What causes metatarsalgia? is like asking how long is a piece of string? or what causes a sore knee? There is no answer as there is no diagnosis of “metatarsalgia“, just like there is no diagnosis of “sore knee” and just like we do not know how long the metaphoric piece of string is.. “Metatarsalgia” simply means pain in the forefoot – as such there can literally be 100’s of different causes of that, so it is simply not possible to give a specific cause of metatarsalgia unless you know what the specific diagnosis is that is causing pain in the forefoot.
Pain in the forefoot could be a callus, a plantar plate tear, a Morton’s neuroma, Freiberg’s disease, a stress fracture, intermetatarsal bursitis, an osteoarthritis in the joint, fat pad atrophy, early rheumatoid arthritis, sesamoiditis and many more. It should be clear from this short list is that they are all totally different, have different causes, different symptoms, different treatments and different outcomes.