What is Adson's Sign?
What it is: It is the decrease in ipsilateral radial pulse or the presence of subclavian bruit when the patient extends the neck, rotates the head towards the side being tested and holds their breath.
Why its used: It is an indicator of thoracic outlet syndrome
How its done: The test is performed by having the patient in a sitting position, hands resting on thighs. The doctor then palpates both radial pulses as the patient rapidly fills the lungs by deep inspiration and, with breath held, hyperextends the neck and turns the head toward the 'affected' side. If the radial pulse on that side is decidedly or completely absent, the result is considered positive.