Your posture is a bunch of building blocks -
- The connection of your feet to the earth. Using the whole foot when you walk, spreading your toes, keeping your ankles flexible and finding your centre of balance.
- The cavity of your pelvis that relies on the above as it's foundation plus the feeling that the back muscles and the abdomen muscles keep it feeling centred and allow the spine to feel weightless.
- The chest that relies on the above as it's foundation plus the flexibility of your intercostal muscles to feel the calm power of the breath that opens the space for the heart to roam freely.
From here you don't need to hold the weight of the world on your shoulders since you distributed it evenly throughout the body.