Last night I was working on Shoulders and I was in my 3rd set of Shoulder Presses and on the 13th rep I felt a slight stingr, It was only 315lbs. I am used to much moreI thought nothing of it then hit the "heavy" set and moved on to Lateral Raises with 85lbs and on the 18th rep of my warm up set i had to drop the weight and head out because my shoulder was throbbing and I couldnt lift my arm up. So today im heading to a therapist/accupuncturist and see what they can do. Any ideas on what it possibly can be? Im pretty nervous about it.