What causes us to expand or collapse? What resonates (or even spicier, what is the shadow) that so happens to collapse or expand the body? Once the qualia is found, this is what is doing the expanding and collapsing.
Expansion can be thought of as opening and contraction can be thought of as closing.
Someone blows your body up like a balloon till it can no longer expand unless it pops. Then the air gradually leaves as if the life force is sucked from you. Try expansion with inspiration and feel all of the skin breathing. At every surface, feel arrows (energy, qi, awareness) pointing in your direction. If you do not feel the skin breathing, inhale like a yawn and at the peak of the yawn, sustain the feeling. When contracting, feel arrows pointing away from you.
Try expansion/contraction in varying body positions, especially with the fetal position. Also imagine that you are breathing in everything you need, and breathing out everything you do not need (stale air).
Note: With every expansion/opening, there is always a contraction/closing happening somewhere. For instance, contraction or closing of the body into a curled ball happens to open/expand the back.
The two extremes of the contraction (like Hijikata’s Boxed Body of which Figure 1 is a good example) or expansion (like pipe about to burst) are examples of deterritorializations or the extreme ends of the regeneration/reduction of typical human uses of size.
The natural form we take when we expand our body is inspiration, though we can also utilize expiration when expanding the body (and hence inspiration when contracting the body), which gives a whole new feeling.
This type of breath-guided movement is directionally intense. In other words, it is as if you sacrifice one’s own being (sustainability) to either tyrannically contract (suck the energy/information but in result leaves you shriveled) or tyrannically expand (giving out energy/information like force-feeding or going kamikaze). Such breathing can be utilized to highlight a non-integrated shadow or subbody.
Is when the idea shifts from another channel such as expanded or contracted emotion, sound, human relationship, etc.