The symptom of Morton’s neuroma is ongoing severe pain and burning under the ball of the foot between the third and fourth metatarsal bones.
This condition presents with swelling and inflammation of a nerve that is trapped and constantly pinched and compressed by the adjacent metatarsals. Over time, the site of swelling can become a tumor of nerve tissue.
What causes Morton’s neuroma?
There are three different contributing causes of Morton’s neuroma:
- Wearing footwear with a concave surface under the metatarsal heads: In essence, this causes a drop of the heads of the second, third, and fourth metatarsals, significantly increasing the load they bear. The concave supportive surface of the footwear may be a result of the footwear design – or caused by a breakdown or compression of its midsole or insole material, with long-term use.
- Long-term use of footwear or insoles that provide excessive cushioning: This causes the body to stop producing robust soft tissue padding under the metatarsal heads. This creates a highly sensitized area.
- Failure of the foot muscles to correctly align the bones of the feet into strong and dynamically adaptable arches: This leads to foot instability and torsional forces on the metatarsal bones.
These causes can present simultaneously and can worsen the severity of the symptoms and difficulty in eliminating the causes.