spiral gesture to cross contour figure drawing

you don't have to draw the ribs and hips, but learning to keep them in mind, even in the simplest form, will help you navigate the figure as you draw. The rib cage and pelvis (hips) are hard bone, connected by the thin spine, and separated by all of the soft tissue of the abdominal cavity (intestines, muscle, fat). You can envision the abdomen as a squishy oval, over which the two opposing hard skeletal components of rib cage and pelvis move (typically in different directions).