Overview
what it is and why it mattersRadial tunnel syndrome is when one of the deep nerves of the forearm gets squeezed as it passes through a narrow channel just past the outer elbow. The channel is the radial tunnel, walled in by the bony radial head, surrounding muscles, and a tight fibrous arch. The squeezed nerve causes a deep, aching pain in the outer forearm. The classic confusion is with tennis elbow, both cause pain on the outer side of the elbow. The tell-apart: tennis elbow hurts right at the bony bump on the outside of your elbow; radial tunnel hurts about 2 inches further down your forearm. True radial tunnel syndrome causes pain only, not weakness. If your fingers or wrist also stop working, that is a more severe nerve compression with a different name (PIN syndrome).
Symptoms
what you may notice- Deep, aching pain in the outer forearm, not right at the elbow bump, but about two inches further down the forearm, in the muscle belly.
- Pain with twisting and gripping, turning a doorknob, wringing a towel, or using a screwdriver brings on the ache.
- Worsening with repetitive forearm use, the pain builds during sustained gripping or twisting activities and may linger for hours afterward.
- No numbness or tingling, unlike many nerve problems, radial tunnel syndrome causes pain only, not the pins-and-needles you would expect from a pinched nerve.
- Resemblance to tennis elbow that doesn't respond to tennis elbow treatment, if you have been treated for lateral epicondylitis without improvement, this may be the real diagnosis.
Diagnosis
exam first, imaging secondThe pattern is pain in the outer forearm a couple inches past the elbow that gets worse with resisted use of the forearm and wrist. A focused physical exam of the elbow and forearm sorts it out. Telling it apart from tennis elbow is the hard part because both hurt around the outer elbow. The most reliable test is a numbing injection placed precisely into the radial tunnel: if your pain disappears for the few hours the medicine works, that confirms the nerve is the culprit. MRI and nerve-conduction tests usually look normal in this condition.
How We Treat It
what we try first, in orderRadial tunnel syndrome almost always settles with patient, non-operative care. The treatments below are listed in the order we usually introduce them: the first three are the everyday foundation, and each later step is added on top of the ones before, not instead of them. Surgery sits at the very end of the line, reserved for the few people whose pain has not quieted after a long, structured trial of everything else.
1
Activity modification
Cut back on the movements that aggravate it, repeated wrist extension and forearm twisting (think turning a screwdriver, cranking a wrench).
2
Physical therapy
Physical therapy uses gentle nerve-gliding exercises, shoulder-blade strengthening, and stretching of the forearm muscles to take pressure off the squeezed nerve.
3
NSAIDs
An over-the-counter anti-inflammatory like ibuprofen can take the edge off while you give activity changes and therapy time to work.
Radial tunnel injection
An ultrasound-guided injection of numbing medicine, sometimes paired with a steroid, placed precisely into the radial tunnel does double duty: it confirms the diagnosis (your pain disappears for a few hours) and often quiets the pain for a longer stretch.
Surgical Options
if non-operative care isn't enoughIf a long, structured trial of activity changes, therapy, and injections has not quieted the pain, surgical decompression, a small operation that opens the tight fibrous arch and frees the nerve from anything pressing on it, is the next step.
Providers Who Treat Radial Tunnel Syndrome
sports-medicine team
Frequently Asked
questions we hear in clinicHow do I know it’s this and not tennis elbow?
Both hurt on the outer side of the elbow, which is why the two get confused so often. The tell-apart is where the pain sits: tennis elbow hurts right at the bony bump on the outside of the elbow, while radial tunnel pain is about two inches further down the forearm, in the muscle belly. If you’ve been treated for tennis elbow without improvement, radial tunnel syndrome may be the real diagnosis.
Why don’t I have any numbness or tingling?
Unlike many nerve problems, true radial tunnel syndrome causes pain only, not the pins-and-needles you’d expect from a pinched nerve. If your fingers or wrist also stop working, that points to a more severe nerve compression with a different name (PIN syndrome), which is treated differently.
What confirms the diagnosis?
The most reliable test is a numbing injection placed precisely into the radial tunnel. If your pain disappears for the few hours the medicine works, that confirms the nerve is the culprit. MRI and nerve-conduction tests usually look normal in this condition, so a normal scan does not rule it out.
Will I need surgery?
Usually not. Most people improve with activity changes, physical therapy, and injections. Surgery (a decompression that opens the tight fibrous arch and frees the nerve) is the next step only if a long, structured trial of non-operative care hasn’t quieted the pain.
What activities make it worse?
Twisting and gripping are the main aggravators, turning a doorknob, wringing a towel, or using a screwdriver. The pain builds during sustained gripping or twisting and may linger for hours afterward, so cutting back on repeated wrist extension and forearm twisting is the first thing we ask you to do.
Further Reading
authoritative sourcesExternal patient-education references and related OSI pages for additional background: