Free radicals are renegade substances. They are the great white sharks of the subatomic. These are not nice guys. Free radicals are molecules that are missing an electron, which makes them unstable. This makes them crazy. So what do they do? They rush around trying to steal an electron from some other molecule and in the process they bash into our fragile cell walls and tear apart normal atoms; they even damage the delicate genetic blueprint stored in our DNA. That's a lot of destruction. And we are getting hit with about ten thousand of these every single day.
Not everything these free radicals do is so very terrible. Some of it is actually pretty good. Without free radicals we wouldn't have plastic, bread wouldn't turn into toast, we wouldn't have any hydrogen peroxide (and so would have only natural blondes), we wouldn't have medicines that fight fungus like athlete's foot or that kill bacteria.
But the dark side of free radicals is what causes masterpieces to deteriorate, rubber to get brittle, cars to rust, apples to turn brown, butter to turn rancid, and us to age, sicken and die.
On a first consideration it would seem that the bones, joints, and muscles should be discussed from a mechanical and engineering point of view; always with the appreciation that they are imbued with that mysterious quality, life. This allows them to grow, renew themselves after wear and tear, and repair themselves after being broken and torn apart. They make up a machine of enormous complexity but with the advantage of taking care of itself. Nothing else in this world can take the abuse which the living body does.
But this is a small part of the story. Always nature has more than one use for any system of our body. The solid bone makes the framework, but it is also a storehouse of such things as calcium and phosphorus, which are needed for the chemistry of the body and which in emergency can be dispensed by the bones. Most remarkable is the manufacture of the blood cells in the marrow of the bones.
Were one asked the function of the muscles, the obvious answer would be that they move the framework. I know that I cannot tell all that muscle tissue does. It helps in the circulation of the blood and the lymph; it stores sugar, which can be released and burnt for quick energy; its contractions produce heat and the resulting waste products help to stimulate respiration. Living tissue deteriorates with disuse so that the enthusiasts for physical exercise have a lot on their side.
Even if you can afford to pay for transportation, you had better keep your muscles in shape.
In order that the complex mechanism of the hand may work so wondrously, it is abundantly supplied with blood and nerves. All of you have had your pulse taken at the wrist. Your nurse or doctor counts beats here because there are few places in the body where so much blood surges through an artery near the surface. Yet I can assure you that if that radial artery is cut, plenty of blood will get to the hand by other routes. Nature intends to look out for that important hand.
Nature has also provided plenty of nerves to move all these important muscles and give plenty of feeling. The ulnar nerve is over on the little finger side, the median in the middle, and the musculo-spiral on the thumb side. A warning may be issued right here. If these names are really important to you, look them up. I may be using old-fashioned names. In my student days we called the first bone in the wrist the scaphoid, which is Greek for "like a boat." A young physician just graduated would not now understand me, for he says "navicular," which is Latin for "like a boat." In my childhood, the oldsters were buried by undertakers. Later when I began to sign death certificates they were collected by morticians. Now I find from the yellow pages of the telephone book that funeral directors have taken over. Fashion rules in anatomy or death.
Many of the nerves of the body have a specialized function. They are either motor for moving muscles, or sensory for feeling. The nerves of the hand are mixed. Thus the ulnar moves some muscles, especially the smallest giving the most accurate movements. But it also gives feeling in the skin. If the ulnar nerve has been cut, a pin prick will not be felt on the little finger or on the adjacent half of the ring finger. The feeling of the other side of the ring finger is supplied by the median nerve as are the other fingers. The musculo-spiral supplies little feeling in the skin. I do not expect you to remember all this but you can see that a surgeon who does can tell pretty well what nerves have been injured. The palm of the hand may in the manual laborer become very tough and calloused and yet retain much sensitivity and pliability. Its toughness and strength are due to the fact that beneath the skin and firmly attached to it is a sheath of so-called fascia which is very dense, strong tissue. The anatomists describe three main furrows or creases which allow the necessary pliability. There are always numerous minor creases on which palmists base their interpretations of character. It is safe to say that palmistry's occult claims are analogous to those of phrenology in the last century. Bumps on the outside of the skull were then supposed to reveal the inner secrets of men's personalities. They were more likely to be due to accidents.
