Morley test: How to perform and interpret it for TOS

Key takeaways

The Morley test screens for thoracic outlet syndrome by pressing directly on the brachial plexus in the supraclavicular fossa.

A positive result reproduces the patient’s own arm symptoms, such as radiating paresthesia, rather than plain local soreness.

Neurogenic thoracic outlet syndrome accounts for over 90% of cases, so this test speaks mainly to that subtype.

No single provocative test confirms thoracic outlet syndrome, so pair the Morley test with Adson’s test and the Roos test.

Practice management software like Pabau keeps each special test result, the side tested, and your reasoning in one client record.

Arm tingling with a heavy, aching shoulder is one of the harder patterns to sort out. Nerve roots, the brachial plexus, and the peripheral nerves can all produce it. The Morley test takes about a minute and helps you narrow the field.

There is a catch, though. Firm pressure above the collarbone feels unpleasant to plenty of people who do not have thoracic outlet syndrome (TOS). Read the wince as a positive result and you send the wrong patient down a TOS pathway.

The Morley test, also called the brachial plexus compression test, presses on the plexus in the supraclavicular fossa. It counts as positive only when that pressure brings back the patient’s familiar arm symptoms, not just a wince. Getting that distinction right starts with knowing exactly what sits under your fingers.

What the Morley test presses on, and why that works

That precision matters because the brachial plexus sits unusually close to the surface in the supraclavicular fossa. That fossa is the shallow dip just above the clavicle, lateral to the sternocleidomastoid. Press there and you load the plexus trunks with very little tissue in the way. That is exactly why a heavy-handed press produces a false wince instead of a true finding.

The plexus forms from the C5 to T1 nerve roots. It then travels through the scalene triangle, bounded by the anterior scalene, the middle scalene, and the first rib. The subclavian artery shares that narrow space. That is why TOS symptoms range from tingling and weakness through to color change and swelling.

Compression at the outlet usually traces back to one of three sources. Scalene hypertrophy is common in overhead athletes. A cervical rib, an extra rib arising from the C7 vertebra, is present in roughly 0.5% to 1% of people. The rest usually come down to a tight costoclavicular space.

An imaging review of neurogenic TOS names the same anatomical culprits, plus post-traumatic callus on the clavicle or first rib. Press into a space that is already crowded and symptoms follow. That is the whole mechanism behind the test.

How to perform the Morley test in five steps

Consistency matters more than force here. Change your finger placement or your pressure and you change what you are loading, which changes what the result means.

1. Seat the patient: Sit them upright with the neck neutral or slightly extended and the arms resting in the lap. Do not add head rotation yet.
2. Find the landmark: Palpate just above the clavicle, medial to the upper trapezius and lateral to the sternocleidomastoid. In most patients the plexus trunks are palpable there.
3. Apply pressure: Press down into the fossa with two or three fingertips, perpendicular to the trunks. Hold for 30 to 60 seconds.
4. Ask the right question: Ask whether the pressure brings on their familiar symptoms, not simply whether it hurts. Local soreness carries far less weight than radiating paresthesia.
5. Record it: Note the side tested, the exact symptom you reproduced, and your verdict. Digital intake forms keep that detail attached to the client record instead of a loose sheet of paper.

Always test the quiet side as well. Pressure tolerance varies enormously between people, so the asymptomatic side gives you a personal baseline to compare against.

A physical therapy EMR can hold the full TOS battery as one assessment template. The Morley result then arrives with its context attached, rather than as a lone plus or minus in a note.

A positive Morley test reproduces symptoms, not just tenderness

The test is positive when compression brings back the symptoms the patient walked in with. Discomfort under your fingers, on its own, does not qualify.

So what counts as positive? Any of the following, as long as the patient recognizes the sensation as their own:

• Deep aching or pain in the supraclavicular region
• Radiating paresthesia into the arm, often following a C8 to T1 pattern
• Neck tenderness that matches their usual complaint
• Reproduction of the presenting complaint, which is the strongest of the four findings

And what counts as negative? Pressure produces nothing beyond mild local tenderness, which the patient describes as different from their own symptoms. That lowers your suspicion. It does not clear TOS when the history still points that way.

Write the finding down while it is fresh. Record which symptom returned and on which side, then file it in the patient records alongside your reasoning. Six weeks later, that one line is what tells you whether the picture is improving.

What a positive result says about TOS, and what it does not

A positive Morley test raises suspicion for thoracic outlet syndrome. It does not diagnose it. The distinction matters, because the next step is a differential, not a treatment plan.

TOS splits into three subtypes. Neurogenic TOS involves the brachial plexus and accounts for over 90% of cases. Venous and arterial TOS make up the remainder. Because the Morley test loads the plexus directly, it speaks mainly to the neurogenic group.

When the test comes back positive, work through these alternatives before you settle on TOS:

• Cervical radiculopathy: C7 and C8 root irritation mimics TOS closely. Spurling’s test and a cervical screen help separate the two.
• Cervical rib: A structural finding that raises the odds of genuine TOS. A plain film or CT confirms it.
• Carpal or cubital tunnel syndrome: Distal entrapment overlaps in the hand and forearm. A run of hand nerve tests narrows it down.
• Brachial neuritis: Severe shoulder girdle pain first, then weakness as the pain settles. Rehab leans on staged brachial neuritis exercises rather than outlet decompression.
• Pancoast tumor: Progressive pain with no mechanical explanation. Imaging comes before any further provocative testing.

