Peter Paul Rubens (1577-1640)
STUDY FOR THE FIGURE OF CHRIST ON THE CROSS
black and white chalk, some bistre wash
20 3/4″ × 14 9/16″ (528 × 370 mm)
British Museum, London
Rib Cage, Posterior Aspect
Observe how Raphael was aware of the influence of the shape of the rib cage and of the deep-lying muscles below upon the form of the superficial muscles of the latissimus dorsi (A) and the trapezius (B).
You can follow the route of the latissimus dorsi as it moves across the rib cage from its origins in the spineous process of the lower six thoracic vertebrae in the area of the median furrow (C), the posterior third of the iliac crest (D), and the external surface of the lower three ribs. It moves out and over the erector spinae (E), often called the “strong chords,” which form a strong relief on either side, with the lumbar furrow in-between. The latissimus goes over the middle and largest of the erector spinae, the longissimus dorsi (F), around the mass of the rib cage (A), and creates a relief (G), where it crosses the inferior angle of the scapula to hold it against the rib cage. As the latissimus curves around the side of the bony framework beneath, it reveals the serratus anterior (H), and cradles the teres major (I), which it holds sling-like at the armpit.
The elongated diamond-shaped muscle of the trapezius is also molded by the deeper muscles beneath, as well as by the rib cage. In this drawing you can easily trace the movements of the trapezius from its central origins in the twelve thoracic vertebrae. The vertebral column is defined by the median furrow (C) and the prominence of the seventh cervical vertebra (J). From here, the trapezius passes over the stretched out rhomboids (K) with a hint of the spinalis beneath. It then moves over the superior angle of the scapula (L), which defines the inner limits of the bulge of the supraspinatus, and inserts in the spine and acromion process (M) of the scapula.
The numerous bodily curves are not easily memorized and you will soon learn to move your lines from anatomical point to point, along a curve, to locate them. These checkpoints will make it easier to locate and define the various lines, values, and shapes.
Raphael Sanzio (1483-1520)
TWO MALE FIGURE STUDIES
pen and ink
16 1/8″ × 11″ (410 × 281 mm)
Albertina, Vienna
Rib Cage, Lateral Aspect
In this figure, Raphael makes you aware of the shape of the rib cage in his flow of line and shading. You can feel the spiral motion of the vertebral column from its beginning at the base of the skull (A) moving around the rib cage to the widest point (B) and then down to the sacrum (C) below.
The scapula (D) follows the upraised arm and glides across the surface of the rib cage. Raphael has indicated this by placing the superior or upper angle of the scapula (E) in a lower position than it would be at rest, and by moving the inferior or lower angle (F) forward as it bulges under the overlapping latissimus dorsi (G). Just below, Raphael has indicated four lower digitations of the serratus anterior (H) protruding from under the anterior border of the latissimus dorsi. The teres major (I) bulges out over the edge of the latissimus dorsi.
The back of the rib cage is enveloped by the trapezius. From its origin low in the vertebral column, you can trace its upward passage over the rib cage. Raphael has revealed strong signs of the rib cage beneath by his shading of the intercostal furrows (J) and by indicating the curves of the posterior ribs (K), which protrude through the flattened-out mass of rhomboids (L). The trapezius moves over the superior angle of the scapula (E), which it holds against the rib cage, and then inserts into the spine (M) and the acromion process (N) of the scapula.
The external oblique muscle (O) flows down over the surface of the rib cage, following the general direction of the lower eight ribs to which it is attached. Just below the tenth rib, Raphael shows a break (P) in the anterior or front border of the oblique muscle, where it breaks into its thick abdominal portion (Q). Raphael knew that from there, the external oblique inserts into the anterior half of the iliac crest. So he continued this border down to the anterior superior iliac spine or front point (R) of the iliac crest of the pelvis.
