Hi, while at work today, I was sitting in a very low chair (elementary school) & hurt my back. I leaned forward to lift a medium sized Rubbermaid bin filled with wooden blocks, and before I could fully lift it something popped/snapped/pulled in the sacral area of my lower back. It hurts to move, especially going from sitting to standing or vice versa. Also, it feels rather warm to touch but the pain muscular.