Shoulder instability is a common injury among athletes. It can result from a traumatic event such as a dislocation. However, multidirectional instability, or MDI, can occur without trauma. MDI often affects people who have loose (lax) shoulder joints. It can result from small, unnoticed overuse injuries. Weakness of the shoulder joint (rotator cuff) and shoulder blade (scapula) muscles can increase the risk of MDI. Physical therapists first focus on treating the pain and inflammation caused by MDI of the shoulder. When pain is managed, physical therapy can help to strengthen and improve control of the shoulder muscles. Proper treatment can support a return to activity and help prevent reinjury.

Physical therapists are movement experts. They improve quality of life through hands-on care, patient education, and prescribed movement. You can see a physical therapist directly for an evaluation and treatment without a physician's referral. The American Physical Therapy Association’s Find a PT tool can help you find one near you.*

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*A referral may still be required by your insurance policy or corporate policies. Some states may limit the number of visits or treatment type without a referral.

On this page

• What Is Multidirectional Instability of the Shoulder?
• How Does It Feel?
• Signs and Symptoms
• How Is It Diagnosed?
• How Can a Physical Therapist Help?
• Can This Injury or Condition Be Prevented?
• What Kind of Physical Therapist Do I Need?

What Is Multidirectional Instability of the Shoulder?

Multidirectional instability, or MDI, of the shoulder occurs when the shoulder joint is too loose and can move too far in different directions. It develops when the shoulder joint is too flexible (lax) and not stable enough. This can be due to weakness or tears in the muscles and tissues that hold the shoulder together. Many factors can contribute to the development of MDI, including:

• Looseness that is present at birth (congenital)
• Muscle imbalances
• Shoulder blade position
• Variations in shoulder structure
• Certain repetitive activities

When the shoulder becomes loose, the joint may "slip" in and out of its socket. This slipping can occur in more than one direction: forward (anterior), backward (posterior), or downward (inferior). Shoulder looseness may become worse in people who repeat overhead arm movements, such as baseball pitchers or swimmers. Shoulder overuse often contributes to MDI. The condition is less common in people 40 years and older due to the natural stiffening of shoulder tissues with age.

How Does It Feel?

Symptoms of MDI of the shoulder can be different for each person. They also can vary in location and intensity. Sometimes a shoulder dislocation occurs. Often, however, people report their shoulder will "slip" out and then right back into place. They also may feel that their shoulder is about to slip out of its socket. They may change their activity to prevent it. Some people avoid certain movements due to fear their shoulder will “pop out.”

MDI can cause pain in different parts of the shoulder. For example, you might feel pain in the front of the shoulder when pitching a baseball or all over your shoulder after activities like swimming.

Signs and Symptoms

Signs and symptoms of MDI of the shoulder vary from person to person but may include:

• Pain and/or looseness (instability) with pushing, pulling, or carrying heavy objects.
• Pain and/or looseness when performing an overhead activity.
• Pain and/or looseness during or after exercise.
• A feeling that the shoulder is "shifting" (including in bed at night).
• The sensation of the shoulder slipping out of its socket and back into it.
• Fear of putting the shoulder in certain positions.
• Numbness and tingling sensations in the affected arm.
• Clicking and popping sensations with movement.
• Weakness when performing athletic movements, especially overhead and away from the body.
• Loss of performance ability in sport activities.
• Fatigue with repetitive activity.

Symptoms of MDI can vary widely. Your health care professional may ask questions about your health history. They also may perform a thorough exam to diagnose your unique condition correctly.

How Is It Diagnosed?

Your physical therapist will ask about your health history and check how your shoulder moves in different positions. They also will test the strength of your rotator cuff and shoulder blade (scapular) muscles. Your physical therapist also may check your core strength, if any nerves are involved, and your overall muscle control.

To see how much your shoulder moves, your physical therapist may gently pull your arm downward or push your arm forward or backward within the joint. They will use a variety of tests to diagnose shoulder MDI.

For a more detailed diagnosis, a physician may order X-rays to rule out bone fractures. They may use an MRI to look for injuries in the shoulder complex, such as a labral tear.

How Can a Physical Therapist Help?

Your physical therapist will evaluate your shoulder injury for areas of weakness and muscle imbalance. The first step in treatment is to manage pain and inflammation. Your physical therapist may advise you to stop or change activities that make your injury worse. They can show you ways to reduce pain without needing strong medications like opioids.

Your physical therapist can design an exercise plan to help you get your shoulder stronger and more stable. They also may work on your core strength and body awareness. At first, you'll do gentle exercises close to your body. This can limit discomfort and help your muscles work better. Once your shoulder is stronger and more stable, your physical therapist will add exercises that match your activity goals. Doing these exercises can enable your body to handle the demands of your activities, work, or sport.

Physical therapists can help athletes with MDI gradually return to their sport. When your physical therapist gives the go-ahead, you may begin doing overhead activities like throwing or swimming in intervals. They will schedule appropriate rest times in between exercises. Your physical therapist will design the right treatment program to fit your needs and goals.

Can This Injury or Condition Be Prevented?

Although shoulder MDI can’t be completely prevented, physical therapy can lessen the effects of shoulder looseness. Controlling MDI of the shoulder falls into three categories:

• Strengthening exercises. These focus on strengthening the shoulder blade muscles and the rotator cuff. This helps improve shoulder mechanics and fix muscle imbalances. Treatment can help increase body awareness and muscle control. Athletes may do these exercises three to four times a week.
• Monitored activity levels. It is important to keep track of your activity level. For example, baseball players use pitch counts to avoid overuse injuries; swimmers keep track of their weekly swimming distance. Staying within the recommended amounts can help athletes protect their shoulders and prevent injury.
• Proper form and technique. Using the right form and technique is crucial when engaged in a sport. Good coaching from a qualified professional can help prevent injuries, especially in young athletes.

What Kind of Physical Therapist Do I Need?

All physical therapists are prepared through education and experience to treat a variety of conditions or injuries. You may want to consider:

• A physical therapist who is experienced in treating people with MDI of the shoulder. Some physical therapists have a practice with a sports or orthopedic focus.
• A physical therapist who is a board-certified clinical specialist or who completed a residency or fellowship in sports or orthopedic physical therapy. This physical therapist has advanced knowledge, experience, and skills that may apply to your condition.

You can find physical therapists who have these and other credentials by using Find a PT, the online tool built by the American Physical Therapy Association to help you search for physical therapists with specific clinical expertise in your geographic area.

General tips when you're looking for a physical therapist (or any other health care provider):

• Get recommendations from family, friends, or other health care providers.
• When you contact a physical therapy clinic for an appointment, ask about the physical therapists' experience in helping people with MDI.
• Be prepared to describe your symptoms in as much detail as possible, and say what makes your symptoms worse.