Chest
Added 2023-05-21 23:14:06 +0000 UTCthis joint took me a long time to understand and even still I don't know it by heart
big notes:
The pectorals hook into the shoulder at the very top of the bicep and run diagonally/up to the collar, laterally across the midchest, and diagonally/down to the upper abs.
That anchor point is in front of the shoulder muscle, and is pressed upwards and more forwards when the arm raises overhead. The closer to the shoulder, the more movement the pec experiences in different positions. It experiences a drastic diagonal stretch when the arms are raised, and drawing these shapes properly is key to making the anatomy appear convincing.
As the arms move overhead, the bicep (in neutral poses) continues to face inwards; you see the top of the bicep when the arm is lowered, and the underside of the bicep when the arm is raised.
The rear deltoid and latissimus muscles become more visible as the arm raises higher, both in overall visibility and light exposure. When the arms raise the ribs usually inflate slightly, increasing their width and pushing surrounding muslces outwards. The muscles rotate forwards slightly to accommodate for the stretching that occurs in the arm and pectorals, making them appear larger in front view. Major shadows are cast on those muscles by the pectorals when the arms are lowered because they are acting as barriers for light to reach them. Those shadows become less prominent as the deltoid and lats move forward and slightly out, and the arms no longer act as obstructions for light to hit.
those are a lot of the things I keep in mind
