13 1/2″ × 9 1/2″ (343 × 242 mm)
British Museum, London
Muscles and Bony Landmarks, Posterior Aspect
The hand is like a puppet show run by strings. The strings are the long tendons of the extrinsic, or long, muscles of the hand that are situated in the forearm. They move to the hand by way of the wrist.
Most prominent at the wrist are the bony extremities, or styloid processes, of the radius (A) and ulna (B). If you draw a line between these two landmarks, you will see that it crosses the wrist obliquely, not horizontally. When you analyze this, you will notice that the more prominent and more anterior (frontal) radial styloid descends lower than that of the ulna.
The back of the grasping hand is convex. Passarotti has massed the hand along the prominent metacarpal of the index finger (C). Below this, he uses contoured hatchings to suggest the egg-like shape of the first dorsal interossei (D), also called the abductor of the index finger. This mass reaches from the bone of the thumb to the bone of the index finger and turns the skeleton into a hand.
Place your thumb upon the styloid of the radius. Move it slowly upward until at the back you feel the bump of Lister’s tubercle (E). This landmark is on a line with the most prominent third metacarpal (F) that lies highest on the back of the hand. The long extensors of the fingers (G) are suggested in the center of the hand, reaching by their four tendons to their insertions in the second (H) and third (I) phalanx of each finger. The knuckles indicate the position of the heads of the second to fifth metacarpals, and the slight flexion of the fingers reveals the greater prominence of the knuckle of the third (J) metacarpal.
Passarotti has strongly contrasted the skin wrinkles over the mid-phalangeal joint (K), which he has blocked in with straight lines. He has relegated the index finger to the area of shade and subdued the contrast at its middle joint by the less obvious contour line (L), thus preserving the simplicity of the two dominant value areas of light and dark.
Bartolomeo Passarotti
STUDIES OF HANDS AND NUDE FIGURES
pen and brown ink
16 1/8″ × 10 3/8″ (410 × 263 mm)
Ashmolean Museum, Oxford
Muscles and Bony Landmarks, Lateral Aspect
Like the great toe, the thumb has only two phalanges, a distal (A) and a proximal one (B), which are divided by creases at the joint (C). Dürer has accented the head of the first metacarpal (D), which protrudes with slight flexion of the thumb against the ball.
The highlight (E) on the proximal phalanx follows the single line of the extensor tendons to the head of the metacarpal. Above this point, they divide into the tendon of the extensor pollicis brevis (F) at the radial side, and the obliquely moving tendon of extensor pollicis longus (G) in the ulnar direction. Between them, they create the hollow of the anatomical “snuff box” (H). Here, it is only slightly indicated—it is most visible when the thumb is extended to its utmost.
The flexion wrinkles (I) at the back of the hand are always seen when the wrist is extended. Below, the gentle contour of the abductor pollicis longus (J) leads into the dominant mass of the thenar eminence (K) which overlaps the hollow of the palm and the hypothenar eminence behind (L).
Dürer highlights the edge of the first dorsal interossei or abductor of the index finger (M). His contour lines run slightly oblique to the long and short axis of the muscular masses.
Albrecht Dürer (1471-1528)
STUDY OF THE HANDS OF GOD THE FATHER FROM THE HELLER ALTARPIECE
8 1/4″ × 11 5/8″ (209 × 295 mm)
Kunsthalle, Bremen
Muscles and Bony Landmarks, Medial
If the hand is allowed to assume its own position of rest, like the hand on the far right in del Sarto’s drawing, it will always be in slight palmar flexion, bent inward toward the palm. In this position, the proximal phalanx (A) tends to extend, with a compensating flexion or bending of the middle (B) and distal (C) joints. This is a position of rest, with the muscles in balance, but with little practical function possible.
The hand on the far left is also in slight palmar flexion. With the fingers slightly flexed and hooked around the material, the wrist pulls inward. In this position, the strength of the grasp is weak because the long finger extensors are stretched. (If the fingers were bent into a fist, the wrist would have to be extended straight out.) The police are well aware of this and, accordingly, disarm an opponent by forcing his wrist into palmar flexion so that his grasp is weakened.
