I can't help but notice the number of commenters who say that they made a particular movement (bending down. picking something up, twisting, etc.) when "suddenly" something popped, tore, or some other kind of relatively simple simple thing happened. In my own case after seemingly have recovered from a bad fall (about 7 months), I was out weed whacking. You know how you sort of twist your torso back and forth. Well, I finished up and went into the house. About and hour or so later all this pain came rushing in... lower back, buttocks, down my right leg to my foot. All the pain that I thought had been resolved. I had not felt that since my accient. With all that said, I am curious as to how many of you had any kind of accident or something else that brought you pain, but then subsided until that "sudden" return.