There are four muscles in the shoulder that start on the scapula (shoulder blade) and attach to the ball in your shoulder joint to help your shoulder move. These muscles (red in the picture below) turn into tendons (the white part) as the muscles get closer to the bone. The tendon is the part that actually connects to the bone. The term rotator cuff is a general term referencing the specific area where the tendon connects to the bone. Thus, the term rotator cuff tear means a tear in the tendon where it connects to the bone.
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