The Muscles of the Leg and Foot
The first series of the movements just described is effected, mainly, by three muscles. Of these one (A, fig. 12) raises the heel while the other two (B, fig. 12, and C, fig. 13) raise and support the ankle. The muscle which acts upon the heel is one of the largest and most powerful in the body; and well it may be, for in raising the heel it has to raise the whole weight of the body. Its fibres, accumulated at the middle and upper part of the leg, form the “calf;” below they taper into a thick tendon (a) connected with the hinder extremity of the heel-bone, and called the Tendo Achillis. The name, it need scarcely be said, refers to the tale of Thetis holding her son Achilles by this part when she dipped him in the river Styx. Her hand prevented the part from coming in contact with the water; and so it did not partake of the invulnerability which was conferred upon the rest of his body by the immersion. We read, accordingly, he was finally killed by a wound in the heel2.
The other two muscles (B and C) also descend from the leg and terminate in tendons (b and c) which pass, one on either side, behind the projections (D and E) which we call respectively the inner and outer ankle, to the inner and outer edges of the instep. They assist to raise the ankle, and support it so as to prevent its swerving from side to side; and they permit it to play to and fro upon them, like a pulley upon ropes running under it, in a safe and easy manner. The inner (b, fig. 12) of the two tendons passes, as before mentioned, beneath the head of the key-bone, and adds greatly to the strength of the arch. It is, moreover, the chief agent in effecting the two movements which are associated with the elevation of the heel, viz. the turning of the sole inward and the flexion of the foot.
The second series of movements—the raising the toes, the turning the sole downwards, and the straightening the foot—are effected by two muscles (F, fig. 12, and G, fig. 13), the tendons (f and g) of which pass, one in front of the inner ankle, and the other in front of the outer ankle, to the respective edges of the instep. These require much less power than their opponents; and the muscles on the front of the leg are, therefore, smaller and weaker than those behind.
A question of practical interest here suggests itself. How is the balance between these antagonistic muscles maintained, and the proper position of the foot preserved? If the muscles which cause the elevation of the heel and the other movements associated with it are so much stronger than those which produce the opposite series of movements, and if, as we know to be the case, muscles are always, even when a limb is at rest, contracting with a certain amount of force, why do not those of superior power gain and maintain the ascendancy, and hold the limb in the position to which they have a tendency to draw it? And why, in this instance, are not the feet kept with the heels raised and the soles inturned and bent? The reply is, that the ill consequence suggested is prevented, and a proper adjustment between the opponent sets of muscles, in this and other parts of the body, is effected through the medium of the nervous system. That system institutes friendly relations, and compels an orderly and harmonious action of the several muscles; and it does so by frequently exerting its influence upon them, keeping them in drill, as it were, and enforcing the habit of yielding in a kindly manner to one another.
You have often observed, and perhaps wondered at, the almost incessant, semi-involuntary and, seemingly, meaningless movements of infants, especially the peculiar sprawlings out of their fingers and toes. Now these are for the purpose of keeping the different sets of muscles in practice and in order, till the will acquires a due control, when they gradually cease. They are going on before birth as well as afterwards; and when they are deficient, or when they take place irregularly, in consequence of an imperfection in the nervous system, the limbs are liable to become deformed. The feet, under these circumstances, are often drawn into the very position I have just mentioned; the sole is turned inwards and upwards, so as never to touch the ground; the heel and the toes are approximated; and the foot rests upon the ground on the outer side, or quite on the fore part, of the instep. Such a condition constitutes one of the most common forms of what is called “club foot.” Children are often born with one or both of their feet thus distorted. Happily, however, if they be submitted in time to the modern improved modes of treatment they may usually be set right. The accompanying woodcut gives a sketch of the foot of a young woman who had not the good fortune to be thus attended to.
The muscles compose the flesh or chief part of the bulk of a limb. The “calf” is almost entirely made up of the fibres of the “calf-muscle.” But at the ankle there are no muscles. As they descend the leg, all the muscular fibres disappear, and there are only tendons. These, though much thinner than the muscles, are very strong; and they are the cords or ropes by which the muscles pull upon distant parts. As they pass over the ankle they are strapped down close to the bones by means of stout sinewy cross-bands, which prevent their starting from their places when the muscular portions pull at them.
Two especial advantages result from this arrangement.
First, the lower part of the leg and the ankle are reduced in size. Thereby the resistance to the passage of the limb through the air is lessened; and when it is upon the ground, the leg is less in the way of the other foot which is swinging, to and fro, beside it. An elegance of shape is also thereby imparted. The “pretty ankle” owes much of its charm to the mode in which the tendons are disposed. How comparatively thick and clumsy would the ankle be if the tendons of the toes took the straight course represented by the line a in the drawing, instead of being bound down, as they are, to the curve of the ankle!
Secondly, the obliquity with which the tendons run to their insertions is increased by this arrangement; and the velocity of the movements to which they minister is increased also. True, a loss of strength is involved in such a disposition, but the gain in velocity is of more importance. If (to refer again to the diagram, fig. 15) the tendon ran in a straight course from the front of the leg to the great toe, the angle at which it joined the toe would enable it to act with more strength; but the movements connected with it could not be so quick as they now are.
We find in the construction of the human frame many instances in which strength is sacrificed to rapidity of movement in this and other ways. Scarcely any conceivable amount of strength, for instance, would be an adequate compensation for a loss of that celerity of movement of the hand which enables us to strike a blow and drive a nail. No wonder, therefore, that strength is here sacrificed to obtain celerity. And the same principle holds good for other parts.
