Thursday, February 9, 2012

A shear model of the human body:


Dear Friends,

The human body consists of more than 200 bones and more than 600 muscles; these are coordinated by the nervous system and the brain to produce the very complex movements that the human body is capable of.

There is sufficient evidence to show that humans unlike other animals end up distorting their bodies so that they are much weaker than they ought to be; they also end up having many ailments that can be traced to this distortion of the body.

To understand the nature of these distortions we take recourse to various models. So far we have presented three models:

1. In the guy rope model ( Fig 4, of my website www.humanposture.com) we introduced the idea of treating bones in the body as struts and the muscles as guy ropes. In this model we bring out the idea that these guy ropes (muscles) are arranged very close to the struts (bones) making the arrangement very fine tuned and critical.

2. Another guy rope model in Fig 5 of the above website, which brings out the idea that if the struts (bones) were to be distorted beyond a certain limit it would become very difficult for the system to recover on its own.

3. Super sandwich model in the website http://www.thesupersandwichmodel.blogspot.in/. This brings out the idea that it is very difficult to correct a postural problem locally, since the distortions will get related in very complex ways to distortions in the rest of the body.

We will now introduce a fourth model ‘A shear model’ of the human body. Using this model we can more easily answer a lot of questions regarding faulty posture. 

If we take a section of the body say, at the upper arm, we will find the following layers: skin (which itself is in multiple layers), then a number of different muscles that overlap and finally the core consisting of a bone. When we move the forearm, these different elements will slide one over the other to apply force and to produce movement. Force is applied within this system by putting the bones in compression and the muscles in tension.
My very strong suspicion based on my own efforts to correct my posture is that when our posture becomes faulty this system of elements smoothly sliding over one another will go haywire in many parts of the body. The whole setup can sort of congeal, restricting the free relative sliding of the various elements: the system congeals to provide additional support to a system which is no longer in proper balance.  

The role played by the skin (which may not be very elastic) in this process - which facilitates relative sliding motion - needs to be investigated. If for instance the skin has got overstretched, or perhaps contracted, how is this reconciled with what is underneath in the process of posture correction? I do not have sufficient knowledge of human anatomy and physiology to answer these questions myself. (Someone with better knowledge can try to fill in the blanks). With this new model we will now try to answer a few questions.

1. Why is correction of posture so difficult?
 The elements in the human body would have sheared to different positions. Correcting posture will involve bringing the elements back to their correct relative alignment.

2. Why is correcting posture an issue in the first place? After all people do manage to ‘function’ one way or another.
Practically all adults will be functioning in faulty ways. There will be many areas in the body where the free shearing of elements will be inhibited: these inhibitions will provide support to the parts of the body where motion is relatively smooth and the shearing action is facile.

3. Could we be stepping into the fire from the frying pan in the process of posture correction?
People with bad posture (that is most people) will have two distinct areas in their bodies: areas that are arthritic and areas where movement is relatively smooth. The danger in starting to correct our posture is that (when we don’t understand what the heck we are doing - which seems to be more or less the situation at the moment) we could end up compromising the areas where the movement was relatively smooth so far. In other words we could end up increasing our level of tension, and in reality have worse posture than before!!

4. How do we solve this problem?
My hope is that once we understand the correct way to balance the head:   http://headbalance.blogspot.in/  we may be able to get out of the gridlock more quickly.

5. Does the above problem give strength to the argument made by many that good posture has nothing to do with ‘posture’ per se?
Yes. We must be very sharp about how we plan to correct our posture. In the absence of proper knowledge correcting posture can increase our level of tension and make us less flexible.

Regards,
Selvaraj