• theequinedocumentalist

Bio-Tensegrity and Farriery

Updated: Jun 24, 2021

Every biological entity is made up of systems upon systems, existing in symbiosis for the collective good. Even our own evolutionary story is one of endosymbiosis. Bacteria interacting with other organisms to create more powerful systems, held together by “some kind” of connective tissue.

Bio-tensegrity helps us to understand why the whole is greater than the sum of its parts as synergy begets efficiency over millennia of self-organisation. Until now we have tried to understand pathological causation by breaking down systems into their simple mechanics, perhaps losing sight of the complexities of the integration of each sum and its relationship with an even wider system. When we begin to look at the entire system, yes it becomes complexed, but long-term system wide soundness is achievable with integrative system wide repair, perpetuation is ended with creating system wide neuro-musculoskeletel harmony.

These concepts are the basis of studies into kinetic chains and myofascial trains, Levin et al (2017) described closed kinetic chains as modular units, within wider system units, responsible for organism wide locomotion. Every part of an organism is intertwined with every other, right down to a microscopic level. The complexities of the relationships between the units mean the organism can react to external stimulus much quicker than the capabilities of the nervous system allow. It also means that physiological dysfunction within any part of any unit has direct effect on that unit, the wider system units and the entire organism.

kinetic chains and myofascial lines are a way of understanding equine locomotive pathogenesis in a deeper and more integral way. Considering the position and orientation of every anatomical point, along each myofascial line associated with the presenting pathology, potentially leads to primary, secondary and complimentary issues being addressed in unison, resulting in more complete treatment.

These may not seem like considerations for farriery intervention, but the hoof is simply one part of an extensive biomechanical system that is far too often compartmentalised. Recognising hoof morphology as a result of entire system wide state and orientation doesn’t detract from established interventions, rather it can add understanding to their efficacy and point toward extra professional intervention that will compliment, ultimately resulting in more complete resolution of symptoms. There is a need for the farriery industry to have a more integral view of its role, you can not change the orientation of the hoof without affecting its myofascial connections, its neural, vascular and epithelial relationship with the wider system. Conversely, not changing a dysfunctional hoof will predispose that same system to pathology.

The fibrous myofascial web that encompasses the entire body can be seen in this image as the myofascial lines extending all the way into the hooves.

Farriery, for the main, is concerned with locomotion, so myofascial trains and kinetic/muscle chains are important factors in modern and integrative farriery. These systems transfer pulling forces along musculoskeletal meridians too and from the hoof. The simplistic muscle-bone understanding of movement fails to explain the far more complexed reactions of the entire body to movement. Wolf's law expresses this as bones remodel to cope with the forces placed upon them, so how much more is the hoof going to respond to these same influences. It is this capability of the body to respond that means simple mechanics never quite answer the questions of pathogenesis.

The horses body can be considered as a tensegrity structure, a balance between compressive and tensile forces, where all of the points of the structure respond to any localised stress and the weakest point is where pathology will present, even if it is at the opposite end to the primary stress. This concept helps to explain perpetuation of pathologies and the common pathological chain of events after treatment of assumed primary pathology. If the treated anatomical point was the weakest point of the tensegrity structure but the primary stress is not relieved then the next weakest point may succumb. The myofascial lines are routes of strain throughout the horses body, the hooves being the point of contact with the ground are points at which stress is constantly applied to the tensegrity structure. Any other point at which stress can be applied to the horses entirety, for instance tack, rider, riding style etc can and will also affect the integrity of the whole and the weakest section may fail. We know that the hoof is a deformable yet integral part of this tensegrity structure which is why it is a useful tool in assessing the strains on the wider system by noting its morphology. Early signs of morphological changes to the hoof could be a sign of pathological changes within the wider system.

Even within the hoof we can see tensegrity principles having an effect on farriery related parameters.

The compressive forces of the GRF are transferred to tensile forces via the laminal attachment and the very makeup of the hoof on a cellular level is evolved to endure compressive and tensile forces and use them to dampen the forces of locomotion. The pedal bone is suspended in a network of tension while under constant compression.

Something important to remember when considering the role of fascial tissue and its transference of pull, is that it is plastic and not elastic in nature although it will suffer creep with strain over time. Stretched quickly it will tear, but it is this mechanical nature that provides its benefits. We can see within the equine digit how it plays a role in keeping structures in place and how tensegrity is used to support the fetlock for example.

The tendons, ligaments and annular ligaments of the digit hold up the fetlock like a suspension bridge. This image helps to show how any change in orientation will affect every structure within the digit. Lower the heels and the Deep Digital Flexor tendon (DDFT) will be under more tension, for example.

The role of the DDFT as a tensegrity structure has been recently quantified by Osborn et al (2019) which highlighted the importance of phalangeal orientation on its integrity and predisposition to exceeding its elastic limit. But that tendon is an extension of a muscle further up the limb, connected to a bone within a much wider system, so that change in orientation does not affect only the structures within the digit. The links between anatomical position and orientation of the hoof (or otherwise) and pathology, spread throughout the entire musculoskeletal system, with the formation of kinetic chains and the myofascial lines, through both direct myofascial tissue and through mechanical connections via bone junctions. The Myofascial lines are a comprehendible way of understanding the tensegrity nature of the organism as a whole, while kinetic/muscle chains are a mechanical way of understanding units within that organism. For the sake of concision we will concentrate on the hind of the horse as it has a closer working relationship with the trunk of the horse considering its direct skeletal link.