Raphael Sanzio (1483-1520)
TWO NAKED FIGURES CROUCHING UNDER A SHIELD
black chalk
10 1/2″ × 18 15/16″ (266 × 223 mm)
Reproduced by gracious permission of Her Majesty the Queen
Royal Library, Windsor
External Oblique
Sometimes we use analogies to clarify our understanding of anatomical functions. The lower and fleshy abdominal portion of the external oblique (A) is often compared to the folds of an accordion as it stretches out or bunches up between the two moving bony systems of the rib cage (B) and the pelvis (C). Like the sternocleidomastoid that links head and rib cage, the changing shape of the external oblique (A) is also formed by the movement of the larger masses which it connects.
In the two figures on the right, this spiral mass of the external oblique (A) resembles a teardrop elongated between the two larger bony masses. In the thin superior or thoracic portion of the oblique (D), the artist has defined its upper limits by toothlike bulges that interlock with the four slips of the serratus anterior (E).
The tip of the tenth rib (F) marks the base of the rib cage and the upper limit of the abdominal portion of the external oblique. It also marks the base of the construction line (G) where rib meets cartilage, the major plane break on the mass of the rib cage.
On the figure on the left, which continues the sequence of movement across the page, the rib cage is flexed upon the pelvis and inclined to the side. We see the change in size, shape, and direction of the external oblique as it is compressed like an accordion between thorax (D) and pelvis (C). While the thoracic portion follows the direction of the rib cage to which it is attached, the abdominal portion (A) becomes much smaller. Its upper border is defined by a curved line (H), and its lower limit is inserted into the iliac crest (I).
The flowing movement of the spiral-like mass of the external oblique allows the artist to maintain a continuity and rhythm in line and shading in the transition from rib cage to pelvis. You will discover many such harmonic transitions throughout the body.
Jacopo Pontormo (1494-1556)
STUDIES
red chalk
16 1/8″ × 10 5/8″ (410 × 270 mm)
Musée des Beaux Arts, Lille
Rectus Abdominis
The rectus abdominis might first be thought of as a link in the front of the body between the rib cage and the pelvis. From its origin in the pubis (A) this long, almost flat, and vertical muscle reaches as far up as the fifth, sixth, and seventh ribs (B).
The uppermost transverse or lateral line (C) follows the shape of the false ribs that make up the thoracic arch. Directly below this lies the division of the middle transverse line (D). Put your pencil on the tip of the tenth rib (E) and follow the contour of this line (D) across the upper abdomen. Notice that this lateral line lies about halfway between the infrasternal notch (F) above and the umbilicus or navel (G) below and marks the upper level of the abdominal portion of the external oblique (H). Note also that Michelangelo purposely placed the lowest (I) of the usual three lines dividing the rectus abdominis a little above the navel.
The hatching marks of great artists often suggest the direction of the muscle fibers. Michelangelo’s hatchings reveal his easy familiarity with these directions when they suit his design needs. His hatchings (J) over the lower portion of the rectus abdominis follow the general direction of the fibers of the deep internal oblique which, with the superficial external oblique (H), covers the rectus abdominis. His upward hatchings (K) suggest the vertical movement of the fibers of the rectus abdominis. After having established the dominant upward flow in the larger and lower portion of the rectus, Michelangelo now masses in the upper rectus (L) with horizontal lines, emphasizing its flow into the rib cage.
Michelangelo Buonarotti (1475-1564)
YOU
TH BECKONING; A RIGHT LEG
pen and ink over black chalk
14 3/4″ × 7 7/16″ (375 × 189 mm)
British Museum, London
Muscles of Back and Shoulder Girdle
An important aspect of drawing the back lies in deciding where the scapula (A) is positioned. You should also be aware of the direction of the arm, since the scapula always follows the direction of the humerus bone of the upper arm. In this drawing, Tiepolo shows us two opposite positions of the arm, demonstrating how each acts upon the muscles of the upper back.
