What do you think of when you think posture? Do you think of standing or sitting up straight? Or do you think of posture as the way your body adapts to its activity. I'd like to introduce the idea of posture as something dynamic, meaning it changes and is flexible, rather than being something static or solid or a shape one strives to obtain as and then maintain.
A dynamic posture is the opposite of a prescriptive idea of posture (the one in which you may have felt pressure to 'stand or sit up straight'). Posture is not about 'standing up straight' but is about being in alignment and moving with ease in whatever activity you're doing. Having a dynamic or moving approach to posture allows the body to be in the shape that is most suitable at the time.
No living being is static, the body is always in motion. A body that is not in motion is dead. Even when asleep or unconscious the body still moves, it has to, it has functions to perform to keep you alive. So instead of posture being some fixed shape that doesn't move either, whether rigid and upright or continually slouched forward towards a screen your posture needs to to keep you balanced, neither one extreme or the other but constantly fluctuating depending on the situation.
By becoming more bodily aware you notice how your posture (or shape) is at a particular point in time. You begin to notice when you're out of alignment because you no longer feel good in your shape. Once you notice how you feel then then you can adjust your way of standing, sitting or moving to feel better. This allows the body to back into balance, rather than forcing it to be something that looks like 'good posture'.
I would say that you have 'good' posture when you stand and move with ease; how you stand and move without putting undue pressure on any part of your body for long periods of time. By enquiring into how you are standing and moving, rather than striving for a pre-conceived idea of 'good' posture, you allow yourself to make different choices and ease into different, less effortful ways of standing, sitting and moving.
Exploring somatic movement and Pilates are excellent ways to develop your body awareness and get a sense of your own moving, standing, sitting body and will help you do these things with more ease. Book in a session with me if you'd like to explore somatic movement or Pilates.
By allowing your posture to be dynamic, you allow yourself the space to get back into balance so that you can move, sit and stand with more mobility and freedom.