An interdigital neuroma or Morton’s Neuroma is compression and aggravation of the common interdigital nerve. It is located between the metatarsal heads. One theory is overall compression of the forefoot. Side to side, tight shoes, high heeled shoes, soccer shoes, or ski boots, can cause excessive pressure on the interdigital nerve. This pressure can aggravate the nerve and can be very painful. When the nerve becomes irritated, the body tries to protect and the nerve and it becomes covered in a bundle of protective tissue which in turn makes the nerve larger and more sensitive to pressure.
This can sometimes be felt in the forefoot between the metatarsal heads towards the web space and when pressure is applied to the neuroma, the pain is reproduced. Another theory is that the interdigital nerve is irritated by the intermetatarsal ligament. Sometimes this ligament can sag downward toward the nerve, thus the transmetatarsal arch decreases which compresses the nerve. The entrapped and damaged nerve can cause aching and burning in the forefoot. Pain, numbness, or an electrical shock sensation is also common on the toes. The foot usually feels better without the shoe on. The desire to remove ones shoe and massage the forefoot is common, and is usually a very urgent desire. Interdigital neuromas are most common between the third and fourth metatarsals, but can appear between any of them. Shoes with a low heel and a wide and deep toe-box should be worn. High-heeled shoes with tight toe boxes should be avoided. A custom orthotic to address underlying biomechanics works very well. The device should have good arch support, and a good transverse metatarsal arch support to spread the metatarsal shafts to relieve pressure on the interdigital nerve. Ask your health care professional which will be best for you.