Radial tunnel syndrome, or radial nerve entrapment as it is sometimes called, is when the radial nerve gets compressed or restricted in the tunnel it passes through. This elbow injury is more often caused by rotation of the wrist/lower arm rather than repetitive extension like tennis elbow, but the symptoms of both these injuries can be similar.
Radial nerve entrapment symptoms
The symptoms of radial nerve entrapment are very similar to those of tennis elbow and so it can be difficult to determine which of these conditions is causing the elbow pain.
Symptoms also include pins and needles or tingling in the hand and outer forearm. Tenderness may be felt in the muscles of the upper forearm with the maximum point of tenderness is about 4-6 cm down from the lateral epicondyle with tennis elbow this point is just below the bone. The patient may also experience aching in the wrist and pain may also radiate upwards into the upper arm.
Specific tests to help diagnose radial nerve entrapment will reproduce pain on resisted supination or turning the palm of the hand up and pain on extending the middle finger against resistance
The radial nerve divides into two branches at the elbow. These are the superficial radial nerve and the posterior interosseous nerve (PI nerve). It is the PI nerve that may become entrapped in the forearm. Compression of the PI nerve may occur at several locations in the elbow and upper forearm.
Radial nerve entrapment is more common in those who pronate and supinate the arm repetitively or turn the hand over, whereas tennis elbow is usually caused more by repetitive wrist extension or bending the wrist back.
Treatment involves rest and in particular avoiding any repetitive wrist movements. Applying ice cold therapy to the elbow and forearm may help relieve symptoms.
A doctor may prescribe anti-inflammatory medication and a professional therapist may use soft tissue massage to release the supinator muscle which is often the cause of entrapment. Neural stretches will also be given as part of physical therapy. In severe or persistent cases a surgeon may operate to decompress the nerve which is generally successful.