20: Raphael. The left arm activates trapezius and other related muscles.
22: Raphael. Right arm bent, raised. "The trapezius moves over the superior angle of the scapula
(E), which it holds against the rib cage, and then inserts into the spine
(M) and the acronmion process (N) of the scapula."
28: Tiepolo. Left scapula retraction. Right scapula protraction.