DaVinci, Biotensegrity, and Shifting Paradigms in Cerebral Palsy

I have finally managed to put together a previously promised post on what I termed "masts and riggings" that was intended to shed some light on the complexity of human engineering and architecture.  The reality was that this was an obviously bold task...as the human organism contains infinite complexity.  Therefore I decided to be somewhat more humble and attempt to convey a relatively universal conceptual description of a broader perspective on "how things work". 

I have used the adjacent DaVinci sketch before, simply because it is both elegant and simplistic at the same time.  It serves the relevant anatomical understanding, and also builds a link to the more "generic" diagrams I will insert later in the post.

There are essentially two (2) elements that embody how the human organism is engineered: Compression and Tension (Biotensegrity).  

Compression:  Those elements that are engineered to either absorb compressive forces or to distribute compressive forces.

Tension:  Those elements that exact longitudinal forces within the organism. 

As crudely illustrated in the image above, the neck is an excellent example to use in order to project the relevance of the broader perspective. The light blue squares represent the vertebrae themselves, the light green ovals are the intervertebral disks, and the red arrows are representative of the longitudinal "pull" of any given set (or group) of skeletal muscles.  In effect, there is no "true" static position of the head...rather it is always in a state of dynamism...which is characterized by a constant exchange (or shifting) of compressional and tensional priority.  Therefore, in order for this generic system to function, there MUST be a tensional AND compressional component involved.  Without the tensional aspect, the vertebrae would effectively fall to the ground...without the compressional aspect, there would be no dynamic movement or performance. 

As the head / neck perform some dynamic movement, the distribution of tensional and compressive forces will redistribute and result in the maintenance of an ultimately equally stable system.   This effectively defines how the biotensegral concept explains the ability for the body to perform activity that defies conventional Newtonian understanding. 

To this point, the message is relatively clear and is likely to already be well understood and integrated.  It isn't until we introduce the "third dimension" of explanation that the broader understanding takes root.
The generic images (even "en vivo" images) only depict a 2-dimensional reality.  Therefore, the third dimension is necessary in order to accurately assess and extrapolate.  The third dimension can be considered as: 

Radial Symmetry: Radial symmetry is used to define the circumferencial quality of the structure.  This added dimension is important because it ultimately defines the overall competence of the tensional and compressional components...therefore having a direct influence on the resulting movement and control. 

When radial symmetry (circumferencial characteristic) is reduced, the resultant tensional potential is reduced (or in some cases produces a state of relative "stiffness").  In addition, the deficient compressional manifestations that typically are associated with CP result in an insufficient compressional competence.  The physical reality and complexity of the architecture in the neck result in multiple manifestations of this structural breakdown (poor head control, improper neutral position of the head, chaotic movements, etc..) 

The image below is a cross sectional view of the neck at approximately C5-C6 (mid lower neck).  The cross-sectional views are always the most challenging due to the simple fact that they are casually dismissed...however they represent the precise third dimension that is necessary for a fully understanding of complexities.  

As eloquently indicated, the neck itself is neatly sheathed in different layers of fascia which are continuous with each other throughout the organism.  With this fresh perspective, it becomes clear that the "muscle and bones" that occupy this image represent a very small percentage of the actual reality...and that radial symmetry ("how things are laid out circumferencially") plays an important role. 

Therefore, if we extrapolate this understanding to larger "landscapes" (chest, abdomen, and pelvis), the relevance of volumetric characteristics becomes even more prominent.  The CP individual manifests this under-appreciated dimension to the extreme...they typically manifest significantly deficient volume in the chest, abdomen, and pelvis.  This directly alters the tension / compression equilibrium and ultimately (given that development of the trunk DRIVES the development of the periphery) cascades to the limbs. 

Im summary, an intrinsic understanding of the biotensegral relationship (compression and tension) as well as the added third dimension will ultimately provide for a more informative perspective.  It only requires the conceptual intergation in order to effectively extrapolate into the physical reality.