Why should we strive to have good posture? Good posture allows the nerves to exit the spinal column without interference and thereby carry messages properly to all the muscles, organs, and glands in the body. Conversely, abnormal posture, i.e. shoulders hunched, head forward, stomach bulging, results in altered biomechanics of the muscles and spine and increases the likelihood of spinal degeneration and injury.
For appropriate postural alignment (when looking at a person from the front to back) you should observe the nose, chin, Adam's apple, sternum and naval in a straight line. Likewise, the earlobes, shoulders and hips should be level. When looking at the body from the side there are three spinal curves that should balance at these specific landmarks: the ear canal should line up over the tip of the shoulder; both of the above should in turn align with the hip bone and the knee.
Stretching and strengthening specific muscles helps to maintain proper posture. Similarly, maintaining good spinal alignment while standing, sitting, and lying down also help to maintain proper posture. Sitting in any seat should maintain the curves of the spine just as they are in proper standing posture. It is important to support the curve of the lower back by sitting on your sits bones, by sitting up tall and by pulling your lower abs in without collapsing your spine. Sitting on a wallet is not advised, because it creates unnatural curves in the spine, muscle imbalance and misalignment of the vertebrae.
One way to find correct sitting and standing posture is to slouch completely. Then sit or stand fully erect; as you relax by about ten percent from this exaggerated position, you will most likely be correctly aligned. However, maintaining this posture may require stretching and strengthening of the muscles and chiropractic adjustments to the spine.
There are several simple exercises you can do to help strengthen postural muscles.
Focus on a fixed object at eye level. While holding your gaze on this object, pull your head straight back over your shoulders. This will realign the ears over the shoulders. When this movement is executed properly, it promotes the "double chin" look.
Try to elevate the pubic bone, while decreasing the arch in the small of your back. Another way to do this would be to "thrust" the hips forward while simultaneously tightening the abdominal muscles. If you do this lying flat on your back you will feel the small of you back press into the surface you are lying upon.
The rhomboid muscles are located between you shoulder blades. Use these muscles to pull your shoulder blades together. Do not let your shoulders come up toward your ears and do not stick out your chest. This is a very small movement.