Adson’s sign



Adson’s sign: the loss of the radial pulse in the arm by rotating head to the ipsilateral side with extended neck following deep inspiration.



It is sometimes used as a sign of ((thoracic outlet syndrome)) (TOS)



It is no longer used as a positive diagnosis of TOS since many people without TOS will show a positive Adson’s syn.



Thoracic outlet obstruction may be caused by a number of abnormalities, including: degenerative or bony disorders, trauma to the cervical spine, fibromuscular bands, vascular abnormalities, and spasm of the anterior scalene muscle. 



Symptoms of TOS are due to compression of the brachial plexus and subclavian vasculature, and consist of complaints ranging from diffuse arm pain to a sensation of arm fatigue.



The test is positive if radicular symptoms are reported and secondary to a diminished or lost of the radial pulse.