November 20, 2012
Polydactly (extra fingers) is one of the 10 most common pediatric orthopedic conditions, and this condition has been studied as early as the days of Charles Darwin, who suggested that the condition of having more than the usual number of fingers or toes (polydactyly) was an ancient trait, now mostly formant, that occasionally reappears due to some hereditary misstep.
Basically, there are three polydactyly variants:
A – most common is the variant featured with an extra pinky (see picture above)
B – less common is the variant featured with an extra thumb
C – rare is the variant featured with an extra index finger, middle finger or ring finger
A few (recent) reports about polydactyly:
The ‘Vitruvian Man’ – Leonardo da Vinci‘s famous drawing from the year 1487 – can be described as one of the earliest sources presenting guidelines for hand anthropometry. Today, plays hand anthropometry a considerable role in the fields of design, ergonomics, and even architecture! An update presenting data from e.g. the NASA and the US army.
The drawing, which is in pen and ink on paper, depicts a male figure in two superimposed positions with his arms and legs apart and simultaneously inscribed in a circle and square. The drawing and text are sometimes called the Canon of Proportions or, less often, Proportions of Man.
Interestingly, Leonardo’s comments for the proportions of th e ‘Vitruvian Man‘ includes a few passage where the hands and fingers are mentioned, quote:
“For the human body is so designed by nature that the face, from the chin to the top of the forehead and the lowest roots of the hair, is a tenth part of the whole height; the open hand from the wrist to the tip of the middle finger is just the same; the head from the chin to the crown is an eighth, and with the neck and shoulder from the top of the breast to the lowest roots of the hair is a sixth; from the middle of the breast to the summit of the crown is a fourth. If we take the height of the face itself, the distance from the bottom of the chin to the under side of the nostrils is one third of it; the nose from the under side of the nostrils to a line between the eyebrows is the same; from there to the lowest roots of the hair is also a third, comprising the forehead. The length of the foot is one sixth of the height of the body; of the forearm, one fourth; and the breadth of the breast is also one fourth. The other members, too, have their own symmetrical proportions, and it was by employing them that the famous painters and sculptors of antiquity attained to great and endless renown. Similarly, in the members of a temple there ought to be the greatest harmony in the symmetrical relations of the different parts to the general magnitude of the whole. Then again, in the human body the central point is naturally the navel. For if a man be placed flat on his back, with his hands and feet extended, and a pair of compasses centred at his navel, the fingers and toes of his two hands and feet will touch the circumference of a circle described therefrom. And just as the human body yields a circular outline, so too a square figure may be found from it. For if we measure the distance from the soles of the feet to the top of the head, and then apply that measure to the outstretched arms, the breadth will be found to be the same as the height, as in the case of plane surfaces which are perfectly square.”
Leonardo da Vinci’s comment about the proportion of the average hand was quite right, but the field of anthropometry has later developed more precise methods in order to describe the most important individual variations concerning the human body. Various sources of anthropometric hand data indicate the average hand length is close to 11% of body height (usually slightly smaller). Leonardo’s ‘Study of arms and hands’ is another of his drawings.
Today, anthropometry plays an important role in industrial design, clothing design, ergonomics and architecture where statistical data about the distribution of body dimensions in the population are used to optimize products.
DATA FROM THE NASA & US ARMY:
In the last decade of the 20 century reports became available developed by the NASA & the US army – which include data for at least 20 characteristics of the human hand shape, including e.g. hand length, hand breadth & finger length. The data in the picture above represents static human physical characteristics of the adult hand, presented in 2000 by the Department of Defense Human Factors Engineering Technical Advisory Group.
The picture below presents at the bottom some average data based on German, UK & American populations – which provide useful ‘points of reference’ in the perspective of biometry & Multi-Perspective Palm Reading.
Finally, regarding Leonardo da Vinci it might be interesting to notice here that in 2008 a report was published describing characteristics of his fingerprint:
December 12, 2010
Since Winston Churchill’s use of the ‘V-sign’ in 1941, this gesture is generally recognized as a sign for ‘victory’. But outside the UK, Ireland, New Zealand and Australia few people are aware of the insulting version of almost the same gesture: a ‘v-sign with the palm inwards’, which is often recognized as an alternative for ‘the finger’. Earlier this month British scientists found that finger length is involved in the severity of the insulting version of the V-gesture.
Scientists at the recent FIFA meeting that awarded the 2018 World Cup to Russia have discovered that people with long middle fingers are capable of increasing the severity of the traditional two-fingered ‘V gesture – with the palm inwards’.
‘Prince William’s gesture was noticeably more aggressive than that of David Cameron, who has a relatively short middle finger,’ said Professor Thomas Boycott from Cambridge. ’The Prince’s gesture was a clear ‘Fuck you, you lying twat with knobs on’, whilst Cameron’s was more ‘Up yours, you stupid tosser’.’
V-signs have been given throughout history, with long-fingered people performing best. Short-fingered Winston Churchill’s gesture when telling journalists to stop taking photographs was incorrectly taken as a ’V for Victory’.
‘Then again,’ added Boycott, ‘what about that short-fingered man who swerved to avoid me this morning and merely gestured to indicate I should eat a hot dog with plenty of ketchup on it? Most peculiar, in the circumstances.’
The word ‘dermatoglyphics‘ was first coined by Harold Cummins in 1926, and refers to the study of the characteristics in the skin ridges of the hands and the feet. What are the most common dermatoglyphic characteristics?
In most populations around the world is the ‘ulnar loop’ the most observed fingerprint pattern (see: the fingerprint of the pinky finger in the picture above). Loops are most frequently found on the little finger (and middle finger); loops are least frequently found on the pointer finger.
The variations in the dermatoglyphics of the handpalm are much more complex than the variations in the fingerprints. An important element concerns the presence of the ‘palmar triradii’ (see: a, b, c, d, and t in the picture above): normally each finger is featured with a palmar triradius – triradius t belongs to the thumb (the thumb mouse – a.k.a. as the ‘thenar’, or in palmistry: ‘mount of Venus’ could be recognized as the third phalange of the thumb).
T = L + D – 1
More details available via:
Picture: example of a normal pattern of dermatoglypics [NOTICE: If the ‘c-line’ is ending between the ring- and middle finger it always creates a palmar ‘loop’, which implicates that the author of the picture has missed 6th palmar triradius between/below the c and d triradius]