Overview, Causes, & Risk Factors

Axillary nerve dysfunction is the lack of normal electrical transmission through the axillary nerve, which activates the shoulder muscles.

What are the causes and risks of the injury?

This type of injury usually occurs when the axillary nerve is stretched or pinched. The stretching or pinching is usually caused by a shoulder dislocation, surgery, or a bone fracture.

Symptoms & Signs

What are the signs and symptoms of the injury?

The most common complaint is shoulder weakness, especially when lifting the arm out from the side of the body. Sometimes the shoulder can still go through a full range of motion, although with less power. Within weeks of the injury, the muscle over the outside of the shoulder will become noticeably smaller. The skin over the shoulder may also become numb.

Diagnosis & Tests

How is the injury recognized?

Axillary nerve dysfunction is usually diagnosed when the healthcare provider exams the individual and listens to the history of the problem. The nerve injury can be confirmed by electrical testing, such as electromyography (EMG), of the muscles involved.

Prevention & Expectations

What can be done to prevent the injury?

The best prevention is to be cautious and avoid injury. Sports safety guidelines should be followed by children, adolescents, and adults.

Treatment & Monitoring

What are the treatments for the injury?

In most cases, recovery occurs on its own within several months. Physical therapy helps to maintain the full range of motion of the shoulder and to strengthen surrounding muscles. If there are no signs of recovery after 3 to 4 months, surgery may be needed. If the nerve function cannot be restored, other options include muscle transfer or fusion of the shoulder.

What are the side effects of the treatments?

Surgery can result in infection, bleeding, and allergic reaction to the anesthesia.

What happens after treatment for the injury?

An exercise program to maintain shoulder flexibility and strength should be continued after treatment. The return of sensation and motion should be monitored, and any worsening of symptoms should be reported to the healthcare provider.