I often hear people refer to the muscles that encircle the shoulder at the “rotator cup.” This of course is a misnomer. The muscles that surround the shoulder are correctly referred to as the “rotator cuff.”
The definition of a “cuff” according to the Merriam-Webster Dictionary is as follows: “Something (such as a part of a sleeve or glove) encircling a wrist or other object.”
The word “cuff” aptly describes how the supraspinatus, infraspinatus, teres minor, and subscapularis tendons come together and form a sheath like structure that encircles the head of the humerus. This “cuff” provides both stability and drives movement.
I have also had a few patients over the years tell me that they have strained the “performance muscle.” Same mistake, different story…