A Biomechanical Character - ZBrush Creature Design: Creating Dynamic Concept Imagery for Film and Games - page 366

Figure 6-39: The arm is started by duplicating and scaling a series of cylinders at the shoulder.
4. The arm is constructed from basic box and cylinder primitives, as seen in Figure 6-40 . A polygon box is
created and positioned to serve as the basis for the humerus bone. Since I know these arms will be covered
in organic tissue, I'm not too concerned with details outside the joint and articulation areas.
Figure 6-40: Continuing to develop the arm by adding primitive boxes and cylinders