Anatomy 101: rotator cuff

Written by:  Melanie Talastas-Soriano BA-Kin, CAT(C), ISSA-CPT 
                      Athletic Therapist, Personal Trainer 
 
It is important to understand your body when you experience pain or injury. Knowing the names of the muscles, where they are located and its individual function help with rehabilitation and caring for that injury.
  
Rotator cuff are groups of muscles that originate from the scapula (shoulder blade) and inserts into the greater tubercle of the humerus (upper arm). These muscles are responsible for rotating the shoulder – internal and external rotations and assists with other shoulder movements like flexion, extension, abduction and adduction.  
​
Rotator Cuff Muscle Group 
Muscle: Supraspinatus 
Location: Supraspinatus groove above the spine of the scapula 
Function: External rotation and the 1st 15 degrees of shoulder abduction 

Muscle: Infraspinatus 
Location: Infraspinatus groove below the spine of the scapula 
Function: External rotation 

Muscle: Teres Minor 
Location: Lateral-mid of the scapula 
Function: External rotation 

Muscle: Subcapularis 
Location: Anterior portion of the scapula on the subscapularis groove 
Function: Internal rotation and adduction 
​
Remember the word SITS as the acronym for the rotator cuff muscles. 
  
Most common injury associated with rotator cuff is tendonitis or impingement specifically to the supraspinatus. There is a minimal space to where the tendon inserts onto the humerus that postural imbalance can cause impingement with shoulder movements. 

Repetitive movement of the shoulder is a huge contributor to the inflammation of the rotator cuff tendons. Sports that require repetitive throwing motion puts the tendon muscles into stress which then causes pain. At a workplace that require lifting overhead can develop rotator cuff tendonitis as well.
 
However, a complete tear of the rotator cuff muscle group may require surgery. Depending on the person and the surgeon they are speaking to, a traditional therapy is recommended to help with the shoulder range of motion and strengthening.