Shoulder Instability

Last Updated August 2022 | This article was created by editorial staff and reviewed by Beth Oller, MD

What is shoulder instability?

Shoulder instability is the term doctors use when your shoulder is slightly out of place or feels like it is. In this case, “instability” means the shoulder joint isn’t stable. This means the bones aren’t held together as tightly as they should be. This is different from shoulder dislocation. That is when the shoulder is completely out of place. In this case, shoulder ligaments are torn and cannot hold the joint in place.

Symptoms of shoulder instability

Pain and weakness are the main symptoms of shoulder instability. The pain can start suddenly or slowly. It may hit you just as you throw a ball, for example. If it happens suddenly, you may also feel numb all the way down your arm.

If shoulder instability comes on slowly and over time, it may only be painful at certain times. Shoulder motions like throwing may hurt. But the pain isn’t as bad as the pain of a sudden injury. Your shoulder might be sore when you move it. It might feel loose in its joint. You also may have numbness or tingling with instability that comes on slowly.

What causes shoulder instability?

The most common cause of shoulder instability is an injury. Shoulder instability occurs when the ligaments and muscles are overused. Shoulder muscles and ligaments can become overused if you often throw a ball, hit hard with your shoulder in a football game, or serve a volleyball really hard. Repeating the same motion over and over again, age, and performing manual labor also can cause shoulder instability.

How is shoulder instability diagnosed?

Your doctor will look at your shoulder. They will move your arm around to find signs of instability. Your doctor may also take X-rays. The X-rays will show if your shoulder bones are in the right place. Your doctor might want you to have a magnetic resonance image (MRI) scan. An MRI lets your doctor see the bones, ligaments, and other parts of your shoulder in greater detail.

Can shoulder instability be prevented or avoided?

There’s no way to prevent shoulder instability. But you can reduce the chances of it occurring by protecting yourself from a sports-related injury. If your job involves repeat motions or manual labor, find ways to give your muscles a rest.

Shoulder instability treatment

Treatment for shoulder instability depends on how bad your injury is and how important it is for you to have a strong shoulder. Some people need physical therapy. After an injury, apply ice to the injured area and rest the shoulder in a sling for one or two weeks. After resting the shoulder for several days, it’s important to begin an exercise program designed to strengthen your shoulder muscles. Avoid overuse for the next month.

Living with shoulder instability

If your shoulder instability is due to your job, talk to your doctor about ways to treat the pain with over-the-counter medicine. If it’s sports-related, some people stop playing sports and avoid things that might hurt their shoulder again. If you don’t want to give up sports or can’t change your job, talk to your doctor about resistance and weight-lifting exercises. Ask about physical therapy. Both can help strengthen your shoulder muscles.

Questions to ask your doctor

  • What is the likely cause of my shoulder instability?
  • What is the best treatment option for me?
  • Will I need physical therapy?
  • How long before I can expect relief from my symptoms?
  • I play a sport. When can I return to my normal level of activity?
  • Is it possible that my symptoms could return?
  • Is it safe for me to exercise? What kind of exercise should I do?


OrthoInfo: Chronic Shoulder Instability