muscle spasm
"Having severe muscle spasms and pain in my shoulder after ACDF neck surgery.  At first I was on methocarbamol and Percocet for post operative pain. That went away in about a week but 4 weeks post op I'm still having spasms and pain in my shoulder trapezoidal muscle.  I found that I didn't need the Percocet anymore, the methocarbamol alone does the trick without any noticeable side effects.  It had the additional benefit of relieving my low back pain that I have had for decades. Obviously some others do suffer side effects but it is worth a try, for me it works better than any anti-inflammatory."