At the beginning of this section, you sculpted the general shapes of the posterior deltoid, trapezius, infraspinatus, and the teres muscles. Together, these muscles shape the shoulders and upper back, and now you will sculpt the muscles of the lower back. The largest muscle in the mid-lower back is the latissimus dorsi. This muscle originates and fans out from the middle of the back to its insertion at the medial aspect of the humerus. Note that the superior medial aspect of the latissimus is covered by the trapezius (Figure 4.17). Use the Wax tool to build up the shape of the latissimus as shown in Figure 4.18, and then try freezing the surrounding anatomy with the Freeze tool and use the Grab tool to pull the muscle out, slightly. Next, using the Contrast and Pinch tools, define the edges of the back muscles.
FIG 4.17 The Surface of Posterior Lower Torso Is Made Up of the Inferior Aspects of the Trapezius, the Latissimus Dorsi, and the External Oblique.
FIG 4.18 Sculpt the Large Latissimus Dorsi Muscle, Define the Furrow along the Middle of the Back, and Then Shape the Gluteus Medius and Gluteus Maximus Muscles.
Along the midline of the back, there is marked furrow formed by the skeleton (spine and ribs), the deep muscles of the back, and on the surface by the trapezius and latissimus. Make sure to accentuate this midline furrow with an inverted Bulge and Smooth tool to blend. Above the buttocks, the midline furrow is formed by erector spinae muscles. Once you are done with the back, take a moment to shape the gluteus medius and the gluteus maximus muscles as shown in Figure 4.18. Together, these muscles form the buttocks. The upper medial aspect of the buttocks and the lower back form a marked “V" shape right over the sacrum.
