How to differentiate between transmitted and expansile pulsations

If you are palpating a swelling like an abdominal swelling infront of the aorta, You have to decide whether the mass you feel is pulsatile/expansile in itself (in which case your fingers will move outwards A ) or whether the pulsation is transmitted through other tissue (in which case your fingers will move upwards B ).See diagram below

Also in transmitted pulsation you can make this pulsation disappear if you can move the swelling away from the aorta ( if you put the patient in the knee-elbow position, an enlarged intra-abdominal swelling which was transmitting aortic pulsation will get away from the aorta and the pulsations will disappear)