What’s Going On In There?
The rotator cuff is a group of muscles in the shoulder that hold the humerus (the upper-arm bone) in the shoulder socket and allow arm rotation—hence “rotator.”
The two most common rotator cuff injuries are a tear in a muscle or tendon (a strain) and inflammation of a tendon (tendinitis).
Another issue in this area is the scapula (shoulder blade) and the muscles surrounding it. When those muscles aren’t strong enough to keep the scapula tracking the way it should, you get a condition called scapular dyskinesis. That can put too much load on the rotator cuff muscles and cause tendinitis or bursitis.