Totally sucks, Cradler.

Here is what I can tell you from my own nagging back issues (lumbar area). I have found that the worst thing I can do is to do absolutely nothing. If I lay around my problem gets worse. In fact, I have read in general that staying mobile on an injured back is the right answer MOST (not all) of the time. In conjunction, I would say to try to stretch it out if it is a muscular problem and not a pinched nerve/disk issue. However, the best bet (if this is something new) is to hit the doctor. The only reason I treat/diagnose my own issue is because I have been to the doctor multiple times for the exact same issue. It is muscular in nature and the doctors all admit there is little they can do. I wouldn't suggest you self diagnose on this first time. If it ends up being a chronic problem like I have, then you will have a better idea of how to handle it without needing to seek medical help.