Strange foot problem

Yesterday I came inside and I had difficulty walking without my foot hurting. Even sitting, the top of my foot hurt, between the ankle bone and center of my foot. I put a cold compress on it and took 2 aspirin and went to bed.

I don't remember twisting my foot, dropping anything on it, etc.

This morning it started hurting when I got up. I was about to get some aspirin so I could go out and get my chores done and it felt as though something "moved" in my foot. I don't know how else to describe it. Then, after a few minutes it quit hurting on a continual basis.

I notice that if I press down on my entire foot it is fine; but, if I only press down with my heel elevated the same area hurts a very little bit.

Is there a nerve or tendon in that area that may have caused the problem?