Hammer toe is a contracture or bending of one or both joints of the second, third, fourth, or fifth(little) toes. This abnormal bending can put pressure on the toe when wearing shoes, causing problems to develop.
Hammer toes usually start out as mild deformities and get progressively worse over time. In the earlier stages, hammertoes are flexible and the symptoms can often be managed with noninvasive measures. But if left untreated, hammer toes can become more rigid and will not respond to non-surgical treatment.
The most common cause of hammer toe is a muscle/tendon imbalance. This imbalance, which leads to a bending of the toe, results from mechanical (structural) changes in the foot that occur over time in some people.