Hind foot

“ The small splint bones, however, resting behind the principal bone of the foot represent those portions (metacarpals) of the second and fourth digits which extend from the wrist to the fingers properly so called, and are to be viewed as traces of a foot composed of three toes in an ancestral form of the Horse, which we shall discuss presently. In the Tapir, the hind foot is composed of three well-developed toes, corresponding to the three middle toes in man, and in the Rhinoceros both feet are provided with three toes formed of the same three digits. ”

“ The disease is confined almost exclusively to the fore feet, because of the greater weight which they support, and because the heel of the fore foot in action first strikes the ground and thus receives much more shock or concussion than the heel of the hind foot, in which the toe first makes contact with the ground. ”

“ An over-reach can only occur when the fore foot is raised from the ground and the hind foot reaches right into the hollow of the fore foot. When the fore and hind feet in this position separate the inner border of the toe of the hind shoe catches the heel of the fore foot and cuts off a slice. ”

“ With the condition confined to one fore-foot, the animal is able to get up and down with a moderate degree of comfort. At intervals, therefore, he rises to take nourishment, and as soon as his wants are satisfied again lies down.
With the disease in a hind-foot matters are not taken so comfortably. The patient finds that with each day's increasing weakness the difficulty that at first he had to raise himself with only one sound hind-foot becomes enormously increased. ”

“ It is comparatively seldom that navicular disease is found to exist in the hind feet, and the preference which it shows for the fore ones may possibly be found in the difference which exists in the conformation of the limbs. The straight fore-leg allows the weight to fall directly on to the feet, while in the hind one it is first broken and diffused in passing through the angle forming the hock, so that by the time it reaches the foot the sharp edge of concussion is removed and the foot escapes the injury which is inflicted through the straighter column in front. ”

“ The reason, of course, is that the hind-feet are carried forward in order to be placed upon the heels, while the fore are taken backwards to relieve the hind of the body-weight.
In like manner the movements of the animal will vary with the feet affected. With only the front-feet diseased the animal is, comparatively speaking, comfortable. The hind-feet take the weight, and the animal stands for long periods together, resting alternately first one fore-foot and then the other, moving often in a circle of which his body is the radius, and his hind-limbs the centre. ”

“ Soon each toe has one joint, and the inner toe becomes set off from the rest. Later, the two longer fingers show two joints, and, finally, the inner toe becomes a thumb with two joints, while each finger has three; and now the hind-foot closely resembles the hand of the higher quadrumana and man, while its fore-feet, much earlier developed, remain more animal-like, the great-toe being set off not so far from the others, but the fingers quite long. The hind-limbs are primarily much shorter than the front, but, developing faster, soon equal and afterward outgrow the others. ”

“ The extensor pedis is usually attacked by extension of the disease from a necrotic cartilage, or results from the infliction of a severe tread in a hind-foot. In this case the diseased structure has nothing between it and the articulation, the synovial membrane in one position actually lining its inner face. The result is that a condition of synovitis is easily set up, and the case aggravated by that and by arthritis.
With the flexor tendons attacked pain is always very great, and lameness is excessive. ”

“ In this case prevention may be brought about either by shoeing with a shoe whose ground surface is wholly concave, or by bevelling off the sharp border (see Fig. 110, a, p. 236) . When the tendency to overreach is not excessive, prevention may in many cases be effected by simply placing the shoe of the hind-foot a trifle further backwards than would ordinarily be correct, thus allowing the horn of the toe to project beyond the shoe. ”

“ You are likely to find the hind feet abnormally long, perhaps longer than the front feet. Lower the toes of hind feet as much as they will stand, shorten toes by rasping off as much as the foot will stand, do not touch the heels or have the inside of foot higher than the outside. Now use a light hind shoe, with side calks, the calks to be one and a half to two inches long, and tapering towards the toe of shoe. ”

“ The fore-feet, which are nearly as perfectly developed as the hind-feet, have large crooked claws, while the hind-feet are somewhat like those of a kangaroo, though not so powerful. The sole of the foot is somewhat broader and more elastic on account of a thick layer of fat under the skin. ”

“ The toe-piece is screwed into the toe of the shoe when the horse is about to be exercised, and forms a powerful point of leverage with which to stretch the contracted tendon, and the shoe, being thin at the heels, admits of this. The advantage of this form of toe-piece over the ordinary form of fixed toe-lever is that it can be removed when the horse is in the stable; while the curved point diminishes the danger of the horse hurting itself—a danger always present if it is on a hind-foot. (See also Treatment of Purulent Arthritis in Chapter XII.) ”

“ For reasons which will appear when considering the causes of the disease, the hind feet are not liable to be affected. Usually but one fore foot suffers from the disease, but if both should be attacked the trouble has become chronic in the first before the second shows signs of the disease. ”

“ The hind limb far exceeding the fore-limb in height, mainly causes the attitude of back-arching when on the ground. The fore foot is a kind of diminutive flat-nailed hand, with a proportionally short thumb, and it is hairy above, but naked below, and all the fingers have expanded cushions on their last joints. The hand is not capable of being closely clenched, and the thumb reaches only to the middle of the palm. The hind feet are large, and there is a strong great [Pg 227] toe-thumb. ”

