Costoclavicular test: How to perform, interpret, and document

The costoclavicular test is a provocation test for thoracic outlet syndrome (TOS). It narrows the space between the first rib and the clavicle so that neurovascular compression symptoms reappear. The patient braces both shoulders back and down for 30 to 60 seconds while you monitor the radial pulse. The result is positive only when the pulse diminishes and the patient’s familiar symptoms return.

TOS is one of the hardest musculoskeletal conditions to diagnose. Physical examination tests still carry the first clinical decision, according to the Journal of Orthopaedic and Sports Physical Therapy. The test goes by three names: The costoclavicular test, the military brace test, and Eden’s test. All three describe the identical maneuver.

This guide covers the anatomy, the step-by-step protocol, how to read the result, and how the test compares with the rest of the TOS battery. It closes with the five elements your assessment note needs.

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Key takeaways

The costoclavicular test compresses the space between the first rib and clavicle to provoke TOS symptoms. It is also called the military brace test or Eden’s test.

A positive result requires both radial pulse reduction and reproduction of the patient’s symptoms. Pulse obliteration alone appears in 16% of healthy subjects, so it is not diagnostic.

Published sensitivity ranges from 50% to 94% and specificity from 53% to 100%, depending on TOS subtype and study design.

Run the test alongside the Adson, Roos, and Wright tests rather than on its own, because no single maneuver confirms or excludes TOS.

Pabau’s structured clinical records and digital forms help physical therapists and osteopaths document special test findings, laterality, and grading in a single patient encounter.

What the costoclavicular test is and when to use it

The costoclavicular test is a physical examination maneuver that places the shoulder girdle in an exaggerated military brace posture. That posture compresses the costoclavicular space and reproduces the symptoms of thoracic outlet syndrome. Clinicians reach for it when a patient reports unilateral upper limb paresthesia, arm heaviness, or vascular changes that worsen in particular arm positions. It is particularly indicated when:

• The patient reports symptoms with overhead activity, carrying loads at the side, or wearing a heavy bag or backpack
• There is a history suggestive of neurogenic TOS: Diffuse aching into the arm, fourth and fifth finger numbness, or weakness of the intrinsic hand muscles
• Vascular TOS is suspected: Arm swelling, discoloration, or asymmetric radial pulse at rest
• The patient works in a forward-head, rounded-shoulder posture with frequent scapular depression
• Initial cervical screen (Spurling’s, upper limb tension tests) is negative but upper limb symptoms persist

Musculoskeletal physical therapists, osteopaths, and sports medicine clinicians all use the maneuver as part of a standard TOS provocation battery. Understanding the anatomy it targets comes before administering it.

Anatomy: Understanding the costoclavicular space

The costoclavicular space is the narrow passage between the inferior surface of the clavicle and the superior surface of the first rib. It serves as a conduit for the brachial plexus and the subclavian artery and vein. When this space narrows, the neurovascular bundle is compressed, producing the characteristic symptoms of TOS.

The military brace position draws the shoulders sharply back and down, which approximates the clavicle toward the first rib. The costoclavicular space reaches its smallest functional dimension in that position. That is the mechanical rationale for the test.

How to perform the costoclavicular test: Step-by-step protocol

Precise technique determines whether the costoclavicular test produces a reliable result. Sloppy positioning is the most common reason for false negatives and inconsistent findings between clinicians.

Patient positioning and clinician setup

Seat the patient upright on a treatment plinth or chair with no back support, so the shoulder girdle is free. The clinician stands or sits at the patient’s side or slightly behind.

1. Locate the radial pulse bilaterally before the maneuver begins. Note baseline amplitude on both sides. This gives a reference point for comparing pulse changes during the test.
2. Instruct the patient to draw both shoulders back and down simultaneously, as if standing to attention in a military brace posture. The scapulae retract and depress, and the chest rises slightly. This is the end position of the maneuver.
3. Ask the patient to hold this position for 30 to 60 seconds while continuing to breathe normally. Some protocols extend this to 90 seconds if symptoms are slow to appear.
4. Monitor the radial pulse continuously on the symptomatic side throughout the hold. Note whether the pulse diminishes, becomes weaker, or obliterates entirely.
5. Ask the patient to report any symptom reproduction: Numbness, tingling, heaviness, or pain into the arm, forearm, or hand. Record the onset timing and distribution.
6. Release the position and reassess the pulse and symptoms immediately. Changes that resolve promptly on releasing the brace carry more diagnostic weight than those that persist.

What to monitor during the maneuver

Track three signals at once: Radial pulse amplitude, symptom reproduction by location and quality, and the patient’s ability to sustain the position. A patient who cannot hold the military brace without compensating at the neck or ribcage is not performing the test correctly.

Note the side tested, whether bilateral testing was performed, and the hold duration. This matters for documentation, particularly in medicolegal contexts or when tracking change over serial assessments.

