Whenever I play any sport where there is side to side movement my time playing gets cut short because of pain in both feet right on the ball of my foot a on the edge of my arch just under my big toe. If you look at the bottom of my feet it looks like a dark line about an inch and a half long that follows the outline of the ball of my foot along the arch on the inside of my foot. It looks like a little fine dark line just under the skin. I often develop blisters on either side of it when playing basketball, tennis, or racquetball. Even if I have not had any sports activity for months the line is still there. If I press my finger down on the spot on my foot where it is I feel discomfort. It gets very tender when I play sports which is why I need help figuring out what it is.

Help please!!!

Mike