Male Arms

Been looking at anatomy so I can break down the structure to better inform my thumbnails when preparing to animate.

Today I have been looking at male arms a little closer. Firstly I looked at the muscle structure a little closer, broke it down into the different parts then simplified the structures further in order to give a clearer idea of the shapes involved.

I then applied the basic structure to photos of people in various positions and as you can see in the bottom left of the image below started to apply these shapes to cartoon images with unrealistic proportions. 

Finally I then tried to apply the shapes to different builds and in poses not from reference