Muscle weakness

“ And as weakness of muscle is attended with unsteady, irregular, and sometimes even spasmodic action of its fibres, so it is with weakness of mind. Its efforts are fitful, and it is easily thrown off from its balance. ”

“ It has been stated, that the excessive use of the muscles, as much as their inactivity, tends to weaken them. Nothing is more painful, than the keeping a muscle constantly on the stretch, without any relaxation [Pg 133] or change. This can be realized, by holding out an arm, perpendicularly to the body, for ten or fifteen minutes, if any one can so long bear the pain. Of course, confinement to one position, for a great length of time, tends to weaken the muscles thus strained. ”

“ The muscle-engine, in like manner, deteriorates if it is allowed to stand idle. Sometimes this occurs in disease. In paralysis the limb cannot move, and the inactive muscles waste, become thin and flaccid, and undergo curious molecular changes, converting the muscular matter into fatty-like particles. ”

“ When the fibres of which a muscle is composed have become thus altered by fatty degeneration they become softer according, to the amount of it; they are more easily torn and may even tear across when the muscle is being used during life. The more a muscle is thus degenerated the weaker it is, because it contains less muscular substance and more fat. Not only do the heart and other voluntary muscles thus degenerate, but those of the arteries also. ”

“ To this we may attribute pallor, ill-health, and affections of the chest. All the bones are more or less under the command of the muscles, and in such a case as that which we are supposing, it is the weakness of the muscles of the back that has caused the deformity; and, as a natural consequence, the exercise of those muscles will restore their healthy action, and with it the figure to its natural position.
As a general rule, one arm is stronger than the other, and requires a separate exercise to restore the equilibrium ”

“ Infantile paralysis, which often appears suddenly, muscular atrophy, which develops slowly, progressive and chronic atrophy of the muscles, are also forms of muscular disease, combined with destruction of the accompanying nerve tissue.
A special group of muscular diseases consists of amyloid (fatty) degeneration of vital muscle substance, as for instance of the heart, the kidneys, the liver. These are also caused by faulty composition of the blood, which does not feed the muscles with the substances required and thus causes them to degenerate by developing too much fat. ”

“ If the nerves which supply a limb are totally destroyed, it shrinks with extraordinary rapidity, although the main blood supply remains perfect. At the same time a limb may be paralyzed as to motion and yet undergo but little wasting, because certain nerve fibers (called trophic, because they have to do with nutrition) are left intact. In bedridden patients, again, in spite of a total want of exercise, the muscles often do not shrink in any great degree. Hence we see that nervous currents or impulses may influence the growth of a muscle apart from actual exercise. ”

“ Perhaps you have seen the leg of a fowl cut off at the joint, and know if you take hold of the strong cords you can move the toes up or down. So the muscles and tendons move in our feet [Pg 42] and hands in the same way. Every step we take, one muscle lifts the toes in front, and another pulls up the heel behind.
If a person sits still much of the time, he will have weak, small muscles, because he does not use them. That is one reason why people are so very weak after being ill. ”

“ If the injury be really to the nerves which control the muscles, as is generally the case, the matter is more difficult. The muscle swells, but this is primarily due to the overstrain of the nerves in the sudden effort they make to bear a crushing load on the muscle. The pain is from pressure in the swelling, and also from inflammatory action. ”

“ The separation of the nervous influence and the muscular irritability, although it has led to many highly instructive speculations, is not without its 229 difficulties, when viewed with reference to the Idea of Vital Power. If the irritability of each muscle reside in the muscle itself, how does it differ from a mere mechanical force, as elasticity? But, in point of fact, it is certain that the muscular irritability of the animal body is not an attribute of the muscle itself independent of its connexion with the system. ”

“ The restriction of a healthy muscle causes it partially to lose its functioning ability, and habitual restraint and unnatural pressure brought to bear upon the muscles of the trunk result in local congestion and in displacement of special organs. Lungs, liver, and intestines, together with the organs of reproduction, suffer from the constrictive effects of the corset, and lack of nourishment, due to restricted circulation thus produced, causes atrophy of muscular tissue, since the latter is not adequately rebuilt. ”

“ The paralysis is usually symmetrical on both sides. Although the extensors are affected most, the flexors nearly always participate, and a careful investigation will show that they are weakened. If the paralysis continues, there is a wasting and degeneration of the muscle, but this is seen in paralysis from any cause. The muscular affection may cause deformities in the hands, shoulders, &c. Anæsthesia of portions of the skin is generally present in a greater or less degree. ”

“ The peculiarities which have been described in station, locomotion, and the act of rising to a vertical position nevertheless all depend on such anatomical lesions of the muscles of the back and lower extremities as render the adequate performance of their functions impossible. Thus, the widening of the base of support by straddling the legs is necessitated by weakness in all the extensor muscles of the limbs—the glutæi, quadriceps, and gastrocnemii—which by their tension should normally provide solid columns for the support of the trunk. ”

“ The greater the displacement of the line of gravity, the greater the muscular effort required to maintain the equilibrium of the body. Up to a certain extent, exercising the muscle develops the strength and size of the muscle. On the other hand, when a muscle within the body is unused, it wastes; when used within certain limits, it grows. But when the corset splint is applied to the body of the young girl, it supplants the functions of the abdominal and back muscles, which is to hold the trunk erect, and these muscles gradually grow weak and waste. ”

“ Such employments call into action the muscles that support the spinal column in an erect position, and the languor or uneasiness is muscular pain. The long-continued tension of a muscle enfeebles its action, and eventually destroys its contractility. ”

