Here's a quick exercise to determine the state of your posture. Stand up straight with your back against the wall. The back of your head, your back itself, your glutes and your heels must be in contact with the wall at all times. Now, lift your arms up into a position that looks like this:

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Your forearms being perpendicular to the ceiling, while your upper arms are parallel to the ceiling.

  1. Now, while maintaining the 90 degree angle with your arms, attempt to have both your elbows touch the side of your rib cage, or above your obliques, while keeping all body parts mentioned above (including the back of your hands, elbows, and rear deltoids)touching the wall. Go as far as you can go, and squeeze your shoulder blades for about 2-3 seconds. Then return to original position.

  2. Then, in one fluid motion from step 1, lift your arms to the ceiling, creating a "Y" with your arms, while keeping all mentioned body parts against the wall at all times. Return to original position.

If you find that this exercise is difficult, though it does indicate that you have poor posture, there is no need to worry. Work at it day by day, as this exercise helps improve your posture naturally. After you complete it, you'll notice that your posture looks a lot more upright, in a relaxed, natural way.

I myself had poor posture from sitting in front of a fucking computer all day. After finding out about this, I did this exercise/stretch every morning. 12 reps, 3 sets. In 3-4 weeks I had people claiming that I had grown at least half an inch. Cheers seddit!