The cause is essentially the two 'knuckle bones', adjacent to the nerve, pinching it.
Over time, the cover of the nerve thickens and is 'more compressed, like a 'lobster' claw squeezing the delicate nerve.
Instead of removing is surgically, which has all kinds of bad complications, just have a qualified Podiatric physician make a customized insert (custom orthotic) for you that has a small bump added (cookie) which effectively spreads these knuckles apart when the foot purchases the ground.
If this doesn't solve the problem, the nerve can be calmed down with an injection or more of alcohol or cortisone.
The key again is the custom orthotic with a metatarsal or neuroma cookie.
Try, at all costs to stay away from neuroma surgery! OUCH...
DR ANDREW CARVER