Calf muscle

“ The far larger and more important thigh muscles and calf muscles, the great muscles of the trunk and chest, have perhaps in some of these systems no more work to do, when added together, than the muscles of the arm alone. ”

“ A good functional result is usually obtained by relaxing the calf muscles and fixing the foot in the position of extreme plantar flexion with the knee flexed, but in some cases it is advisable to peg the fragments, either through the skin or after exposing them by operation. ”

“ The calf muscles are frequently painful and excessively tender and somewhat swollen or infiltrated; the hamstring tendons or the tendo Achilles may be sore and slightly swollen and the site of slight subcutaneous hemorrhages. ”

“ When the fore limbs are fully extended, on the contrary, the shoulder blade is extended forward on the smallest and narrowest part of the chest, the arm bone with its muscles is in great part applied against the side of the back part of the neck, and the forearm is continued forward by the side of the head so that the nose lies between the knees. In this natural presentation the presenting body of the calf forms a long wedge or cone, the increase of which is slow and gradual until it reaches the middle of the chest. ”

“ After leaving the abdominal cavity it gives branches to the accessorius, the obturator, and, the pubio-femoral, or adductor longus muscle.
The crural plexus gives off another large nerve trunk which extends downward. Shortly after emerging from the plexus it gives off a muscular branch to the ilio-femoralis, or gluteus medius muscle. It then passes between this muscle and the shaft of the femur, to the inner posterior surface of the thigh, and to the inner surface of the knee. It gives off a branch to the structures of the knee. ”

“ In woman it is generally less curved, smoother, and more slender than in man, and as bone is rough when the muscles attached are powerful, the right clavicle, being used more, is generally rougher and thicker than the left. Among the muscles attached are the large neck muscle, the sterno-cleido-mastoid, whose tendons form the presternal notch, the trapezius, the pectoralis major, and the deltoid. ”

“ It is only by reason of the homology of situation with the corresponding muscle in man that we give the name under which we are studying it; indeed, its structure is different, for it does not present the long, broad, aponeurotic tendon which, in its superior part, characterizes this muscle in the human species.
It arises above from the inferior surface of the ischium, and from the tuberosity of the same bone. In the pig, and especially in the horse, it passes further upwards, to arise from the aponeurosis of the coccygeal muscles. ”

“ In the development of the calf, as in after life, the muscles are subject to cramps, and in certain cases given groups of muscles remain unnaturally short, so that even the bones grow in a twisted and distorted way. In one case the head and neck are drawn round to one side and can not be straightened out, even the bones of the face and the nose being curved around to that side. In other cases the flexor muscles of the fore legs are so shortened that the knees are kept constantly bent and can not be extended by force. ”

“ Certain slight differences as to the muscles first affected are observed, but it is practically always the homologous muscle (the physiological action of which more nearly resembles the human muscle) which is the one to be affected in the animal, not the anatomical homologue. Thus, for instance, in the cat the spinal muscles, and particularly the quadriceps extensor, is the muscle which is first affected through the medium of the anterior crural nerve. ”

“ This gives the muscle greater play than in us, and enables it to lift, more slowly perhaps, but more efficiently, for the arm-bone between the joint and the place where the muscle is attached, is the long arm of a lever which is shorter in man. Below the globular head of the arm-bone is the shaft or cylindrical part of the bone which gives origin to the three-headed muscle called triceps, and is covered by the two-headed one (biceps) already mentioned, besides the deltoid. ”

“ Musculus plantaris (Fig. 5) .—Small and slender, this muscle lies on the posteromedial surface of the crus, beneath the pars interna of the m. gastrocnemius and originates by fleshy fibers from the posteromedial surface of the proximal end of the tibia immediately distal to the internal articular surface. The belly extends approximately one-sixth of the way down the crus and gives rise to a long, slender tendon that inserts on the proximomedial edge of the tibial cartilage. ”

“ The muscles of the front thigh have a most intimate connection with those already mentioned; and, for ordinary purposes, a fair development of them is more necessary than of those below the knee. In common walking, for instance, while the calf gets something to do; the thigh gets far more, especially when the step is low and flat, and the heel never raised far from the ground. A man will often have large and strong thighs; and yet but indifferent calves. ”

“ Another exercise for the same muscles, which can also be learned in a moment, and a little of which will suffice at first, is running on the toes, or, rather, on the soles and toes. Here the whole weight is held by, and pushed from, first the muscles of one calf, then of the other. ”

“ To correct the deviation of the hind limb is, however, very difficult, as the limbs themselves are out of reach and can not be used as levers to assist. If nothing can be done by pushing the body of the calf back and rotating it and by pressure by the hand in the passages, the only resort appears to be to skin the calf from the shoulder back, cut it in two as far back as can be reached, then push the buttocks well forward into the womb, bring up the hind feet, and so deliver. ”

“ The amount of variation reported by a worker depends in large part on the degree of variation that he considers significant.
[Pg 447]
Individual variation in the muscles and in the nerves will be discussed separately; that of the muscles (excluding innervation) will be considered first.
Muscles
Considering the number, rather than degree, of variations, the most variable muscles are: Mm. flexor digitorum longus, obturator, caudofemoralis, and extensor hallucis longus. The first-mentioned muscle exhibits 14 different variations in the specimens studied. ”

“ The Muscular System of Farm Animals. —The muscular system is too elaborate, the number of muscles too great, and their modifications for different purposes too complex for consideration in detail in the present volume. All muscles are either striped or unstriped (as examined under the microscope) , according as they are under the immediate control of the will or not. The heart muscle forms an exception, for it is striped though involuntary. The essential characteristic of muscle fibers is contractility, which they possess in high degree. ”

“ The muscles which we find there are, consequently, more or less numerous. In the dog and cat they are: a portion of a muscle which we do not normally meet with in man—the omo-trachelian—then in a decreasing extent: supraspinatus, levator anguli scapulæ and splenius.
In the pig: the omo-trachelian, supraspinatus, and the terminal portion of the sterno-prescapular—the anterior part of the lesser or deep pectoral muscle. ”

“ These are the most judicious species of manufactured calf-skin; like their great “godfather,” they are perfect as a whole; from the binding at the top to the finish at the toe, there is a beautiful unity about their well-conceived proportions: kindly considerate of the calf, amiably inclined to the instep, and devotedly serviceable to the whole foot, they shed their protecting influence over all they encase. They are walked about in not only as protectors of the feet, but of the honour of the wearer. ”

“ A fourth muscle exists, which veterinary anatomists include in the study of the three portions of the triceps which we have just been discussing, in giving it the name of small extensor of the forearm. But, as this muscle is no other than the anconeus, and as, in human anatomy, we describe the latter, according to custom, in connection with the forearm, it is when on the subject of the latter that we will concern ourselves with it. ”

“ The first branch, sometimes large, sometimes small, passes to the lymphatic gland in the hollow of the shoulder, and to the adjacent muscles; it supplies the clavotrapezius, acromiotrapezius, levator scapulæ ventralis, splenius, occipitoscapularis, and rhomboideus. A second branch passes between the subscapularis and supraspinatus muscles, dividing into various branches which supply the muscles named. The third branch pierces the supraspinatus muscle, just craniad of the acromion process, and ramifies in that muscle. ”