The length and direction of the heel affords a good illustration of the principle of which I am speaking. When the heel-bone runs out to a considerable distance, and nearly straight, behind the ankle, as it does in some of the lower animals and in the inferior races of mankind, it presents a better leverage to the calf-muscle, which is, then, enabled to raise the ankle with a less amount of effort; but there is proportionately less velocity. Accordingly, in the more perfectly formed foot, such as we find it in the higher races of mankind, the heel-bone, instead of running out backwards, descends very obliquely, almost vertically.
In this instance, the loss of strength, which is thus incurred for the purpose of acquiring celerity in movement, is usually compensated for by the greater development of the calf-muscle. Hence the high heel and the well-developed calf go together; and, like most of the other features of good bodily formation, they are, on the whole, best marked in the nations which are endued with the highest intelligence, and which are, in this way, physically, as well as mentally, qualified to occupy the foremost places in the human family. Thus, we may mark a relation between the heel and the brain; and, as the comparative anatomist is able by the inspection of a bone to trace out the skeleton to which it belonged, so might it be possible for the human anatomist, by observing minutely the peculiarities of the heel and the other features of the foot in any particular race of men, to form some estimate of the capacity and conformation of the skull, and thereby, of the amount of intelligence.
Contrast the foot and leg of the European (fig. 16), as represented in the drawing reduced from the Farnese Hercules, with those of the Negro (fig. 17), the drawing of which was taken from a native of Sierra Leone. In the former the leg is plump and the calf well developed; the foot is compact and well arched; the heel descends nearly vertically; and the inner ankle stands clearly out and is raised high above the ground. In the Negro the leg is thinner and the calf is not so well defined; the foot is long, flat, and sprawling; the heel is more horizontal; and the inner ankle does not show clearly, and almost touches the ground.
Contrast also the outline (fig. 19) of the foot of the same Negro with that (fig. 18) of an Englishman. Both were traced upon the ground, and reduced upon the same scale. The Negro was 5 ft. 2 in. in height; the Englishman was 6 ft.; both were of the same age: yet the Negro’s foot was considerably the larger. It was 11 inches long, 3 1/2 inches across the middle of the instep, and 10 1/2 inches round the balls of the toes. Whereas the Englishman’s foot was less than 10 1/2 inches long, was 2 1/2 inches across the middle of the instep, and 9 1/2 inches round the balls of the toes. Even in this simple outline how much less shapely is the African’s foot. Some allowance must be made for the fact that the Negro was more accustomed to go barefooted than the Englishman; and the pressure of the boot or shoe has, in some degree, the effect of giving compactness to the foot.
In the native Australian the leg is commonly still more lanky, there being less calf than in the African; and in the Monkey the heel is quite horizontal, the sole is flat, and the muscular fibres of the leg are continued low down, close to the ankle, instead of being concentrated higher up; so that the leg has nearly the same thickness from the knee to the foot, and there is no calf at all. Indeed, in the Gorilla (see fig. at page 91) the circumference of the leg increases towards the ankle. Thus, the calf may be regarded as the characteristic of Man; and a well-developed calf is a characteristic of the higher members of the human species. The pride, therefore, which is felt in a well-formed leg is not altogether a senseless folly, but finds some excuse in the fact that its foundation lies deep in the laws of physiology and ethnology. It must be confessed, that the fashion which, in the last century, dictated the knee-breeches, the silk stocking, and the shoe, evinced a truer appreciation of the dignity and beauty of the human figure than do the modern investments, which quite cover up the limbs, encumbering their movements and hiding the beauty of the leg and ankle.
In the addition of the high heel to the shoe we recognise an effort to improve upon the original, by exaggerating one of the peculiar features of the human foot; but it results in a failure, as is invariably the case with such strainings after a greater perfection than nature has given. It increases the apparent height of the person and of the arch of the instep; but it throws the weight too forward upon the toes, and detracts from the length and security of the step. Moreover, by causing disuse of the elevators of the heel, it interferes with the full growth of the calf.
This is, however, a harmless piece of vanity in comparison with the monstrous efforts of the Chinese to mould the foot to their ideal by squeezing the heel and the toes together. They effect this to such a degree that (fig. 20) the heel-bone descends vertically from the ankle, the plantar arch is bent to an acute angle, and the foot is so crumpled up that all movement in it is effectually prevented, and the part is reduced almost to a mere stump. These observant and ingenious people have caught, it may be, the idea that compactness, elevation of instep, and sudden descent of heel are characteristics of the well-formed foot, and may urge that they are helping nature to perfection in the direction which she has herself indicated. But in their silly attempt at the preternatural, in this impious use, as it were, of fire stolen from heaven, they simply burn and cripple themselves, and render themselves ridiculous, and give to all other nations the much needed lesson that it is enough for man to follow as a humble imitator of his Maker’s works, and that his attempts to alter, or improve upon, any part of the wondrous design of creation will assuredly have the effect of spoiling and defacing it3.
It seems that the several races of mankind are usually rather proud of their peculiarities, and that each has an inclination to make much of, and artificially exaggerate, the points in which it differs from the others. Thus the Chinese are remarkable for the spareness of their hair and the smallness of their feet; so the men shave their heads, leaving only the pig-tail, and the women squeeze up their feet in the remorseless manner we have seen. The Singhalese, who are flat-footed, are said to consider it one of the requisites for a ‘belle’ that the soles of her feet should not have any hollow. The red Indians of America delight in staining and painting their skins of a lively red colour. The Columbian tribe of Indians increase the natural lowness of their forehead by flattening it out in infancy, and succeed in bringing about a deformation of the skull almost as remarkable in its way as is the effect of Chinese cramping upon the foot. These people also take pains to reduce the small quantity of hair upon their eyebrows, lips, and chin, by plucking it out.