I spent the following week sleeping very carefully to try not to aggravate it more. Of course, controlling exactly what position you're sleeping in is a bit of a challenge -- as in, the back would feel better at night and worse again in the morning -- but it was gradually healing up.
By Saturday, things were substantially improved, if not perfect. And then, while I was sitting down to read the mixer manual on my recording laptop and then standing up to try to find the right setting on the mixer to get everything configured for recording The Tooles' concert, I found that I was sitting down on a chair that was no longer where it had been when I stood up. (It's a long story...)
Now the chair had been there all of the other times that I tried to sit on it, so when I sat down, I sat down with authority.
When the chair is not there, sitting down with authority turns into free fall in short order.
And so I found myself sitting on the floor, a bit surprised by this turn of events.
Declining the proffered help, I levered myself up on a much less useful chair (less useful in the sense that it was not actually in the spot that I had intended to sit down in), pulled the chair over, and sat down to read some more of the mixer manual. And eventually, the mixer was correctly configured and we could finish the sound check and the recording gear check.
While we were eating dinner, I laid my right arm on the table and realized that something was not right. (So to speak.) Normally, my arm would lie flat on the table, but now it was on something. I turned my arm over and found a ginormous goose egg. I had seen goose eggs on the noggin before, but never on an arm, let alone my arm.
Happily, by the following morning, the goose egg had reduced in size to a much smaller lump that doesn't much like to be poked at. It's still sore, but seems to be working on that whole "healing process" thing.
The outside of the lower section of the arm has produced a really big purple bruise.
And I am reliably informed by daisy_knotwise, who has a license to do so, that there is a substantial bruise on my butt, which would explain why my tailbone is being a bit sore, especially after extended sitting.
On the other hand, the original injury to the back is almost better now.
I am working hard not to break anything else before Windycon...