A Biomechanical Character - ZBrush Creature Design: Creating Dynamic Concept Imagery for Film and Games - page 370

3. The muscles of the bicep and forearm are created with ZSketch. First append a ZSphere into the tool
and draw a chain down the length of the forearm ( Figure 6-48 ).
Figure 6-45: Create the chest muscles.
Figure 6-46: Create the deltoid muscle.