Part 7
/Young/ children have all their joints small, but they are thick and plump in the spaces between them; because there is nothing upon the bones at the joints, but some tendons to bind the bones together. The soft flesh, which is full of fluids, is enclosed under the skin in the space between the joints; and as the bones are bigger at the joints than in the space between them, the skin throws off in the progress to manhood that superfluity, and draws nearer to the bones, thinning the whole part together. But upon the joints it does not lessen, as there is nothing but cartilages and tendons. For these reasons children are small in the joints, and plump in the space between, as may be observed in their fingers, arms, and narrow shoulders. Men, on the contrary, are large and full in the joints, in the arms and legs; and where children have hollows, men are knotty and prominent.
/Chap. XXXV./--_Of the Joints of the Fingers._
/The/ joints of the fingers appear larger on all sides when they bend; the more they bend the larger they appear. The contrary is the case when straight. It is the same in the toes, and it will be more perceptible in proportion to their fleshiness.
/Chap. XXXVI./--_Of the Joint of the Wrist._
/The/ wrist or joint between the hand and arm lessens on closing the hand, and grows larger when it opens. The contrary happens in the arm, in the space between the elbow and the hand, on all sides; because in opening the hand the muscles are extended and thinned in the arm, from the elbow to the wrist; but when the hand is shut, the same muscles swell and shorten. The tendons alone start, being stretched by the clenching of the hand.
/Chap. XXXVII./--_Of the Joint of the Foot._
/The/ increase and diminution in the joint of the foot is produced on that side where the tendons are seen, as D E F, _Plate I._ which increases when the angle is acute, and diminishes when it becomes obtuse. It must be understood of the joint in the front part of the foot A B C.
/Chap. XXXVIII./--_Of the Knee._
/Of/ all the members which have pliable joints, the knee is the only one that lessens in the bending, and becomes larger by extension.
/Chap. XXXIX./--_Of the Joints._
/All/ the joints of the human body become larger by bending, except that of the leg.
/Chap. XL./--_Of the Naked._
/When/ a figure is to appear nimble and delicate, its muscles must never be too much marked, nor are any of them to be much swelled. Because such figures are expressive of activity and swiftness, and are never loaded with much flesh upon the bones. They are made light by the want of flesh, and where there is but little flesh there cannot be any thickness of muscles.
/Chap. XLI./--_Of the Thickness of the Muscles._
/Muscular/ men have large bones, and are in general thick and short, with very little fat; because the fleshy muscles in their growth contract closer together, and the fat, which in other instances lodges between them, has no room. The muscles in such thin subjects, not being able to extend, grow in thickness, particularly towards their middle, in the parts most removed from the extremities.
/Chap. XLII./--_Fat Subjects have small Muscles._
/Though/ fat people have this in common with muscular men, that they are frequently short and thick, they have thin muscles; but their skin contains a great deal of spongy and soft flesh full of air; for that reason they are lighter upon the water, and swim better than muscular people.
/Chap. XLIII./--_Which of the Muscles disappear in the different Motions of the Body._
/In/ raising or lowering the arm, the pectoral muscles disappear, or acquire a greater relievo. A similar effect is produced by the hips, when they bend either inwards or outwards. It is to be observed, that there is more variety of appearances in the shoulders, hips, and neck, than in any other joint, because they are susceptible of the greatest variety of motions. But of this subject I shall make a separate treatise[13].
/Chap. XLIV./--_Of the Muscles._
/The/ muscles are not to be scrupulously marked all the way, because it would be disagreeable to the sight, and of very difficult execution. But on that side only where the members are in action, they should be pronounced more strongly; for muscles that are at work naturally collect all their parts together, to gain increase of strength, so that some small parts of those muscles will appear, that were not seen before.
/Chap. XLV./--_Of the Muscles._
/The/ muscles of young men are not to be marked strongly, nor too much swelled, because that would indicate full strength and vigour of age, which they have not yet attained. Nevertheless they must be more or less expressed, as they are more or less employed. For those which are in motion are always more swelled and thicker than those which remain at rest. The intrinsic and central line of the members which are bent, never retains its natural length.
/Chap. XLVI./--_The Extension and Contraction of the Muscles._
/The/ muscle at the back part of the thigh shows more variety in its extension and contraction, than any other in the human body; the second, in that respect, are those which compose the buttocks; the third, those of the back; the fourth, those of the neck; the fifth, those of the shoulders; and the sixth, those of the Abdomen, which, taking their rise under the breast, terminate under the lower belly; as I shall explain when I speak of each.
