The "Not So Rotator" Rotator Cuff

Rotator cuff injuries are commonly diagnosed.  Most of them, with no specific diagnosis as to which rotator cuff muscle(s) are the problem.  More importantly, for rehabilitative purposes, we should have a better understanding of what this "rotator cuff" actually does.


When we learn about the rotator cuff in anatomy class, we look at the four muscles that make up the rotator cuff:  supraspinatus, infraspinatus, subscapularis, and teres minor.  We tend to look at these muscles in isolation.  For instance, we see the supraspinatus as a ABductor (lifting the arm away from the body), the infraspinatus (and teres minor) are external rotators (pointing thumbs backwards with palms facing to the sky) and that the subscapularis is an internal rotator (allowing us to reach into our back pocket).  Unfortunately, this has guided many rehabilitative programs based on simple/isolated movements for each individual muscle.

If you look at the shoulder joint from a biomechanical standpoint, these muscles do very little of the isolated movements.  This is due to the fact that out big muscles around our shoulder do the "heavy lifting" or gross movements while the "rotator cuff" group acts as stabilizers.  Even more important is how they perform this stabilizing function.  When the "rotator cuff" group contracts in concert (all muscles contract at once), they provide a tremendous amount of COMPRESSION for the shoulder joint (holding it in place) while the "heavy lifters" do all the movement.  In my opinion, the "rotator cuff" should be renamed the "compressor cuff" 

There is utility to doing isolated rotator cuff exercises (you know the ones I mean...the ones that you always see people doing at the gym with the therabands).  However, their utility is limited and really should be used as the basis for simple"compressor cuff" rehabilitation.  Once activation and stability is achieved through simple exercises, progressive exercises offering challenges in different movements and planes should be added to make sure the "compressor cuff" is providing COMPRESSION (and thus, increasing stability) through an entire range.