Carnivore has helped my back/joint pain (keeps inflammation down so I don’t have the flare-ups). I’m not sure fasting ever did.
During an active flare-up the only thing that seemed to work well was weed, which I generally don’t like, but for my back pain it was basically a miracle cure. CBD helps some, but not nearly as much.
Fasting couldn’t possibly hurt, though.
The fasting will help get rid of old cells and generate new ones along with stimulating growth hormones. It’s definitely a helpful tool, but for a crick, maybe soak in hot tub with Epsom salts, use biofreeze or something similar. If you can, go get a deep tissue massage for an hour. It’ll hurt, but be worth it. You’ll need to drink a lot of water after the massage.