hoof takes a lot of energy – energy that will be extracted from the impact with the ground.
- The hoof wall reduces concussive vertical forces as well by the compression of horn material at ground impact. The more that the hoof wall is compressed, the greater the counteractive compressive stress, and so the greater is the shock absorption. The high moisture content and optimal elasticity of the hoof wall are crucial factors in this.
- The coronary cushion exerts a shock absorbing and vibration damping function, much like the digital cushion does – albeit to a lesser degree due to its smaller volume.
- Damping takes place at a micro level as well. The wafer-thin layer of articular hyaline cartilage in the coffin joint reduces the vibrations. In addition, it ensures an even distribution of pressure on the underlying bone tissue.
- The flexibility and elasticity of the dermis, its dermal lamellae and the subcutaneous connective tissue play a small but important role in vibration damping too.
In a healthy hoof all these structures are in good shape and condition. They work together to minimise any possible damage done to the hoof in the first instance, and therefore to the rest of the horse’s body as well.