Habitual structure is a characteristic of Structural Posture, in which no pressure is applied to the configuration of muscle, tendon and bone and the body is at rest.
Body structure is the configuration of muscles, ligaments, tendons and bones that hold the body together.
Our posture, or the way we hold our body, is fundamental to how well we function as human beings.
How we hold our upper body is our body grip. People with better body grip tend to be more functional and emotionally fit.