I have been researching and I believe this SAN is also my problem. I started with rotary cuff injury due to my right arm getting twisted up over my head with a foot on my back. I felt tearing the tearing occur. A few months later my neck really started bothering me more and more. Ended up having 4 damaged cervical disc right side of my neck which was not a huge surprise. Had C5-C7 fused. Still alot of shoulder , head and neck pain. Year later CT scan showing C5/C6 had failed. Had second surgery from back to redo C5/C6 using rods and screws. My shoulders were killing me after the surgery. I could hardly lift my arms. Started PT about six weeks later. Thought things were looking up then noticed that I could not lift/shrug my left shoulder well. The shoulder pain just keeps increasing and if it were not for the gabapentin and tylenol every couple of hours I wouldn't move. At this point I can't shrug my left shoulder at all. I although have not arm pain in both arms. Can't tilt head toward shoulders. I can't rotate head to right without pain very far. Rotating to left is now worse since the shoulder pain has increased more. The funny thing is I had no issues at all with my left shoulder prior to the last redo surgery. Now it doesn't lift and this shoulder is more painful than my right. It feels like I have a 1000 pounds sitting in my shoulders. It seems like the more I exercise the worse I get.