/Chap. XLVII./--_Of the Muscle between the Chest and the lower Belly._
/There/ is a muscle which begins under the breast at the Sternum, and is inserted into, or terminates at the Os pubis, under the lower belly. It is called the Rectus of the Abdomen; it is divided, lengthways, into three principal portions, by transverse tendinous intersections or ligaments, viz. the superior part, and a ligament; the second part, with its ligaments; and the third part, with the third ligament; which last unites by tendons to the Os pubis. These divisions and intersections of the same muscle are intended by nature to facilitate the motion when the body is bent or distended. If it were made of one piece, it would produce too much variety when extended, or contracted, and also would be considerably weaker. When this muscle has but little variety in the motion of the body, it is more beautiful[14].
/Chap. XLVIII./--_Of a Man's complex Strength, but first of the Arm._
/The/ muscles which serve either to straighten or bend the arm, arise from the different processes of the Scapula; some of them from the protuberances of the Humerus, and others about the middle of the Os humeri. The extensors of the arm arise from behind, and the flexors from before.
That a man has more power in pulling than in pushing, has been proved by the ninth proposition De Ponderibus[15], where it is said, that of two equal weights, that will have the greatest power which is farthest removed from the pole or centre of its balance. It follows then of course, that the muscle N B, _Plate II._ and the muscle N C, being of equal power, the inner muscle N C, will nevertheless be stronger than the outward one N B, because it is inserted into the arm at C, a point farther removed from the centre of the elbow A, than B, which is on the other side of such centre, so that that question is determined. But this is a simple power, and I thought it best to explain it before I mentioned the complex power of the muscles, of which I must now take notice. The complex power, or strength, is, for instance, this, when the arm is going to act, a second power is added to it (such as the weight of the body and the strength of the legs, in pulling or pushing), consisting in the extension of the parts, as when two men attempt to throw down a column; the one by pushing, and the other by pulling[16].
/Chap. XLIX./--_In which of the two Actions, Pulling or Pushing, a Man has the greatest Power_, Plate II.
/A man/ has the greatest power in pulling, for in that action he has the united exertion of all the muscles of the arm, while some of them must be inactive when he is pushing; because when the arm is extended for that purpose, the muscles which move the elbow cannot act, any more than if he pushed with his shoulders against the column he means to throw down; in which case only the muscles that extend the back, the legs under the thigh, and the calves of the legs, would be active. From which we conclude, that in pulling there is added to the power of extension the strength of the arms, of the legs, of the back, and even of the chest, if the oblique motion of the body require it. But in pushing, though all the parts were employed, yet the strength of the muscles of the arms is wanting; for to push with an extended arm without motion does not help more than if a piece of wood were placed from the shoulder to the column meant to be pushed down.
/Chap. L./--_Of the bending of Members, and of the Flesh round the bending Joint._
/The/ flesh which covers the bones near and at the joints, swells or diminishes in thickness according to their bending or extension; that is, it increases at the inside of the angle formed by the bending, and grows narrow and lengthened on the outward side of the exterior angle. The middle between the convex and concave angle participates of this increase or diminution, but in a greater or less degree as the parts are nearer to, or farther from, the angles of the bending joints.
/Chap. LI./--_Of the naked Body._
/The/ members of naked men who work hard in different attitudes, will shew the muscles more strongly on that side where they act forcibly to bring the part into action; and the other muscles will be more or less marked, in proportion as they co-operate in the same motion.
/Chap. LII./--_Of a Ligament without Muscles._
/Where/ the arm joins with the hand, there is a ligament, the largest in the human body, which is without muscles, and is called the strong ligament of the Carpus; it has a square shape, and serves to bind and keep close together the bones of the arm, and the tendons of the fingers, and prevent their dilating, or starting out.
/Chap. LIII./--_Of Creases._
/In/ bending the joints the flesh will always form a crease on the opposite side to that where it is tight.
/Chap. LIV./--_How near behind the Back one Arm can be brought to the other_, Plate III. and IV.
/When/ the arms are carried behind the back, the elbows can never be brought nearer than the length from the elbow to the end of the longest finger; so that the fingers will not be seen beyond the elbows, and in that situation, the arms with the shoulders form a perfect square. The greatest extension of the arm across the chest is, when the elbow comes over the pit of the stomach; the elbow and the shoulder in this position, will form an equilateral triangle.
/Chap. LV./--_Of the Muscles._
/A naked/ figure being strongly marked, so as to give a distinct view of all the muscles, will not express any motion; because it cannot move, if some of its muscles do not relax while the others are pulling. Those which relax cease to appear in proportion as the others pull strongly and become apparent.
/Chap. LVI./--_Of the Muscles._
/The/ muscles of the human body are to be more or less marked according to their degree of action. Those only which act are to be shewn, and the more forcibly they act, the stronger they should be pronounced. Those that do not act at all must remain soft and flat.
