A hammertoe is a condition that occurs when there is an imbalance in the ligament and muscles that surround the joints of the toe, notes WebMD. This causes the toe's middle joint to bend, and it becomes stuck in the bent position. The bent toe causes issues such as irritation and rubbing.
Hammertoes are classified as rigid or flexible, notes WebMD. Flexible hammertoes can generally be treated without surgery, but rigid hammertoes require surgery to restore full functionality to the toe. Hammertoes are caused by injury to the toe or arthritis and can be a genetic condition in some people.