POSTURE

Our upright stance and the sedentary nature of so many modern occupations have contributed to many of our internal and back problems. Good posture is absolutely essential in helping to maintain health and fitness.

Posture is the term used to refer to the way we stand and move about. Man's normal upright stance has taken millions of years to evolve, and the process is briefly repeated in the life of each baby who at first can only move about by crawling on all fours. The bent-up positions of the womb are changed gradually by natural stretching and kicking reflexes, and a child may be 12 to 15 months old before he is strong and well-balanced enough to stand upright.

POSTURE AND THE FORCE OF GRAVITY

The overwhelming physical force to which the human body is subject is the earth's natural pull or gravity. Man's centre of gravity - the point where his weight is balanced - is in the lower back and pelvis.

Good posture is primarily a matter of efficiently balancing the body weight around this point, not only when you are still but when you walk, sit, run, work, play games and so on. Whatever movements are made the weight on all sides of that point has to be equal - otherwise you will topple over.

Because this area of the back is the focus of so many of the body's movements, and it bears the brunt of any lifting, it is particularly vulnerable to injury, damage and disorders.

MUSCLE CONTROL

Man's erect posture is only achievers and maintained by a fine muscular adjustment concentrated on his centre of gravity and supported by the ligaments of the spine.

Muscles can only act by shortening or contracting, not by stretching. Therefore to reverse a movement another muscle has to act in the opposite direction. Each muscle can also work together with other muscles to produce a balanced movement by pulling at the same time, but not with their full power.

Well-balanced movements require not only muscular power but relaxation in those muscles which act in the opposite direction. Economy and precision of muscular effort which are essential to good posture are greatly improved where stress is absent. A person who is mentally relaxed will as a result be physically relaxed and therefore able to stand and move well.

THE ROLE OF NERVOUS SYSTEM

Posture is not simply a matter of muscle control. The muscles themselves have to be controlled and this is done by the nervous system. In a child who is learning to stand and walk this process of keeping balance is a conscious one, but soon habit patterns develop and it becomes subconscious or automatic.

Messages indicating the position of various parts of the body in space, and in relation to each other, are transmitted from nerve endings in the skin and in the muscles themselves to the spinal cord and brain. Signals are then sent to activate the correct muscles for any necessary movement or change in position.

Thus poor balance, abnormal posture, muscular weakness and poor co-ordination of movements may be due to disorders of the nervous system or of the muscles themselves. The connection is such that if, for example, a muscle loses its nerve supply it can no longer contract and begins to waste away.

GOOD AND BAD POSTURE

Apart from disorders of balance, people's posture may be either good or bad. Good posture depends largely on keeping all the postural muscles of the body toned and balanced. This requires the conscious effort of maintaining good posture at all times, and of taking adequate exercise to keep all the joints and muscles in a healthy condition.

To ensure correct posture and avoid strains and unnecessary accidents, posture training is needed. The appropriate exercises can be enjoyable and help people to learn how the body works and how to take sensible care of it. Maintaining good posture or correcting bad posture will not only transform the appearance but substantially benefit the health. A person who makes this effort will feel fresher at the end of the day.

Bad posture has quite specific ill effects. Round shoulders, a curved spine, slack abdomen and drooping chest cause faulty digestive and bowel function as well as breathing problems. In addition, bad posture and poor relaxation contribute to many accidents in the home, at work and on the streets.

Bad stance and movement can particularly affect the hip joints and the lowest joint of the back, which are more prone to developing arthritis in later life. Lumbago, slipped disc and sciatica are also more liable to occur.

Another disorder caused by poor posture is foot strain. This often results in a job which involves long periods of standing and walking, with not enough care taken about doing these correctly. An abnormal amount of strain will be placed on the ligaments and bones of the foot arches causing pain. This possibility may be diminished by doing simple exercises to strengthen the feet and ankles.