With the backward movement of the left arm, notice that the inferior angle of the scapula (B) protrudes slightly as it rotates around the rib cage toward mid-back. The direction of this motion, while urged on by the rhomboids (C), is countered above by the forward and downward movement to the front of the body of the upper portion of the scapula. This is indicated by the position of the acromion process (D), where the deltoid (E) is attached.
The bulges of the contracting infraspinatus (F) and teres minor (G) muscles inform us that they are assisting the deltoid (E) in the outward and backward rotation of the arm. At the side, notice the mass of the teres major (H).
Observe how the forward position of the right arm has stretched the two large muscles of the back—the trapezius (I) and the latissimus dorsi (J)—tightly over the curving form of the rib cage. The bulge of the infraspinatus (K) clues us to the position of the underlying scapula, the inner border of which Tiepolo has accentuated with his contoured hatchings (L).
The rhomboid (M) is barely visible under the outer edge of the trapezius. From beneath the extended latissimus dorsi muscle, you can follow the contours of the serratus anterior (N), serratus posterior inferior (O), the side of the ninth and tenth ribs (P) just above the external oblique (Q), and two major prominences of the erector spinae muscles: the iliocostalis (R) and the longissimus dorsi (S).
The direction of the curve of the center line of the back, from the seventh cervical vertebra (T) through the protrusions of the three or four thoracic vertebrae (U) to the sacrum (V), shows the exact position of the rib cage in perspective. Tiepolo has further used his knowledge of structure to place the dominant plane break of the back (W) along the upper portion of the line of the angle of the ribs, further defining the position and mass of the underlying rib cage.
Giovanni Battista Tiepolo (1696-1770)
NUDE BACK
chalk on tinted blue paper
13 9/16″ × 11″ (344 × 280 mm)
Staatsgalerie, Stuttgart
Pectoralis Major, Male
The massive, blocklike pectoralis muscle in this well-developed male figure widens the chest beyond the area of the rib cage, but it still reveals the arched form of the rib cage beneath by the contours of its muscular bundles and grooves.
The pectoralis major, which covers the upper half of the rib cage, extends vertically from the pit of the neck (A) to the ensiform cartilage (B). Its lower and larger portion (C) attaches to the anterior surface of the sternum (D), where you can count the protrusions of five ribs.
In the fold at the side of the pectoralis (E), Michelangelo indicates the beginning of an intermuscular line that curves along the base of the upper and clavicular portion (F) of the pectoralis to its insertion in the clavicle (G). Following along the clavicle, note the little slip of a connection (H) and, to the left, the recession (I) below the bend in the clavicle, beneath which the pectoralis minor attaches to the scapula.
Notice the angular pose of Michelangelo’s figure. The shifting of weight on the torso due to the slightly lifted leg thrusts the pelvis on the left into the rib cage. The line of gravity runs from the pit of the neck to the inner ankle of the foot that carries the weight. By the simple lifting of a leg, Michelangelo was suggesting the beginnings of a gesture, since the body in symmetrical balance implies stillness.
Michelangelo Buonarotti (1475-1564)
MALE NUDE WITH PROPORTIONS INDICATED
red chalk
11 1/2″ × 7 1/8″ (289 × 180 mm)
Reproduced by gracious permission of Her Majesty the Queen
Royal Library, Windsor
Pectoralis Major, Female
In this drawing Dürer correctly positioned the breasts (A) in the middle third of the rib cage. The large female breast (A) covers the lower half of the pectoralis major. The pectoralis major, upon which the breasts lie, originates in the sternum or breast bone (C), is located below the pit of the neck (B), and inserts at the side in the humerus bone (D).
Dürer was well aware of the pull of gravity on the fatty mass of the breast. He was also aware that the upper rib cage is smaller in the female than in the male, and so allowed ample space at the armpit between trunk and arm. At this “axillary tail” of the breast (E), where the mass of the pectoralis major crosses over the pectoralis minor to go under the deltoid (F) and into the humerus (D), he put his shading well up where the plane breaks on this mass. By adding a little gray highlight below, he keeps the armpit “full of air,” avoiding flatness and the dark “hole” that students often make when their shading is a solid dark. He similarly avoids flatness on the sphere of the breast itself by adding a reflected light to the dark side of this mass (G).