/Chap. LVII./--_Of the Bending of the Body._
/The/ bodies of men diminish as much on the side which bends, as they increase on the opposite side. That diminution may at last become double, in proportion to the extension on the other side. But of this I shall make a separate treatise[17].
/Chap. LVIII./--_The same Subject._
/The/ body which bends, lengthens as much on one side as it shortens on the other; but the central line between them will never lessen or increase.
/Chap. LIX./--_The Necessity of anatomical Knowledge._
/The/ painter who has obtained a perfect knowledge of the nature of the tendons and muscles, and of those parts which contain the most of them, will know to a certainty, in giving a particular motion to any part of the body, which, and how many of the muscles give rise and contribute to it; which of them, by swelling, occasion their shortening, and which of the cartilages they surround.
He will not imitate those who, in all the different attitudes they adopt, or invent, make use of the same muscles, in the arms, back, or chest, or any other parts.
MOTION AND EQUIPOISE OF FIGURES.
/Chap. LX./--_Of the Equipoise of a Figure standing still._
/The/ non-existence of motion in any animal resting on its feet, is owing to the equality of weight distributed on each side of the line of gravity.
/Chap. LXI./--_Motion produced by the Loss of Equilibrium._
/Motion/ is created by the loss of due equipoise, that is, by inequality of weight; for nothing can move of itself, without losing its centre of gravity, and the farther that is removed, the quicker and stronger will be the motion.
/Chap. LXII./--_Of the Equipoise of Bodies_, Plate V.
/The/ balance or equipoise of parts in the human body is of two sorts, viz. simple, and complex. Simple, when a man stands upon his feet without motion: in that situation, if he extends his arms at different distances from the middle, or stoop, the centre of his weight will always be in a perpendicular line upon the centre of that foot which supports the body; and if he rests equally upon both feet, then the middle of the chest will be perpendicular to the middle of the line which measures the space between the centres of his feet.
The complex balance is, when a man carries a weight not his own, which he bears by different motions; as in the figure of Hercules stifling Anteus, by pressing him against his breast with his arms, after he has lifted him from the ground. He must have as much of his own weight thrown behind the central line of his feet, as the weight of Anteus adds before.
/Chap. LXIII./--_Of Positions._
/The/ pit of the neck, between the two Clavicles, falls perpendicularly with the foot which bears the weight of the body. If one of the arms be thrown forwards, this pit will quit that perpendicular; and if one of the legs goes back, that pit is brought forwards, and so changes its situation at every change of posture.
/Chap. LXIV./--_Of balancing the Weight round the Centre of Gravity in Bodies._
/A figure/ standing upon its feet without motion, will form an equipoise of all its members round the centre of its support.
If this figure without motion, and resting upon its feet, happens to move one of its arms forwards, it must necessarily throw as much of its weight on the opposite side, as is equal to that of the extended arm and the accidental weight. And the same I say of every part, which is brought out beyond its usual balance.
/Chap. LXV./--_Of Figures that have to lift up, or carry any Weight._
/A weight/ can never be lifted up or carried by any man, if he do not throw more than an equal weight of his own on the opposite side.
/Chap. LXVI./--_The Equilibrium of a Man standing upon his Feet_, Plate VI.
/The/ weight of a man resting upon one leg will always be equally divided on each side of the central or perpendicular line of gravity, which supports him.
/Chap. LXVII./--_Of Walking_, Plate VII.
/A man/ walking will always have the centre of gravity over the centre of the leg which rests upon the ground.
/Chap. LXVIII./--_Of the Centre of Gravity in Men and Animals._
/The/ legs, or centre of support, in men and animals, will approach nearer to the centre of gravity, in proportion to the slowness of their motion; and, on the contrary, when the motion is quicker, they will be farther removed from that perpendicular line.
/Chap. LXIX./--_Of the corresponding Thickness of Parts on each Side of the Body._
/The/ thickness or breadth of the parts in the human body will never be equal on each side, if the corresponding members do not move equally and alike.
/Chap. LXX./--_Of the Motions of Animals._
/All/ bipeds in their motions lower the part immediately over the foot that is raised, more than over that resting on the ground, and the highest parts do just the contrary. This is observable in the hips and shoulders of a man when he walks; and also in birds in the head and rump.
/Chap. LXXI./--_Of Quadrupeds and their Motions._
/The/ highest parts of quadrupeds are susceptible of more variation when they walk, than when they are still, in a greater or less degree, in proportion to their size. This proceeds from the oblique position of their legs when they touch the ground, which raise the animal when they become straight and perpendicular upon the ground.
/Chap. LXXII./--_Of the Quickness or Slowness of Motion._
/The/ motion performed by a man, or any other animal whatever, in walking, will have more or less velocity as the centre of their weight is more or less removed from the centre of that foot upon which they are supported.
