I carried a carton of water out of the drugstore to the car on Christmas Eve. I am thinking I must have strained my back then. It didn't show up until yesterday when I sat on the floor ~ must have been the position I was in. Whatever.... it hurts and I am not moving about well at all. No telling how long this will last. I know better than to lift heavy things. I did this before ~ lifting heavy boxes during our move. It took several days for my back to feel normal again. So, I wait and hope it stops screaming soon!!!