<prompt> Adson test is used for determining vascular suffiency. It is useful in -Peripheral vascular diseaseVaricose veinsCervical ribAV fistula  <response>: Ans. is c i.e., Cervical rib. Adson test -It is a prorocative test for thoracic outlet syndrome. This test is positive in cases of compression of subclavian artery as noted by a radial pulse deficit when patient is placed in positions provoking compression of subclavian artery by a cervical rib or tightehed anterior and middle scalene muscles. 