Pectus Carinatum vs Pectus Excavatum Theory

What are the differences between pectus excavatum and pectus carinatum? Or should it be more right to ask what the similarities are? Or would it be to question if they have anything to do with each other at all?

When having a look at people with those conditions there are two similarities that are the most important I believe.

1. The compression of the back causing the spine to have an unnatural curve called kyphotic spine (it can be so small that it is almost unnoticeable, especially for excavatum).  

2. The back leaning posture.

This makes it likely to believe that Carinatum and Excavatum have the same environmental factor. And what is that main factor? Wrong ergonomics (ordinary shoes that lifts the human heels) that keeps the body out from the perfect vertical ergonomic line and puts the upper back under pressure.

When having a look at a typical person with carinatum there is one big difference compared to excavatum (except the sternum).

The abdominal area, the pelvis and the lower rib cage are intact (or mildly distorted). If the pelvis does not rotate (as in the case with excavatum) there will be a much greater stability in the abdominal area so the abdominal muscles keeps the lower rib cage intact. This will lead to that the rotation of the thorax will take place in the upper part of the thorax (from the sternum and upwards). The abdominal area is able to withstand the pressure from the upper back. And because the lower rib cage is intact the diaphragm will work a lot better and keep the pressure under the sternum and it will play a key role when the sternum starts to be pushed out by the ribs. The ribs and the diaphragm will work together to push it out. Why does the diaphragm push it out? It is the same answer as for pe but in a different way. The chest cavity is smaller than it should be and the diaphragm is over dimensioned compared to the space and it will continue to push it out until the space has become largely enough.    

Pectus Excavatum: The diaphragm push the lower ribs out together with the rotation and compression of the whole thorax after birth. Before birth it is only caused by the rotation and compression.

Pectus Carinatum: The diaphragm push the sternum out together with the rotation and compression of the upper part of the thorax. Before birth it is only caused by the rotation and compression. A stronger abdominal area will make the sternum to move the opposite way compared to excavatum.

Once pectus carinatum is fully developed the diaphragm has the space it requires to operate normally. The problem in the case of pectus excavatum is that the abdominal muscles constantly works to close the lower ribs. This will lead to that the diaphragm and the abdominal muscles will keep up a struggle between them and raise the need for energy (food) constantly over time. This will not be the case for people with pc because there are no muscles that struggles hard to pull in the sternum. It will therefore be less likely that people with carinatum are very skinny.

Pectus Excavatum: Much greater demand for energy constantly.

Pectus Carinatum: A little more demand of energy, especially in the initial stage of the development of the condition.

The male-to-female ratio is relatively similar. 3:1 for pe and 4:1 for pc (according to wikipedia). This fits well in to my theory that there is a specific reason why men are over-represented. Men are generally taller and have bigger feet which will cause a higher moment (newton meter, Nm) when the feet are lifted up under the human heels and the tallness will cause the person in question to go very far away from the perfect vertical ergonomic balance line.

Illustrations and "Thorax Rotation Syndrome" (working title): Here