I think the gesture is most important. Even more important the muscles and hair and skeleton. If the gesture is not captured then the rest of the accuracy with skeletal structure and musculature is useless information.
Gesture and key landmarks of anatomy are extremely important in figure drawing.
Some good areas to pay close attention to are the joints, shoulders, elbows, wrists, knees, and ankles. If we ignore these parts, the limbs will feel like noodles. Without proper gesture, the figure will feel either unbalance or stiff. Gesture is like the rhythm and beat of a musical piece. Without that the music is lacking.