Hand

At the tétrapodes

Although there exists a unquestionable Homologie between the Membre S of the mammals, only some tétrapodes has hands. The others have Patte S, Nageoire S and of wings

The forelimbs of the Homo sapiens, all the members of the Primate S have hands. Quadrumane (of the Latin quadrumanus four hands) is an expression used to indicate a monkey which dates from the 18th century. By opposition the man was described as “bimane”.

The hands in the primates are an example of homology. The members fronts of the raccoons, have also hands, it is in this case an example of evolutionary Convergence.

The hand of the human ones

Except exceptional case (genetic mutations, etc), the hand comprises five fingers , which is:

the inch;
the index;
the major ;
the annular ;
the auricular .

As their name indicates it, the index is used to point, show, the major is longest of the fingers, the annular (see Anneau) is the finger which carries the alliance and the auricular is the finger which is used to scrape the Oreille. For more details, one will refer to the Leitartikel: Finger .

The fist indicates the closed hand (all folded fingers).

The Paume of the hand indicates the interior of the hand, i.e. the part which is not visible when the hand is closed. This one is marked by three Ride S deep, present as of the birth, called Lignes of the hand.

Os

A human hand comprises at least 27 Os:

the carpus (wrist) comprises 8 bones, in two lines of four. They all are connected to the bone of before arm;
the Métacarpe (palm) comprises 5 bones, for each finger;
the phalange S (fingers) comprise 14 of them: 2 for the inch, 3 for the other fingers:

the distal phalange, which carries the nail (abr: P3);
the average phalange (abr P2) (the inch does not have any);
the phalange proximale (abr: P1), which connects the finger to the metacarpus.

Muscles

One distinguishes two categories of muscles acting on the hand: the extrinsic muscles which are not limited to the area of the hand and the intrinsic muscles whose insertion is limited to the area of the hand.

Extrinsic muscles:

radial Flexor of the carpus (Mr. flexor carpi radialis )
long Muscle palmar (Mr. palmaris longus )
ulnar Flexor of the carpus (Mr. flexor carpi ulnaris )
surface Flexor of the fingers (Mr. flexor digitorum superficialis )
deep Flexor of the fingers (Mr. flexor digitorum profundus )
flexor long Muscle of the inch (Mr. flexor pollicis longus )
Muscle long radial bungee cord of the carpus (Mr. flexor pollicis brevis )
Muscle runs radial bungee cord of the carpus (Mr. extensor carpi radialis brevis )
ulnar Extensor of the carpus (Mr. extensor carpi radialis longus )
Extensor of the fingers (Mr. extensor digitorum )
Muscle long bungee cord of the inch (Mr. extensor pollicis longus )
Muscle runs bungee cord of the inch (Mr. extensor pollicis brevis )
Extensor of the index (Mr. extensor indicis )
Extensor of the little finger (Mr. extensor digiti minimi )
long Muscle delivery of the inch (Mr. abductor pollicis longus )

Intrinsic muscles:

interosseux Muscle palmar (Mr. interossei prize lists )
interosseux Muscle dorsal (Mr. interossei dorsal )
Muscle lombrical (Mr. lumbricales )
Adductor of the inch (Mr. adductor pollicis )
short flexor Muscle of the inch (Mr. flexor pollicis brevis )
Muscle opposing of the inch (Mr. opponens pollicis )
short delivery Muscle of the inch (Mr. abductor pollicis brevis )
Muscle opposing of the little finger (Mr. opponens digiti minimi )
short flexor Muscle of the little finger (Mr. flexor digiti minimi brevis )
Adductor of the little finger (Mr. adductor digiti minimi )
Palmar cutaneous or Short palmar (Mr. palmaris brevis )

Droitiers and left-handeds person

The majority of the human beings have a hand definitely more skilful than the other. It is often about the right hand (nearly 80% of the French are droitiers, for example - a little more often the girls than the boys, since only 30% of the left-handeds person are lefts-handed person). From this difference were born conventions from orientation. The “clumsy” hand draws its various names ( left , wounded , penecho , seneco , will senestra , stanca , left …) negative adjectives or is at the origin of negative adjectives, when they are not both at the same time: the left word for example has just warped (to wound) and can now have the clumsy direction of or awkward .

A person who is also at ease with the right hand which the left hand is known as ambidextrous .

