you might want to go to a specialized running store and see if they can recommend a specific shoe for your foot type and running form. it may keep whatever this is from ailing your foot from flaring up.
of course, running on concrete is probably a bad idea anyway. you'll note that pretty much every stadium running track in the world is a soft surface. concrete absorbs almost no energy, so it's your joints that bear the brunt. maybe a good pair of shoes will help. in my experience, though, concrete killed my knees.