Del Sarto knew that the plane break at the back of the medial side of the hand was at the edge of the fifth metacarpal (D). The mass of the abductor of the little finger (E) gives softness to the side of the hand. It originates in the pisiform bone (F) and from the tendon of the flexor carpi ulnaris (G) that has its insertion in the pisiform.
It is an error to think that simply because a muscle is named after a function (like adductor, flexor, or extensor), it is the only action that muscle is capable of. Quite the contrary. For example, although the abductor of the little finger (E) moves it away or abducts it from the ring finger (H), it also stabilizes the metacarpophalangeal joint (I) when the thumb opposes the little finger. The abductor of the little finger (E), also a weak extensor, helps straighten the little finger.
You should also be aware that a motion is seldom performed by a single muscle or tendon. The moving part also needs a stable base to work from which is controlled by muscular action. As an example, if you place your thumb on the anterior or frontal border of the opposite hand just below the pisiform bone (F) and abduct and adduct the little finger, moving it back and forth, you will feel the movement of the tendon of the flexor carpi ulnaris (G) as the muscle contracts to stabilize the ulnar border of the wrist.
Andrea del Sarto (1486-1531)
STUDIES OF HANDS
chalk
Uffizi, Florence
Extension
The wrist can turn and bend in any direction and at any angle. Here, it is in hyperextension or dorsiflexion, extended straight out and back. In the opposite position of palmar flexion, the wrist can almost make a right angle. Try to touch your wrist and see. Also, it can move much further in ulnar flexion (adduction) than it can in radial flexion (abduction), its opposite movement.
The extensor muscles at the back and the opposing flexor muscles at the front of the wrist, overlie, stabilize, and act upon the joints of the wrist, and have their ultimate attachment to the metacarpals and phalanges of the fingers. The strongest wrist motors are the two radial wrist extensors in the back of the hand, and the opposing flexor carpi ulnaris (A) at the front.
If the ring and little fingers in this drawing were extended with the other fingers, they would all be unequal in length: the middle finger (B) longest, the ring finger (C) next with the index or forefinger (D) a close third in length, and the little finger (E) the shortest. When the fingers are partially flexed together, their tips form a straight line. When they are fully flexed, they touch the palm at the midpalmar crease (F) (known in palmistry as the head line) that lies between the thenar (G) (or life line) and distal (H) (or heart line) creases.
Davide Ghirlandaio (1452-1525)
DRAPED YOUTH AND THE INSIDE OF AN OPEN HAND
Uffizi, Florence
Flexion
The versatility of the hand is based not only upon the mobility of its skeleton, but upon a mechanical chain of joint and muscle action that extends all the way to the trunk. The hand must be positioned properly, opposing muscles must be stabilized, and joints must be rendered immobile to prevent unwanted motion.
The wrist of Delacroix’s model (left) is bent backwards in order to facilitate flexion (or curling) of the fingers. Note the flexion folds (A) at the back of the wrist. If the model were to grasp a hammer, she would be using a power grip. If she were to hammer in a nail, let us say, the additional strength would be provided by the wrist, elbow, and finally the shoulder. At the wrist, the stronger flexor carpi ulnaris (B) and the extensors come into play. The triceps
(C) and the brachialis (D) stabilize the elbow. At the shoulder, the lower two-thirds of the latissimus dorsi (E), the inferior portion of the trapezius (F), the pectoralis in front, and the deltoid (G) are important contributors to powerful hand action.
As you can see in the drawing on the right, the mobile skeleton of the hand gives it a cuplike shape. The very flexible metacarpal of the thumb (H), and the mobile mass of the two metacarpals and phalanges of the ring and little finger (I) can move the mass of the hand inward from the more stable mass of the metacarpals of the index and middle finger (J). Thus your hand becomes birdlike in motion, the two wings at the side closing in upon the central mass when you grasp at objects.
The hand in Delacroix’s drawing holds the compass loosely in combination of the hook grip of the ring and little fingers, and the precision grip of the thumb and index fingers. The abductor policis (K) and first dorsal interossei (L) (the abductor of the index finger) hold the thumb and index finger lightly against the compass.