But no part of the body is entirely sufficient to itself. Some of the motions of the hand, for instance, start at the elbow. Possibly a professional pianist could earn a living if his hands were always held palms down, but I cannot think of any other workman who could do his job without some roll of the hand which has to start at the elbow.
The hand allows man to use tools. If you have watched the cleverest trained ape use the simplest tool, a spoon for instance, you realize that he really has a modified paw. He has nothing like the range of motions of a human hand. No wonder that we speak of a good workman as being handy with his tools.
Small as the hand is in comparison to the rest of the body, it has twenty-seven bones, counting those in the wrist; and there are nearly half a hundred joints. There are so many ligaments supporting these joints that I doubt if they all have names.
Right here you should be reminded that in speaking of the front, back, inner, and outer sides of the hand, we consider the man as standing upright with his little fingers to the seams of his trousers and his thumbs out. Hence the palm is the front, even though when you are standing at ease or walking about you habitually hold your hands in the opposite position. There is rather a small amount of motion in any of the joints and the direction of the movement is usually very limited. Compare them with the shoulder joint which with the aid of some motion in the shoulder blade allows the arm to move across the front of the body for 360°, a full circle, and about three-quarters of a circle in a plane at right angles to this, not to mention much motion in the third plane.
The one finger that really has a fair amount of varied motion is the thumb. What a foolish metaphor we use when, in speaking of a man who is clumsy with his hands, we say that he is all thumbs. Lose your thumb and your hand is not much better than an elaborate hook. Your forefinger is easily the best of your four fingers, but, if you lose it, you soon learn to substitute your middle or even your ring finger. You cannot substitute a finger for your thumb.
This is because the thumb is set off to one side with an arrangement of joints and muscles very different from that of the fingers. This allows the front or working part of the thumb to be opposed directly to the front of the fingers. The most delicately sensitive skin of the body is found on these soft front pads. So highly may the feeling and finely adjusted motions here be developed that we often speak of the "educated finger" of the surgeon.
The motions of the digits require many muscles, some of which start as high as the elbow and have long tendons running through tunnels. Who of you ever heard of the seven interossei and four lumbrical muscles of the hand? Yet these eleven little slips allowed Benvenuto Cellini to fashion his magnificent jewels and Fritz Kreisler to charm us with his violin. Either man could have lost many pounds of thigh or calf muscles, of which you are so well aware, yet the world would have lost little.
We can command our big muscles and they usually obey, but not always; and they often work on their own. You can stop your muscles of respiration, but not for long, and they keep up their motion throughout life with usually no attention from you. Also you would be a poor ball player if you thought out all your motions. Quick skillful motions are automatic.
Striated muscle tissue is "flesh," and in man it constitutes approximately 50 per cent of the weight of the entire body. If you wish to see how the fibers appear, look at a piece of cooked corned beef that has not been cut across, but has been teased out.
Despite all the modern gadgets and labor-saving devices, practically all of us have to use our muscles. It is important to understand how to use them in an efficient manner. Muscles do their work by contracting; that is, by shortening. If a muscle shortens quickly, it has to use more energy to move a certain load. If it shortens slowly, the time in which it is expending energy is increased. For continued, efficient work the trick is to learn the happy mean.
A few people see an illustration of this trick in the performance of their automobiles. Every engine has a definite speed at which it works best. Below this it does not move smoothly. Above this, resistance builds up with wasting of fuel. Of course with muscles or motors it does not follow that this ideal speed is best for practical purposes. Time is valuable as well as energy. I am not offering this as an excuse for reckless drivers in city streets. Life, limb, and auto bodies are also valuable.
It may be a decided advantage for muscles to move slowly. They have two chief tasks: to make motion and to hold position and the same muscles may have to take on both jobs. As our physiologist friend says: "It might be very nice if we could move our arms a hundred times more quickly; but not if the consequence was that we could not hold them out horizontally for more than a second."
