The rotator cuff is a group of muscles and tendons that form a cuff over the shoulder. These muscles and tendons hold the arm in its "ball and socket" joint and are involved in essentially all shoulder motions.
Update Date 5/9/2015
Updated by: C. Benjamin Ma, MD, Assistant Professor, Chief, Sports Medicine and Shoulder Service, UCSF Department of Orthopaedic Surgery, San Francisco, CA. Also reviewed by David Zieve, MD, MHA, Bethanne Black, and the A.D.A.M. Editorial Team.