Delacroix has accentuated the action of the latter muscle by placing his dominant plane break on its curved mass.
Eugéne Delacroix (1798-1863)
BACK VIEW OF FEMALE FIGURE, HAND WITH DIVIDERS
chalk
Musée des Beaux Arts, Besançon
Adduction
Terms of wrist movement are based on the anatomical position of the hands being at the sides and the palms turned forward. Adduction means to draw inward or toward the center or median line of the body. Abduction, its opposite, to move away from this center line. Because the arm is flexible and can move in many directions, the terms ulnar deviation and radial deviation are also applied in order to explain the action of the wrist. Ulnar deviation refers to adduction or a movement toward the ulna, and radial deviation refers to abduction or a movement toward the radius.
The strong flexion folds (A) in Dürer’s drawing of the hands opening a book suggest adduction of the wrist toward the ulnar side or ulnar deviation. Movement in the opposite direction toward the radius is called abduction or radial deviation.
At the back of the hand, the tendons of the long extensors (B) move underneath the veins (C) following the direction of the metacarpals, where they form the knuckles (D).
The direction of the lines of shading describe the contour of the forms beneath. Dürer kept his highlight at the fifth metacarpal (E) close to the dark area because he wished to portray the back of this hand as relatively flat. He similarly squared up the two strongly lit fingers of this hand. By contrast, in the hand on the left, the separation of the highlight and the dark by larger masses of middle tone contributes to the illusion of roundness. The change in the direction of the curves of the wrinkles (F) over the middle joint of this dominant ring finger, is a clue to the direction of the first phalange.
The index (G) and ring (H) fingers are pressed inward or adducted toward the middle finger (I), or midline of the hand. The little finger (J) is moved away or abducted from the midline by the action of the abductor digiti minimi, located in the hypothenar eminence (K).
Albrecht Dürer (1471-1528)
PREPARATORY DRAWING FOR CHRIST AMONG THE DOCTORS
pen and wash
9 13/16″ × 16 3/8″ (249 × 415 mm)
German National Museum, Nuremberg
Abduction
The term abduction means movement outward or away from a center or median line. In the anatomical position where the arms are at the side and the palms are facing forward, the abducted wrist moves outward, moving sideward away from the body in the direction of the thumb. This wrist movement is also termed radial deviation. Abduction of the fingers describes sideward motion away from the middle finger or midline of the hand. By contrast, the thumb is abducted when you move it out from the palm at right angles to it, and adducted when you move it into the palm and down on the index finger.
The wrist (A) at the right in this drawing is in abduction or radial deviation. This is carried out primarily by the flexor carpi radialis muscle of the anterior forearm (see plate #22 at the back of the book) and by the two radial extensors or supinator group of the wrist (B). The limited motion of abduction is always increased by the additional movement of the wrist toward the palm, or palmar flexion. The other wrist (C) is in slight adduction also with palmar flexion.
Learning about the hand will help you study the foot, for you will find many similarities. But there are structural differences relating to function. The butterfly-like hand has become a flexible extension of man’s intellect, whereas the foot is structurally designed to withstand great weight and pressure. The more you can see the relationship between structure and function, the more the study of anatomy will reveal universal design principles.
Jean-Baptiste Greuze (1725-1805)
A SEATED NUDE
red chalk on heavy cream paper
17 1/2″ × 14 1/2″ (445 × 370 mm)
Paul J. Sachs Collection
Fogg Museum of Art, Harvard University, Cambridge
8
THE NECK
AND HEAD
Neck, Anterior Aspect
The inner base of the column of the neck arises out of the circle of the first ribs and follows the curve of the spinal column at the back. At the front, the lower limit of the neck is formed on each side by the clavicle (A), from the jugular notch (B) (or pit of the neck) to the acromion process (C) at the side.
