Shoulder pain and injuries are extremely common and can be caused by a variety of causes such as exercise, age, overuse injuries or trauma. In fact, they account for nearly 20 percent of visits to the doctor’s office. When shoulder pain interferes with your ability to do the things you need to each day, it’s time to seek medical advice.
The shoulder is a large ball-and-socket joint. It is made up of bones, tendons, muscles and ligaments that hold the shoulder in place and also allow movement. The shoulder joint consists of the clavicle (collar bone), scapula (shoulder blade) and humerus (upper arm bone). A group of muscles and tendons, known as the rotator cuff, stabilize the shoulder and hold the humerus within its shallow socket (the glenoid). Because of the complexity of muscles and ligaments and the lack of bony constraints, the shoulder is capable of extensive motion.
- Arthritis such as osteoarthritis that can cause bone spurs
- Rotator cuff tendonitis and tear
- Tendonitis — The mildest rotator cuff injury is tendonitis (tendon inflammation). Tendonitis can develop with repetitive overhead activities, such as playing tennis, pitching, raking, shoveling or painting. Tendonitis also can arise secondarily from joint degeneration due to osteoarthritis. It produces pain like a toothache radiating through the upper arm that can awaken you from sleep. Reaching overhead or behind your back is painful.
- A torn rotator cuff, sometimes called “pitcher’s shoulder” or “tennis shoulder,” is the most common cause of shoulder pain. The rotator cuff tendons can split or tear suddenly with injury, or slowly by rubbing against bone spurs. Untreated tears can weaken the arm, make it difficult to raise it and visibly shrink muscles. Pain occurs during motion and also at night.
Bursitis, which typically accompanies rotator cuff tendonitis, involves painful inflammation of the bursa (the fluid-filled sac that surrounds the rotator cuff and provides lubrication and protection from the overlying bony shoulder tip. Bursitis is most often caused by repetitive motions (overuse), or repeatedly bumping or putting pressure on the area. Less often, bursitis is caused by a sudden, more serious injury.
- Impingement syndrome
Swelling and inflammation of tendons and/or bursa can place undue pressure on tendons as they pass between the upper arm bone and the shoulder tip. In its cramped space, blood flow to the swollen tendon is reduced, and it begins to deteriorate. This syndrome is due to bursitis, inflammation, sometimes tearing of the rotator cuff, and bone spur formation producing pain and limiting range of motion. Symptoms include discomfort and, sometimes, acute shoulder pain when raising the arms above the head, reaching into a back pocket or while sleeping on the affected shoulder.
A partial or complete dislocation from trauma can result in instability. Recurrent dislocations cause pain and unsteadiness when raising the arm or moving it away from the body, and a feeling that the shoulder is “slipping out of place” when reaching overhead.
- Frozen shoulder
The joint capsule surrounding the shoulder can shrink, making movement painful and stiff. Reluctance to use the shoulder brings increasing stiffness, restricted motion and a persistent, dull aching.
- Labral tears
The labrum is a cartilage cuff around the socket that encircles the head of the upper arm bone to hold it within its shallow bony socket. This cartilage can tear with injury to the shoulder. It also becomes more brittle with age and thus susceptible to weakening. Aching in the shoulder, “catches” in the shoulder when moved, and pain with some activities may signal a torn labrum.