See article on the Sinistrality

Gestural

The gestural one of the fingers and the hands constitutes a true language. So much of gestures are universal, their significance, on the other hand, is generally cultural.

Leitartikel: Gestural of the fingers and the hands

The hand and sciences

Humanity

Darwin wrote that “the man would never have reached his dominating place in the world without the use of his hands”. One could give to that a political connotation; the philosopher Engels for example wrote a test entitled Of the role of the hand in the transformation of the monkey into a man : the hand becomes here synonymous with work and dignity. In the postindustrielles companies, the work of the hand is developed and represents the quality of clothes industry: “hand made”, “bent hand”, “collected with the hand”. Contrary, “to keep the hands in the pockets”, “to be lazy” (hair which can push only for lack of use) are current expressions to nominate a person which is restive with the work, somebody the lazy one, which does not do anything. It is also a sign of membership of a social class: “callous hands” for those which are employed with manual duties, “white hands” for those which have intellectual professions or which do not need “to dirty the hands” to work - the expression “to dirty the hands” also means “to be compromised”.

Measure

The hand is a frequent measuring instrument. Measure quantity (a " main" of flour, a " hand " of paper, in printing works), measurement of distance (them “through fingers”, in surgery, “Empan” - distance which separates the inch from auricular in the open hand -, the “inch”, the hand, the finger, the palm, etc).

The hand is used to count and the decimal system probably comes from the number of the fingers of the two hands.

Leitartikel: To count on its fingers

Writing

Hieroglyphic writings such as the Egyptian writing or the writings Maya and Aztèque often use the hand, which symbolizes the action.

The etymography of the Chinese, in particular by the study of the characters on bronze, reveals that the hand often uses the composition of the C-Ws communication, for example for the words " fenêtre" (which represents two hands pushing of the windows) or " brush/peindre".

Economy

The invisible hand of the market is an economic concept developed by Adam Smith (English liberal economist) according to which all would occur as if a invisible hand arranged the things so that the sum of the private interests leads to the general interest.

The hand and religions, magics and beliefs

Shiite Islam

In the Shiites, the hand of Fâtima (Khamsa), girl's name preferred of Mahomet, symbolizes in the tradition, the place of the woman and is a supposed talisman to draw aside the evil. In certain cultures, the true hand (of flesh) is used as amulet.

In Islam traditionalist, there should not be contacts between the hands of a man and a woman not-grooms other than the family, unless a clothing interposes.

Christianity

For the Christianity, the hand occupies an important place. It is by showing its marks ( “see my hands and my feet” ) that Jesus proves his identity with its disciples. He and of many other miracle-workers (miracle-workers) of the gilded Légende catholic use their hands to carry out wonders and in particular, to cure the patients.

Raised hands upwards or the united in front of the body are used by the believers to take a posture of prayer.

Clairvoyance

The Chiromancie is a Divinatory art in which the “indicator” studies the “lines of the hand” and from of deduced the destiny from the subject. In this discipline, one considers that the hand is made up of " lignes" (furrows in the skin) and of " monts" (prominent parts). Chiromancy is a very old art. Aristote, Hippocrates and Jules César are interested there but, like all arts divinatoires, it does not rest on any scientific base.

In a register pseudo-scientist, the morphopsychologists of the 19th century deduced qualities and the defects from the subjects studied by measuring the intervals between the various parts the body, and their lengths. The hand had a central importance there.

Symbolic system

Universal tool of communication, the human hand is often used like symbol.

Art

the first form of painting carried out by the man, there is close to 40 000 years, they are negative or positive prints of hands. One is unaware of obviously the direction of these prints of hands, one thinks that they always do not have the same significance: some with these painted hands have fingers in less, perhaps following ritual mutilations (caves of Maltravieso, of Gargas, Tibiran). These mutilations seem to concern mainly the men.
the hand is in the center of the traditional Indian dances
the proportions between the bones of the index to the wrist corresponds to the famous Golden section and was used as reference to construction of the Pyramide S of Egypt, of the Parthenon and of the Cathédrale s.
In the same way, the proportions between the palm of the hand and the distance between the fingers, with or without the inch, respectively called empan and palm correspond to the proportions of the Golden section.
C' is starting from these proportions that the builders of Cathédrale S used, for their measurements, a measuring rod made up of five stems articulées.
Il is appropriate to recall on this subject which one can have fun to seek the golden section a little everywhere in nature - one will always find of them examples - and which, in addition, all that is theoretical since there are not two people made similar and of which the proportions are the same ones. The painters often wanted to see the golden section as bases “perfect” harmony and beauty, but it is not founded, more especially as they are the artists who imposed the gold section like gun of beauty: difficult to say now if this mathematical characteristic has “objectively” an intrinsic beauty or if this beauty does not proceed 2500 years of tradition of representation of beautiful by mathematics, in condition of course of considering mathematics from an esthetic point of view… and not to confuse them with the crowned geometry.

