A Caution
A drawing teacher of mine once told this cautionary tale about anatomy and figure drawing.
It used to be the custom that an art student would spend quite a bit of time drawing from plaster casts before being allowed to draw from life. These casts were taken from heroic Greek statuary and models of the flayed figure, so the students had a solid foundation in anatomy before being faced with the living model.
Finally the first day of life drawing would come. A model would take her position on the stand - a slender girl in a relaxed pose. And the students would proceed to draw her as if she were a stonemason, coated in straining muscles from head to toe.
Anatomy is useful for conceiving the shape of the figure, but should not become a preconception that cannot be shaken off. Certain hard-working artists are prone to drawing figures that look anatomical rather than artistic. This is not unacceptable in particular kinds of illustration, but fine art drawing should be more sensitive. Use whatever information you can get, but don't let it use you.
The artist continually seeks the underlying principles. Anatomy, line, shape, and mass must work together to create a cogent figure drawing.