Of course, what muscles can do depends on many factors: their size, their manner of construction, and the material of which they are composed are the more important ones. Their normal function varies incredibly. Thus it has been said that the wing muscles of a gnat (insects so small that the Indians called them no-see-ums) can perform a motion in a thousandth of a second; a hummingbird in a hundredth; and the swimming muscle of a whale in a full second.
Not only have the muscles themselves counted, but also the skill with which they are handled. Consider the whip action with which a big league pitcher accumulates speed. As his leg, lifted high in the air, comes down, it speeds the body forward; the shoulder muscles speed the arm; the muscles across the elbow accumulate; the snap of the wrist smoothly adds on and finally the finger tips are traveling at the speed with which the ball leaves. This has been estimated at over 120 feet a second - a ninth of the velocity of sound.
A physiologist who has read the Book of Judges tells how Gideon selected three hundred men from his army of thirty-two thousand and conquered the Midianites. He sent home twenty-two thousand who were "fearful and afraid." Then he dismissed all who bent on their knees to drink, keeping those who lapped water from their palms. The ways of those primitive people were strange. I would have picked those limber enough to have bent their knees to quaff liberally from the stream.
Our scientist has a similar test for a modern army in a modern building. He would first have got rid of the twenty-two thousand fearful and afraid of exercise, who would have waited for the elevator to take them down two floors. The remainder he would have marched down into a subway, and have chosen the three hundred who ran up the escalator, "improvident of energy and impatient of delay."
Most people believe that physical fitness helps in resistance to infectious disease. There is practically no good evidence to this effect. Before the days of antibiotics the finest athletes might succumb to pneumonia as promptly as any weak-looking little specimen.
In a state of nature the demand for physical exercise is satisfied as instinctively as the demands imposed by hunger, thirst, and cold. Perhaps the best demonstration that you can get in so-called civilized life is that of school children at play. They are young animals. Observe how after a short period of imposed inactivity they just have to move violently about. But modern life interferes with this exercise. I saw recently the cynical remark that we spend five thousand dollars a year to provide a bus so that our children may not have to walk to school and fifty thousand dollars so that they may have a gymnasium where they can get exercise.
Posture has long been thought of in terms of standing and sitting and correct posture as the erect position assumed when one is under inspection, but posture should really be considered as the sum total of the positions and movements of the body throughout the day and throughout life. The above is the opinion of an orthopedic surgeon who leads an active outdoor life.
Good posture changes with age. The very young child is more like a four-legged animal than a man. As the child gets moving about, he is potbellied and sway-backed - that is, like an old horse with a sagging back. But gradually, as he approaches manhood, the belly becomes less and less prominent and the curve of the back lessens.
In the past the ideal standing posture held up to us was that of the soldier on inspection: the chest expanded, the shoulders thrown back, the toes turned out. This tense strained position is uncomfortable and inefficient. Who has ever seen an athlete perform efficiently with the toes turned out? The big toe is the part of the foot which does the work.
The argument for chairs designed for proper posture is based on the assumption that the occupants will conform their positions to the shape of the chairs, or vice versa. Children in their formative years are squirming organisms. They will not fit any shape of chair for long. Cats, the most efficient of athletes, always take loose slouchy attitudes when resting. The best quality of a chair would seem to be its comfortableness. It is safe to say that any posture taken temporarily while at rest is unimportant. It is only habitual bad posture which is harmful.
As the muscles are the only factor of posture controllable by the individual, exercises are the principal treatment. Sports are the pleasantest forms of exercise, and to be efficient at these it is necessary to apply the principles of posture in motion. For any of the muscles, the restful position, of course, is relaxation. But each muscle has its opponent. When you bend a joint as far as possible, you stretch the muscle on the other side. A position in-between rests both muscles. From this position each muscle is ready to do its work quickly and efficiently. Hence you see that when a person starts to rise from a chair, climb a ladder, run, walk, box or do any other active motion, his arms, legs, back and in general all his joints are somewhat bent and relaxed and thus ready for motion in any direction.
Proper attire helps this moving posture. The high collars of the old days are gone and the neck can now bend. Tight heavy clothing interferes with rhythmic movement.
To sum up: Don't expect your young child to have the posture of a man. If he grows up with a tendency to round shoulders and caved-in chest, give him setting-up exercises in loose clothing and remember that the moving posture is the important one, not that standing at attention for inspection.
