A corn itself is cone-shaped and usually develops if a shoe rubs against the toes for a prolonged period. As the skin thickens, the corn forms a knobby core that points inward. Hard corns develop on toe joints, usually on the little toe. A shoe that squeezes the front of the foot may cause one toe to rub against another forming a corn between the toes, which is usually soft. These corns can be painful, however, if they harden and rub against each other.
Ingrown toenails can occur in any toe but are most common in the big toes.
They usually develop when tight fitting or narrow shoes put too much pressure on the toenail and force the nail to grow down into the flesh of the toe. Fungal infections, injuries, abnormalities in the structure of the foot, and repeated pressure to the toenail from high impact aerobic exercise can also produce ingrown toenails. The first metatarsal bone is the one that attaches to the big toe. As this bony growth develops, the bunion is formed as the big toe is forced to grow at an increasing angle towards the rest of the toes. Bunions often develop from wearing narrow, high-heeled shoes with pointed toes, which puts enormous pressure on the front of the foot and causes the foot and toes to rest at unnatural angles.