I play occasional table tennis. Talk on the cell phone a lot, w/o headphones
, often I will feel the pressure in the shoulder area from this, which soon disappears after a long talk.
Someone mentioned a virus. I did have a strong case of strep throat, which coincided with the problem. I'm not sure if the bacteria had anything to do with causing this.
I get the sense that from reading all your comments, any PT, MRI, etc., might not help.