What you need to know about subluxation of the humeral head

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The shoulder is comprised of a ball at the head of the humerus, upper arm bone and the socket known as the glenoid fossa. It is important to note that the ball is two-thirds bigger in size than the shallow socket which is a design that makes the shoulder joint highly mobile in the body. The mobility of the shoulder joint comes at the cost of stability. Dislocations are likely to occur in the shoulder more frequently than in any other joint in the body. Subluxation is basically an incomplete dislocation in which the humeral head is moved but does not totally move out of the socket.

If you suspect that an individual sustained subluxation due to an injury, it is best that you are prepared to handle the issue. All you have to do is to register for first aid training today.

What are the types?

A traumatic subluxation can occur from injuries that drives the ball to the border of the socket at the back, front or bottom of the joint. Take note that the displacement is typically towards the front when the arm is placed in a vulnerable position such as when throwing a ball.

Dislocations are likely to occur in the shoulder more frequently than in any other joint in the body.

As for atraumatic subluxation, it occurs without any significant injury. This type of instability usually occurs in both shoulders, either multidirectional or familial.

Potential causes

Various causes of traumatic subluxation include a direct blow, falling on an outstretched arm or the arm forced into an awkward position. These commonly occur during sports such as skiing or contact games as well as vehicular accidents.

The cause of atraumatic subluxations can be benign as reaching to the back seat of a car. The contributing factor to the atraumatic instability includes development issues such as a flat glenoid fossa and slack ligaments. As for the neuromuscular factors, it includes muscular imbalance due to a stroke while the predisposing factors include an injury that has not healed properly.


Muscle weakness, pain and numbness can occur due to tears to the joint capsule or on the lining as well as from stretching of the muscles, ligaments and other soft tissues. Additionally, the individual can also suffer from sensations of slackness or instability of the joint.


The doctor will come up with a diagnosis based on the symptoms, description of the injury and the result of the physical examination. In most cases, an X-ray is required only when complications are suspected.

Treatment for subluxation of the humeral head

In most cases, the shoulder joint rolls back into place without requiring medical care. An exception is subluxation caused by neuromuscular inequity. For a stroke victim, subluxation is considered as an ongoing issue that entails continuous management.

The doctor will prescribe the application of ice and medications to help ease the inflammation and pain. A sling is applied to stabilize and allow the joint to rest. In some circumstances, surgery might be required to repair the torn or slack ligaments.

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