Compressive Strategies - Are They Happening Simultaneously or One After the Other?

I was wondering if you could expand a little bit upon the difference between upper and posterior Compressive strategies. The idea of how they are represented within the pelvis and the thorax. And another question I had on top of that if it's not too much would be like are these happening simultaneously? Or are they happening one after the otherLike how does that work and what are the differences? Okay, so the the simple answer is yes, they're happening simultaneously But in a sequential nature because of the way that fluid volumes move inside of the human body.