re: Pinched nerve in my upper back

if you have radiculopathy into your arm, it is either coming from your cervical spine or somewhere in the arm. the fact that you can squeeze you shoulder blades together and eliminate symptoms means it's possibly postural related. go to a PT. the fact that you can eliminate the symptoms with one simple movement means this is possibly fixable with PT. if the PT can't help, they'll send you the doctor.