an example of calculation of the golden section on the index (calculation of point of bone with articulation):

distal Phalange = 2 cm; average phalange = 3 cm; phalange proximale = 4,8 cm.

On the basis of the distal phalange and multiplying each time by 1,618 one obtains the approximate value length of the other phalanges. On another hand, even if the absolute distances are different, the proportions approach statistically with the central value.

To be able

In many cultures, the sovereigns have sticks of command which represent hands.
In Heraldic, the closed hand means the secrecy and the opened hand, confidence.

Psychology

the hand is often the ambassador of a person when it is not the model reduces symbolic system, almost a Homoncule: handshake (with many alternatives), hand-kissing, but also slap, opera hats and slaps are with the number of the rare forms of physical contact conventionally allowed inter-people in our everyday lives including between individuals not sharing a particular intimacy. Within this framework, a soft hand or a comes up of iron are famous being the mark of a particular temperament.
It is often the hand which is used to stop a negotiation, to engage: “tope-là”
L' mutual membership of the husbands is as symbolized by a ring as they carry to the hand. Moreover, it is said that the father of promised grants to give to the hand his girl.
Until the beginning of the 19th century the nudity of the hand of a woman was the sign of her rendering in love: the lover had “all” when its beautiful “took off the gloves”.
the hand is used to give and receive: “the hand which gives is much happier than that which receives” (Acts of the Apostles)
the hand is, par excellence, the body of the caress.

Mutilations, decorations

At the time prehistoric, the prints of mutilated hands are very current (cf section " art").
At the Yakuzas, it is not rare to voluntarily cut a finger as a sign of tender, to wash a fault.
In many cultures, the hand is the support of permanent or temporary traditional tattooings (tattooings with henné). Tattooings of the hand have the characteristic not to be able to be hidden.

Justice

Amputation

In certain cultures or certain countries, one slices (or one sliced) the hand of the robbers. It is in particular the case of the states which apply the Koranic law: the robber and the robber, to both cut hand (S.AL My-idah 5:35) .

Compensation for the personal injuries

Because of its qualities necessary to a good body integrity, the body damages concerning the hand profit from the attribution of rates of disability more important than of other parts of the body. The courts hold account, in their appreciation, of the exerted trade.

Expressions using the word hand

To have two left hands and to have five inches with each hand : to be awkward
To be lazy : to be lazy
To put the hands in dirty oil : to confront itself with a problem in manner practices
To put the shoulder to the wheel : to contribute its share to a work
To put the hand at the pocket : to take part
financially of to wash the hands : not to be interested in a problem. The most known reference is allotted by the bible to the Roman procurator of Judaea Pontius Pilate (MT 27,24).
To pass the hand : to let its place
Give a knack , to lend strong hand : to help
To hold between its hands : to be the only person in charge of a destiny ( Be discrete, my reputation is between your hands. )
To tighten the hand : to offer its assistance
to put its hand of It to cut , or: to put its hand of it at fire : in being absolutely certain ( It is without danger, I would put my hand of it to be cut. )
Play of hand, play of unpleasant : phrase of Provence meaning that pretended violence often leads to real violence
caught red-handed Être : taken in red-handed

See too

Washing of the hands
Glove
dactylologic Language of the signs French
Alphabet

External bonds

See a detailed diagram of the bones of the hand (seen dorsal).
Fracture of the hand, the General practitioner , n°2137, September 18th 2001
To examine a wound of the hand, the General practitioner n°2093, February 16th 2001
Foundation Claude Verdan - museum of the hand.
Museum of the culture of the hand. (Wolnzach)

Random links: