A 40-year-old accountant presents to the office for pain in…

A 40-year-old accountant presents to the office for pain in his right shoulder with decreased ability to move. He played the position of pitcher on his college baseball team and had injured his shoulder at that time; however, with physical therapy, he had a full recovery. Over the past weekend, he was moving furniture into a new office, including file boxes. He has normal bulk of the muscles of the shoulder. He has pain to palpation of the supraspinatus and infraspinatus muscles. He has severely impaired abduction of the right glenohumeral joint & + drop arm. Based on this information, what is your most likely diagnosis?