Lately I have been having problems with the bottom of my feet. I will just stand up or get out of my truck and as a bend my foot and start to walk, it feels like it is tearing the muscle down the middle of the width of my foot (not lengthwise). It stays sore for a day or so and I have to walk "flat footed" to keep my foot from bending as I walk because it feels sore. It happens with both feet. I started having this problem about three months ago and it has happened enough times that I am starting to wonder.

What is wrong with me?