I heard that too but only for the first 48 hours to rest and this happened 3 weeks ago and is moving all around my back not just the original area. I did a lot this morning and can feel it let me tell you but I do think the sitting for too long strains it. I am so sensitive I move the wrong way and I am in pain for a long time.Remember when I hit my head I had a horrible head ache for a week and most people I think would of not even felt it after an hour. So frustrating