@TNP I wish. I do use heat packs sometimes to help with it, but it's actually long-term 'it refuses to fix' damage. There's apparently a thing where, in a car accident or other impact trauma, the body locks up like a rock -- that whole thing you're either supposed or not supposed to do, depending on what year's expert is in vogue -- and usually in a few days, it releases.
Except for a few of us, where Murphy's Law decides to intervene and certain muscles take several months, years, etc. to release, if they ever do.
(He can't actually even touch my lower back without me screaming.)
There's weird surgical shit they can apparently do that's rarely if ever covered, and... nngh. It involves cutting up the muscle fibers in various places and HOPING they heal right and... yeeeeeeeeahnothanks.
I'm kinda lucky in that I have all manner of solutions for the stuff that spazzes out normally, got slept on wrong, decides to cramp up like mad, and so on, but this is... meh. I saw a chiropractor about it in North Carolina who did all the testing, sent me on to the hospital, etc. and we found out this likely wasn't going to change (especially not with no insurance save through the school at the time).
When it happened, a few years before that, my folks sent 19-year-old me to the chiropractor they trusted because he went to their church, and... uh. I knew he was a complete quack at the time (not a statement on the profession, but on this individual), but in too much pain to move and with a 106 degree fever, I couldn't do shit about it. (His solution for a week-long 106 degree fever and a complete inability to move: take no more than 6 regular strength tylenol per day, do not go to the hospital no no no no hospital. Yeah. Kinnnnnnda lucky I'm alive.) So it may have been fixable back when if not for, well... that motherfuckin' guy.