Interpreting the results: Positive vs negative findings

A positive costoclavicular test requires two findings together: Radial pulse diminution and reproduction of the patient’s familiar symptoms. Either finding in isolation is insufficient for a positive interpretation.

One caveat governs the whole interpretation. Pulse obliteration during shoulder retraction and depression happens in plenty of healthy people. Nord and colleagues put five TOS maneuvers to blinded testing on normal volunteers and on patients with carpal tunnel syndrome. The costoclavicular maneuver returned a false positive in 16% of the normal subjects.

The same study shows how widely that error rate varies between maneuvers, which is the argument for choosing a battery rather than a favorite test. The figures below are the share of healthy volunteers who tested positive on each one.

Those rates climbed steeply in the carpal tunnel group, where the costoclavicular maneuver produced a false positive in 48% of patients. A patient with an established distal entrapment will therefore light up this test for reasons that have nothing to do with the thoracic outlet. Always cross-reference the pulse finding against the symptom report.

Diagnostic accuracy: Sensitivity, specificity, and what the evidence says

The diagnostic accuracy of the costoclavicular test varies considerably across published studies, largely because TOS itself has no gold-standard diagnostic criterion. Figures should be interpreted with that limitation in mind.

• Sensitivity: Ranges from approximately 50% to 94%. The spread tracks the TOS subtype studied and the outcome measure used, whether symptom reproduction alone or combined pulse and symptom criteria.
• Specificity: Ranges from approximately 53% to 100%, with lower specificity seen in studies that include large asymptomatic control groups
• Inter-rater reliability: Moderate. Subjective symptom reporting and variable pulse palpation technique both limit reproducibility between examiners.
• Clinical utility: Most useful when used as part of a battery alongside the Adson test, Roos test, and Wright test, rather than in isolation

The American Physical Therapy Association (APTA) clinical practice guidance on TOS assessment consistently recommends using multiple provocation tests. No single test carries sufficient diagnostic accuracy to confirm or rule out TOS on its own.

Comparing TOS provocation tests: Costoclavicular vs Adson, Roos, and Wright

The costoclavicular test is one of four main TOS provocation tests used in clinical practice. Each targets a different anatomical compression site and patient position, which is why combining them improves diagnostic yield.

When to use the Roos test instead

Reach for the Roos stress test first when a patient reports fatigue-type symptoms that build gradually during overhead activity. Its 3-minute dynamic load replicates occupational strain more closely than a static military brace hold. The trade-off is specificity, since almost half of healthy subjects test positive on it.

The costoclavicular test suits symptoms provoked by shoulder depression loads instead, such as carrying bags or sitting in a slumped desk posture. Using both in the same session maximizes diagnostic coverage across the three TOS compression zones.

Limitations and differential diagnoses to consider

The costoclavicular test has meaningful limitations that every clinician should understand before acting on its findings. Recognizing what can mimic a positive result prevents unnecessary onward referral.

• False positives from cervical radiculopathy: C8 or T1 nerve root compression produces the same fourth and fifth finger paresthesia as neurogenic TOS. Shoulder positioning changes cervical nerve root tension as well as outlet compression, so the test can reproduce those symptoms too.
• Carpal tunnel syndrome: Median nerve compression at the wrist produces hand paresthesia. In an already symptomatic patient, that can look like reproduction during the test. A positive Phalen’s and negative TOS test battery helps differentiate.
• Double crush syndrome: Peripheral nerve compression at two sites (e.g. carpal tunnel plus TOS) means both conditions coexist. A positive costoclavicular test does not exclude distal compression.
• Asymptomatic pulse obliteration: Radial pulse changes without symptoms occur in healthy subjects during shoulder bracing and should not be recorded as a positive finding.
• Pancoast tumor: An apical lung tumor can produce unilateral arm paresthesia and Horner’s syndrome that mimics TOS clinically. Red flags such as progressive unilateral weakness, weight loss, or night pain warrant urgent imaging regardless of provocation test results.

When TOS and cervical radiculopathy cannot be separated clinically, thoracic outlet syndrome MRI and nerve conduction studies give the clearest answer. A clean cervical screen strengthens the case for the outlet, so run Spurling’s test before committing the patient to that pathway.

Next steps after a positive result

A positive costoclavicular test finding opens a clinical decision pathway, not a diagnosis. The next step depends on whether the presentation suggests neurogenic, arterial, or venous TOS.

