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Shoulder instability: What is it and can physio help?

Updated: Sep 21, 2021

What is the shoulder joint?

The shoulder is a ball-and-socket type of joint that permits a wide range of movement. It is one of the most complex joints in the human body as well as being the most mobile joint.

Shoulder anatomy with main landmarks to explain shoulder instability

Your shoulder is made up of three bones: upper arm bone (humerus), shoulder blade (scapula), and collarbone (clavicle).

The head of the humerus fits into a shallow socket in your shoulder blade. This socket is called the glenoid. Strong connective tissue, called the shoulder capsule, is the ligament system of the shoulder and keeps the head of the humerus centered in the glenoid socket.

The shoulder also relies on strong tendons and muscles to keep it stable.

What is shoulder instability?

While the shoulder has a great range of motion, it can lose its stability. This problem occurs when the structures that surround the shoulder joint do not work to maintain the ball within its socket.

If the joint is too loose, it may slide partially out of place, a condition called subluxation. However, if the joint comes completely out of place, this is called a shoulder dislocation.

Shoulder subluxation image with landmarks. Shoulder subluxation drawing
Shoulder subluxation

Instability of the shoulder joint can be in one direction, e.g anterior instability; or more than one direction, also known as multidirectional instability.

What causes an unstable shoulder?

Shoulder instability is most commonly caused by two different problems.

Post-traumatic shoulder instability: A bad injury to the shoulder can cause the shoulder to become unstable by stretching or tearing the ligaments of the shoulder away from the bone.

Genetic condition: Some people are born with somewhat loose shoulder ligaments. For these people, instability can occur without any trauma or following relatively minor injury.

What are the symptoms of instability?

People who has shoulder joint instability can sometimes feel the ball of the shoulder come out of its socket or “give way”. This is commonly associated with pain. Often, the episodes of giving way occur with specific activities or positions of the arm, such as throwing a ball or reaching behind the body.

Additional symptoms can include a decreased range of arm/shoulder motion, swelling, and bruising.

How do we diagnose shoulder instability?

The physiotherapists here at Breathe Physio and Pilates will take a complete history and perform a thorough physical examination. The examination includes palpation to check for points of tenderness as well as determining the range of motion and strength. The degree of shoulder looseness or laxity of the shoulder joint can also be assessed by specific tests during the examination.

What is the role of physiotherapy?

Physiotherapy plays a significant role in preventing recurrent instability by strengthening the surrounding shoulder musculature to help keep the shoulder in place. The goal of therapy is to restore shoulder motion and increase the strength of the muscles around the shoulder. Strong muscles, especially those of the rotator cuff, are required to protect and prevent the shoulder from re-dislocating or subluxing.

Once full function of the shoulder has returned, the patient can gradually return to activities.

Athletes benefit greatly from physiotherapy as an early diagnosis and treatment action can prevent further damage to the joint and preventing them to no longer being able to perform at their desired level.

When do I need surgery?

Any patient who continues to have recurrent dislocation or feelings of instability during sporting activities despite extensive physical therapy and rehabilitation are candidates for surgery.

If you are experiencing symptoms of shoulder instability and would like to have it checked, book a consultation with one of our physiotherapists here! Feel free to give us a call on (07) 3061 7128 if you have any questions.

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