Structural Posture

Lead In

What is structural posture? Today I am going to examine in more depth how muscle, tendon and bone work together to create your posture. We will examine the concepts of habitual and dynamic structure.

Intro

In the previous presentation on Posture we discussed how we can split posture into two distinct components, structural and voluntary.  Here we expand on what we mean by structural posture.

Definition of structural posture

Image
Human anatomy male muscles

Structural posture is that part of our posture that is defined by the configuration of muscle, ligament, tendon and bone and which remains to some extent outside of our voluntary control. Muscle, ligament, tendon and bone hold our body together, and this is relatively stable and consistent due to the rigidity of bones and the stiffness and elasticity of tendons and ligaments. If our body was more like a jellyfish and not stable in structure, then there are a lot of things we simply wouldn't be able to do.  Structural posture is something we share with all other vertebrates, like mammals, birds, reptiles, amphibians, and fishes.  Without structural posture vertebrates would not have the distinctive shape and structure that we are all familiar with.

Main Event

In the previous presentation on posture I explained that bones are rigid and generally do not flex at all, nor do they stretch. They supply unmoving, rigid structure. The tendons and ligaments are elastic. They are the springs in the body, and will stretch slightly when we move but always returning to their original shape. Ligaments join bones together at the joints and tendons join muscle to bone. Muscles in contrast, are flexible and their main purpose is to supply movement. Muscles contribute to structural posture in a different way.  They have tensile strength.  They are like rope.  When you pull rope it provides resistance and will hold.  When you push the ends of the rope together, however, there is no resistance.  Muscles behave just like this.  In fact the only way we can use muscles is to stretch them.  When not stretched they are just limp bits of flesh hanging on our bones.

We have big muscles, such as those in our arms and legs, which evolution has woven into a matrix of sometimes opposing forces that work in concert with tendons, ligaments and bones, to provide us with complex movement such as walking and running, jumping and swimming.  We also have many smaller muscles, some of which work in closely with ligaments and tendons to help maintain structural posture.  Examples of the latter include the intercostal muscles which join between the ribs, and the nose, eye and forehead muscles which help construct features in the face.  These are the muscles that are crucial to emotional fitness and during the course of these presentations we focus almost exclusively on them.

I've said that structural posture is to some extent outside our voluntary control. Now let's describe that part of structural posture that is potentially in our control.  Whenever we do things with our body and we come up against the boundaries set by our muscles, ligaments, tendons and bones, we tend to retreat to avoid hurting or breaking something.  We could, however, persist with pushing the boundaries, and in so doing apply pressure and stretch muscles, ligaments and tendons to temporarily change the structural configuration.  As we know, because of the elastic nature of tendons and ligaments, once that pressure has been released, the body quickly returns to the previous state.

We now have two different states we can explore, which we can call habitual and dynamic structure, as follows.

Habitual Structure

Habitual structure is the configuration of muscle, ligament, tendon and bone that your body has when it is operating within structural limits.  This involves using muscles for movement, but without overly stretching ligaments or tendons.  Let's understand this by focusing on the face and the chest.  You can voluntarily move many muscles in your face; smile vibrantly, or frown like a clown, but when you relax them all, your face will return to the same posture each time.  You can voluntarily breathe into your chest and expand, or flex the muscles to lift heavy objects, and when you relax them, again, the chest will return to the same posture each time.  During the course of those actions, if you don't put much stress on tendons and ligaments, then that is your habitual structure.  Although you might voluntarily move some muscles, take up a different pose, and put a small amount of stress on your body, the underlying structure doesn't change.  The small muscles and their associated ligaments and tendons that make up your underlying structure remain the same.

Dynamic Structure

Dynamic structure is the configuration of muscle, ligament, tendon and bone that occurs when you stretch beyond those boundaries.   As we know this is temporary and upon release, the elasticity of ligaments and tendons will ensure that the structure returns to the habitual state.   

Technology

The human body is a mechanical engineering system of muscles, ligaments, tendons and bones.  In engineering, stress is described as the application of force to a structure that does not damage its integrity.  All structures are built with some level of stress tolerance in place.  By activating muscles and stretching tendons and ligaments, we cause stress to parts of our body and create a dynamic structure.  Provided this does not break any muscles, ligaments, tendons or bone then this is a normal and healthy activity.

Most of us know what it is like to build muscle mass by lifting weights, doing press ups or similar.  This involves stretching muscles and enduring pain, after which the muscles gradually grow in size.  Dynamic structure is similar, but the target is primarily tendons, and to a lesser extent, ligaments, rather than muscles.  Because tendons and ligaments are stiff and much harder to stretch than muscles then more effort is required to make changes and changes can only be made in smaller increments.  The way to build your structural posture is to do exercises that stretch the ligaments and tendons to create enhanced habitual posture.

Personal experience

At university I studied, a year of engineering, a year of architecture and finished off with a degree in psychology, so I bring a hard science approach to human behaviour.  The ideas expressed here represent an hypothesis for you to test, but I wouldn't be publishing them unless I had tested them myself and found that they are valid.  

Recap

The basis of human posture is the configuration of muscles, tendons, ligaments and bones that make up our structure.  This structure is stable and consistent over time.  The most relevant structures in our body are the chest and the face. It is useful to distinguish between habitual structure which is the structure that is formed by our daily habits, and dynamic structure, which occurs when we go outside our normal boundaries and try something new.

Challenge to audience

I challenge you to look at your body as a complex structure of muscles, tendons, ligaments and bones and understand better how it works.  It is your body and there are many things you can change.

X