Let us first examine the question of chest development. The respiratory movements— their rate—their amplitude—are determined by the condition of the blood in the lung. The harder the muscles work the greater is the volume of impure blood which reaches the lungs and the greater must be the chest movement to supply the respiratory exchange. In children the best respiratory exercises are obtained by allowing them to run in play, to contest in games. The condition of the blood thus produced will stimulate the free respiratory movements and a natural development of the chest. No artificial breathing exercises will improve on Nature's mechanism. When men and women lead sedentary and quiet lives their lungs are partly shut down; the respiratory system works at less than half its capacity. It is important that at one period of the day at least the lungs should be tested to their full power, for if we do not use them occasionally at their full capacity, then our ability of responding to an effort will certainly be lost in time. The true test for our chest and lungs is : are they equal to meet the demand made on them by physical efforts ?
If we examine men and children closely we shall see that no two individuals use exactly the same movements of the chest in breathing; our respiratory movements vary as much as our handwriting. Both can be improved; but there is no absolute ideal; each must be improved or corrected according to its type.
In recent years the writer has had opportunities of examining the greatly expanded chests of men who were ardent pupils at schools of physical culture. In every case the respiratory movements differed in type from those in men of corresponding age who were in fit condition, but had not gone through a special training. When a breath is taken by a normal man it is usual to see the upper wall of the abdomen—the epigastric region—swell forwards under the pressure caused by the descent of the diaphragm, and the viscera under it. In those with specially expanded chests this movement is absent; the diaphragm in those pupils instead of depressing the viscera is held up by them and exerts its strength in lifting the whole chest upwards. The greatly expanded chests do not indicate respiratory capacity, for it is seen that the artificial expansion of the chest has been obtained by elevating the ribs to an inspiratory position. In normally formed chests the ribs are placed obliquely, sloping forwards and downwards. When a breath is taken the capacity of the chest is increased by raising the ribs to a position which is nearer the horizontal. In specially, but wrongly, trained men the ribs, even during expiration, are maintained in an inspiratory position, the respiratory capacity of the chest being thereby limited. When these expanded chests are lighted up by means of X-rays the heart is seen to be big and hypertrophied, the lungs are more voluminous than they should be in healthy young men. Such pupils are artificially overtrained ; when the exuberance of youth is over they will fare worse in life than those who have kept themselves naturally fit. The lungs are really delicate and complex structures, and the fact cannot be overemphasized that they can be injured by over-expansion quite as readily as by compression of the chest. So far as concerns the form of chest our ideal must not be the prominent expanded type so often portrayed on the posters of the professors of physical culture.
Unless the muscles of the back are kept in use in the young the spinal column is certain to develop irregular and injurious curvatures. We have already pointed out that in the erect posture, whether seated or standing, all the muscles of the spine are in action. Continuous action soon produces fatigue. The child, seated at the school desk, quickly discovers how the sense of fatigue may be relieved. The weight on the spine is relieved by inclining the head until it is supported by the arm flexed on the desk. Further ease is obtained by allowing the body to bend sideways and obliquely, for in this manner the side joints of the vertebrae come to rest on each other and thus the muscles are relieved. In a short time the bones and muscles accommodate themselves to the assumed posture; only special exercises and great care will prevent spinal deformities from becoming permanent. Modern teachers are well aware of the danger of keeping their pupils seated or standing for a long lesson; they rest their pupils by giving them exercises. The natural exercises are those of play—running, jumping, climbing— all forms of active games.
In every healthy individual there must be a correspondence between the size of the heart and development of muscles. Modern physiologists are keenly alive to the part which muscles play, not only in using the blood but also in forcing it back to the heart. Normal chest movements also assist the circulation. It is, therefore, evident that those movements of the body used as morning exercises—flexion and extension of the body, movements of the limbs—are really means by which we can exercise both our hearts and lungs. The greater the current of blood forced towards the chest the greater must be the activity of heart and lungs.
There is one aspect of muscular and breathing exercises which is often overlooked. Right exercises should also improve our control of muscles ; no muscle acts by itself ; it is always acting against an opponent.
When the index finger is bent not only are the bending muscles in action but so are the extending ones. From beginning to end of the act the mind automatically controls or balances the one set against the other. Teachers of singing, as the writer learned from the well-known treatise on singing by Mr. Shakespeare, are well aware of this. They strive to teach their pupils to balance and control their respiratory movements; from the point at which inspiration begins to the point at which the following expiration ends, both muscles of expiration and inspiration are in action, and at every phase of the act are under not a conscious but an automatic control. In learning to sing the control of the muscles is at first conscious; by practice it becomes unconscious.
It was the writer's intention to discuss what may be termed the ideal form of the human body; the subject, however, is too complex to be dismissed in a paragraph, and must be alluded to only. Artists of all ages have striven to shape their ideal of the human figure so that the head, the neck, the body and extremities bear a definite relationship to each other. The height of the head is accepted by most modern artists as a standard ; French artists think that the height of the head, measured from the level of the crown of the head to the level of the chin, with the model's eyes directed forward in a horizontal plane, should equal one eighth or 12.5 per cent, of the stature. Anthropologists find that the head is about 13 per cent, of the average male stature, and 14 per cent, of the average female stature, while in a baby at birth in place of being one-eighth it is almost a fourth (23.5 per cent.) of the total height of the body. The ancient artists of Egypt and Greece constructed the ideal human frame so that the stature was 7 1/2 or 7 2/3 heads in length—thus conforming to the proportion which anthropologists have found to be true of modern man. It is quite certain that no artist or medical man has ever seen a human body which conforms in every detail to the absolute ideals which have at various times been postulated. The ideal is really a composite and imaginary figure and the ordinary man and woman need not be disappointed if in the shape and proportion of their bodies they fall far short of the classical ideals. After all the true test of the body is how it stands the wear of time and the work of life; the best of health may be sheltered within a rugged, ugly body. What one may well envy is the easy pose, the well-balanced action of the muscles which characterize such classical figures which are really beautiful.