Understanding the Allen Test (for TOS) Assessment
To detect vascular compression of the **subclavian artery** as it passes under the Pectoralis Minor muscle (Pec Minor Syndrome, or Hyperabduction Syndrome).
Watch How It's Done
How do I start?
Patient is sitting or standing. Arm is abducted to 90° and externally rotated.
What happens?
The examiner palpates the **radial pulse**. The patient is instructed to **rotate the head away** from the tested side. The position is held for 1 minute.
In Plain English
What Does a Positive Result Mean?
A **diminution or disappearance of the radial pulse** and/or reproduction of the patient's hand/arm symptoms.
Helpful Tip:
This test is highly sensitive but not specific, as the pulse can diminish in healthy individuals in this extreme position.
Safety First
This guide is to help you understand what happens in a clinic. Do not try to diagnose yourself. If you have severe pain, swelling, or cannot put weight on your leg, please visit an urgent care center or your doctor immediately.
Other Thoracic Outlet Tests
Costoclavicular Test (Military Brace Test)
To detect compression of the neurovascular bundle between the **clavicle** and the **first rib** (Costoclavicular space).
Hyperabduction Test (Wright's Test)
To detect vascular compression of the **subclavian artery** due to entrapment under the **Pectoralis Minor tendon** (Pec Minor Syndrome).