I tweaked my back the other day simply by existing. I didn't lift anything, get up from a chair, lie down in an odd position. I was simply standing and then it hurt. I'll go to the chiropractor tomorrow to get them to crack my back in that one specific way they do for the SI pinch. I'll pay them $50 for the privilege of that 30 seconds. And then I'll need to do it about 4 more times before my back feels normal again.