[Introduction to the knowledge of subcutaneous sliding system in humans]

The mobility of our body structures is so intrinsic and natural to us that we tend to take it for granted. The very fact of being able to pinch your skin and lift it, then let it go and see it return to its initial shape and texture in just a few seconds may seem banal enough until you begin to think of all the elements involved. The same is true when you bend your fingers and think of the movement of the flexor tendon across the palm without external translation. For decades, scientists thought that the skin was simply an elastic structure with loose connective tissue and a more or less virtual space. However, in biomechanical terms, this explanation is very vague. These old concepts developed more than 50 years ago have evolved thanks to the impact of research at the microscopic level, and the global, mesospheric concept has been abandoned. And yet, surgical dissection in vivo demonstrates that there are only tissue connections, simply a histological continuum without any clear separation between skin and hypodermis, the vessels, the aponeurosis and the muscles. In fact, visible everywhere are structures, which ensure a gliding movement between the aponeurosis, the fat structures and the dermis. As they studied this system of gliding between the various organs, in particular at the level of the tendons, the authors noted the existence of a type of system composed of cables and veil-like structures that they term the Multimicrovacuolar Collagen Dynamic Absorption System (MCDAS). This system looks totally chaotic in organization and seems to function in a manner far removed from traditional mechanical structures. The functional unity of this sliding system is dependent upon a polyhedral three-dimensional crisscrossing in space of the microvacuoles, whose collagen envelope is type 1 or type 4 and whose content is made up of proteoglycoaminoglycans. The dynamic of this multimicrovacuolar system allows all of the subtle movements that occur within the body, thanks to its pre-stressed nature and the molecular fusion-scission-dilacerations that it is capable of. In this way, the system is mobile, can move quickly and interdependently, and is able to adapt is plasticity. This notion of microvacuoles is a fascinating one because it provides an explanation for the system's space-filling ability. The matter is composed of elements. However, although they seem to be arranged in a haphazard manner, this is not the case. In fact, they occupy space in an optimal manner. If we accept this notion of microvacuoles, then it becomes possible to explain certain pathologies occurring with age, such as edema, obesity, aging and inflammation. This sliding system is to be found everywhere in the body and would seem to be the basic network of tissue organization. For this reason, it should be thought of in global terms. Since it constitutes the inseparable link and occurs in all living structures and at many levels, could it be that it the basic architectural design of Life?