According to Cunha, the below factors can cause or worsen hammer toes:
Genetics: Some people are born with a foot structure that is more prone to developing hammertoes. For example, having high arches or a second toe that’s longer than the big toe can increase your risk. Some genetic disorders can also predispose people to hammer toes.
Trauma: Foot injuries, such as a broken toe that heals in a bent position, can lead to hammer toes. In some cases, severe trauma can cause muscle imbalances that lead to hammer toes.
Age: With age, the ligaments and tendons of your foot can become weaker and less flexible. In some cases, this causes the toes to bend into a hammer-like position.
Medical conditions: Some conditions, such as diabetes and neurological concerns, can cause muscle weakness or nerve damage in your feet which could lead to hammer toes.
Wearing ill-fitting shoes for prolonged periods: Per Cunha, this is one of the most common causes of hammer toes. Shoes that are too tight, narrow, or high-heeled can push the toes into a bent position. Over time, the toe muscles can become unable to straighten, leading to a permanent change.