In this drawing, the head, and the neck which always moves with it, are rotated to the viewer’s right. The sternocleidomastoideus (D), the most prominent muscle in the neck, spirals vertically downward, filling a large portion of this mass. This rotator, sometimes called the “bonnet string” muscle, extends from its cordlike origin in the manubrium (E) of the sternum and the inner third of the clavicle (F) to the mastoid process (G) behind the ear. The sternal head (H) swells just below the angle of the jaw (I) as it pulls the head back and rotates it toward the trapezius (J) at the side.
With the rotation of the head and neck, the prominent landmark of the thyroid cartilage or Adam’s apple of the larynx (K) is also pulled to the side. The middle line of the neck (L) that runs from the mental protuberance (M) (the center of the chin bone) to the pit of the neck (B) overlaps the relaxed sternocleidomastoideus (N) on the other side. This lowered sternocleidomastoideus is pushed obliquely toward the posterior triangle of the neck (O) and overlaps the anterior edge of the trapezius (J) at the shoulder.
A shaded down plane marks the submaxillary or digastric triangle and the area of the mylohyoid muscle (P). The posterior belly of the digastric muscle (Q) moves along the lower border of this triangle to the hyoid bone (R) at the front.
The thyroid cartilage (K), which is very prominent in the male neck, is accented by the strong contoured hatchings (S) that mark its down plane.
Domenico Beccafumi (1485/6-1551)
STUDY FOR PART OF THE MOSAIC FRIEZE OF THE SIENA CATHEDRAL PAVEMENT
pen and bistre wash
8″ × 11 5/8″ (203 × 295 mm)
Bequest of Meta and Paul J. Sachs
Fogg Art Museum, Harvard University, Cambridge
Neck, Posterior Aspect
The contour of Michelangelo’s lines suggest the ball and egg shape of the head. The cylinder of the neck is formed on the spinal column, follows its curve, and takes on its supple character. At about the level of the middle of the ear, Michelangelo’s strong curve at the back of the head suggests the occipital protuberance (A), which is the upper limit of the neck. Below this eminence lies the bony ring of the atlas—the first cervical vertebra—on which the head moves forward and backward in flexion and extension, and beneath it, the axis on which the head is rotated. Together with the five vertebrae below, they form the back of the column of the neck.
Powerful ligaments and muscles, called the strong chords of the neck, connect the base of the skull and the vertebral column. They help to keep the head erect and assist in its movements. The trapezius or table muscle (B) moves down from its origin in the
occipital protuberance. Molding itself on the deeper layers of muscle, the trapezius creates a longitudinal elevation (C) on each side of the nuchal furrow, the central furrow of the neck. This furrow follows down along the spines of the vertebrae to the important landmark of the seventh cervical or vertebra prominens (D). An imaginary line drawn from the seventh cervical to the acromion process (E) of the scapula defines the lower border of the posterior of the neck.
The outline of the upper section of the trapezius (F) is widened by the mass of the scalenus and the levator anguli scapulae beneath. The upper mass of the sternocleidomastoideus (G) outlines the neck above. Below, the outline changes direction as the fibers of the trapezius project obliquely upward from the acromion process (H) to about the fifth vertebra (I).
Michelangelo places the plane break along the upper edge of the trapezius (J) where a transverse fold (K) marks the sternocleidomastoideus (G) as it twists into the trapezius. In the light area, he subdues the contrast at the nuchal furrow, and in the dark mass of the face, he minimizes the reflected light to unify his two big values.
Michelangelo Buonarotti (1475-1564)
FIGURE STUDY FOR THE BATTLE OF CASCINA
black chalk over stylus
7 5/8″ × 10 1/2″ (194 × 267 mm)
Albertina, Vienna
Neck, Lateral Aspect
The sternocleidomastoideus (A), coursing down from its mastoid and occipital insertions behind the ear (B) to its origins in the sternum (C) and the inner clavicle (D), covers a wide area of the lateral region of the neck. Boucher has emphasized its middle portion (E) with contoured hatchings. At the pit of the neck (C), where the two sides of this “bonnet string” muscle (the sternocleidomastoideus) meet the front line of the neck, he has placed a dark accent.
Anatomy Lessons From the Great Masters Page 9