The effective use of your body is extremely extensive. Actors for instance learn the necessity of adjusting their bodies to convey or communicate roles and status. For instance wide stance with an elevated forward chin enhances status. It tells the audience that you're somebody. On the flip side by adjusting your feet to be pigeon-toed, keeping your head tilted down slightly, and collapsing your chest signifies lowered status.
These are two extreme forms of using your body to convey status, but the discrete use of such subtleties allows you to adjust your role accordingly. For instance if you are meeting with a high powered attorney to discuss tempered litigation, and you want to show dominance and status, then you can act in a more dominant matter by allowing your chin to be forward, head high and standing tall. Additionally you can take up more physical space; this is a signifier of status and importance, typically used in acting scenes to make the actor appear larger than himself.
If on the other hand, you want to play a submissive role strategically, then you can consciously close in your space a little. You can narrow your space and bring in your shoulders slightly. A leveled or slightly below level chin will suffice to show submissiveness. Acting submissively does not mean you are, or that you will allow yourself to be steamrolled. It is used as a strategy to engage the other party on their own terms, giving you the ability to position yourself in a more subtle fashion. Additionally, playing a slightly submissive or cooperative role is one of the best ways to disarm whomever you are dealing with.
Napoleon, the infamous French emperor, used such a strategy against the Austrian and Russian armies in the battle of Austerlitz. After having received intelligence that Napoleon appeared confused, and had assumed a defensive position, the Austrain/Russian forces descended for the kill. Napoleon had staged a perfect submissive role, and by making the enemies believe he was submitting, he made them fall right into his trap. The outcome was one of Napoleon's most impressive victories.
Keeping the Grand Strategy in mind, that is, by keeping the end in mind; you can choose the appropriate strategy to gain advance towards your preferred outcome.
(excerpt from upcoming book on Communication)