When thinking about your posture, imagine gravity acting on your body like water in a down hill stream.
Gravity likes to find its most direct line to the ground, and water will keep flowing downward unless it is caught in pools and eddies which prevent it from flowing freely.
In our own bodies, we create bends and kinks as we allow ourselves to collapse, creating our own pools and eddies for gravity’s downward force. When gravity becomes caught in one of these “kinks”, the forces which should be moving throughout your body become focused or caught in this one smaller area. This area is usually the one which eventually attracts your attention with aches and pains as it asks you to kindly take the pressure off it and get those forces moving again.
It’s easier than you may think to address. Be the river. Allow the kinks to ease out and the folds to uncrumple by taking a moment to gently expand your body upwards and outwards. Every so often through the day, think of carrying yourself lightly and buoyantly, and feel the forces flowing freely through you without restriction.