Structurally, our bodies are built with tensigrity.  Meaning the strength and balance of our bodies is determined by the balance of continuous tensile forces provided by the fascia vs.. leaning on compressive forces provided by the bones.  The bones act more as spacers.  Think of a suspension bridge.  This allows us to weather and sustain a variety of pressures and movements from outside forces without injury, especially when we’re young before we’ve built up restrictions from use or trauma.