Pronation

“ It is first of all necessary to say that in man, when the fore-limb hangs beside the body, and the dorsum of the hand looks backwards, the two bones of the forearm are parallel, and that this position is known by the name of supination. It is also necessary to remember that there is another attitude, in which the radius, crossing the ulna, and carrying the hand with it, displaces the latter in such a way that the palmar surface looks backwards. This second position is known as pronation. ”

“ If properly performed, in a tolerably healthy subject, the surgeon should not be satisfied with any results short of almost perfect restoration of motion in the joint. Flexion and extension to their full extent, with a very considerable amount of pronation and supination, are to be expected, with proper care, in a patient of average intelligence. ”

“ A hollow is felt below the end of the humerus, on the outer and fore part, and there is a corresponding prominence behind; the head of the bone is found unnaturally moveable on rotation, and this motion is difficult and painful; the arm is extended, presenting a twisted appearance, and flexion is very limited. Extension is to be made, along with pronation.
Sometimes the radius is displaced forwards. The coronoid process of the ulna is occasionally broken off; there is no deformity during flexion of the elbow, but when the limb is extended, the olecranon is drawn upwards. ”

“ The position of the upper limb is typical: the arm and forearm hang close to the side, with the forearm extended and pronated; the deltoid, spinati, biceps, brachialis, and supinators are paralysed, and in some cases the radial extensors of the wrist and the pronator teres are also affected. The patient is unable to supinate the forearm or to abduct the arm, and in most cases to flex the forearm. He may, however, regain some power of flexing the forearm when it is fully pronated, the extensors of the wrist becoming feeble flexors of the elbow. ”

“ If the dislocation is outwards, the extension is to be made as above, but the thong at the perineum is to be passed by the opposite parts, I mean the groin and clavicle. The surgeon is to propel the limb from without inwards, the lever being fastened into one of the furrows formerly prepared, and an assistant fixing the sound nates that the body may not yield. In dislocations forwards, the patient being stretched, a strong man is to apply the palm of the right hand to the affected groin, and press down with the other hand, so that the depressing force may be exerted downwards, and to the knee. ”

“ The upper part of the trunk is known as the thorax, or chest, and the lower part as the abdomen. The portions of the trunk to which the arms are attached are the shoulders, and those to which the legs are joined are the hips, while the central rear portion between the neck and the hips is the back. The fingers, the hand, the wrist, the forearm, the elbow, and the upper arm are the main divisions of each of the upper extremities. ”

“ For if the accident be recent and the patient young, we may sometimes succeed in reducing the limb by grasping and rotating the thigh this way and that. When the dislocation is inwards we may sometimes accomplish our purpose by bending the limb at the groin inwards frequently and strongly. If the dislocation does not yield to these means we must have recourse to extension, first with the hands, certain assistants grasping the thigh and leg and pulling the limb downwards, while others grasp the body at the armpits and pull upwards. ”

“ Conditions of Impaired Mobility of Joints.—There are four conditions of impaired mobility in joints: rigidity, contracture, ankylosis, and locking. Rigidity is the fixation of a joint by involuntary contraction of muscles, and is of value as a sign of disease in deep-seated joints, such as the hip. It disappears under anæsthesia.
Contracture is the term applied when the fixation is due to permanent shortening of the soft parts around a joint—muscles, tendons, ligaments, fasciæ, or skin. ”

“ When the hip-joint has been dislocated, and long delay has made it impossible to restore the parts to their proper places, the head of the thigh-bone, imbedded in the surrounding muscles, becomes fixed in its new position by attachments of fibrous tissue, which afford support enough to permit a halting walk. ”

“ Neither does the limb at the groin admit of flexion as in the sound limb, and the head of the bone is felt at the perineum too prominent. These, then, are the symptoms attending dislocation of the thigh inward. ”

“ They are constantly bowed over their task, performing a rhythmic, alternating movement of flexion, extension and torsion of the trunk upon itself, while at the same time there is a slight undulation in a backward and forward direction, accompanying the rising and falling of the arm holding the hammer. These movements of extension and flexion of the trunk involve the whole vertebral column, while the pelvis remains practically motionless. ”

“ The bones are fastened together at the movable joints by stout sheets or bands of connective tissue known as ligaments. These hold them in place very securely and as additional support the muscles which surround every joint help to prevent the bones from slipping out of place. At nearly all the joints of the body the combined action of ligaments and muscles is sufficient to guarantee the joint against dislocation ”

“ If the body, when projecting under the integuments, be gently compressed, it yields to the pressure, changes its situation, and, according to the impression it has received, moves either to the internal or the external side of the joint, or reciprocally from one side to the other, passing also behind the rotula, behind the inferior ligament, or sometimes behind the tendon of the extensor muscles. ”

“ In considering the structure of the human neck, of which the centre is the vertebral column, composed of several bones, the connexion of which forms a series of sockets, so that there can be no hitting of a joint, it is not possible to ensure a quick and perfect separation by any means which shall be liable to moral or physical variations in strength or dexterity. ”

“ The ultimate position of the limb and degree of shortening will depend much upon the extent to which the head and neck of the femur is destroyed, upon the inclination of the pelvis, and also upon the portion of the acetabulum which is most diseased. The joint becomes tender, the slightest motion causing much pain, and the parts around appear swollen. The patient retains the limb in the most comfortable position, and it is generally bent upon the pelvis and inverted. ”

