The primary function of the hoof capsule is protection. It is a hard outer shell of thickened skin that covers soft inner structures that surround the bones.

Strength for the equine hoof wall comes through unity; not only with a very tight
lamellar bond between the wall and sole, but also unity in the wall itself which
is in effect an arch, one of the architecturally strongest forms known to man.
A good analogy for comparison would be a stone arch bridge that is a pile of
rocks spatially arranged so the individual parts can act in unity with great
strength. Without unity it is just a pile of rocks!

So it is with the hoof wall, an arch that remains incredibly strong so long as
it remains complete, continuous and unbroken.