Adson’s Test for Thoracic Outlet Syndrome

Adson’s Test (also called the Adson Maneuver) is a physical examination procedure used to assess Thoracic Outlet Syndrome (TOS), specifically the vascular subtype involving arterial compression. The examiner monitors the radial pulse while the patient performs a breath-hold and head rotation, looking for pulse changes that suggest subclavian artery compression at the scalene triangle.

Thoracic Outlet Syndrome: A Brief Overview

The thoracic outlet is the space between the clavicle and first rib through which the brachial plexus, subclavian artery, and subclavian vein pass on their way to the arm. Compression of any of these structures produces TOS. Three subtypes exist, with very different prevalence rates:

• Neurogenic TOS: brachial plexus compression; ~95% of all TOS cases
• Venous TOS: subclavian vein compression; ~3–5% of cases
• Arterial TOS: subclavian artery compression; ~1–5% of cases — this is what Adson’s Test targets

Because arterial TOS represents a small minority of presentations, the test has a narrow clinical application by design.

Anatomy: The Scalene Triangle

Adson’s Test evaluates the scalene triangle, a three-sided space bounded by:

• Anterior wall: anterior scalene muscle
• Posterior wall: middle scalene muscle
• Floor: first rib

The subclavian artery passes through this triangle. The brachial plexus runs through the same space, which is why arterial and neurogenic symptoms can coexist, though Adson’s is designed specifically to detect arterial compression.

Cervical ribs are an important anatomical variable. Present in roughly 0.5–1% of the population, a cervical rib is an anomalous bone arising from C7 that further narrows the scalene triangle. Cervical ribs are strongly associated with arterial TOS, and their presence improves the predictive value of Adson’s Test.

During the test maneuver, ipsilateral neck rotation combined with extension tightens the anterior scalene, reducing triangle volume and compressing the artery against the first rib or cervical rib if present.

How to Perform Adson’s Test

Starting Position

The patient sits or stands with both arms relaxed at the sides. No specific shoulder abduction or external rotation is required — this distinguishes Adson’s from the Allen Test for TOS, which positions the arm in 90° of abduction.

Test Procedure

1. Locate and maintain light contact with the radial pulse on the side being tested.
2. Ask the patient to take a deep breath and hold it.
3. Ask the patient to extend the neck (look upward) and rotate the head toward the tested side (ipsilateral rotation).
4. Hold the position for 10–15 seconds while monitoring the radial pulse.
5. Ask whether any symptoms are reproduced: arm pain, tingling, numbness, or heaviness.

Repeat on the opposite side for comparison. The breath-hold, neck extension, and head rotation together tighten the anterior scalene and reduce scalene triangle volume simultaneously.

Interpreting the Result

A clinically meaningful positive result requires both of the following:

• Reduction or obliteration of the radial pulse
• Reproduction of the patient’s familiar symptoms: paresthesia, heaviness, pain, or color change in the hand

Pulse obliteration alone is not a positive result. A 2025 systematic review found specificity as low as 9% in some studies — meaning the test produces a false positive in the majority of people who do not have TOS. Radial pulse loss in this position is common in healthy individuals, making it an unreliable finding on its own.

When pulse loss occurs alongside reproduction of familiar symptoms, the result is more clinically relevant, but imaging confirmation is still required before concluding arterial TOS is present.

Diagnostic Accuracy

A 2025 systematic review (Osman et al., Cureus) pooled six studies with 305 participants and reported the following findings:

Measure	Value
Sensitivity	72–92%
Specificity	9–53%
False positives	Frequent in healthy volunteers and in patients with overlapping conditions such as carpal tunnel syndrome
Predictive value improves when	Cervical rib is present, or when combined with other provocative tests

The high sensitivity means a negative result provides some reassurance that arterial TOS is unlikely. The consistently poor specificity — the lowest reported was 9% — means a positive result carries minimal diagnostic weight on its own.

A 2017 clinical bottom line (Hixson et al., Journal of Sport Rehabilitation) reviewed the evidence for all clinical TOS tests and concluded that use of Adson’s Test should be discontinued for the differential diagnosis of thoracic outlet syndrome, based on only Grade C evidence. The same review found better diagnostic support for the Halstead maneuver, Wright’s test, Cyriax Release test, and supraclavicular pressure test.

Clinical Limitations

• Wrong subtype for most presentations. Neurogenic TOS accounts for roughly 95% of cases. Adson’s Test targets arterial compression. It was not designed to assess the condition most patients with TOS actually have.
• High false positive rate. Based on the reported specificity range, false positives occur in a substantial proportion of people without TOS, including healthy volunteers.
• Not a confirmatory tool. A positive result should trigger further investigation, not a TOS diagnosis. Imaging, including duplex ultrasound, MRI, or CT angiography, is required to confirm arterial compression.
• Subjective endpoint. Palpating radial pulse changes during an active patient maneuver introduces examiner variability. Interrater reliability data is limited.

