An interesting article in The Horse discusses the findings of Hilary Clayton of Michigan State University shows that a technique that leveled the hoof to the live sole, lowered the heels, beveled the toe, and rounded the peripheral wall where the sole, frog, and bars were left intact was beneficial to the horse and was over time able to correct under run heels. It also showed that the frog, bars and sole should play a part in weight bearing. The whole article can be read on The Horse website