So after years of lifting 100 lb coils of cable and not having back problems (knee and foot problems, yes, but the back's generally fine), what finally gives me a pain in the back?
Putting in fucking holiday lights, that's what.
It's the constant bending down and straightening up that's done it (stretch up to reach the top of the hedge, bend down to anchor the lights to the base, repeat for 10 hours). My lower back's killing me, but it's not bad enough to warrant my staying home so I'm just torturing my co-workers by bitching about it.
I've got an ice pack on it right now. Hopefully it'll feel better by morning for my next shift of bending and stretching.
"TUESDAY" AM UPDATE: It feels much better this morning - I figure if I put the ice pack on it during lunch, I should be fine.