alen's test

a 40 years old heavy smoker man presented with trophic/arterial(tender small,well defined dry whitish/pale based shallow ulcer )ulcer over tip of left index.it arises the suspicion of arterial ulcer due to blocked palmar arch (ulnar/radial artery)
procedure:asked the patient to clench a fist, now compressed both ulnar and radial artery by my two thumbs for about 1 minute and then asked him to open the fist
palm was pale paper white
then released the pressure from radial artery but no color change was visible(as radial artery failed to re establish palmar arch)
then released pressure from ulnar artery and gradually palm became pink to red as circulation/palmar arch was re established solely by ulnar arterial contribution