Hammertoe is a condition in which one or more of the second, third, or fourth toes are involuntarily curled downward at the proximal interphalangeal joint (shown below in red). A downward curl at the distal interphalangeal joint (shown below in green) is known as a mallet toe. If the toes are curled downward at both joints, the condition is called claw toe.
Hammertoes are often caused by improperly fitting shoes that constrict and bend the toes. If this artificial positioning of the toes is maintained over time, the muscles can eventually shorten to accommodate it. Hammertoes can also be caused by damage caused by different forms of arthritis, and sometimes occur in conjunction with a bunion, where the inward, sideways position of the big toe pushes the toe next to it downward.
Treatment is usually nonsurgical in nature, ranging from switching to looser fitting shoes, to special exercises and/or physical therapy. Generally, surgery to correct hammertoes is only done when a person experiences pain or movement limitations as a result, and nonsurgical treatments have not led to improvements.