Article: Your body has natural curves in it, and good posture helps promote them. To have good posture while you sit, you need to keep your shoulders back, your chest open, and your back straight and tall. To keep your shoulders back, you need to move your shoulders back and push your chest out more. You should feel your head move back as well. This should open up your chest and tuck in your abdomen muscles.  Your back should straighten naturally as you push your shoulders back and open your chest  Make sure you keep your shoulders straight and relaxed. They should not be elevated, rounded, or pulled too far backward. Now that you have your shoulders and chest aligned, it is time to learn to stand and walk with better posture. Start with your shoulders aligned with the rest of the spine and your abdomen pulled in. Keep your feet hip distance apart and balance your weight easily on the balls both feet. Relax your knees and hang your arms to the side. Imagine there is a string from the bottom of your feet to the top of your head, keeping your body aligned and balanced. To check your posture, you need to stand against the wall. Your head, shoulder blades, and buttocks should touch the wall and your heels should be 2-4 inches away from the wall. Take your arm and run the palm of your hand along the wall along the space at your lower back. If you are standing with correct posture, your hand should just fit in the area.  If there is more than a hand's width worth of space, you are pushing your stomach and hips out too much. You should contract your abs and pull your back toward the wall more. If your hand cannot fit, you are hunched too far forward and you need to push your shoulders back.

What is a summary?
Keep good form while sitting. Stand up straight. Check your posture.