LOL…I have no clue, but I have an inkling to how it could of happened. I went bowling on Tuesday and I was being silly by stomping my feet and when I stomped on my right foot, in play, I think I stomped a little too hard. Otherwise, I could have pulled the muscle while I was sleeping. I have a tendacy to move a lot at night. Silly, huh? Guess who will not be stomping anymore? Me!