Anatomy study from Bodies in Motion. There are a few interesting things going on here:
On the main drawing the red and blue overlay shows the relative tension/relaxation of the muscles in this climbing pose. The red arrows show the ‘kinematic chain’ transmitting the force from the hands to the torso.
To the left, I’ve removed the latissimus dorsi to show the attachments of the external obliques onto the ribs and how they interdigitate with the serratus anterior. Finally, in the upper left there is an exploded view of the upper arm showing the distinct heads of the deltoid (anterior, lateral, posterior) and the biceps (short and long heads) and also how the biceps overlays the brachialis on the humerus.
Timelapse of the drawing coming soon…