Good posture is one of the keys to living a healthy and pain free life. Unfortunately most of us don't have good posture. And what is worse is that most of the body mechanics we use at our jobs, at school or at home do not help us maintain a good posture
There are four basic elements that are integral in maintaining good posture: the S-Curve, your muscles, balance and above all movement.
The most important thing about a good posture is that it is a dynamic posture. It should always be moving, at least a little bit. A static posture is pain and injury waiting to happen. In fact static positioning is a common torture method for self inflicted pain.
Your weight is transferred to the ground (or chair, bed, etc.) through only a few points of contact. All that pressure on those points creates "pressure points". The pressure point is often the result of blood vessels being collapsed or flattened closed restricting your circulation. By moving you never put too much pressure on one point for too long to receive the negative effects of a pressure point.
Pressure points are why you toss and turn in your sleep or fidget in your chair. They are also why foot insoles sell so well. Orthotic insoles and well designed shoes can spread the pressure over the entire foot bed and not on limited points.
The S-Curve refers to the shape of a healthy spine when viewed in profile. The spine has a concave section at the lower back. The small of your back and lumbar should form a slight hollow. The spine continues upwards producing a convex area between the shoulder blades. So if you looked at a right profile of the spine (as opposed to the left profile) it would follow an "S" shape.
The spine, with its many vertebrae, is a flexible support column for you upper body that's kind of like s spring mount. It's able to absorb a lot of force and strain due to its design, but if it gets out of the S-curve you magnify the strain on your spine and can cause serious injury.
Maintaining a posture that distorts the S-curve for prolonged periods of time can be quite damaging and should be avoided or at least well managed with adequate breaks, stretching and exercise.
The S-curve and shoulder and pelvis alignment are supported with muscle balancing. The muscles on the left and right side should be equally strong. If you've had an injury or have a weak muscle in some other way then other muscles start to compensate. The muscle imbalance can throw the entire skeleton system out of whack and cause a lot of problems from back pain to Thoracic Outlet Syndrome.
Correcting any muscle imbalance is the first step to a good posture. Often this requires specific training of the afflicted muscle and should be done under the direction of a medical professional, physical therapist, personal trainer or someone else with training in strengthening specific muscles safely.
Muscle Strength & Balance
Ensuring your muscles are strong enough to hold your body in a good posture is the next element to consider. The body should be held in place by your muscles. It shouldn't be resting on itself. Joints will take excessive damage when used without muscle control. And internal organs and structures can cause serious suffering if compressed because you let all your muscles relax and slump.
One of the most common posture problems is slumping your shoulders or hunching your back. This then leads to back pain and a downward spiral. This is most often a consideration for those who are overweight or aging. If you are overweight you are placing more stress on your muscles constantly and they will need to be strengthened to compensate. Or the excessive weight needs to be lost.
The elderly benefit from strength training to maintain muscle mass and density and that helps keep their posture in alignment. In general everyone will benefit from a balanced strength training regime in terms of supporting good posture.
Maintaining good balance helps support good posture. But balance is in part due to a healthy and aligned spine as well as strong and balanced muscles. Inversely a healthy spine needs good balance, and so on. All of these elements support each other for good posture.
To keep good, balanced posture you should keep your trunk slightly forward of your pelvis so more weight is on your toes than your heels. But don't lean forward. You don't want to overload your toes. Left to right weight distribution should be even as well.
A good posture is a dynamic posture that is strong and balanced and supports a healthy S-curve. But they also differ depending on your activity.
Specifics on Postures