MO...worth exactly what you paid for it:  Now that the issue is identified, and there are no bulging or herniated discs to be wary of, if it were me, I'd be in the chiropractor's office this morning. I've fought S-I (sacro-illiac) issues several times over the years. One or two (at most, 3) trips to my good chiropractor and the issue is resolved. It's usually a result of moving the 'wrong' way or lifting 'wrong', so it recurs because we are creatures of habit.  Talk to friends, etc and find a good chiropractor that she can relate to, and give it a shot. It will not make it worse, and I'd give a 95% probability of good relief.