“ When, however, any one of the various muscles whose integrity is necessary for the automatic performance of any act becomes affected, let the lesion be in the muscle itself or anywhere in the nerve-substance between it and its centre, or in that centre itself in such a way as to hinder its free response to the nervous stimulus, then the will has to be especially directed to the act in order to counteract the effect of the disability, and some other muscle or group of muscles must be substituted in the place of the one incapacitated. ”

“ Observe that but few of the muscles in the economy are found between two levers so great, consequently are capable of being so much distended, and especially of being so with a force greater than that of their contraction; for every muscular rupture supposes the excess of the external motion, which distends, over that of the fleshy fibres which contract to oppose this distension. If the external efforts were concentrated upon a single muscle, they would be able more often to overcome the resistance ”

“ In other words, he exchanges muscle for fat, and as the fat increases he has less and less muscular strength to carry it. It is as though in a motor-car one added hundreds of pounds of weight to the body and reduced the horse-power of the engine. Pretty soon the man becomes so heavy around the waist that he notices his discomfort, and it produces exhaustion; now he becomes more and more averse to exercise, and the facia, or fat, having the better of the battle, begins to penetrate even the fiber of the muscles. ”

“ The arm as a whole would grow neither pale nor cold, it would not become clumsy or heavy, you would not lose your feeling in it, but nevertheless if you tried to bend your arm you would find you could not do it. You could not make the biceps contract, though all the rest of the arm might seem to be quite right.
What does this teach us? It teaches us that the power which a muscle has of contracting when called upon to do so, may be lost and regained, and that it is lost when the blood is prevented from getting to it. When a cord is tied round the whole arm, the power of the whole arm is lost. ”

“ That is to say, in the average constitution, no superfluous strength is possessed by any of the appliances for circulating the blood. Take, again, a set of motor organs. Great strain here causes the fibres of a muscle to tear. There the muscle does not yield but the tendon snaps. ”

“ Exercising a muscle develops it up to its physiologic capacity, but if a muscle is habitually overworked, pathologic results occur, and instead of a quick, sharp contraction of the muscle, the contractions will be weak and uncertain, and, if carried too far, the muscle may eventually atrophy from overwork. ”

“ The muscle may be impaired by a local disease which affects it alone, or it may share in morbid processes which also involve other and distant structures.
Sedentary occupations, leading as they do to poor nutrition of the muscular system from want of proper use and exercise; malnutrition from a diet deficient in amount or defective in kind, or in childhood from too rapid growth; the chronic wasting diseases; the state of convalescence from acute maladies; and, finally, degenerative diseases of the muscles themselves,—all favor the development of myalgia. ”

“ He should make frequent attempts by stretching the rigid groups to overcome the spasm, which in large muscle-masses may be done by grasping with both hands, taking care not to pinch, and pulling the hands apart in the line of the muscle's long axis, thus stretching the muscles. Pressure will sometimes accomplish the same end, and it will be found in certain cases that by kneading during action,—that is, while the patient endeavors to produce voluntary contraction,—the result will be better. ”

“ They form a large part of the whole bulk, and no healthy man can have unhealthy muscles. Ignorant people sneeringly say that they have no ambition to lift weights or bend pokers; but they should remember that they are dependent upon their muscles for their bodily warmth, and also to save their internal organs from being oppressed by their own weight.
The bones of the skeleton do not rest one upon another; they are jointed, and kept slung in position by springing bands of muscle attached to their levers. ”

“ These cases are generally accompanied by round shoulders and flat chest, protrusion of the abdomen, and rotation of the vertebræ.
A muscle can be developed only by the active contraction and relaxation of its fibers. Continuous tension quickly tires and lowers its tone, so that exercises given for increasing muscular power should be comparatively quick and frequently repeated, while those that aim at the stretching of muscles and ligaments should be slow and long maintained. ”

“ The actual structural change is the visible effect of the law that over-use of a muscle produces over-growth or hypertrophy. This is not a law of disease, but of purposeful utility, designed to meet emergencies of life. Still there is a further law in nature, that long-continued excessive use of any muscle leads to a form of hypertrophy28 which cannot maintain its vitality, but degenerates. Arteries must be treated as muscles, for their muscular coats contract and dilate, as circumstances demand, under the control of the nervous system. ”

“ We must, therefore, consider the contraction of a muscle as an extremely rapid trembling of its most minute parts. When we become weaker through illness or from any other cause, we tremble because the contractions are so drawn out and distended as to show the elements composing them. ”

“ A general involvement of the voluntary muscles of the entire body is exceedingly rare.
As stated, the disease may begin in the lower extremity, but much more rarely. It is very seldom that the same order of invasion pursued in the upper extremity is followed in the lower—that is, beginning with the interossei. It may begin in the thigh and involve it alone, or extend to both [p. 550] thighs, or both legs as well. Under these circumstances weakness of the legs is a striking symptom, the patient being unable to stand, often falling down or requiring a cane or crutches to assist him. ”

“ As functional disability is frequently due to the affected muscle being over-stretched, it is of the first importance, when the acute symptoms are on the wane, that every care should be taken to prevent the weak muscular groups being put upon the stretch, and the greatest attention should be paid to the posture of the limb during convalescence. For example, if the child is allowed to lie with the wrist flexed, the flexor muscles undergo shortening, and the extensors are over-stretched and are therefore placed at a mechanical disadvantage. ”

“ The muscle that bends the elbow acts at disadvantage, and this is greatest when the arm is nearly or quite extended, as the angle of action is then least. This disadvantage is further increased by the attachment of the motive muscles near the joint. ”