Medatarsal Stress Fracture? Extensor Tendinitis? or something else (Read 542 times)

I'm ramping up mileage for early Spring Marathon. I recently noticed a dull pain on the top of my left foot. My amateur web based diagnosis leaves me with these 2 possibilities. The pain is dull and it does not get worse during running. I have run about 2 or 3 times since I noticed. It kind of warms up during running and I can sense the ache, but it's not bad at all. But I of course would like to eliminate this as something that could turn out to be serious. I can find the spot on the top of my foot with my finger and when i press hard, I can feel it. Again, not excruciating. Could it just be a bruise of the metatarsal? or maybe my shoes were tied too tight for a few runs? I realize that ultimately a sports doctor should diagnose,,, but I am hopeful that some out there might have similar experience and some insight. Thanks in Advance