Which one you land on changes the plan. So does how you explain it. Clear patient education at this stage stops a screening finding from hardening into a diagnosis in the patient’s mind.

Why the Morley test cannot stand on its own

The Morley test has never been validated as a standalone diagnostic test. Published accuracy data for it is thin, and none of it comes from large studies with confirmed TOS populations. Treat any quoted sensitivity or specificity figure with caution.

Part of the problem sits with the condition rather than the test. TOS has no gold standard reference test, which weakens every accuracy study in the field. Diagnosis stays clinical, built from history, examination, and imaging together.

Compare that with a validated decision rule such as the Ottawa ankle rules, which were built and tested to give a dependable yes-or-no answer. The Morley test was never designed to do that job. Its value is showing you where the symptoms are coming from.

Four limitations are worth keeping in mind:

• Trapezius myofascial pain and cervical spondylosis both produce supraclavicular tenderness, so false positives are common
• Applied pressure varies between clinicians, which makes results hard to compare across a team
• No validated pressure threshold or gauge protocol has been published
• Symptoms are often positional, so a patient who only flares with the arm overhead may test negative at rest

Repeat testing is where the test earns its keep. Recheck at four to six weeks, and outcome tracking will show whether pressure tolerance and symptom spread are moving in the right direction.

How the Morley test pairs with Adson’s and the Roos test

Experienced clinicians rarely run the Morley test alone. The combination of results is what points you toward a subtype, because each test loads a different part of the outlet.

Wright’s test and the costoclavicular maneuver load different spaces. Hyperabduction squeezes the pectoralis minor space under the coracoid, while bracing the shoulders down and back closes the costoclavicular space. Run the battery in the same order every time and the pattern becomes readable. First rib mobility deserves a look in the same session, since a stiff first rib narrows two of these spaces at once.

Overhead athletes are where this pays off most. Swimmers, throwers, and gymnasts build scalene bulk and shift first rib position, so they earn the full battery. Sports medicine software keeps those repeat results side by side across a season.

Which patients need the test, and when to refer

Use the Morley test when the history already points at the thoracic outlet. Applied to every tingling arm, it generates more noise than signal. These presentations earn it:

• Insidious arm paresthesia, especially in a C8 to T1 pattern with a clean cervical screen
• Neck or supraclavicular pain that radiates and worsens with the arm overhead or under load
• Overhead athletes with repetitive scalene loading, such as swimmers, throwers, and gymnasts
• A first rib or clavicle fracture in the history, since the outlet dimensions change
• Work that holds the arms elevated for long stretches, including hairdressing, painting, and assembly lines

Red flags to rule out first

Some presentations need imaging before any provocative test. An apical lung mass, a primary bone tumor of the first rib or clavicle, and unexplained cervical lymphadenopathy all sit in that group. Provocative testing adds nothing there, and it can cost the patient weeks.

When to refer on

Refer when a positive test comes with progressive neurological loss, such as motor weakness or thenar and hypothenar wasting. Vascular signs deserve the same response, including color change, swelling, or a temperature difference between the arms.

Failure to improve after six to eight weeks of conservative care also warrants a vascular surgery or neurology opinion. Do not keep a progressive presentation on conservative care without a specialist opinion.

How Pabau keeps every special test finding in one record

A Morley result tends to end up in three places at once. A tick on a paper assessment sheet, a line buried in the treatment note, and the clinician’s memory of what the patient actually said. Six weeks later, the comparison is guesswork.

Practice management software like Pabau puts the whole assessment in one place. You can build the TOS battery as a form, so Morley, Adson’s, Roos, and Wright’s are prompted every time. Each result saves straight into the client record, next to your reasoning note and any referral letter.

The payoff arrives on the second visit. You can see what you found last time, on which side, and under how much pressure, so you judge change instead of recalling it. Physical therapy practice software can also flag intake answers that suggest TOS, so the right tests get prompted at the first appointment.

Keep every special test finding in one record

Pabau lets physical therapy and musculoskeletal practices build structured assessment templates, capture special test results, and attach clinical reasoning to the client record. Your six-week review becomes a comparison instead of a fresh guess.

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Conclusion

The Morley test is quick, cheap, and anatomically honest. It tells you the brachial plexus is irritable at the outlet, which is genuinely useful information. But it will never hand you the diagnosis, so treat a positive result as a reason to keep looking.

In practice, run it inside a battery and always test the quiet side too. Then record the exact symptom that came back, rather than a bare plus or minus. Do that consistently and your review appointment turns into a real comparison.

Most of that discipline is won or lost in the documentation. Book a demo to see how Pabau keeps special test findings, reasoning notes, and outcome measures together in one client record.

Continue your research

Need to separate neck pain from shoulder pain? Arm squeeze test shows how one quick maneuver helps point to cervical root irritation instead of the shoulder itself.

Want a structured way to examine the neck? Head and neck assessment walks through a full examination sequence you can run before any provocative testing.

Looking for conservative options after a positive screen? Neck pain exercises covers the loading and mobility work that often forms the first phase of care.

Need objective numbers to track progress? Range of motion assessment explains how to measure and record movement so repeat visits are comparable.

Building out your special test toolkit? Posterolateral drawer test applies the same interpret-with-caution logic to knee instability testing.

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