<unk>  is seen during abduction and external rotation at the shoulder, where there is loss of the radial pulse in the arm.  It can be a sign of thoracic outlet syndrome.  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 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, frequently aggravated by carrying anything in the ipsilateral hand or doing overhead work such as window cleaning.
As cited in the literature the<unk>  is loss of radial pulse while turning the head to the contralateral side, slightly elevating the chin and breathing in.
Adson's sign
Rigler's sign
Pemberton's sign
Kussmaul's sign
Hegar's sign
Goodell's sign
Rovsing's sign
Cullen's sign