“ Not only the articulations themselves must be so modified as to bear greater stress, but also the numerous ligaments which hold the parts of each in place. Nor can the bodies of the bones remain unstrengthened; for if they have no more than the strengths needed for previous movements they will fail to bear more violent movements. Thus, saying nothing of the required changes in the pelvis, as well as in the nerves and blood-vessels, there are, counting bones, muscles, tendons, ligaments, at least fifty different parts in each hind leg which have to be enlarged. ”

“ Whatever may be the cause of the superiority of the flexors, the fact cannot be doubted. 1st. In hysterical convulsions, in those of infants, in all the spasmodic motions in which the will has no part, the contractions take place much more in the direction of flexion than in that of extension. 2d. In old people the flexors finally become superior to the extensors; for example, the fingers and toes are almost uniformly bent. ”

“ The pedicles extend back from the body on either side and support two broad plates of bone, the laminæ, whose juncture at the back completes the spinal foramen for the passage of the cord. At their juncture is the spinous process, which can be felt beneath the skin, while the transverse processes project from the juncture of the laminæ with the pedicles. All the processes are for the attachment of muscles that move the spine. The body is formed of cancellous bone with a compact layer outside. ”

“ If no means are taken to replace the bone, and painful feelings subside along with the swelling, the limb remains long useless, and is the seat of occasional lancinating pains, but at last motion and utility are to a certain extent restored by the formation of a new joint—the head of the bone, and the parts on which it rests, mutually accommodating themselves to each other, by degrees, and permitting a limited extent of motion. ”

“ To preserve the erect posture, for instance, we see that certain weights have to be neutralized by certain strains: each limb or other organ, gravitating to the Earth and pulling down the parts to which it is attached, has to be preserved in position by the tension of sundry muscles; or in other words, the group of forces which would if allowed bring the body to the ground, has to be counterbalanced by another group of forces. ”

“ If the joints of the jaw, shoulder, elbow, knee, finger, &c., can be replaced, the same, they think, must be true of all parts, nor can they give an account of why the femur cannot be put back into its place.... They might have known, however, that from the head of the femur arises a ligament which is inserted into the socket of the hip bone ... and if this ligament is once ruptured the thigh bone cannot be retained in place’. ”

“ The joints, or rather the ends of the bones which form them, display also in their configuration another use. The nerves, blood-vessels, and tendons which are necessary to the life, or for the motion of the limbs, must, it is evident in their way from the trunk of the body to the place of their destination, travel over the moveable joints; and it is no less evident that in this part of their course they will have from sudden motions, and from abrupt changes of curvature, to encounter the danger of compression, attrition, or laceration. ”

“ In bilateral cases the trunk appears well grown in contrast to the short lower limbs, the hollow of the back is exaggerated, the abdomen protrudes, the perineum is broadened, and the buttocks are unduly prominent. The gait is waddling like that of a duck, the trunk lurching from one side to the other with each step. In untreated cases the deformity and disability become more pronounced as the capsular and round ligaments are further stretched, the shortening and limp become more marked, the patient is easily fatigued by walking or standing, and is usually unfitted for earning a living. ”

“ Hence, to make larger horns of use, additional sizes must be acquired by numerous bones, muscles, and ligaments, as well as by the blood-vessels and nerves on which their actions depend. On calling to mind how the spraining of a single small muscle in the foot incapacitates for walking, or how permanent weakness in a knee-ligament will diminish the power of the leg, it will be seen that unless all these many changes are simultaneously made, they may as well be none of them made—or rather, they would better be none of them made ”

“ Rigidity.—The pain produced by movement of the diseased portion of the spine causes reflex contraction of the muscles passing over it, and the affected segment of the column is thus rendered rigid. If the palm of the hand is placed over the painful area while the patient attempts to make movements of stooping, nodding, or turning to the side, it is found that the vertebræ implicated move en bloc instead of gliding on one another. ”

“ The bones which make up the lower part of the spine are much larger than those at the top. Little soft cushions are placed between all these bones, something like India-rubber. These cushions are to keep the body and brain from being jarred, just as the springs in our carriage help you to ride easily. They also help us to bend the body backward or forward as we choose. You see if the spine was one long straight bone we could not bend at all. If we keep bending over while walking or working, after a time the cushions will get used to that position and we shall have a bad figure. ”

“ Movement of a section of the spine composed of several vertebrae is not, in the true sense, an Adjustment. It is the single vertebra which must be moved.
The movement should be one calculated to bring the vertebra to its normal position in the most direct manner possible. Such a movement should be used as will reverse the direction of the forces which subluxated the vertebra. It should be applied to the transverse or spinous processes, or to the lamina, as is sometimes done in the case of the Atlas, according to the kind of subluxation. ”

“ The position of the trunk, spine and buttocks is most essential. In extending the spine the men must feel that the trunk is being stretched up from the waist until the back is as straight as it can be made. ”

“ When there is a small sub-luxation of many vertebræ together, the distortion occasions a circular flexure of the spine, and in this case some are apt to be deceived, and take it for a complete dislocation of one spine, whereas a complete dislocation of one spinal vertebra does not produce a circular but an angular flexure of the spine, which is attended with more danger. ”