The human spine bears the same relation to the body as a whole as the trunk of a tree does to the rest of the tree. If the trunk is strong the entire tree is sturdy and vigorous. If the spine is strong the body as a whole possesses a similar degree of strength. Therefore, the necessity for a strong spine is readily apparent.
This strength is necessary not only because the spine is what may be termed the foundation for our entire physical structure but also because therein are located the nerves that radiate to each organ and every minute part of the body. These spinal nerves control the functional processes of all our bodily tissues and structures. If the spine possesses a proper degree of strength, if the bony structure is properly proportioned, and if the alignment of all the vertebrae is everything that can be desired, you are then practically assured of the pulsating vitality which is a part of superb health.
It is an interesting fact that the spine is the central and fundamental structure of all the higher organisms on this earth. In the course of the evolution of life on this planet there developed from the very simplest forms of animal organisms two different higher forms of life- on the one hand the vertebrate animals, possessing an internal skeleton, and on the other hand the insects, clams, crustaceans and other creatures that have their skeletons on the outside, as one may say, in the form of shells. The legs of an insect, for instance, are small tubes with the muscles inside. The limbs of vertebrate animals, on the other hand, have the muscle outside the bone. Invertebrates commonly have the main nerve trunk in front, or underneath, instead of at the back, and likewise often have their brains in their abdomens. Some of them, such as the grasshopper, even hear with their abdomens. But all vertebrata have the great nerve trunk at the back, contained in the spine and with a bulb on the front or upper end constituting the brain. In fact, a vertebrate animal is primarily a living spine, and all other parts of the body are in the nature of appendages. The limbs, for instance, and in the higher animals the ribs and other parts of the skeleton, are simply attached to the spine, or are offshoots from it. In the fishes these limbs take the shape of fins. In the higher developments of life they assume the form of legs.
All the higher animals, as we know, have evolved from the fishes and reptiles, and all in common possess a spine which in its fundamental characteristics is very much the same now as when it was first evolved. In other words, the spine is a bodily structure as old as the rock-ribbed hills. It has stood the test of time, and therefore must be regarded as the most highly perfected mechanical structure in the body. Its strength combined with its flexibility and its perfect adjustment as a container for the central nervous system, makes it perhaps the most wonderful structure in the body outside of the brain and the spinal cord itself. While other organs and features of the body have been changed and modified to such an extent in the various species which have been evolved that they can hardly be recognized as having a common origin, yet the spine has remained substantially the same. It is true that the spine has been shortened in many species as the result of the loss of the tail, but this means only the dropping off of a part of it and does not greatly alter its fundamental character.
The human spine, however, differs from that of other animals in respect to its suitability for the erect posture. Man is the only animal in the world who can straighten his body and stand perfectly erect. Even the anthropoid apes when standing on their feet assume a somewhat oblique position. The vertebral column in animal life was first developed on the horizontal plane, and so, naturally, when man was evolved and adopted the erect position, certain modifications of the spine were necessary. A new strain developed on the vertebral column which was due to the new position, and so there came about certain changes in its structure. For one thing the spine became less flexible and gained in stability, especially in the lower sections. The sacrum, for instance, is created by the fusing together of several vertebrae into one bone for the sake of greater strength and stability. The sacrum in man is much broader than in animals, for it must supply solidity and strength to the lower part of the spine, thus adapting it to the vertical position, and in the same way the lower vertebrae generally are comparatively broader and heavier, gradually decreasing in size and tapering toward the top of the spine like the trunk of a tree.
This particular feature of the human backbone is worthy of special consideration because it is the upper section of the spine, in which the vertebrae are smaller and tapering, that weakness is most likely to exist. It is in this upper section of the spine that strength is most needed in order to preserve it in perfect alignment, and keep the body properly erect. And it is for this reason, as the reader will see, that exercises affecting the upper parts of the spine are most important. Therefore I have given them special attention.
The curves in the human spine are characteristic, illustrating in another way the modification of the vertebral column that has been made necessary by the erect position. The new-born baby has a backbone that is almost straight, and in this respect it bears a strong resemblance to that of many of the lower animals. The typical human curves, however, begin to take form as soon as the child learns to sit up, and they become more marked as he learns to walk and run. These curves are essential to maintaining the balance of the body in the erect position.
