Amazing information. I have this exact problem with my right arm. Since December I have had difficulty with "tingling" in my lower right arm. I originally thought I was sleeping wrong on it. I got progressively worse till this week I went to a Chiro. and he took x-rays of my column. He said it was a pinching of the nerve since the sensation comes on so fast. My spinal column leans to my right side in my lower neck and with my increased muscularity at my shoulder, when I lift my arm up it pinches the nerve which already has less space to move because of my spinal slant. My left arm has no problem. I am now doing adjustments with icing to slowly adjust the vertebrae. I got so bad last week I had difficulty doing any tricep activity.
I owe this all to heavy lifting, eating right, great workouts, and poor posture while sleeping. So many things in our bodies are interconnected.