The mechanics of the blood circulation through the horse foot can best be described as an additional heart, working as a ‘sucking (arterial blood flow to the foot) and pushing (venous blood return to the heart) pump’. This takes place during the swing (sucking) and stance (pushing) phase of the stride.
1. The “sucking” phase: Swing phase (the hoof is lifted in a neutral/unloaded position).
The coffin bone is in a neutral position: unloading the foot allows arterial blood to enter the foot and the capillaries to be filled. Venous blood is prevented from flowing back into the foot by valves. With the inflow of arterial blood, nutrients and oxygen are provided to the foot.
2. The “pushing” phase:
- Impact and Mid-stance (the hoof expands and the coffin bone descends into the hoof): Arterial blood flow diminishes as pressure builds up in the hoof. Loading of the foot squeezes the blood in the venous plexi and out of the foot into the digital veins providing hydraulic shock absorption.
- Push-off (the hoof starts to unload and contraction takes place): there is a secondary pumping action of venous blood out of the foot as the foot unloads and the hoof contracts supporting the heart and systemic circulation.
The mechanics of blood circulation through the horse foot are closely related with the ability of the heels to expand and contract. Research clearly shows that heel movement (the key variable of hoof deformation) is not negatively affected by the Twin™ Shoe, compared to the barefoot hoof, whereas a traditional shoe restricts heel movement approximately 36% compared to the barefoot hoof.
The Twin™ Shoe allows for proper circulation of the foot, which is important for proper hoof growth and quality, shock absorption, temperature control of the lower limb and supporting the heart and systemic circulation during exercise. As such improving the overall health and performance of the horse.