Adson's Test: How to Check for Thoracic Outlet Syndrome

Adson's Test is a key diagnostic maneuver used by physiotherapists to assess for Thoracic Outlet Syndrome (TOS), a condition caused by compression of nerves or blood vessels in the upper chest. Click the sections below for details.

1. Purpose

The primary purpose of Adson's Test is to **test for** Thoracic Outlet Syndrome (TOS). Specifically, it tests for compression of the subclavian artery and/or brachial plexus as they pass through the interscalene triangle, which is formed by the anterior and middle scalene muscles.

2. How to Perform

1. The patient is positioned in sitting.
2. The examiner locates and palpates the patient's radial pulse on the affected side.
3. The examiner slightly abducts, extends, and externally rotates the patient's arm.
4. The examiner instructs the patient to "Turn your head to look at the shoulder being tested."
5. The examiner then instructs the patient to "Tilt your chin up (extend your neck) and take a deep breath and hold it."
6. The examiner monitors the radial pulse for any changes.

3. Positive & Negative Sign

Positive Sign (Test is POSITIVE):
A positive test (indicating compression) is one or both of the following:

• A significant decrease in the strength of, or complete disappearance of, the radial pulse.
• A reproduction of the patient's familiar symptoms, such as numbness, tingling, or pain down the arm.

Negative Sign (Test is NEGATIVE):
A negative test is when the radial pulse is maintained and no symptoms are reproduced.