Simian hand: Ape hand deformity: Ape hand deformity, is a deformity in humans who cannot move the thumb away from the rest of the hand. It is an inability to abduct the thumb. Abduction of the thumb refers to the specific capacity to orient the thumb perpendicularly to the ventral (palmar) surface of the hand.
The thenar transverse crease runs vertically around the base of your thumb. An STPC used to be called a “simian crease,” but that term is no longer considered appropriate.
The examination of the hand and nails can lead to a number of diagnoses. Some of these include liver disease (Terry's nails), kidney disease (Lindsay's nails), .
A violent tendency is found when other features, as well as the Simian Line, are present. If the thumb is very straight with no waist, a lack of reason will be very marked. When the Simian Line is found on both palms, look out for a short thumb.
This degree of paralysis is usually accompanied by marked atrophy of the thenar muscles. The appearance of a paralyzed, atrophic thumb lying parallel instead of perpendicular to the fingers resembles an ape’s hand, and has been called the simian hand, ape hand or monkey paw deformity.(1,2).