Here’s a study of the pectoralis major muscle I did. Gotta be able to draw a good pair of pecs.
I’ve been studying the origins and insertions of the deltoid muscles.
Then I tried to apply this to a sketch:
I’m still trying to improve my anatomy drawing.
I’ve found that if I learn where muscles start and end, I feel more confident drawing them.
Here is a study of three of the muscles at the back of the shoulder: the Infraspinatus, Teres Minor and Teres Major.