Video 1 - Stand at the Wall
Since the wall provides a template of correct posture where all your load-bearing joints— ankles, knees, hips and shoulders—are aligned, this is a great way to assess your posture. When standing at the wall, your heels, butt, and upper back should contact the wall. If you feel like you are going to fall forward, then move your heels out slightly. When you do this, your head might or might not touch the wall, depending on your upper back position. Either way, don’t force it back by overextending your neck. Instead, be sure to keep your chin parallel to the ground.
It's also important to realize that changing posture not only requires moving the bones, but also includes a shift in your nervous system and brain. When you stand in alignment against the wall, it works on your proprioception—awareness of your body position in space and relationship of your joints to each other. In other words, the brain learns a new orientation for your body. At first, it may feel wrong because your brain thinks that your standard position, which is not aligned, is straight. However, over time, your brain will recognize this new position as correct. It’ll then feel “wrong” in your old posture.