DAYTON, Ohio — When most people think of good posture, they think of shoulders pulled back, head held high, chin up and back flat.

In reality, good posture is more about trying to keep the natural curves of the back in balance when standing, sitting or lying down. When these curves are in their resting or neutral state, they experience the least amount of strain.

Good posture improves circulation and breathing, boosts the nervous system, enhances exercise performance, reduces risk of injury and accelerates healing from injury.

The spinal column has many important functions, including providing support and protection of the spinal cord and nerve roots. It consists of small bones, the vertebrae, stacked one on top of the other like blocks, and discs that act as shock absorbers and allow the spine to move.

The cervical (neck) area of the spine supports the weight of your head, the thoracic (mid-back) area provides stability and support to the upper back, while the lumbar area of the spine relates to the lower back. Below the lumbar area is the sacrum, which connects the spine to the lower half of the body. At the bottom of the spine is the coccyx or tailbone.

When the vertebrae are misaligned, the natural curves in the spine are thrown out of place, creating stress and strain on muscles, joints and ligaments, which in turn, affects posture.

Many myths and misconceptions exist about how to establish good posture. In her book "8 Steps to a Pain-Free Back," author Esther Gokhale uses historical and scientific evidence to help sort fact from fiction.

Myth 1: If you want to correct poor posture, just straighten up.

Forcing a straight body position does nothing to address the root cause of poor posture and can bring about muscle tension and distortion of the spine. Eventually, the discomfort and fatigue causes most people to return to slouching.

Myth 2: Keeping your chin up and chest out constitutes great posture.

Pushing the chest out and tilting the head back creates muscle tension and exaggerates the cervical and lumbar curves, potentially hindering circulation to these areas and pinching nerve roots.

Myth 3: Having good posture requires mental and physical effort.

The body strives to heal itself, and when posture is good, you look and feel better naturally. As new movement patterns are established, they become a habit, increasingly instinctive and natural, doing away with the need to have to remind yourself to adjust body position.

Myth 4: It's too late to change my posture.

It is never too late to change your posture for the better. The body is resilient and was designed to move, and so it adapts well to most activities. Study after study reveals that even people in their 80s and 90s can make significant changes in their posture, giving them greater mobility, independence, health and quality of life.

If you are unaccustomed to being active, work toward conditioning the body gradually over time. Although muscular strength is vital for support and stability of the spinal column, relaxation of muscles is also important. When muscles are overworked, risk of injury increases, so allow time for rest and recovery.

Myth 5: You should always breathe through the belly.

"Breathing through the belly has been regarded by some experts as the only way we should breathe," Gokhale said. "In fact, different kinds of breathing are needed for different kinds of movement. Belly breathing is appropriate when you have an elevated need for oxygen (as when you are running) or breath control (as when you are playing the saxophone).

"Otherwise, when at rest, inhalations should primarily expand the chest cavity and lengthen the back, only slightly moving the belly. Movement of the chest and back helps in maintaining normal rib cage size and shape, and fosters healthy circulation."

Myth 6: Good posture naturally comes about from being physically fit and active.

Gokhale explains, "This would be like driving around with a crooked axle, hoping that the driving alone will straighten it out." If a person has poor posture, underlying issues must be addressed. Increasing activity levels does not guarantee a solution and can result in injuries instead of improvement.

Far better to focus on good posture in its own right, or alongside increased activity. Once you have obtained good posture, you will get much more out of your activity; which in turn feeds into helping to maintain your results.

Marjie Gilliam is an International Sports Sciences Master certified personal trainer and fitness consultant. She owns Custom Fitness Personal Training Services. E-mail: marjie@ohtrainer.com. Her website is at www.ohtrainer.com. This article appeared in the Dayton Daily News.