shoulderinjuries
Our hands are used all day long to manipulate our environment from the time we wake up until the time we go to sleep. Whether it’s turning off our alarm clock, brushing our teeth, eating or using our electronic devices to everything in between, our hands are needed to grasp, touch, push or pull objects. A key component to getting our hands in contact with these objects is our shoulder joint. This joint allows our arm to move our hand in all positions above, below, in front or behind us. In fact, the shoulder joint has the most mobility of any other joint in the body. Consequently, the shoulder joint and surrounding soft tissue undergoes high levels of stress to keep it in proper alignment. This is why the majority of the extremity joint injuries seen in physical therapy clinics are related to shoulder injuries. In order to know if you have a shoulder injury, you must first understand what makes up the shoulder complex and how it can be compromised to create pain and dysfunction. The shoulder complex consists of four different joints: the two main being the glenohumeral (arm bone and shoulder blade which create a ball and socket attachment) and a pseudo joint, the shoulder blade gliding over the ribs (scapulothoracic). Two other joints connect the collar bone to the shoulder and sternum. The passive soft tissue (capsuloligamentous) structure keeping the shoulder joint together is the glenoid labrum which creates a vacuum pressure at the joint along with ligaments providing more stability to the joint. The dynamic stabilizers of the shoulder are what most people commonly refer to as the “rotor cup,” which technically is called the rotator cuff. This is comprised of four muscles which originate on the shoulder blade and attach to the top of the humerus—the unofficial fifth rotator cuff tendon is a part of the biceps muscle. A large part of our program is training these muscles in order to effectively maintain a neutral alignment of the joint (keeping the ball centered on the glenoid) while moving through various shoulder positions. This ball and socket joint size ratio has been compared to a golf ball sitting on a tee—another reason why it’s such a challenge to maintain stability in this joint. Shoulder injury occurs when an outside force is imparted upon any of these bony, cartilaginous, or musculotendinous structures in two ways. One is when a high velocity or high
by Richard Fame, MSPT, Supervisor Rochester Regional Health Physical Therapy Center at Midtown Athletic Club
load is imparted upon the shoulder over a short time frame. Another is more chronic in nature as a result of minor alterations in shoulder alignment which can cause micro-damage and eventually pain and dysfunction. Here are some of the basic and common shoulder injuries seen: Shoulder impingement. This occurs when the space within the glenohumeral joint is compromised and when the arm is moved into certain positions (usually overhead, across body or behind back) can cause a compression on the rotator cuff tendons or joint capsule. Bursitis. A fluid-filled sac (bursae) in the shoulder joint gets compressed or sheared upon and subsequently becomes inflamed and painful. Tendonitis. When the rotator cuff tendons become inflamed and painful secondary to excessive tensioning or shearing (as with an impingement). Can lead to rotator cuff tears. Arthritis. Occurs when cartilage at the joint interfaces becomes worn, and bone-on-bone contact ensues creating pain and decreased range of motion. Shoulder instability. When the shoulder joint slips out of place or out of socket. Caused by non-traumatic laxity of joint or following a shoulder dislocation injury. When assessing a shoulder injury we look at all of these components along with overall posture of the shoulder, shoulder blade and upper spine. We also consider overall flexibility of the larger muscles which surround the shoulder joint and strength or relative tolerance to resisted activities of the rotator cuff. A program is then established to fix the faulty mechanics leading to the symptoms. Sometimes the report of shoulder pain does not occur local to the shoulder— in some cases a compromised nerve in the neck can refer pain to the shoulder. This too must be considered. Many shoulder injuries occur due to poor positioning of the shoulders and in the exercise world—poor techniques and alignment with weight training to group exercise classes. If you notice any shoulder pain, have it examined early so the proper adjustments can be made to your daily activities and exercise program to help avoid wearing a sling after it’s too late.
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