What is the Rotator Cuff?

By Amy Elliott, MSPT
00a66393In my ten plus years of experience, it has come to my attention time and again that there is much confusion regarding the rotator cuff.  Folks seem to know they have one, though often the pronunciation gets a bit butchered (with my personal favorite variation being “rotor cup”).  There is also very little consensus as to what it is exactly, and what it actually does.  For many people, just the mention of those two little words, “rotator cuff,” inspires terror as they have somehow become associated only with pathology of the structure and subsequent surgical intervention. In fact, the rotator cuff is actually a normal part of our anatomy that, when functioning properly, keeps our shoulders healthy and pain free.  It truly gets a bad rap, so let’s clear the air once and for all by filling you in on all things rotator cuff.

Understanding the Basics of the Shoulder Joint

To truly understand the (very important) role the rotator cuff plays, one must first understand a little bit of the basic anatomy of the shoulder joint.  Like the hip joint, it’s considered to be a ball and socket type of joint.  However, unlike in the hip, the socket portion of the shoulder joint is very shallow.  The fit of the hip joint is nice and snug and thereby very secure, while the “ball” portion of the shoulder joint sits in the socket more like a golf ball on a tee and is therefore inherently less stable on its own.   This is where the rotator cuff comes into play, providing much needed
support to an otherwise precariously structured joint.

2016-04-28 (1)2016-04-28What is the purpose of the rotator cuff?
The rotator cuff provides stability to the otherwise loosey goosey shoulder joint, but that still doesn’t explain what it IS exactly. Surprisingly to some, it is actually a group of muscles (four in total – see photo) and their tendons that surround the shoulder joint, creating a cuff (hence the second part of its name!) that helps to secure the upper arm bone in its socket.  All four muscles draw the arm bone inward towards the socket and they also work to rotate the upper arm bone, either internally or externally, depending on the specific muscle (hence the first part of its name!).  A good, healthy rotator cuff therefore not only decreases wear and tear on the shoulder joint by providing stability, but also allows us to move our arms in such a way as to reach the back of our heads or scratch an itch on our lower back.

Because the rotator cuff is made up of muscles and tendons, it is similarly susceptible to strains and tears as other muscles in the body when subjected to overuse or injury.  Overuse injuries occur most often with repetitive overhead motions or while straining to lift something heavy overhead, including weights in the gym.  Poor posture can also put the muscles of the rotator cuff at a higher risk of injury by impeding blood flow and contributing to impingement, a syndrome caused by pinching the rotator cuff muscle between the upper arm bone and the collar bone.


Symptoms of a rotator cuff injury include:

  • dull ache in the shoulder that is often worse when you lie the affected side
  • more intense pain with certain movements, particularly reaching overhead or behind your back. 

Most rotator cuff injuries that result from overuse respond well to physical therapy.  Treatment in physical therapy is aimed at restoring proper posture, proper joint mobility and improving strength and flexibility of the shoulder musculature, including the rotator cuff itself.  Rarely, or in the case of serious injury, more aggressive treatment or surgery is required to repair major tearing of the rotator cuff tendons.

If you have concerns about your rotator cuff, or are interested in learning more about how to keep it strong and your shoulder healthy, ARC Physical Therapy offers free 30 minute consultations at all of our locations.

Contact us today if you’re interested, we’d be more than happy to take a look and offer our suggestions!


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