of Hand & Nerve System (Why
Fascinating True Facts about Hand
Hand Surgery as a recognized surgical specialty did
not exist until World War II.
At that time, US Army Surgeon General Norman Kirk arranged for military hand
injuries to be treated at regional specialty centers. Dr. Sterling Bunnell, a
civilian general surgeon who had written a book about the care of the hand,
was assigned the task of supervising and training a nucleus of hand surgery
specialists. This group became the first
generation of surgeons in the modern specialty of hand surgery.
During the Gallic wars, Julius Caesar ordered the
thumbs of captured warriers amputated so that when they returned to their
country, they would serve as examples and be unable to bear arms again. This
practice was later used in a number of wars and in the slave trade.
In the absence of any other
proof, the thumb alone would convince me of God's existence.
Injuries: One Fourth of
athletic injuries involve the hand and wrists:
- Nerve disorders
- Finger clubbing
- Carpal tunnel syndrome
- Fractured bones
- sprains, strains, cuts, and bruises
We work our fingers by remote control. Of course,
in one sense, we work all of our moving body parts by remote control - the
control center is our brain. However, the fingers are special, because there
are no muscles inside the fingers. The muscles which bend the finger
joints are located in the palm and up in the mid forearm, and are connected to
the finger bones by tendons, which pull on and move the fingers like the
strings of a marionette.
- When the hand is kept wet, the skin of the
palm wrinkles. Why? The exact mechanism is not known, but it is clearly
controlled by nerves.
When the nerve which supplies feeling to an area of skin on the palm is cut,
that area of skin not only becomes numb, loses
its ability to wrinkle when wet. It also loses the the ability to sweat.
- The wrinkles on the back of the finger
knuckles are actually dimples,
and mark areas where the skin is attached to the tendon beneath the skin.
- Finger joints only have wrinkles and creases
if the joint moves. If a finger joint stops moving, the creases eventually
- One out of six of congenital anomalies
recorded on birth statistics involve the upper extremities.
- White children are four times more likely
than black children to be born with webbed fingers.
- Black children are ten times more likely than
white children to be born with extra fingers.
- Each hand contains
(plus or minus... everyone is different, and everyone counts these things
- 29 major and minor bones (many
people have a few more).
- 29 major joints.
- At least 123 named ligaments.
- 34 muscles which
move the fingers and thumb:
- 17 in the palm of the hand, and
- 18 in the forearm.
- 48 named nerves:
- 3 major nerves.
- 24 named sensory branches.
- 21 named muscular branches.
- 30 named arteries and
nearly as many smaller named branches.
The muscles which power the fingers are strong -
strong enough for some people to climb vertical surfaces supporting their
entire weight at times by a few fingertips. The muscles which accomplish this
feat are stronger than you might imagine, for the biomechanics
of the hand require that
the force generated by the
muscles which bend the fingertips must be at least four times the pressure
which is produced at the fingertips.
- The thumb is controlled by
And moves in
such a complex fashion that there are 6
separate descriptive terms just for particular directions of movement of one
thumb joint - the basal
joint, at the base of the thumb.
Almost 90 per cent of women and 80 per cent of
men in the age group 75-79 years have x-ray evidence of osteoarthritis in
their hands <·>.
Contrary to popular opinion, humans - homo
sapiens - are not the
only primates possessing opposable thumbs. Chimpanzees and monkeys can oppose
the thumb to the index digit. What
makes the human hand unique in the animal kingdom is the ability of the small
and ring fingers to rotate across the palm to meet the thumb, owing to a
unique flexibility of the carp metacarpal joints of these fingers, down in the
middle of the palm. This is referred to as "lunar opposition" and
adds unparalleled grip, grasp, and torque capability to the human hand. This
feature developed after
the time of Lucy, a direct human ancestor, who lived about 3.2 million
Do fingernails have feeling? No, but the
fingernail extends deep beneath and behind the skin of the cuticle, and
nerves on the back of the finger around the cuticle sense forces transmitted
from the tip of the fingernail. The brain integrates the sensations from the
nerves of both the fingertip pad and cuticle to give a complex enhanced
perception of pressure and shear at the fingertips. Loss of a fingernail
changes the feeling on the palm side of the fingertip.
