In essence, the hoof is a flexible and adaptable structure, which yields under the pressure of the impact with the ground, dissipating the concussion in a depression, compression and lateral expansion of the various parts.
The Hoof Mechanism is the 3-dimensional, viscoelastic (i.e. able to dissipate energy and self-reversing) deformation of the hoof (i.e. change in hoof geometry) that takes place during movement (loading and unloading of the foot/limb) as described below.
Dimension 1: Transverse (X-Y) plane around the Z-axis (Yaw): outward (expansion) and inward (contraction) movement (Heel Movement) supporting and stimulating proper shock absorption, circulation, and hoof horn health.
Dimension 2: Frontal/Longitudinal (Y-Z) plane around the X-axis (Roll): Independent up (abduction) and down (adduction) movement, balancing the hoof bone within the hoof from side to side (Lateral Flexibility) allowing adaptation to uneven footing and turns, improving surefootedness, biomechanics and hoof horn health.
Dimension 3: Sagittal (X-Z) plane around the Y-axis (Pitch): forward (flexion) and backward (extension) movement, balancing the hoof bone within the hoof from toe to heel (Sagittal Flexibility) allowing proper alignment of the internal structures when moving on a straight line, improving surefootedness, biomechanics and hoof horn health.
Research performed on the Twin™ Shoe, 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 by approximately 36%.
See below the Hoof Mechanism/Flexibility in a barefoot hoof, a hoof shod with a traditional one piece shoe and a hoof shod with a split Twin Shoe.
Hoof Flexibility in a barefoot hoof
Comparison of a Hoof Shod with a traditional one piece steel shoe (unsplit Twin Shoe) and with a split Twin Shoe.
See how the Hoof shod with a traditional shoe cannot flex as it would do in barefoot. The hoof is locked in a rigid plane by the one piece steel shoe.
See how the Hoof shod with a split Twin Shoe can flex as it would do in barefoot. The hoof is freed up at the toe and no longer locked in a rigid plane.
Natural Hoof Flexibility with a split Twin Shoe.
See how the Hoof can flex in all directions as it would do in barefoot.
Heel Movement of a Hoof (live horse) shod with Twin Shoes:
Heel Movement Before splitting the Twin Shoe: see how the Heel Movement is limited before we split the Twin Shoe as the Hoof is constrained in a rigid one-piece shoe.
Heel Movement After splitting the Twin Shoe: see how the Heel Movement is unconstrained and acts as in barefoot once we split the Twin Shoe.
Under load bearing conditions, the dorsal hoof wall rotates palmar/plantar-distal (backwards-downwards) around the coffin bone (figure below: #1 – sagittal flexibility), the quarters flare outwards, the sole and frog move downwards and the heel expands (figure below: #2-3 – heel movement).
Heel expansion occurs regardless of the loading pattern, but more heel expansion occurs when pressure is applied directly to the frog. Furthermore, the hoof is able to adapt to uneven footing or turns by the independent (side-to-side) up and down movement of the heels (figure below: #4 – lateral flexibility).
Red Arrow: descending body weight.
Pink arrows: movement of the phalanges (P2, P3) as the limb gets loaded.
Bright green arrows: ground reaction force.
Light green arrows: dissipation of forces through the digital cushion, ungular cartilages, hoof wall, laminae and bones.
Orange arrows: movement of the hoof capsule when loaded with
#1: palmar/plantar-distal rotation of the dorsal hoof wall,
#2: outwards flaring of the quarters and heel expansion,
#3: downward movement of the sole and frog and
#4: independent up and down movement of the heels.
P1 – proximal phalanx or long pastern bone, P2 – middle phalanx or short pastern bone, P3 – distal phalanx or coffin bone.
Research performed on the Twin™ Shoe, 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 traditinoal shoe restricts heel movement by approximately 36%.
Impact of Twin™ Shoes on Hoof Mechanism: Twin™ Shoes allow for a normal functioning hoof mechanism (research proven) and as such proper shock absorption and blood circulation of the hoof!