rotator cuff vs body structure

rotator cuff and body structure both are nouns.

Word	Noun	Adjective	Verb	Adverb
rotator cuff	Yes	No	No	No
body structure	Yes	No	No	No

As nouns, body structure is a hypernym of rotator cuff; that is, body structure is a word with a broader meaning than rotator cuff:

rotator cuff: a supporting structure of the shoulder consisting of the muscles and tendons that attach the arm to the shoulder joint and enable the arm to move
body structure: a particular complex anatomical part of a living thing and its construction and arrangement

Other hypernyms of rotator cuff include anatomical structure, bodily structure, complex body part, structure.

rotator cuff (noun)	body structure (noun)
a supporting structure of the shoulder consisting of the muscles and tendons that attach the arm to the shoulder joint and enable the arm to move	a particular complex anatomical part of a living thing and its construction and arrangement