Cyriax Release Test

The Cyriax Release Test is a clinical examination technique used to evaluate thoracic outlet syndrome (TOS) and related neurovascular compression affecting the upper extremity. Named after Dr. James Cyriax, this test aims to decompress the thoracic outlet by positioning the shoulder girdle in a way that relieves pressure on the neurovascular bundle.

How to Perform the Cyriax Release Test?

The patient sits upright with elbows flexed to approximately 90 degrees and forearms, wrists, and hands maintained in a neutral position. The patient is asked to relax the shoulder girdle.

The examiner stands behind the seated patient and performs the following steps:

1. Initial grasp: Place both hands under the patient’s forearms, supporting them from beneath
2. Trunk positioning: Gently lean the patient’s trunk backward approximately 15 degrees from vertical
3. Shoulder elevation: Lift the patient’s shoulder girdle upward to its end range of elevation
4. Sustained hold: Maintain this position for a full 3 minutes

See Also: Adson Test Maneuver

What is the Positive Cyriax Release Test?

A positive Cyriax Release Test is indicated by:

• Relief of symptoms during the sustained position (release phenomenon)
• Disappearance of neurological signs such as paresthesias, numbness, or weakness that were present before positioning
• Improvement in vascular signs if they were compromised

The positive finding suggests that the neurovascular structures were being compressed at the thoracic outlet, and the test position has relieved this compression by:

• Elevating the clavicle away from the first rib
• Increasing the costoclavicular space
• Reducing tension on the brachial plexus and subclavian vessels

See Also: Thoracic Outlet Syndrome 

Negative Test

If symptoms persist or worsen, or if no change occurs during the 3-minute hold, the test is considered negative, suggesting that thoracic outlet compression may not be the primary source of the patient’s complaints.

Clinical Considerations

Duration: The 3-minute hold is essential, as the release phenomenon may not occur immediately. This extended time allows for adequate decompression and symptom resolution.

Patient communication: Throughout the test, maintain dialogue with the patient about their symptoms, asking specifically about changes in numbness, tingling, pain, or weakness.

Differential diagnosis: A positive test supports the diagnosis of TOS but should be correlated with other clinical findings, patient history, and additional provocative tests (such as Adson’s test, Roos test, or Wright’s test).

Safety: Monitor the patient for signs of discomfort or fatigue during the sustained hold, particularly in the examiner’s arms and the patient’s tolerance of the backward-leaned position.

References & More

1. Gilbert, Kerry & Isom, Krista & Hall, Rachel & Leathers, Bret & Sheppard, Nathan & Sawyer, Steven & Sizer, Phillip. (2004). Rate of False Positive Using the Cyriax Release Test for Thoracic Outlet Syndrome in an Asymptomatic Population. Journal of Manual & Manipulative Therapy. 12. 73-81. 10.1179/106698104790825374. ResearchGate
2. Hooper TL, Denton J, McGalliard MK, Brismée JM, Sizer PS Jr. Thoracic outlet syndrome: a controversial clinical condition. Part 2: non-surgical and surgical management. J Man Manip Ther. 2010 Sep;18(3):132-8. doi: 10.1179/106698110X12640740712338. PMID: 21886423; PMCID: PMC3109687. PubMed
3. Brismée JM, Gilbert K, Isom K, Hall R, Leathers B, Sheppard N, et al. Rate of false positive using the cyriax release test for thoracic outlet syndrome in an asymptomatic population. J Man Manip Ther 2004;12:73–81. Google Scholar
4. Orthopedic Physical Assessment by David J. Magee, 7th Edition.