Sculpting - Blender Master Class: A Hands-on Guide to Modeling, Sculpting, Materials, and Rendering - page 82

Figure 6-23: Adding shape keys for different poses. Top left: The Shape Keys panel found in the Object Data tab of the
Properties editor. Top right: Selecting the arm to move it to a new position to make the previously hidden areas of the arm
and chest more accessible. Bottom: The new pose applied in Sculpt mode and a separate, similar shape key for the legs.