rotator cuffs

Noun

rotator cuff (plural rotator cuffs)

1. A set of four smaller muscles in the shoulder responsible for rotating the humerus (upper arm bone).
   • In my quest for world records, I ruined both my rotator cuffs. The cuff, a group of four relatively small (but important) shoulder muscles which control inward and outward rotation of the humerus, is particularly vulnerable to the kind of trauma gymnastics, weighlifting and powerlifting inflict.1988, Frederick C. Hatfield, “Powersource: Ties that bind”, in Ironman, 47 (6): 21