Good movement requires that we use our skeleton precisely and accurately for support. Unfortunately, it is difficult for us to feel our skeleton and it goes out of our awareness. So, I love anything that helps us visualize our skeleton.
In this cute, short (2 minute) video, Mia Hurst demonstrates what happens when she slouches. We can see the lengthening and shortening of the spine. We can see the expansion and collapse of the ribs. We can see how the ribs and pelvis come together to reduce constrict her breath. The part I love, though, is watching her hip joints move as she moves her legs. Check it out: