What is anterior interosseous nerve syndrome?

Anterior interosseous nerve syndrome is a nerve disorder in the elbow and upper arm that causes pain and weakness in the hand. Muscles or ligament-like tissues compress a branch of the median nerve in the forearm. It may decrease athletic performance in sports that require pinching of the thumb and index fingers. This nerve does not supply sensation to the skin; as a result, there is no numbness associated with it.

What causes anterior interosseous nerve syndrome?

•  Pressure on the anterior interosseous nerve at the forearm caused by swollen, inflamed, or scarred tissue, ligament-like tissue, or pressure between muscles of the forearm

•  Possibly, a virus causing inflammation and dysfunction of the nerve

What increases the risk of developing this condition?

•  Sports or occupations that require repetitive and strenuous forearm and wrist movements (rowing, weightlifting, body building, tennis, squash, racquetball, carpentry), particularly rotation of the wrist and hand

•  Poor physical conditioning (strength and flexibility)

•  Inadequate warm-up before practice or play

•  Diabetes mellitus

•  Hypothyroidism (underactive thyroid gland)

What are the symptoms of anterior interosseous nerve syndrome?

•  Pain in the upper forearm, usually vague

•  Inability to pinch your thumb to index finger tip to tip (make the OK sign)

•  Thumb weakness, particularly bending the thumb, or weakness of the index finger

•  Frequent dropping of objects and difficulty writing

•  Weakness when turning the palm down against resistance

How is this condition diagnosed?

Anterior interosseous nerve syndrome is diagnosed by an appropriate history and physical examination and often confirmed with a nerve test A

What are the treatment options for anterior interosseous nerve syndrome?

Non-surgical treatment: Initial treatment consists of rest from the painful activity and medications and ice to help reduce inflammation. Stretching and strengthening exercises of the muscles of the forearm and elbow are important. Referral to physical therapy or an athletic trainer may be necessary for treatment.

Surgical treatment: Surgery is sometimes necessary to free the pinched nerve. Surgery is generally an outpatient procedure (you go home the same day) and provides almost complete relief in most patients. We may recommend surgery eight weeks to one year after the onset of symptoms.

When can you return to your sport/activity?

With appropriate treatment, this condition is usually curable, although resolution may occur spontaneously. Spontaneous recovery has been noted from three weeks to 18 months after the onset of symptoms.

How can anterior interosseous nerve syndrome be prevented?

•  Appropriately warm up and stretch before practice or competition

•  Maintain appropriate conditioning:

•  Wrist, forearm, and elbow flexibility

•  Muscle strength and endurance

•  Cardiovascular fitness

Use proper technique and have a coach correct improper technique