When Adson’s Test Still Has Value

The test is not without application. Its relatively high sensitivity makes a negative result somewhat useful when arterial TOS is the primary concern. Adson’s Test is most appropriate in these situations:

• Suspected arterial TOS in a patient with a known or suspected cervical rib — the 2025 systematic review found predictive value improved in this group
• As one component of a multi-test battery, where clustering of positive findings across several tests increases diagnostic confidence
• Initial triage to determine whether vascular imaging is warranted

TOS Testing Battery

No single test reliably confirms or excludes thoracic outlet syndrome. Common tests used in combination include:

• Adson’s Test: arm at side; ipsilateral head rotation, neck extension, breath-hold; monitors radial pulse at the scalene triangle
• Allen Test for TOS: shoulder at 90° abduction and full external rotation; contralateral head rotation; monitors radial pulse in a different arm position targeting the subcoracoid space
• Roos Test (EAST): arms in 90° abduction and external rotation with elbows at 90°; patient opens and closes hands for up to 3 minutes; positive if symptoms appear; generally considered the most sensitive test for neurogenic TOS
• Halstead Maneuver (Costoclavicular Test): military brace posture; tests costoclavicular compression; Hixson et al. (2017) found stronger diagnostic evidence for this test than for Adson’s
• Wright’s Test: arm hyperabducted above the head; monitors symptoms and pulse; Hixson et al. (2017) also found better evidence supporting this approach

Differential Diagnosis

Before attributing symptoms to TOS, rule out conditions with similar upper extremity presentations:

• Cervical radiculopathy (C5–T1): the most critical differential; both conditions produce arm pain, tingling, and numbness
• Carpal tunnel syndrome: the 2025 systematic review specifically noted high Adson’s false positive rates in this patient population
• Cubital tunnel syndrome
• Rotator cuff pathology
• Double crush syndrome
• Raynaud’s phenomenon: episodic vascular symptoms without mechanical compression
• Pancoast tumor: superior sulcus lung tumor that can mimic TOS; important to rule out in smokers with unilateral upper extremity symptoms and shoulder pain

Frequently Asked Questions

What is the difference between Adson’s Test and the Allen Test for TOS?

Both tests monitor the radial pulse to assess arterial TOS, but they stress different points along the subclavian artery’s path. Adson’s uses an arm-at-side position with ipsilateral head rotation, targeting the scalene triangle. The Allen Test positions the shoulder in 90° abduction and external rotation with contralateral head rotation, targeting the subcoracoid area. Clinicians often use both within the same examination battery for this reason.

Is a positive Adson’s Test diagnostic for thoracic outlet syndrome?

No. Even when symptoms are reproduced, a positive result is not diagnostic. The test’s specificity is too low to confirm TOS in isolation. A positive finding should prompt imaging and further workup, not a TOS diagnosis.

Can Adson’s Test be positive in someone without TOS?

Yes, frequently. The 2025 systematic review found high false positive rates in healthy volunteers and in patients with overlapping conditions such as carpal tunnel syndrome. Based on the reported specificity range of 9–53%, false positives occur across a wide proportion of people who do not have TOS.

Does Adson’s Test work for neurogenic TOS?

Not reliably. The test was designed to detect arterial compression, not brachial plexus irritation. Since neurogenic TOS accounts for roughly 95% of all TOS cases, Adson’s Test has limited application to the majority of patients presenting with TOS-like symptoms. The Roos Test (EAST) is generally preferred for neurogenic TOS assessment.

Should Adson’s Test be discontinued?

Hixson et al. (2017) recommend discontinuing it for TOS differential diagnosis based on Grade C evidence. It retains some value for initial arterial TOS screening, particularly when cervical ribs are present or suspected. The practical takeaway: do not use it as a standalone diagnostic test, and do not treat a positive result as confirmation of TOS.

References

• Osman M, Saad A, Venkatachalapathi S, et al. Diagnostic Accuracy and Clinical Utility of Adson’s Test in Detecting Subclavian Artery Compression Associated With Cervical Ribs: A Systematic Review. Cureus. 2025;17(10):e94341. doi:10.7759/cureus.94341
• Hixson KM, Horris HB, McLeod TCV, Bacon CEW. The Diagnostic Accuracy of Clinical Diagnostic Tests for Thoracic Outlet Syndrome. J Sport Rehabil. 2017;26(5):459–465. doi:10.1123/jsr.2016-0051
• Hooper TL, Denton J, McGalliard MK, Brismée JM, Sizer PS. Thoracic outlet syndrome: a controversial clinical condition. Part 1: anatomy, and clinical examination/diagnosis. J Man Manip Ther. 2010;18(2):74–83.
• Sanders RJ, Hammond SL, Rao NM. Diagnosis of thoracic outlet syndrome. J Vasc Surg. 2007;46(3):601–604.
• Magee DJ. Orthopedic Physical Assessment. 6th ed. St. Louis: Saunders/Elsevier; 2014.

Video Demonstration

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