Center for Sports Medicine and Orthopaedics - Medical Information Corns and hammertoes An inherited muscle imbalance or arthritis can cause toes to contract and buckle, forming hammertoes. When this happens, toe joints enlarge and stiffen and become deformed over a period of time. Shoes that are too tight may intensify this problem, so wearing square, open-toed, or prescription shoes may help people with hammertoes. Corns may form when hammertoes rub against the top of the shoe.
Corns are patches of thick, hard skin.
They 're usually painful and make it difficult to wear shoes. Corns can also be formed because of underlying bone problems which can cause excessive irritation. Corns between the toes are called soft corns. It's dangerous to dissolve or cut out corns yourself. Your doctor can trim or protect them if they become painful.