That pic you posted from the anatomy book up higher shows the principle. There is a section on balance in every anatomy drawing book. You haven't been taking your art vitamins.
Basically, understand that movement comes from swinging weight around. When part of your body swings around another part has to counterbalance it. That counter balancing system relies on a set of dynamic arcs and angles in the skeletal system. In the torso the main relationships you need to understand are between the line of the spine, the angle of the shoulders and the angle of the hips. ( The angles as seen in a frontal plan view- a line drawn across the shoulders from acromion to acromion and on the hips from trochanter to trochanter)
For our purposes you need to know that the line of the shoulders and the line of the hips will always be in opposition to each other. If the left hip is up, the left shoulder will be down, and vice versa. It it possible to come up with gestures that violate this rule , but not if the person is standing on the ground with no external forces acting on them aside from gravity. Your picture violates this rule. Further, the weighting is off. Your figure is stepping forward and taking the weight on the front leg. Bio mechanically, that hip must then be higher than the other, but you've drawn it lower.
Why am I writing this? Just go and read the books, do lots of contraposto studies, you'll get the hang of it.
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