That is a bit interesting to me, as it appears that my ON is caused by tightness in that muscle that runs down the neck and into the shoulder.
Always the left side. I call it the 'beartrap' as it bites and won't let go.
My new pain dr has referred me to a clinical physio who is now working out for me a long term home exercise/stretching regimen, which should result in getting some muscle tone back and breaking that cycle. He looks at the psychological, physical and pain as all being linked.
Some deep tissue massage also.
it should then help my mental state as I'm on the edge of depression from it all.
I actually do feel better just from having discussed it yesterday, and being given a plan to get me out of the pain cycle.
This is the first time that anyone has bothered to look deeper into my chronic pain and look for the cause, rather than just treat it.