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 shoulder blade or scapula. Ligaments and muscles are strategically placed to keep 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 help to keep the shoulder joint in place are referred to as the rotator cuff. These four muscles attach to the shoulder joint from the top, bottom and sides to keep the humerus into its socket. They are also the major muscles providing movement of the shoulder and upper arm and therefore can easily be injured. Between the muscle tendons and the bone are small sacs of fluid called bursa. These pads allow easier movement of the shoulder structures by reducing friction. When they get inflamed, it is called bursitis.
Pain in the shoulder is often caused by inflammation of the muscles, tendons or bursa of the shoulder. Like most conditions, there is a spectrum of severity. Rotator cuff disease can be a mild, temporary irritation of the structures from overuse, for example after raking leaves or sleeping on an arm wrong at night. On the other hand, it can be a severe and persistent inflammation from daily repetitive shoulder activity as is common with certain occupations – painters, carpenters, computer workers and hair stylists. It is also common among sports participants such as with throwing/pitching, tennis and weight lifting.
Rotator cuff disease can also be caused by a sudden injury. Falling on a shoulder or an outstretched arm, lifting a heavy object or forceful pulling can cause a tear in the rotator cuff components. As we get older, the likelihood of injuring the shoulder is much higher due to decreased muscle mass and overall loss of strength and elasticity. 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.
A tear in a rotator cuff muscle can range from microscopic damage to a partial or full-thickness injury, depending on the mechanism and the severity of the injury. In some cases, even though the rotator cuff muscle has been torn, individuals may not seek immediate medical attention and the shoulder appears to get better. However, over time the shoulder slowly becomes more painful, especially with certain motions or at night.
Sudden and painful injuries to the shoulder should be evaluated by your doctor. Also, pain in the shoulder that persists or suddenly worsens after temporary improvement should prompt a visit to the doctor. In milder cases, your doctor may recommend resting the shoulder, anti-inflammatory medications, and performing a therapeutic range of motion and strengthening exercises. Often, a physical therapist can assist with the healing process. In more severe cases of rotator cuff injury, imaging such as X-rays and MRI may be needed to determine the extent of the injury.
The content in this column is for informational purposes only. Consult your physician for appropriate individual treatment. Dr. Reynolds practices Family Medicine in Chesterfield.