1. Repeat the full TOS provocation battery (Adson, Roos, Wright tests) to determine whether the costoclavicular space is the primary or only compression site.
2. Order vascular Doppler ultrasound when arterial or venous TOS is suspected, meaning pulse obliteration plus arm swelling or discoloration. Doppler images subclavian vessel flow in provocative positions and is more accessible than MRI for initial vascular workup.
3. Request thoracic outlet syndrome MRI or CT angiography when surgical planning needs imaging of the brachial plexus, cervical rib, or anomalous first rib.
4. Refer for nerve conduction studies and EMG when neurogenic TOS is the primary suspected diagnosis. This is how you rule out carpal tunnel syndrome or cervical radiculopathy as the principal source.
5. Refer to vascular surgery or thoracic surgery when conservative management fails after 6 to 12 weeks of structured rehabilitation. That program covers postural correction, scalene and pectoralis minor stretching, and neural mobilization.
6. Initiate conservative physical therapy immediately for non-urgent neurogenic TOS presentations. Postural correction, shoulder girdle strengthening, and neural mobilization form the first-line evidence-based approach.

Tracking referral status and follow-up outcomes from the patient record saves a great deal of administrative time across a musculoskeletal caseload. The physiotherapy clinic management software a practice runs on decides how smoothly these steps connect from assessment to onward referral.

Documenting the findings in clinical records

Accurate documentation of provocation test findings protects the clinician, supports continuity of care, and ensures onward referrers have a clear clinical picture. The costoclavicular test should be recorded with five elements in the assessment note.

• Test name and variant: Record as “Costoclavicular test (military brace / Eden’s test)” to ensure the terminology is clear across specialties and referral letters.
• Side(s) tested: “Right,” “Left,” or “Bilateral” with comparative findings if both sides were assessed.
• Pulse finding: Describe the radial pulse change using objective language: “No change,” “Diminished,” or “Obliterated.” Where possible, note approximate timing of pulse change onset during the hold.
• Symptom reproduction: Record what the patient reported in their own words, such as “familiar tingling into fourth and fifth fingers.” Add the distribution, whether C8/T1 dermatomal or non-dermatomal.
• Interpretation: “Positive (vascular + neurogenic component),” “Positive (neurogenic only),” or “Negative” with the clinical reasoning that follows from that interpretation.

A well-written SOAP note entry might read: “Objective: Costoclavicular test (military brace/Eden’s test) positive bilaterally, right greater than left. Radial pulse obliterated at 20 seconds on the right. Patient reported reproduction of familiar right arm heaviness and fourth/fifth finger paresthesia. Left side: Pulse diminished at 40 seconds, no symptom reproduction. Assessment: Findings consistent with right-sided TOS at the costoclavicular space; left inconclusive.”

Practices running paper-based or generic digital records tend to lose laterality and timing data between encounters. That detail is exactly what a vascular surgeon reads first. For practices with clinical governance obligations, physiotherapy clinic compliance requirements sets out the documentation standards that apply to special test records.

A referral letter that auto-populates from the assessment record cuts duplication and transcription errors across the care pathway. That is one of the things worth testing when you compare an EMR for physical therapists.

How Pabau keeps special test findings in the patient record

In most musculoskeletal practices the TOS battery gets written up as free text. Laterality, hold duration, and the second of pulse change go into a paragraph that nobody can search later. When the patient returns in six weeks, comparing today’s findings with the last visit means rereading two sets of notes.

Practice management software like Pabau replaces that paragraph with a structured field set. You build the TOS battery once as a digital assessment form. It carries a slot for each test, each side, the pulse grade, and the symptom description. Every clinician in the practice then records the same five elements in the same places.

The form lives on the patient record rather than in a separate document. Serial assessments line up side by side, and a referral letter pulls the findings straight through. Nothing gets rekeyed, so nothing gets dropped between the assessment and the vascular surgeon.

Document every special test finding in one place

Pabau’s structured clinical records let physical therapists and osteopaths capture TOS test results, laterality, grading, and follow-up actions in a single patient encounter. No paper, no rekeying, no lost findings.

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Conclusion

The costoclavicular test is a high-value, low-cost screen for TOS. It earns its diagnostic weight only when pulse change and symptom reproduction appear together. Read the result against the rest of the provocation battery. Treat a lone pulse finding as noise, because 16% of healthy people produce one.

Used that way, the test points you efficiently toward the right confirmatory investigation and the right management pathway. Used on its own, it will send patients for imaging they do not need.

Whatever you find, the note has to carry it. Record laterality, pulse grading, symptom distribution, and the onward referral action in one place. Book a demo to see how Pabau structures that note for a physical therapy or sports medicine caseload.

Continue your research

Need the hyperabduction half of the battery? Wright test for TOS covers the subcoracoid compression site the costoclavicular test cannot reach.

Want a ready-made form for the scalene screen? Adson’s test template gives you the procedure and a recording sheet you can hand straight to a clinician.

Patient confirmed for conservative management? Thoracic outlet syndrome exercises sets out a phased rehab program you can prescribe from the first visit.

Running a musculoskeletal practice and want to stay compliant? Physiotherapy clinic compliance requirements outlines the documentation and governance obligations that apply to special test records.

Managing a physical therapy or sports medicine practice? EMR for physical therapists covers what to look for in purpose-built clinical software for musculoskeletal practices.

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