Family Health: Your shoulder joint - it’s complicated

Shoulders are exceptionally flexible joints. They give us the greatest range of motion of any other joint, allowing for movements as wide ranging as lifting your bag into the overhead bin, paddling a canoe and scratching your back.

That is, until they don’t. Shoulders are made up of three bones and two joints – a complicated arrangement that gives you flexibility but also many opportunities for problems. Anyone who has had a shoulder injury can tell you it can cause lots of pain.

The three shoulder bones are the shoulder blade (scapula), which connects to the collarbone (clavicle) at the AC joint at the top of your shoulder, and also to the upper arm bone (humerus) at the ball-and-socket joint. Any of these areas can have problems from overuse, such as tendinitis, bursitis or arthritis. Shoulders can also have more serious injuries and conditions, such as:

  • Dislocation. One reason shoulders are so flexible is that the ball-and-socket part of the joint is shallow. Compared to your hip joint, where the ball is nearly surrounded by the socket, your shoulder joint is more like a golf ball on a tee. A complex set of muscles, tendons and ligaments hold it in place, but a fall or other injury can still push the ball partially or completely out of the socket. A dislocated shoulder is extremely painful and may also be visibly deformed. Seek care right away and in many cases, most of the pain will be relieved when your arm is replaced into the socket. However, you’ll need to wear a sling that immobilizes your shoulder as it heals. Having a dislocated shoulder makes you more likely to have another in the same joint.
  • Broken collarbone. This is a common shoulder injury, especially in kids and teenagers since their bones haven’t yet hardened. Collarbones typically break from falling on a shoulder, stopping a fall with an outstretched arm or from biking or car accidents. You may have pain, difficulty moving your arm or shoulder, bruising or swelling at the site of the break. More serious breaks can cause the area to appear deformed and your arm or fingers to tingle. If the broken bone ends are aligned, you’ll most likely wear a sling until the break heals – about three to six weeks for kids and up to three months for adults. More severe breaks may require surgery.
  • AC separation. The AC joint is where your collarbone meets your shoulder blade, near the top of your shoulder. Falling on your shoulder or another accident that tears the connective tissues can cause these bones to separate. Your shoulder may then have an abnormal bump or you shoulder may hang lower than usual. In most cases this injury heals on its own in a few weeks or months, but severe AC separations may need surgery.
  • Frozen shoulder. With this condition, pain and stiffness restrict your shoulder’s range of motion. The cause isn’t clear, but it’s more likely to happen after your shoulder has been immobilized after surgery or injury. People with diabetes, thyroid conditions and heart disease are more likely to develop frozen shoulder. Physical therapy restores the lost motion in more than 90 percent of cases, but it can take up to three years.
  • Rotator cuff tear. The rotator cuff is the web of muscles and tendons that holds the bones in place and enables the arm to rotate. Tears can happen from a fall or direct blow to the area, or from overuse and long-term repetitive motions, especially over the head. You’re likely to feel pain when reaching, pulling or just lifting your arm above shoulder level. However, some people with a rotator cuff tear have little or no pain. If the tear isn’t severe, your doctor may recommend home treatment such as ice, avoiding painful movements, and doing stretching and strengthening exercises that can eventually restore shoulder function. In some cases, surgery is necessary to repair the tear.

Most shoulder conditions improve without surgery. Resting the joint is a good start toward healing, but staying inactive too long can make matters worse. Your doctor can tell you when to start exercising, which movements are helpful and how much to do.