Roos Stress Test (Elevated Arm Stress Test - EAST)

The Roos Test, also known as the Elevated Arm Stress Test (EAST), is a provocation test used to diagnose Thoracic Outlet Syndrome (TOS). The test assesses possible compression of the brachial plexus, subclavian arteries, or veins, which may lead to neurovascular symptoms in the upper extremities.

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Clinically Relevant Anatomy

Thoracic Outlet Syndrome (TOS) occurs when nerves or blood vessels in the thoracic outlet region are compressed. This region lies between the cervical spine, the first rib, and the clavicle. Structures that may contribute to compression include:

• Scalene muscles

• Pectoralis minor

• Cervical ribs

• Clavicle and first rib

TOS can be classified into three main types:

• Neurogenic TOS (nTOS): Most common, affecting the brachial plexus.

• Arterial TOS (aTOS): Less common, involving the subclavian arteries.

• Venous TOS (vTOS): Causes venous stasis and arm swelling.

Test Procedure

Starting position[1]:

• The patient sits or stands with both arms in 90 degrees of abduction and external rotation.

• Shoulders and elbows are maintained in the frontal plane of the chest.

Execution:

• The patient slowly and rhythmically opens and closes their hands for 3 minutes.

• The examiner observes for the development of symptoms.

Interpretation of Test Results

Normal findings:

• Only mild muscular fatigue in the forearm

• No significant symptoms

Positive test (suggestive of TOS) may include:

• Gradual increase of pain in the neck and shoulder radiating down the arm

• Paresthesia in the forearm and fingers

Arterial compression:

• Arm pallor during the test

• Reactive hyperemia when the arm is lowered

Venous compression:

• Cyanosis

• Arm swelling

Other positive indicators:

• Inability to complete the test, patient lowers arms due to pain or discomfort

• Reproduction of the patient’s familiar symptoms throughout the upper extremity

Differential Diagnoses

1. Carpal tunnel syndrome

   • Numbness in the first three fingers due to compression of the median nerve.

2. Cervical disc degeneration

   • Pain in the neck and shoulder, but less discomfort in the arm and hand.

3. Orthopedic shoulder conditions

   • Severe shoulder pain not associated with vascular or neurological symptoms.

Evidence and Diagnostic Accuracy

The Roos Test has shown the following diagnostic properties for TOS[2]:

• Sensitivity: 84% (high ability to detect TOS when present)

• Specificity: 30% (low ability to rule out TOS when negative)

• Positive predictive value (PPV): 68%

• Negative predictive value (NPV): 50%

Reliability

• Inter- and intra-tester reliability for the Roos Test is not well documented in the literature.

• It is recommended to combine the Roos Test with other provocation tests to improve diagnostic accuracy.

Studies and Clinical Evidence

A study by Gillard et al. (2001) evaluated the usefulness of various provocation tests for TOS, including Doppler ultrasound, electrophysiological studies, and CT angiography in 48 patients[5].

• Doppler ultrasound was the most reliable for confirming the diagnosis when five or more provocation tests were positive.

• Electrophysiological testing was useful for differential diagnosis and detecting associated neurological disorders.

• CT angiography was not consistently useful for diagnosing TOS.

Clinical Recommendation

Although the Roos Stress Test (EAST) has high sensitivity, its specificity is low. This means that a positive test alone is not sufficient for a definitive diagnosis. For more accurate assessment, the Roos Test should be combined with:

• Adson’s Test

• Wright’s Test

• Costoclavicular Maneuver

• Doppler ultrasound and electrophysiology in suspected vascular or neurogenic TOS

References

1. Brantigan CO, Roos DB. Diagnosing thoracic outlet syndrome. Hand clinics. 2004 Feb 1;20(1):27-36.

2. Lee J, Laker S, Fredericson M. Thoracic outlet syndrome. PM&R. 2010 Jan;2(1):64-70.

3. sptshoulderexamtests. Roos Test. Available from: http://www.youtube.com/watch?v=_dDWNQG1jB0 [last accessed 28/1/2025]

4. Physical Therapy Nation. Roos Test for Thoraci Outlet. Available from: http://www.youtube.com/watch? v=4Jug2ByFRtM [last accessed 28/1/2025]

5. Gillard J, Pérez-Cousin M, Hachulla É, Remy J, Hurtevent JF, Vinckier L, Thévenon A, Duquesnoy B. Diagnosing thoracic outlet syndrome: contribution of provocative tests, ultrasonography, electrophysiology, and helical computed tomography in 48 patients. Joint Bone Spine. 2001 Oct 1;68(5):416-24.