Thank you so much for this article. September of 2015 I received my annual flu shot. It too was administered too high and as soon as the needle entered my arm jerked and I had this immense pain shooting down the arm. I compare this pain to the pain I had with shingles. But the pain never went away. I can't lift that arm more than 45 degrees to the side, have pain when lying on that side and am unable to do many everyday activities. When I went to the doctor to see what was going on I was told that this couldn't have resulted from the flu shot and I must have injured it someway else. I was told this by 4 separate doctors. When the problem did not get any better they finally ordered an x-ray and ultrasound. This showed moderate left rotator cuff tendinopathy most marked at subscapularis tendon where there are at least three tears including a large full-thickness tear of the anterior fibers. Knowing that I am not the only one this has happened to has helped me immensely. Thank you