I had planned to go out caching today.
But yesterday, I woke up with a back pain. It feels a bit like cramp, and it twinges badly if I twist, or stand up, or sit down, or pretty much anything that involves back movement. A day out caching sounded like a day of agony, so I've deferred it.
I don't think there's anything seriously wrong, I think I "pulled a muscle" or sprained a rib or something. I'm hoping that a few days of quietude will fix it.