Not only does proper posture in motion give us ease and conserve our strength but it is necessary for good balance. The other day I watched a lovely year-old child playing about. Seizing a piece of furniture, she would pull herself to a standing position and remain thus erect apparently until bored but not tired. Yet she did not walk. Why not, when she had plenty of strength and often wanted to get to another place? It is because the act of balancing is exceedingly complicated, requiring the teamwork of brain, eye, ear, muscles, nerves, and some remarkable sensations called "proprioceptive." This sounds tough but the word simply has the meanings of "proprietor" and "accept." The brain is just taking sensations from its own body.
This is how it works. You are standing upright but start to topple to the right. Instantly sensations in your muscles, joints, and skin telephone to your brain: "Get busy, he is falling to the right." If you are a tightrope walker, your brain in about a millionth of a second has told your muscles to pull you to the left. The muscles get in the game quickly and some of these same sensations tell them exactly when they have done enough and not too much.
The physical laws of stability are pretty well ignored in the human body. The big drug firms are nice people so I am sure that one of the largest of them will not object when I quote a paragraph from one of its articles: "Take a flexible, somewhat rubbery, oblong, irregularly shaped object weighing in the neighborhood of one hundred and fifty pounds and measuring something under six feet high, with a center of gravity two-thirds of the way up. Put this object in motion and try then to balance it on a couple of bearing surfaces each no larger than twenty square inches. Chances are that it will topple over and crash." The writer is describing a predicament that comes home forcibly in the later years of life when these millionth-of-a-second reactions have gone forever. Of course, people who may be classed as normal vary greatly in the delicacy of their balance. Otherwise circus acrobats would be out of jobs.
Human beings are the only mammals that really stand up straight. Of course, some of the big apes make a pretense of doing so, but certainly none of them has achieved the human ideal - heels together, head up, shoulders back, chest out, and belly sucked in. Many persons in attempting this posture remind one of Dr. Johnson's description of preaching women and dogs walking on their hind legs: "It is not well done. The wonder is that it can be done at all."
This erect attitude has made it difficult for the circulation in man's legs. Hence dilated veins, stagnation of the blood within, and the tissues round about swollen with fluid; changes in the arteries, and many resulting troubles in the tissues. The muscles and tendons have a tough job with all the weight of the body to handle instead of the half which the quadrupeds have on each pair of legs. Then higher up, the balancing puts great strain on the bones, muscles, and tendons.
Inside the abdomen, gravity and the erect position combine to make more trouble for us. Any or all of the abdominal organs may sag down. This is known as visceroptosis, or dropping of the guts. A few swallows of barium and an X-ray examination of a thin, narrow person may sometimes show a most remarkable displacement downward of the stomach and intestines. This leads to one of the few arguments I know of for accumulating fat. As people plump up, they often overcome their visceroptosis.
There is one trouble in which the value of the horizontal rather than the vertical position has been often demonstrated, as is well known to many physicians. That is diarrhea. Many diarrhea mixtures have been used; nearly all of them, I think, have some opium in them which quiets the bowels. They also frequently contain some chalk-like material which, I believe, is supposed to coat the bowels. Abstinence from food combined with the horizontal position for a prolonged period is a simpler treatment but effective.
Now we have Dr. Richard H. Overholt telling us in the Journal of the American Medical Association that "septic bronchiectasis (pus in the small air passages of the lungs. Ed.) is another penalty imposed on modern man for his evolutionary assumption of an erect position." The infected secretions do not travel uphill freely from the lower part of the lung. Standing the patient practically on his head is a well recognized treatment.
We have now arrived at the head and my friend the rhinologist (he treats your nose) continues the sad tale by informing me that man is peculiarly subject to trouble in his sinuses because they do not drain well as he stands erect. We have not much data as to relative positions above the nose, but how often does one see a quadruped with a bald head?
We must retain a reasonableness in all things; not go to extremes as we so often do. But a moderate amount of lounging is good for most of us. (People with sick hearts and difficulty in breathing may be exceptions.) More time in the horizontal position is a common prescription. It may well be used before the onset of illness.