What is instability of the shoulder?

This article is about shoulder instability; it is a condition in which the ball and socket joint of the shoulder becomes loose and moved around its normal location. Shoulder instability conditions may be caused by a chronic tear of the rotator cuff muscle, dislocation, fracture, or other injuries to bones in the shoulder joint. Depending on the severity of the injury, it can take anywhere from six weeks up to six months to recover fully.


Types Of Shoulder Instability

1. Radiocarpal Instability

The clavicle (collarbone) is supported by the scapula and humerus. Radiocarpal instability occurs when the scapula fails to support the clavicle sufficiently. The clavicle can come off of the scapula for several different reasons.

2. Glenohumeral Instability

The rotator cuff comprises four muscles that hold the humerus in place. These four muscles work together to allow the arm to move freely. When one or more of these muscles is torn, it can cause problems with the stability of the shoulder joint.

3. Frozen Shoulder

Develops a painful, hard lump usually seen in middle-aged women. This type of instability develops over time. The joint stiffens and becomes very painful. Treatment includes medications and physical therapy. Eventually, a steroid injection or surgery may be needed to help the pain go away. The long-term increase in pain and decreased range of motion eventually leads to muscle weakness in the shoulder and upper arm regions, which may eventually lead to partial or total loss of function. The causes are not fully understood but could be overuse, strenuous activities, or smoking.

4. Rheumatoid Arthritis

If you have rheumatoid arthritis (RA), you may develop an unstable shoulder (known as functional instability). In RA, your body’s immune system attacks and destroys the lining of your joints and connective tissues, causing shoulder pain and stiffness. The pain often gets worse at night or after inactivity. You may experience mild to severe joint swelling and stiffness, especially in your fingers, wrists, elbows, or shoulders.

Causes Of Instability Of The Shoulder

1. Poor Movement Patterns

Poor movement patterns during sport or activity can cause shoulder instability. For example, throwing with the arm sideways and the elbow cocked away from the body will create instability and stress on your rotator cuff muscles. This poor pattern has been termed throwing with an ‘X’ pattern.

2. Acromioclavicular Joint Sprain

This condition usually happens when a person falls onto their outstretched hand and walks off with a painful arm and shoulder blade sticking out of the socket. It occurs in the shoulder joint, in which the collarbone is separated from the acromion.

3. Labral Tear of Supraspinatus

It is another cause of instability in the shoulder joint. The labrum can be torn when a person falls onto their outstretched arm and its attached supraspinatus developed due to repeated stress on the shoulder joint.

4. Tennis Elbow

When a person brings their arm back to their body, the elbow stays in an extended position while they swing arms forward, the supraspinatus tendon is put under a lot of stress. It causes damage to this tendon and eventually leads to pain and swelling in the shoulder joint.

5. Pectoralis Major & Minor Tears

It is unfortunate as it is often caused by a fall or inappropriate lifting activities. Overuse of the arms can also bring about pectoralis tears.

6. Muscle Tear in the Rotator Cuff

It is another common cause of shoulder instability in athletes, and athletes who are suffering from this condition may develop a temporary or permanent tear in the joint.


Instability of the shoulder is one of the most serious injuries. Many things can cause it, for example, radiocarpal instability, which is common in sprinters and other athletes who have shoulder injuries from repeated impact to the shoulder, and frozen shoulder, which is a painful deformity where you feel a painful lump on your labrum that usually develops in middle-aged women. but what I want to discuss here is the stabilization of the shoulder.

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