A sound hoof has key areas of support that give soundness to the hoof.
Red: is the supportive buttress of the hoof. This is where the horse weights the hoof first. It’s the support system of the hoof. A good buttress is a large platform of support. The proper height of the buttress allows room for the sole ridge to develop.
Yellow: is the sole ride. A proper sole ridge offers support for the horse from seat of corn, around the entire sole to the other seat of corn.
Blue: once you have the buttress and sole ridge, you will see nice concavity develop in the hoof.