1. The Feet

2. Functions of the Hoof The main functions of the hoof are to:
Provide a weight bearing surface
Protect the sensitive internal structures of the foot
Maintain moisture in the foot
Provide grip
Act as a shock absorber

3. Sensitive vs Insensitive Structures
The hoof is a complex grouping of sensitive and insensitive structures which must be kept healthy and undamaged
Sensitive structures
Contains many nerve and blood vessels
Corium
Modified skin tissue within the foot
Lines the hoof with each of its parts named according to the insensitive structure it underlies and produces
Ex. Frog corium (sensitive) lies below and produces the horny frog
Insensitive structures
Horny layer structures
Ex. Insensitive laminae, periople, wall, bars, sole, and frog

4. External Hoof Anatomy
The external surface of the hoof consists of the:
Skin
Coronary band
Rim of specialized skin, includes coronary corium and blood vessels
Hoof wall
Visible, outer covering of horse’s foot
The hoof wall is divided into regions:
The toe
The quarters
The heel

5. External Hoof Anatomy Solar Surface

6. External Hoof Anatomy
The ground surface (solar surface) of the hoof is composed of the sole, frog, bulbs, and bearing edge of the hoof wall
Outer Hoof Wall
The outermost layer of horn cells
Sole
Is a thick plate of flaky horn that covers most of the ground surface and is rounded in such a way that when viewed from the bottom, it is concave
Frog
Is an elastic, wedge shaped mass of horn that fills a triangular space at the back of the foot
Heel bulbs
Formed by the back of the digital cushion

7. Bringing it all together
Internal Hoof Anatomy
Bringing it all together

8. Internal Hoof Anatomy The Elastic Tissues
Elastic tissues are those which are capable of changing shape in response to foot impact
The elastic tissues are:
The digital cushion
The hoof wall
The sole (discussed earlier)
The frog (discussed earlier)
The bulbs of the heel (discussed earlier)

9. Internal Hoof Anatomy The Elastic Tissues
The Digital Cushion
Is the main shock absorber of the hoof
Is bound by the lateral cartilages at the sides, the deep digital flexor tendon above, and the horny frog below
The back of the cushion forms the bulbs of the heel
Good vs. Bad Digital Cushion

10. Internal Hoof Anatomy The Elastic Tissues
The Hoof Wall
Located at the hairline along the top of the hoof wall is the coronary band, which is the primary source of growth and nutrition for the hoof wall
Around the perimeter of the ground surface of the hoof is the white line, which represents the inside edge of the hoof wall at it’s junction with the sole. The white line marks the border between the sensitive and insensitive sole. It serves as a guide to show where nails should be driven when shoeing the horse
The wall grows approx inch (6mm) per month, taking from 9 to 12 months for the toe to grow out. Growth tends to be slower in cold or dry environments

11. The Hoof Wall

12. The Hoof as Shock Absorber
The shock of concussion is dissipated laterally against the hoof wall
As the foot strikes the ground, downward pressure flattens out the concave surface of the sole
This distributes weight laterally against the hoof wall, which expands about a quarter of an inch (6mm)
Hoof as a shock absorber

13. The Hoof as Shock Absorber
With heel pressure, the frog compresses the digital cushion, which then flattens and pushes the lateral cartilages outward in opposite directions
During concussion the navicular bone shuttles the load from the digital cushion through to the short pastern bone, bypassing the coffin bone and relieving some of its load
The conformation of the knee and hock joints also helps reduce the shock of impact

14. The Hoof & Conformation
Closely related to the way it functions and to the form of the limb itself
Differences in the front & hind
Front – rounded toe & broad heel
Hind – Slightly narrower and more pointed
Malformations of the foot may cause actual injury (breakdown of the foot structures, concussion ailments) or predispose an animal to injury (bruising, interference, cross-firing)
Shape and composition of the foot are indicators of the health and general soundness of the whole horse
Tools to evaluate balance