Have you talked to your doctor about this? This is something different from the shoulder pain, I would think. Have you noticed any skipped beats?
No my back and should pain is from the car accident i had in 2002. But I get numbness in my right and left arm without chest pain and in my neck and back going up into my head. My heart does not skip a beat it just beats really fast right as I lay down at night and if I dose off i will wake up gasping for air and shaking. I don't have a doctor right now because I don't have insurance. I just wanted to make sure im not about to have a heart attack.
Now that you mention it, I do wake up in the middle of the night very cold and I shiver hard, not the normal cold chills shiver but uncontrolably and it takes a little longer to stop your self from shaking than if you were just cold. I took one of my husbands klonopin's once and it took a while to calm me down from one of these attacks so I figured i wouldn't let myself get too depending on those, exspecially if they didn't work well to begin with.