Shoulder pain is among the most common musculoskeletal complaints for those seeking medical care. Injuries to the shoulder can occur suddenly, such as with a fall, or develop over a longer period of time due to repetitive overuse, such as with throwing or repeated lifting.
The shoulder joint is a very shallow joint. The upper arm bone, the humerus, has a rounded end that sits on the small and concave surface of the scapula. Ligaments and muscles are strategically placed keepING the shoulder joint in place. This configuration allows the arm a wide range of motion, wider than any other joint in the body. It allows us to easily perform a variety of everyday tasks, such as combing our hair, getting a shirt over our head, and throwing a ball.
The muscles that are involved in keeping the shoulder joint in place are generally well-known; they are referred to as the rotator cuff. These four muscles are attached to the shoulder joint from the top, bottom, and sides to keep the humerus into its socket, but they are also the major muscles providing movement of the shoulder joint. Between the muscle tendons and the bone are small sacs of fluid called bursa. These structures allow easier movement of the shoulder structures by reducing friction.
Shoulder pain is the third most common musculoskeletal reason for seeking medical care. The causes of pain can include inflammation from general strain and overuse; inflammation of the bursa (bursitis); dislocations of the shoulder joint; injury to the bony structures of the joint including fractures; and rotator cuff injuries. Injuries to the muscles of the rotator cuff affect between 3 percent of individuals older than age 30 to about 15 percent of individuals older than age 70.
Rotator cuff disease (RCD) consists of maladies of one or more of the muscles’ tendons, bursitis, or partial- or full-thickness tears of the muscles. An individual may acutely injure a rotator cuff muscle/tendon through a fall, repetitive strain on the shoulder, or a throwing or lifting motion. In some cases, even though the rotator cuff muscle has been partially torn, the individual may not seek immediate medical attention and the shoulder appears to get better. However, over time the shoulder can slowly become more painful, especially with certain motions or at night, or the shoulder may feel weak when performing normal activities.
Since each of the rotator cuff muscles moves the shoulder and arm in a specific direction, your doctor can pinpoint the problem through a series of active and passive shoulder maneuvers and movements on physical examination. In some cases, x-rays can assist in diagnosing bone, ligament, and tendon damage. If a severe injury is suspected, such as a tear, or the diagnosis is still unclear, an MRI may need to be performed.
Many shoulder diseases can be treated with conservative measures which may include a period of immobilization and rest, range of motion and strengthening exercises, ice/heat, and pain/anti-inflammatory medications. A painful shoulder that is not treated properly and is kept immobilized too long, either for treatment or due to pain, can lead to a frozen shoulder. In this condition the tendons and ligaments contract and the joint becomes very difficult to move.
In many cases, physical therapy can help an injured shoulder return to its previous function and strengthen the muscles to prevent re-injury. Severely damaged muscles or tendons may require surgery. Acute shoulder injuries and shoulder pain that persists or worsens should be evaluated by your doctor as soon as possible.
The content in this column is for informational purposes only. Consult your physician for appropriate individual treatment. Dr. Reynolds practices Family Medicine in Chesterfield.