The literature states that shoulder pain accounts for approximately 16% to 21% of all musculoskeletal conditions and is second to only low back pain in prevalence. In this article I am going to address why the shoulder joint is vulnerable to injury and briefly discuss some commonly seen pathologies
Why is the shoulder one of the most commonly injured joints in the body?
The shoulder region is more complex than you might think. It is comprised of 4 joints: the glenohumeral, sternoclavicular, acromioclavicular and the scapulothoracic joint. The glenohumeral joint, what we call a ball and socket joint, and what most people think of as the "shoulder joint," is connection of the upper extremity to the trunk. This joint is one of the most mobile in the body, as we are able to move our arm in a wide variety of ways. Unfortunately, this means we have much less stability, so we rely on numerous structures to keep the shoulder in the right place. The majority of the stability comes from the 4 muscles of the rotator cuff (RTC). Their strength, endurance and co-contraction are vital to normal joint function. These muscles work simultaneously to provide stability while we move our arms to perform functional activities like reaching or carrying objects. If even one of these muscles is not working properly, tissue can be injured, causing weakness, pain and/or a loss of motion over time. Another important structure in the shoulder is the labrum. The labrum increases contact area between the humerus (ball) and the scapula (socket)by making the socket the ball sits in deeper, thus making the joint more stable.
What are 3 common shoulder injuries?
1) Impingement Syndrome
This condition accounts for approximately 44-60% of all shoulder conditions that cause pain. This syndrome involves compression of the structures in the shoulder, and is mainly biomechanical in nature. This multifactorial condition is largely related to poor muscle mechanics, posture, weak RTC, repetitive use and playing overhead sports like tennis, swimming, or any sport which involves throwing. Continued overuse and impingement of these structures can lead to more serious shoulder pathology and possibly a rotator cuff tear. Full tears usually require surgery to allow return to full use of the arm.
2) Rotator Cuff Disease
The 4 muscles of the rotator cuff are asked to do a lot in our daily lives. They are asked to assist in shoulder rotation, maintain the position of the bones during motion, protect during lifting/carrying and stabilize anytime we move our arm. There are a few ways to injure the muscles of the RTC. The first is when there is an excessive force to the muscles/tendons, such as high impact throwing or other high impact mechanism, or landing on your arm. These types of an events cause microtrauma or tears to the tendons/muscles of the cuff. Another way is gradual degradation of the muscles due to the inherently poor blood supply to the tendons of the rotator cuff. This is a part of the natural aging process and another reason it is important to use a shoulder strengthening program to prevent injury.
3) Labral Tear
Most often labral tears occur with high impact injuries, and are often seen in overhead throwing athletes or after landing on an outstretched arm. They are sometimes associated with shoulder dislocations and usually present with clicking/popping and pain during movement. Many times a labral tear requires a surgical repair. Unfortunately, this injury can be career ending for most professional baseball pitchers, with only a 3% chance of return to action after a labral repair.
What can Physical Therapy do for you?
It is vital to keep your shoulder and the structures that support it strong in order to successfully perform all the things you need to do in life. I always tell my patients that we need to set the “base” or foundation of the shoulder before we move our arm. If you’re experiencing difficulty with your shoulder doing the things you want in life, make an appointment with a physical therapist for a thorough evaluation so we can keep you moving! Contact mike@jointventurespt.com if you have any questions.