About a quarter of the motor cortex in the
human brain (the part of the brain which controls all movement in the body)
is devoted to the muscles of the hands. This is usually illustrated with a
drawing of a human figure draped over the side of the brain, body parts
sized proportional to the amount of brain devoted to their movement,
referred to as a homunculus -
as illustrated in this drawing from
Dr. Wilder Penfield's monograph "The Cerebral Cortex of Man.":
study, carpal tunnel syndrome was found in 9 percent of women between
the ages of 25 and 74.
skin of the palm
The skin on the palm side of the hand and
fingers is unique for these reasons and more:
- No hair (the medical term is glabrous).
- Usually neither color nor the ability
- Tough and durable, yet sensitive.
- Anchored down to the bones beneath
through an intermediate layer of fascia.
This arrangement keeps the skin of the palm from sliding around like a
rubber glove when we use our hands to grip and twist. In some people,
this layer of fascia shrinks and thickens, leading to Dupuytren's
When one curls the fingers into a fist, the
fingertips naturally group together side by side. If the fingertips all
bend together, they continue into the palm side by side. However, the natural
tendency is for each fingertip to aim for the same point at the base of
the thumb, which is obvious when touching each finger down to the
base of the palm. For this reason, if a hand problem (stiffness,
swelling, etc.) prevents a finger from meeting the side of the adjacent
fingertip midway into making a fist, that finger will tend to cross over
and overlap the adjacent finger when making a fist.
- "If you can move your finger, it isn't
- "Cold hands, warm heart" Well, it
really depends on why ones hands are cold...
- "Computer use causes carpal tunnel
- "Eating gelatin makes your fingernails
stronger" False -
no evidence to support this.
- "Cracking your knuckles gives you
arthritis" False -
no evidence to support this
- Fingers are never perfectly straight.
Usually, the index, ring and small finger each curve sideways slightly
toward the middle finger, and the middle finger may curve toward either
- The finger
bones are straight on the back side, but curved on the palm side. When
we bend our fingers into a fist, the finger bones produce a shape similar to
in a square, round on the inside, square on the outside.
- When we make a fist, the fingertips
curve through a spiral, not a circle. This is because the lengths of the
finger bones are related in a way seen often in naturally occurring spirals.
These spirals in turn relate to a mathematical series of numbers discovered
by Fibonacci in
1202. In this series, each number is the sum of the previous two numbers: 0,
1, 1, 2, 3, 5, 8, 13, 21, ...and so on. The lengths
of the finger bones approximate
the ratio of the Fibonacci numbers 2, 3, 5, and 8.
- In the absence of any other
proof, the thumb alone would convince me of God's existence.
Sir Isaac Newton
can land men on the moon, but, for all our mechanical and electronic wizardry,
we cannot reproduce an artificial fore-finger that can feel as well as beckon.
hand is the cutting edge of the mind.
can't shake hands with a clenched fist.
fragrance always remains in the hand that gives the rose.
a true friend with both hands.
do not saw the air too much with your hand, thus, but use all gently.
Shakespeare, 'The Tragedy of Hamlet, Prince of Denmark,'Act III, scene ii
preservation of the sacred fire of liberty and the destiny of the republican
model of government are justly considered... deeply,...finally, staked on the
experiment entrusted to the hands of the American people.
Washington, First Inaugural Address, Apr. 30, 1789
the road rise to meet you. May the wind always be at your back. May the sun
shine warm upon your face, the rains fall soft upon your fields and, until we
meet again, may God hold you in the palm of his hand.
not withhold good from those to whom it is due, when it is in the power of your
hand to do so.
impersonal hand of government can never replace the helping hand of a neighbor.
upper limb is the lightning rod to the soul.
art of life is to show your hand.
best helping hand that you will ever receive is the one at the end of your own
are the hands by which we take hold of heaven.
child's hand in yours -- what tenderness and power it arouses. You are instantly
the very touchstone of wisdom - and strength.
ultimate test of a relationship is to disagree but hold hands.
do not die by the hands of the law. They die by the hands of other men.
men don't know what good they hold in their hands until they've flung it away.
n. The 947th method (according to Mimbleshaw's classification) of obtaining
money by false pretences. It consists in "reading character" in the
wrinkles made by closing the hand. The pretence is not altogether false;
character can really be read very accurately in this way, for the wrinkles in
every hand submitted plainly spell the word "dupe." The imposture
consists in not reading it aloud.
striving to be the best is man's duty, it is it's own reward. Everything else is
in God's hands.
make a man happy, fill his hands with work.
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you really need Gloves to ride a Bike