Most of what you know is probably taking your body further from how it is designed to function.
This is no one’s fault it is just the fact that good information is hard to come by.
Thinking in terms of singular muscle groups e.g. the abs, the bicep is limited at some point apart from muscle development. Even then it leads to savage imbalances over enough time. I know this after messing with my own body structure on the quest for muscle size and having chronic injuries to overcome.
The goal of my training and performance protocols is to return the body to a state of balance and to link the entire structure together. From the inside out and from the ground up.
This 3 month supine DNS position and its many variations are at the core of human function.
The ground might be the best teacher there is to mastery of your body (and mind).