When Tennis Elbow Treatment Doesn’t Work, This Is the First Thing to Reconsider
You were diagnosed with tennis elbow. You did the eccentric loading, wore the strap, had the injection, gave it months.
BUUUUUUUUUT it just doesn’t get better, and the pain has always felt slightly lower down the forearm than where everyone keeps pressing.
That gap matters.
Radial tunnel syndrome is compression of the radial nerve just below the elbow, and it produces an aching, deep forearm pain that mimics tennis elbow closely enough to be treated as tennis elbow for a year.
The single most useful distinction is where the tenderness is.
Tennis elbow is tender right on the bony point. Radial tunnel is tender three or four finger-widths below it, in the muscle bulk of the upper forearm.
What the radial tunnel is
The radial nerve runs down the outside of the arm, crosses the elbow, and splits.
One branch handles sensation on the back of the hand. The other, the posterior interosseous nerve, dives into the forearm muscles to run the ones that straighten your fingers.
Over roughly five centimetres of that dive it passes several tight spots:
- fibrous bands in front of the radial head,
- a cluster of small vessels crossing it,
- the firm edge of one of the wrist extensor muscles, and then
- the arch it enters as it burrows into the supinator muscle
That very arch is where most of the trouble sits.
Two things squeeze it there. Repeated forceful twisting of the forearm, because the supinator itself contracts around the nerve. And repeated gripping with the elbow straight, which is a lot of jobs and most racquet and throwing sports.
Pain, not numbness
This is the confusing part, and worth being clear on.
The branch being compressed is almost purely a motor nerve. It doesn’t supply skin. So radial tunnel syndrome produces pain without numbness, which is not what most people expect from a trapped nerve.
The pain is a deep, tiring ache in the upper outer forearm, often worse at night, worse after a day of gripping, and it can radiate up towards the elbow or down towards the wrist.
If the same nerve is compressed hard enough to actually stop working, you get a different problem entirely: weakness with no pain, and fingers that won’t lift. That’s posterior interosseous nerve palsy, and it’s a separate article.
Three things to check yourself
- Where the tenderness lives. Press on the bony point of the outer elbow, then press about four finger-widths below it into the meat of the forearm. Radial tunnel is worse at the second spot. Compare against your other arm.
- Resisted middle finger. Straighten your elbow, straighten your fingers, and have someone push down on your middle finger only while you resist. Pain in the upper forearm rather than at the elbow points at the radial tunnel.
- Resisted twisting. Elbow straight, palm down. Try to turn your palm upwards against resistance. Deep forearm pain there is the supinator working, and the supinator is where the nerve is.
Tender on the bone: tendon. Tender below the bone, in the muscle: think nerve.
An honest note on this diagnosis
I’d rather say this than have you find it elsewhere and wonder.
Radial tunnel syndrome is genuinely contested. There’s no test that settles it: nerve conduction studies are frequently normal, because the compression is intermittent and dynamic rather than constant. Some surgeons treat it routinely and some doubt it’s a distinct condition at all.
A diagnostic injection of local anaesthetic into the radial tunnel is the closest thing to proof. Pain that disappears for a few hours afterwards is meaningful evidence.
It also frequently coexists with tennis elbow rather than replacing it, which is part of why the picture gets muddy. Having one doesn’t rule out the other.
(What I’d take from that: it’s a reasonable thing to raise if you’ve failed months of good tennis elbow treatment. It’s not a reasonable first assumption.)
Treatment, and what actually changes it
Almost all of the work is load management, and the loads are specific.
- Stop the repeated forceful twisting. Screwdrivers, wringing, ratchets, jar opening, serving and topspin in racquet sports. This is the biggest single lever.
- Avoid gripping hard with the elbow straight. Bend the elbow and the nerve loads differently. Carry things closer to your body.
- Splinting that keeps the elbow bent, the forearm turned palm-up and the wrist slightly extended, worn at night, takes tension off the nerve.
- Nerve gliding exercises, which are gentle and specific and shouldn’t reproduce sharp pain.
- Then time. A meaningful trial is 3 to 6 months, not 3 to 6 weeks.
Surgical decompression releases the tight points along the tunnel. Recovery is roughly 6 to 12 weeks back to normal use, and the honest framing is that results are less predictable than tennis elbow surgery. Patients who responded well to a diagnostic injection tend to do better than those who didn’t.
The short version
Aching outer forearm, no numbness, tender below the bony point rather than on it, and months of tennis elbow treatment that went nowhere.
Ask about the radial tunnel, ask about a diagnostic injection, and cut the forceful twisting out of your week while you’re waiting for an answer.
Written by Nigel Chua, hand occupational therapist in practice since 2005. Tens of thousands of hands, wrists and elbows assessed and treated. My credentials are here. This article explains; it doesn’t examine. Forearm pain with actual weakness, rather than just pain, needs assessing now.