“ In a few other families of this order, as the todies, the kingfishers, &c., the foot is called upon to assist in feeding, and we consequently find certain modifications of structure indicative of this office. In order to strengthen the foot and to secure a firmer grasp, the external and middle toes are united almost to the apex, and the strength of the hind toe is considerably increased. ”

“ In the production of opposition changes took place in the hind limbs first and most generally, since all species in which the thumb is opposed possess opposable great toes also—except in the single case of man—while many species occur in which opposition is presented by the hind limbs alone. In this adaptation of the foot to climbing three structural changes were effected—the parts of the limb became more flexible, the joints more widely separable, and the great toe, as has been said, opposed to the group formed by the remaining digits. ”

“ It is, perhaps, more common in the hind-feet than in the fore, and more often met with in heavy draught animals than in nags. The hind-feet are, of course, more open to infection by reason of their being constantly called upon to stand in the animal discharges in the rear of stable standings, while it is a well-known fact that heavy animals have their stables kept far less clean, and their feet less assiduously cared for, than do animals of a lighter type.
In a nag-horse with thrush of both fore-feet lameness becomes sometimes very great. ”

“ Difficulty in rising is greatest when all four feet are affected; is nearly as great when the hind-limbs only are in trouble, but is least when the disease exists alone in the two fore-feet.
THE COURSE OF THE DISEASE AND ITS PATHOLOGICAL ANATOMY.—As with most inflammations of any severity, so with this we may consider the pathological changes taking place in the foot under three headings: (a) The period of Congestion; (b) the period of Exudation; (c) the period of Suppuration. ”

“ This he does by throwing his weight, so far as he is able, on to the heels of the feet affected, and putting the feet slowly forward in a shuffling and feeling manner. The feet themselves give to the hand a sensation of abnormal heat, percussion upon them with the hammer is followed by painful attempts at withdrawal, while any effort we may make to remove one foot from the ground is useless, so great an aversion does the animal show to placing a greater weight upon the opposite foot.
According as the front-feet alone, the hind-feet alone, or all four feet are affected, the symptoms will vary. ”

“ That the close attachment of the plantar aponeurosis to the navicular bursa, and the nearness of both to the pedal articulation, render penetration of a synovial sac or a joint cavity extremely likely.
2. That there is always great difficulty in maintaining strict asepsis of the foot, more especially if it is a hind one.
On the other hand, it may be argued that equal risk to the patient is run in allowing him to remain with a disease (and that disease a progressive one) of the structures so closely antiguous to the navicular bursa and the pedal articulation. ”

“ The cartilages of the fore-feet are thicker and more extensive than those of the hind.
2. THE PLANTAR CUSHION on FIBRO-FATTY FROG.—Composed of a fibrous meshwork, in the interstices of which are lodged fine elastic and connective fibres and fat cells, this wedge-shaped body occupies the space between the two lateral cartilages, the extremity of the perforans tendon, and the horny frog. It offers for consideration an antero-superior and an infero-posterior face, a base, an apex, and two borders. ”

“ The main difficulty in using either lazo or bolas is to ride so well as to be able at full speed, and while suddenly turning about, to whirl them so steadily round the head, as to take aim: on foot any person would soon learn the art. One day, as I was amusing myself by galloping and whirling the balls round my head, by accident the free one struck a bush, and its revolving motion being thus destroyed, it immediately fell to the ground, and, like magic caught one hind leg of my horse; the other ball was then jerked out of my hand, and the horse fairly secured. ”

“ High and narrow heels give an insecure hold of the ground, and throw the weight, which ought to be distributed over the sole, forward on the front part of the base of the toes. This unnatural position, besides rendering the risk of sprained ankles much greater, stretches the fibrous bands which bind the various and complicated bones of the instep into a beautiful arch, strong yet springy. The tough fibres yield, the foot flattens, elasticity and grace of movement disappear to a large extent, and aching pains are complained of. ”

“ The feet are usually cold and sweat excessively. The gait is slouching, and there is a want of spring and elasticity. The lengthening of the foot results in the tendons, especially the flexors, being too short, hence hammer-like contraction of the toes may be brought about. The boots, after being worn, show a bulging of the instep towards the sole, greater wearing away of the sole along the medial border, and, when there is stiff great toe, an absence of the transverse crease on the dorsum opposite the balls of the toes. Footprints may be obtained by wetting the soles of the feet. ”

“ The most common form by far is the inverted, usually denominated varus, in which the patient walks upon the outer ankle, the great toe being directed inwards and upwards. The muscles of the calf and the adductors of the foot are contracted, and hence there is not only elevation of the heel, but a peculiar inward twist of the foot, analogous to supination of the hand. This alteration occasions the most serious impediment to progression, and when it reaches its highest point imparts a most disagreeable aspect to the affected limb. ”

“ The way of their prevention is already made plain, but to remove the disfigurement after it has become a settled thing is a much more difficult matter. The toe must be forced back to its former position, and kept there by a steady, constant pressure, and the parts be allowed time to gradually re-adapt themselves and grow fixed in their proper shape. The straightening of the toe will allow the bones to come nearer together at the joint, and this, when not sore, may perhaps be pushed back slightly, toward the middle of the foot, by the pressure of a narrow boot. ”