There are really three curves in the human backbone, the cervical curve being convex, the dorsal concave, and the lumbar convex, when each is regarded from the forward aspect. If we consider the sacrum and coccyx, there is really a fourth curve, this being concave, although in animals generally the coccyx curves backwards and is extended to form the tail. In some of the lower animals the spine is nearly straight, while in some cases it virtually forms a complete arch from one end to the other.
These curves of the spine are generally more marked in the civilized white races than among the black and savage races, and as a rule they are more pronounced among women than among men. For instance, in comparing the sexes we find that in a woman the lumbar curve is more marked and extends slightly higher than in a man, and that the broad sacrum characteristic of the human race is even wider, being thus adapted to the broader hips and wider pelvic cavity of the child- bearing sex.
Now, the maintenance of a strong and erect spine, and especially of the normal curves of youth is most important. With the weakness of advancing age the curves, particularly in the upper part of the spine, tend to become more pronounced. The more accentuated these curves are the greater is the weakness of the spine and of the muscles of the back that is indicated. It is said that a man is as old as his spine, since the deterioration of the spine means the loss of elasticity and supporting power in the disk-like cartilages between the vertebrae, and also the loss of strength in the muscles and ligaments of the back which tend to hold the spinal vertebrae in place. It is usually found that vigorous old men who are mentally and physically active at eighty or ninety years are those who have maintained an erect bearing until late in life, who have kept their spines straight and strong instead of allowing them to bend over and double up. In other words, the deterioration of the spine means a general loss of bodily vigor and a decline in the nervous energy or vitality.
With the flattening down of the cushiony disks or cartilages between the vertebrae, and also with the dislocation even in the slightest degree of these vertebrae, there is brought about more or less interference with the free action of the spinal cord itself and of the spinal nerves. The pinching of these nerves naturally interferes with the
supply of energy to the organs controlled by them, and causes more or less serious derangement of the bodily functions. If one can keep his spine straight and strong the central nervous system will likewise be healthy and vigorous, and all organs will be supplied with a normal amount of energy and vitality.
The special exercises for the spine which I have recommended for years have the general effect not only of maintaining the proper alignment of the vertebrae and thus promoting the health and welfare of the central nervous system, but also of strongly stimulating the nervous system, and thus toning up the entire bodily organism. All movements of the spine, whether of a twisting or bending character, naturally influence the spinal cord and the spinal nerves in a mechanical way. The result is something akin to a massage of these nerve structures, and in this way, as I have long contended, it is possible directly to stimulate the source of energy and vitality. I am convinced for this reason that muscular exercise for the back is infinitely more important than for any other part of the body, important as it is for all parts. If one has only very little time each day to devote to exercise, then it would pay him best to give that time to movements which will strengthen and stimulate the spine.
The various movements that I am presenting in this chapter have been devised especially to accompany the hot-water regimen that will be described in the following chapter. They are intended not only to add to the strength of the backbone itself, but have been devised with a view to stimulating to an unusual degree the nerve centers located in the spine. As I have already said, the spinal nerves control the functions of all the vital organs, and when the activity of these organs is stimulated not only through increased nerve force but also by the increased supply of blood that will result from the hot water- drinking regimen referred to, then indeed will we have a combination of stimulating forces which will bring about vital changes, in very many cases, little short of astounding in character.
Each of these exercises should be taken until a feeling of fatigue has been noticed, after which you may rest a few moments, breathing fully and deeply with expanded abdomen. You should then be ready to begin the next exercise. There is little danger of soreness from taking these movements when they are combined with hot water-drinking, as recommended in Chapter VI, The water seems to cleanse the tissues of the waste products which ordinarily cause soreness when one begins the practice of exercises to which one is not accustomed. If one possesses unusual vigor, then to the exercises illustrated in this chapter may be added those movements appearing in the following chapter. All of the exercises given in this chapter are designed exclusively for the stimulation of the spine and nerve centers. Those illustrated in the next chapter are intended chiefly to accelerate the circulation throughout the chest, arms, legs and body as a whole, for when going through a treatment of this character it is naturally advisable for one to arouse the activity of all the functions associated with tissue changes throughout all parts of the body.
Although these exercises have not been devised especially for corrective purposes in cases of spinal curvature, yet they will be of exceptional value in all such cases, or at least, where there is no radical mechanical deformity of the vertebral column. Curvatures may be prevented in all cases, or may be decreased, or even reduced entirely by exercise of this type. Incidentally the practice of exercises for improving the spine and giving one the proper erect carriage has a very marked effect upon the chest. An erect position always means expanded chest walls, with plenty of room for the free activity of the heart and lungs.