A careful study of wild horse hooves is changing the way we trim horses. A common theme observed in these hooves is their short overall length, yet a significant amount of horn mass in the walls, soles, and frogs. The walls, soles, and frogs are thick and dense, enabling these horses to travel great distances over rugged terrain barefoot each day while remaining sound. It was noted that natural wear patterns concentrate the main support of the foot in four areas of the sole and wall. These have been referred to as the "pillars" of the foot. Several experts in hoof care believe that emphasizing weight bearing on the pillars during trimming leads to the growth of stronger and healthier hooves.

There are many recommendations on how to do a natural hoof trim. This article explains the principles of natural foot trimming with an emphasis on the four-point method. Also provided is a video produced by Dr Ric Redden showing the method and results of using the four-point trim.

Most proponents of natural trimming agree on the observation that modern trimming techniques often leave the horse's foot too long. This means that the tip of the toe—usually the breakover point—extends too far in front of the foot. As a result, more force is required to lift the foot off the ground, which places additional strain on the toe, the navicular region, and the flexor tendons. The physics behind this is simple: the farther the distance from the foot's center of gravity to the point in contact with the ground, the more force is needed to "rotate" the foot off the ground. This force is primarily generated by the flexor muscles acting through the flexor tendons, which connect to the back of the foot, including the navicular region.

The breakover point is the front edge of the toe wall that makes contact with the ground. As the foot begins to lift off, it must rotate around this point. In a horse wearing shoes, this breakover point aligns with the front edge of the shoe's toe. To better understand how breakover affects gait, consider this metaphor: Imagine your feet are glued to wooden boards of various lengths. If the board is the same length as your feet, walking on it might feel a bit awkward, but it's manageable. However, if the board extends beyond the front of your feet, you would have to rotate over the front of the board to move forward, requiring more muscle effort and increased pressure at the breakover point. This situation is similar to walking in a stiff pair of diving flippers.

The additional force caused by a longer foot and toe causes:

• Increased concussion at the toe: results in white line disruption, toe bruising, toe cracks, and, when severe, separation of the white line from the wall and bone
• Stress on the walls of the quarter results in quarter cracks and breakouts.
• Increases stress on the flexor tendons and structures in the navicular area, which may predispose individuals to flexor tendinitis and pain in the navicular region.

These three regions are commonly associated with problems and lameness in horses. For example, founder is often associated with toe issues, pain in the navicular area is a frequent cause of lameness, and flexor tendinitis is a common condition. Recent hypotheses also suggest that a key area of pain in navicular syndrome stems from strain at the attachment point of the deep digital flexor (DDF) tendon and the impar ligament of the navicular bone.