Thoracic Outlet Syndrome

Arm pain with pins and needles has several possible sources, and TOS is easy to confuse with them. The conditions most often mistaken for it are a pinched nerve in the neck (cervical radiculopathy), cervical disc disease or arthritis, rotator cuff tendinitis, carpal tunnel syndrome and narrowing of the spinal canal ¹.

A few features lean towards TOS ¹:

• Pain and tingling that don't follow a single nerve's territory
• Symptoms that get worse with your arms overhead, or when sleeping with an arm above your head
• Tenderness at the base of the neck or where pectoralis minor attaches at the front of the shoulder

And there's no single test that rules TOS in ^1,6. Two common clinical tests pick up most true cases, but roughly half of people without TOS also test positive on either one alone (more still if they have a pinched neck nerve or carpal tunnel) ¹. No scan confirms TOS either; imaging is used to rule out other causes ¹. Diagnosis rests on the whole picture, not one positive test.

This is mainly a clinical diagnosis, because no single test or scan can rule thoracic outlet syndrome in ¹. You'll be asked about any old neck injury, such as whiplash, and about work or sport that keeps your arms overhead or repeats the same movement ¹. Your arms, chest and neck are checked ², and the base of your neck and front of your shoulder are pressed for tenderness ¹. In the elevated arm stress test you hold both arms up in a 'surrender' position and open and close your fists for three minutes, to see if symptoms come on ¹.

Scans are there to rule other things out ¹: a chest X-ray for an extra rib, nerve conduction studies for a nerve trapped elsewhere, an MRI of the neck for a compressed nerve root ¹.

The first job is working out whether this really is TOS, and where the squeeze is happening, from your symptom pattern, what provokes it, and a cluster of tests rather than any single one ^1,6. If something needs ruling out with imaging, we'll point you to your GP.

TOS treatment targets the specific compression sites, which differs from routine neck or shoulder physiotherapy ¹. Depending on what we find, that can include:

• Understanding your triggers: which positions and activities narrow the outlet, including how you sleep, and how to change them without giving up what matters to you ³
• Exercise prescription and conditioning: stretching and strengthening to reduce pressure on the nerves and vessels ², posture correction, and building control of the shoulder blade, including the serratus anterior muscle that helps hold it in position ³
• Manual therapy: hands-on techniques including mobilisation of the first rib ³
• Sports physiotherapy: athletes whose sport involves repetitive overhead arm movement or heavy lifting are a recognised risk group ⁷, so for them this means a plan that manages overhead training load while symptoms settle

Physiotherapy is the accepted first-line treatment ^1,2,3. But there's no multicentre randomised trial for treating neurogenic TOS ⁴, and one review couldn't establish whether conservative treatment beats no treatment at all, or which type works best ⁵. Reported success rates also disagree: one review found long-term relief and return to work in 59 to 88% of people managed without surgery ¹; another found physiotherapy helped in only 27 to 59% ⁴. Reasonable evidence for trying it first. Not settled evidence.

Thoracic outlet syndrome is a squeeze on nerves or blood vessels, not a tissue injury that heals on a schedule. So on The Well Motion Recovery Path™ you move up a phase on what your arm can do.

• Reset: first, we find your triggers and change the positions that set the arm off, including how you sleep ³, plus manual therapy including first rib mobilisation ³. Expect symptoms to still come and go with overhead tasks. We move you on once flares settle quickly and you sleep better.
• Rebuild: the longest phase. Stretching and strengthening ², shoulder blade control work ³ and sometimes the Cyriax release ³. Expect slow gains. We move you on when the arm copes with what your daily tasks ask of it.
• Return: back to overhead work, driving, sleep or sport. We test the positions that used to provoke symptoms. You leave with a home program and a plan for flare-ups.

How long it usually takes. There is no agreed timeframe, and no multicentre randomised trial of treatment ⁴. One review reports relief lasting beyond 12 months in 59 to 88% of people managed without surgery ¹. Mild cases, and those treated early, tend to improve most ¹. In the first randomised trial, in people who had not responded to conservative care, surgery gave better arm function at three months than continuing it ⁸.

Prevention hasn't been tested for thoracic outlet syndrome, so these follow the causes and triggers that are documented:

• Ration your overhead time. Working with your arms above your head crowds the gap the nerves pass through, and symptoms typically flare with jobs like hanging washing ¹. Do them in shorter bursts, and try not to sleep with an arm overhead ¹.
• Support your arms when you drive. Driving with your arms unsupported stretches the nerve bundle ¹.
• Break up repetitive arm work. Jobs and sports with a lot of repetitive arm movement, building and swimming among them, are recognised causes ². So is gaining a lot of muscle, as bodybuilders do ².
• Look at your posture. Poor posture is on the NHS list of causes ². The stretching and strengthening exercises a physio teaches are aimed at taking pressure off the nerves and blood vessels ².