Anything that causes compression or irritation of the nerve can lead to the development of Morton's neuroma in the foot.
Morton’s neuroma may be caused by the toe bones (metatarsal bones) pressing against the nerve when the gap between the bones is narrow. This causes the nerve and surrounding tissue to thicken.
One of the most common offenders in the development of Morton's Neuroma is wearing shoes that have a tapered toe box (end of the shoe where your toes sit). When wearing a pair of shoes that has a tight or tapered toe box, the toes and metatarsal bones are compressed. This will lead to the metatarsals rubbing against the inter-digital nerves causing irritation of the nerve and thickening of the nerve sheath, resulting in painful symptoms.
Wearing shoes that are too tight can make the pain of Morton’s neuroma worse. This is because the toe bones are more likely to press on the affected nerve if your shoes are too tight.
High-heeled shoes, particularly those over 5cm (2 inches), or shoes with a pointed or tight toe area, can also compress your toes and make the pain worse. This is why women tend to be affected by Morton’s neuroma more than men.
Some people simply have a foot type that is more prone to the development of Mortons’ neuroma. This could be due to mechanical irritation of the nerve in the foot, from something as simple as walking.
Some experts believe that other foot conditions may also be associated with Morton’s neuroma. This is because other conditions may cause the metatarsal bones to rub against the nerve in your foot.
Foot problems that may increase your risk of developing Morton’s neuroma include:
- Abnormally positioned toes
- High arches – Where the arch or instep of your foot is raised more than normal
- Flat feet – Low arches or no arches at all
- Bunion – a bony swelling at the base of the toe
- Hammer toe – where the toe is bent at the middle joint
Activity & Vocation
Another potential causes of Morton’s neuroma are activities that involve repetitive irritation to the ball of the foot and toes. Such activities can include sporting activities such as long distance running, court sports (tennis, squash, badminton), and dancing.
However, simply having an active job which requires you to be moving and on your feet for an extended period of time, such as police and nursing staff and labourers could also lead to the development of a neuroma.
Injury & Trauma
Finally, an injury or type of trauma to the foot or toes, such as a fracture or sprain may also lead to a Morton’s Neuroma.