Not muscular - I get it very intermittently deep between my shoulder blades, and if it gets really bad, it radiates up into my back teeth, which is truly horrible.
It's really longstanding - I first had it 25 years ago! - but it is getting more frequent. By more frequent, I do mean maybe just about four times a year, so I know it's not exactly acute. I'd really like to know what it is, though. It usually goes away overnight with a sleep, but last night I woke up with it at 1am and was awake for a couple of hours with it. When I swallow, it gives me an extra-painful spasm, 3 or 4 seconds later, down in the middle of my back.
The only thing that ever helps is to down a large measure of spirits(!) but that doesn't seem to work as well any more. My feeling is that it's some kind of nerve pain. I know I should get it checked out, but has anyone had similar?