Has anyone had a strained trapezius muscle?

With strains i usually opt for hot, slow and gentle shower, and then sleep, or at least rest. Try not to do anything at all, even if you don’t sleep for a while. Just lay there without allowing activity signals to trigger, and try to breath easy without using that muscle group, or moving in any way that would force it to trigger.

Sometimes naproxen can take a while to noticeably kick in, with more acute pains. I get some pretty severe occasional neck nerve-damage-related migraines, and naproxen is literally the only thing that works, and i almost always have to combine it with a hot shower and drastically reduced activity, or even total cessation. Aspirin and acetaminophen do virtually nothing for me. When one of the bad ones hits, it’s the end of my day.

So, my recommendation includes relaxation and decreased or eliminated movement, and rest. Sleep will most likely help quite a bit, but it might take several days to heal enough that normal motion feels tolerable again, and then up to a few weeks to be fully ready for unmitigated usage.