The nipple (H) and the slightly raised areola surrounding it take on the shading of the sphere on which they lie. The detail of the nipple dies out in the highlight; its dark outline fuses with the darks below that define the dominant plane break of the rib cage (I).
Albrecht Dürer (1471-1528)
LUCRETIA
black ink
13″ × 9″ (334 × 230 mm)
Albertina, Vienna
2
THE PELVIS
AND
THIGH
Structural Points, Anterior Aspect
Architecturally, the pelvis is placed in a strategic location. As a link between trunk and legs, the pelvis serves to coordinate their movement and, at the same time, helps to stabilize the entire body.
The pelvis is often thought of by the artist as a constellation of fixed points. It is fairly easy to draw the lines of muscular masses between the landmarks of their points of origin and insertion. A knowledge of these structural points and of construction lines will help you to see the body in perspective and allow you to vary the design of the body in your drawings.
Follow the edge of the mass of the gluteus medius (A) from its insertion in the external surface of the great trochanter (B) of the femur bone to its origin in the iliac crest, the high point (C) of which is approximately on the level of the navel (D). The line of the external oblique (E) points to the front of the iliac crest (F), also known by artists as the pelvic or front point. The curve of this crest extends slightly outward to include the wide point of the ilium (G). Poupart’s ligament (H), the unofficial dividing line between the torso and legs, extends from the pelvic point (F) to the pubis (I), following along the upper line of the groin (J).
When the pelvis is level, the pelvic points (F) of both sides lie in the same horizontal plane. By drawing lines through these points and by using these points to help see the pelvis as a box shape, it becomes easier, not only to draw the pelvis, but to place it in perspective as well.
Sebastiano del Piombo (c. 1485-1547)
STANDING FEMALE NUDE
chalk
13 7/8″ × 7 7/16″ (352 × 189 mm)
Louvre, Paris
Structural Points, Posterior Aspect
It is very important to know what is happening to the backbone, whether you actually see it, or have to “see through” the body to discover its position. This is because all the major movements and rhythms of the upper masses of the body evolve from this structural core.
When the right leg is raised, you can see the masses of the gluteus maximus (A) and gluteus medius (B) stretched out between their insertions in the great trochanter (C) of the femur and their origins along the iliac crest (D). The stretched position causes the posterior superior iliac spines (E)—that i
s, the back points that form the upper corners of the sacral triangle (F)—to show more as bony eminences than as dimples. The shape of the sacral triangle is further suggested by the accents of the sacral foramina (G). The inferior angle of the triangle (H) indicates the top of the coccyx and ends the split of the buttocks (I).
The sacral triangle (F) is about one-third the width of the pelvis in man, and is vertical. In a woman, the pelvis tilts forward and the sacrum (F) forms a forward-curving equilateral triangle, which, though shorter than a man’s, is wider, in keeping with the shape of her pelvis.
Directly below the back point (E), which is the posterior limit of the iliac crest, is located the sacroiliac joint (J). For all practical purposes, this joint does not permit movement of the pelvis on the vertebral column. What appears to be movement of the pelvis actually occurs above in the relatively mobile lumbar vertebrae (K) of the spine. The strong chords (L) of the back also “extend” the pelvis by their contractions, just as the abdominal muscles in the front “flex” the pelvis.
Variations in the direction and degree of curvature of the spine from the seventh cervical vertebra (M) down through the thoracic (N) and lumbar regions (K), describe the position of the thorax and its relation to the pelvis.
Peter Paul Rubens (1577-1640)
STUDY OF MALE FIGURE, SEEN FROM BEHIND
charcoal heightened with white
Anatomy Lessons From the Great Masters Page 2