I ask this question because I just figured mine out (well, one aspect, anyway).
Last Saturday: I bit the bullet and played 9 holes of golf for the first time since last summer when I started having problems associated with my cervical spine issues. It went great - first two holes I could tell I hadn't played in a while, then my game started to get back to the semi-crappy game I've always had.
Sunday: I felt great. So great in fact, that I did some significant yard work, including lifting large bags of mulch, bending over pulling weeds, etc. I figured I'd probably pay for it, but dang my yard looks good.
Monday: I still felt great. I couldn't believe it - all that lifting and bending and I felt great. So great in fact, that I stood in my kitchen and hand-washed a bunch of pots and pans, grilling tools, knives, etc.
Monday night: OUCH! Lower back is killing me.
Tuesday: OUCH! Lower back is killing me.
So, it looks like I figured it out, at least my sciatic pain. I can't stand for very long or it comes roaring in like a hurricane. Can you believe that? BLT - fine. Standing - not so much.
Do you know what caused your pain?