A test for thoracic outlet syndrome. The patient’s arm is moved back into extension and external rotation with the elbow extended and forearm supinated. The radial pulse is palpated while the patient is asked to tuck the chin, side bend the head toward the opposite side, and rotate the chin toward the side of the extended arm. The patient is then asked to inhale. A positive sign of numbness or tingling in the hand or diminished pulse indicates the brachial plexus or blood vessels are compromised at the site of the scalene muscle.