I didn't fall or bend or anything ( I think) but at work today (i work as a lab assistant in a university computer lab) I suddenly leaned back and a shooting unbearable pain that seemed to come from my spine in the lower quadron soared through my lower back. I don't know what did it but as long as I keep my back perfectly straight, it's only a bearable (but uncomfortable) dull ache. I tried ibuprofen, but it doesn't help much. Anytime I twist, or bend it shoots out again. My friend and coworker who is a bodybuilder said it might be a pinched nerve caused by an out-of-place spinal disck, but I can't afford to throw money around a doctor unless there's really something wrong (something that can't be helped with over-the-counter analgelsics) with me.

Does anyone have advice?