What is a one-sentence summary of the following article?
People who feel uncomfortable about their height may be prone to  slouching. This not only looks bad, but it can cause back pain. For the best posture, keep your shoulders comfortably back. They should never be raised towards your ears or rounded forward. Be careful not to hyper-correct. Your shoulders should not be so far back that you would not be able to stand with your entire upper back against a wall. Just like slouched shoulders, walking with your head down makes you look like you are not confident, and it can cause you pain. Try to hold your head up straight so that your neck is not bending forward or to either side. You should be looking directly in front on you, not at your feet! A good way to tell if your head is straight is to take notice of your chin. It should be parallel to the floor for ideal posture. You should have a slight arch in your lower spine. To find out if your posture is proper, stand against a wall so that your head, shoulders, and bottom touch the wall and your feet are a few inches away. If you can just barely slip your flat hand behind your lower back, your posture is ideal. If you have too much or too little of an arch, make a conscious effort to correct it. Pulling your abdominal muscles in can help straighten your back. While arm and leg posture is not directly related to your height, they are essential to overall good posture. Having your arms and legs in the correct position while walking will make you look much more confident.  Your arms should hang freely by your sides as you walk. Your legs should be about the same distance apart as your hips, and you should distribute your weight evenly on both feet. Be careful not to lock your knees.

Summary:
Keep your shoulders back. Hold your head high. Maintain the arch in your lower spine. Remember your arms and legs.