When the toe muscles get out of balance, a hammer toe can form. Muscle imbalance puts a lot of pressure on the toe's tendons and joints. This pressure forces the toe into a hammerhead shape.
https://www.webmd.boots.com/foot-care/hammer-toes-causes-symptoms-treatment-prevention
A hammertoe has an abnormal bend in the middle joint of a toe. Mallet toe affects the joint nearest the toenail. Hammertoe and mallet toe usually occur in your second, third and fourth toes. Relieving the pain and pressure of hammertoe and mallet toe may involve changing your footwear and wearing shoe inserts. If you have a more severe case of hammertoe or mallet toe, you might need surgery to get relief.
http://www.mayoclinic.org/diseases-conditions/hammertoe-and-mallet-toe/symptoms-causes/syc-20350839
Hammertoe and mallet toe feature an abnormal bend in the joints of one or more of your toes. Moving the affected toe may be difficult or painful. Corns and calluses can result from the toe rubbing against the inside of your shoes.
http://www.mayoclinic.org/diseases-conditions/hammertoe-and-mallet-toe/symptoms-causes/syc-20350839
The hammer toe deformity is the most common deformity of the small toes. It is a common deformity of the foot in which either the second, third, or fourth toe is bent at the middle joint. Medicine Net. com
https://www.medicinenet.com/script/main/art.asp?articlekey=54807
Hammer toes can be a serious problem in people with diabetes or poor circulation. There are two types of hammer toes: Flexible hammer toes. If the toe can still be moved at the joint, it's a flexible hammer toe. That's good, because this is an earlier, less-severe form of the problem. There may be several treatment options. Rigid hammer toes.
https://www.webmd.boots.com/foot-care/hammer-toes-causes-symptoms-treatment-prevention
None of these things will cure the hammer toe, but they may relieve the pain and discomfort: Only wear shoes that are high and broad across the toes. There should be at least 1.5 cm of space between your longest toe and the tip of the shoe.
https://www.webmd.boots.com/foot-care/hammer-toes-causes-symptoms-treatment-prevention
Your genes: you may have inherited a tendency to develop hammer toes because your foot is slightly unstable - such as a flat foot. But high-arched feet can also get hammer toes. Arthritis ; Injury to the toe: ill-fitting shoes are the main culprits of this cause. If shoes are too tight, too short, or too pointy, they push the toes out of balance.
https://www.webmd.boots.com/foot-care/hammer-toes-causes-symptoms-treatment-prevention
The hammer toe deformity is the most common deformity of the small toes. When a hammer toe first develops, it can be bent back into its normal position. If not treated, a hammer toe may become rigid and require surgical correction in order to correct the deformity. Symptoms and signs associated with hammer toe include corns or calluses on the affected toe and pain in the affected area.
https://www.medicinenet.com/script/main/art.asp?articlekey=54807
Hammertoe and mallet toe are foot deformities that occur due to an imbalance in the muscles, tendons or ligaments that normally hold the toe straight. The type of shoes you wear, foot structure, trauma and certain disease processes can contribute to the development of these deformities.
http://www.mayoclinic.org/diseases-conditions/hammertoe-and-mallet-toe/symptoms-causes/syc-20350839
A common cause of hammer toe is wearing shoes that do not fit properly. Poorly-fitting shoes can hold the toes in an abnormal position and result in tightening of the muscles required to maintain that position.
https://www.medicinenet.com/script/main/art.asp?articlekey=54807
what is hammertoe?
The hammer toe is a common deformity of the foot in which either the second, third, or fourth toe is bent at the middle joint. The hammer toe is a deformity of the foot in which either the second, third, or fourth toe is bent at the middle joint.  