If you've ever suffered a dislocated shoulder, then you know that this orthopedic mishap is more than painful: It can leave your arm feeling as though it has come unplugged from your body. Shoulder dislocations are a common problem at all ages, but about one in five strike men and women who are 60 or older.

Treating a dislocated shoulder in a younger person usually ends the misery right away, but that's often not the case for older adults. The problem: Older men and women who sustain these injuries also have accompanying tissue damage that often goes overlooked or is misdiagnosed, according to a study in the October 2012 issue of the Journal of the American Academy of Orthopaedic Surgeons. As a result, a simple shoulder dislocation can end up causing persistent discomfort and limited range of motion that lasts for years.

Living with shoulder pain and stiffness can slow down an active lifestyle and interfere with daily activities as simple as getting dressed or reaching for a book on a shelf. But knowing how to recognize—and prevent—shoulder problems can help keep these hardworking joints in action.

The shoulder: flexible, but unstable

Your shoulders are among your body's largest and most versatile joints. Unlike elbows or knees, shoulders bend up and down, forward and backward. The unique design of the shoulder joint creates this extraordinary flexibility, but it can also increase the risk for certain problems, especially later in life.

Like some other joints, such as the hip, the shoulder is formed by a ball-and-socket structure. In the shoulder, the "ball" is the head of the upper arm bone, or humerus, which rests on a socket-like depression, called the glenoid, in the shoulder blade. Because the head is larger than the glenoid, a sheath of muscles and tendons—the rotator cuff—holds it in place, while also helping to control arm movement.

The downside of the shoulder's tremendous flexibility is that it's a relatively unstable joint. A shoulder dislocation occurs when the head of the humerus "pops out" of the glenoid, or socket. A dislocation often results from some form of trauma, such as a car accident, though even a minor stumble can trigger one.

Imagine you trip over a footstool but manage to break your fall by holding out your hands. As your outstretched palms strike the ground, the force of landing can pull the upper arm backward, causing it to shift out of position. (A shoulder can dislocate forward, backward or downward.) A dislocated shoulder leaves your arm appearing slightly out of place.

Besides pain in the upper arm, you may experience numbness, swelling, a "pins-and-needles" sensation and bruising. Surrounding muscles may go into spasm, adding to the pain.

If you dislocate a shoulder, don't attempt to pop it back into place yourself or allow a friend to try. Instead, go to an emergency room, since great care must be taken not to fracture the arm bone or rupture an artery. The usual treatment for a dislocated shoulder is a procedure known as a closed reduction, in which a doctor manually reinserts the ball of the humerus into the joint socket.

Afterward, you'll need to apply ice regularly to bring down swelling and you may have to keep your arm in a sling for a few weeks. Your doctor may also refer you to a physical rehabilitation specialist, who can help restore your arm's range of motion.

Source: Prepared by the Editors of The Johns Hopkins Medical Letter: Health After 50

Publication Review By: the Editorial Staff at Healthcommunities.com

Published: 28 Jul 2013

Last Modified: 26 Feb 2015