Adson&;s test is elicited in a suspected case of

cervical rib is the extension of costal element(anterior pa) of transverse process of C7 veebra more than 2.5 cm(normal). Cervical rib narrows the scalene triangle Adson&;s test: the hand is raised above after seeing the radial pulse. the patient is asked to take a deep breath and turn the head to the same side. Any change in pulse, i.e. either becoming feeble or absent is noted (Ref: SRB&;s Manual of Surgery , 5th edition, pg no. 429)