What is the Rotator Cuff?

By: Dale J. Buchberger, PT, DC, CSCS, DACBSP

The shoulder is an engineering marvel, designed to allow extreme range of motion in both linear and rotational planes. The architecture of the shoulder allows us to move our arms overhead, behind our back and to throw a ball, all while maintaining stability. The shoulder is commonly referred to as a “ball and socket” joint. The ball is the top of the upper arm or humerus and the socket is the outer edge of the shoulder blade or scapula. A network of ligaments commonly referred to as the joint capsule holds the shoulder joint or glenohumeral joint together. An egg shaped ring of cartilage called the labrum deepens the socket. This is supported by four dynamic structures called the rotator cuff muscles (although incorrect it is not uncommon for them to be referred to as the roto-cup or rotor-cup). The rotator cuff muscles serve to stabilize the shoulder joint and guide the movement that the larger muscles produce. The outer most layer of muscles actually move the shoulder.


The shoulder is the third most commonly injured area of the body behind the lower back and the neck. It has been stated that up to 70% of the population with experience shoulder pain at some point in their life. Incidence of rotator cuff tears has been reported between 25-33% in the general population. This percentage can go higher than 50% once we reach 80 years of age. The real question is how did the rotator cuff tear? There are three common mechanisms that lead to a rotator cuff tear; Overuse commonly seen in athletics, degenerative tears that occur with aging and traumatic tears usually seen in a fall with an out stretched arm.
The general population is at more risk of injury compared to the athletic population simply because they ignore the concept of maintaining strength and flexibility. While aging is inevitable and trauma unexpected; slowing the aging process and improving the ability to withstand the forces of trauma is a choice. However, it is difficult to make the choice, if we don’t have the information.


Traumatic injuries of the shoulder commonly occur if we slip and fall on an outstretched arm, take a tumble down the stairs or land on the point of your shoulder.  In any of these scenarios several things can happen. The shoulder joint can dislocate, meaning the ball has come out of the socket and has to be put back in by a medical provider. The ball can “sublux” meaning it has slipped out and gone back in by itself. During the course of the dislocation or subluxation the bone or cartilage can fracture or tear. It is not unusual to experience a rotator cuff tear during one of these injuries. And like it or not the older we get the more susceptible we are to a rotator cuff tear. After an injury such as these the faster you get to a medical provider and have them evaluate your injury the more efficient your diagnosis and treatment will be. If the injury did not cause a tear or fracture there is a good chance that surgery can be avoided. Unfortunately if a rotator cuff tear has occurred, surgery may be the most efficient route to a satisfactory recovery.


Common signs that you may have suffered a rotator cuff tear include a deep dull ache in the shoulder joint, inability to sleep on the affected side at night, inability to raise your arm over your head to reach a shelf, or difficulty getting dressed or bathing. The shoulder may make audible cracking and popping noises as well.


Time is an important factor when discussing the treatment of rotator cuff tears. It is advised to have the rotator cuff tear surgically repaired within 6-months of the injury in order to achieve the best possible outcome. If more than 6-months goes by the chance of a good outcome is greatly reduced. Generally speaking, full thickness rotator cuff tears that result in retraction of the tendon should be repaired as soon as possible post injury. Rotator cuff tears that do not display retraction of the torn tendon may benefit from a course of physical therapy to help restore range of motion.


The shoulder is the most complex joint in the body. If your shoulders begin to limit your activity or worse yet give you trouble sleeping, it is time to have a professional look at them and provide you with a skilled opinion. If you have lost range of motion or are experiencing severe pain secondary to a fall or trauma you should see a medical provider immediately to have your shoulder evaluated. Remember, just because Aunt Bunny makes a great apple pie doesn’t mean you should get your medical advice from her.