/Chap. LXXIII./--_Of the Motion of Animals._
/That/ figure will appear the swiftest in its course which leans the most forwards.
Any body, moving of itself, will do it with more or less velocity in proportion as the centre of its gravity is more or less removed from the centre of its support. This is mentioned chiefly in regard to the motion of birds, which, without any clapping of their wings, or assistance of wind, move themselves. This happens when the centre of their gravity is out of the centre of their support, viz. out of its usual residence, the middle between the two wings. Because, if the middle of the wings be more backward than the centre of the whole weight, the bird will move forwards and downwards, in a greater or less degree as the centre of its weight is more or less removed from the middle of its wings. From which it follows, that if the centre of gravity be far removed from the other centre, the descent of the bird will be very oblique; but if that centre be near the middle of the wings, the descent will have very little obliquity.
/Chap. LXXIV./--_Of a Figure moving against the Wind_, Plate VIII.
/A man/ moving against the wind in any direction does not keep his centre of gravity duly disposed upon the centre of support[18].
/Chap. LXXV./--_Of the Balance of a Figure resting upon its Feet._
/The/ man who rests upon his feet, either bears the weight of his body upon them equally, or unequally. If equally, it will be with some accidental weight, or simply with his own; if it be with an additional weight, the opposite extremities of his members will not be equally distant from the perpendicular of his feet. But if he simply carries his own weight, the opposite extremities will be equally distant from the perpendicular of his feet: and on this subject of gravity I shall write a separate book[19].
/Chap. LXXVI./--_A Precept._
/The/ navel is always in the central or middle line of the body, which passes through the pit of the stomach to that of the neck, and must have as much weight, either accidental or natural, on one side of the human figure as on the other. This is demonstrated by extending the arm, the wrist of which performs the office of a weight at the end of a steelyard; and will require some weight to be thrown on the other side of the navel, to counterbalance that of the wrist. It is on that account that the heel is often raised.
/Chap. LXXVII./--_Of a Man standing, but resting more upon one Foot than the other._
/After/ a man, by standing long, has tired the leg upon which he rests, he sends part of his weight upon the other leg. But this kind of posture is to be employed only for old age, infancy, or extreme lassitude, because it expresses weariness, or very little power in the limbs. For that reason, a young man, strong and healthy, will always rest upon one of his legs, and if he removes a little of his weight upon the other, it is only a necessary preparative to motion, without which it is impossible to move; as we have proved before, that motion proceeds from inequality[20].
/Chap. LXXVIII./--_Of the Balance of Figures_, Plate IX.
/If/ the figure rests upon one foot, the shoulder on that side will always be lower than the other; and the pit of the neck will fall perpendicularly over the middle of that leg which supports the body. The same will happen in whatever other view we see that figure, when it has not the arm much extended, nor any weight on its back, in its hand, or on its shoulder, and when it does not, either behind or before, throw out that leg which does not support the body.
/Chap. LXXIX./--_In what Manner extending one Arm alters the Balance._
/The/ extending of the arm, which was bent, removes the weight of the figure upon the foot which bears the weight of the whole body: as is observable in rope-dancers, who dance upon the rope with their arms open, without any pole.
/Chap. LXXX./--_Of a Man bearing a Weight on his Shoulders_, Plate X.
/The/ shoulder which bears the weight is always higher than the other. This is seen in the figure opposite, in which the centre line passes through the whole, with an equal weight on each side, to the leg on which it rests. If the weight were not equally divided on each side of this central line of gravity, the whole would fall to the ground. But Nature has provided, that as much of the natural weight of the man should be thrown on one side, as of accidental weight on the other, to form a counterpoise. This is effected by the man's bending, and leaning on the side not loaded, so as to form an equilibrium to the accidental weight he carries; and this cannot be done, unless the loaded shoulder be raised, and the other lowered. This is the resource with which Nature has furnished a man on such occasions.
/Chap. LXXXI./--_Of Equilibrium._
/Any/ figure bearing an additional weight out of the central line, must throw as much natural or accidental weight on the opposite side as is sufficient to form a counterpoise round that line, which passes from the pit of the neck, through the whole mass of weight, to that part of the foot which rests upon the ground. We observe, that when a man lifts a weight with one arm, he naturally throws out the opposite arm; and if that be not enough to form an equipoise, he will add as much of his own weight, by bending his body, as will enable him to resist such accidental load. We see also, that a man ready to fall sideways and backwards at the same time, always throws out the arm on the opposite side.
/Chap. LXXXII./--_Of Motion._
/Whether/ a man moves with velocity or slowness, the parts above the leg which sustains the weight, will always be lower than the others on the opposite side.
/Chap. LXXXIII./--_The Level of the Shoulders._