Friday, February 17, 2017

Hoof and Foot development


In a previous blog post, ‘X Rays, Beyond Balance’, KC La Pierre introduced the exercise of Physiological Sequencing. Understanding how Physiological Sequencing applies to the structures of the equine foot can help us to be more pro-active in our efforts to prevent problems from developing.

To recap; Physiological Sequencing explains the order in which physiological processes occur.
Tissues are grouped into three types, according to the rate they respond to change: Soft Tissue, Dynamic Tissue, and Static Tissue.

Soft Tissue is vascular, meaning it contains blood and nerves. Any change of stimulus to Soft Tissue will immediately change the way the horse holds himself and moves in response. Soft Tissue changes cause the horse to move either more symmetrically or more asymmetrically. Such changes affect the foot almost immediately, as a change to how the horse moves will result in a change to how the stimulus is delivered to the soft tissue of the foot and therefore to the second tissue in the sequence, Dynamic Tissue.

The main Dynamic Tissues of the foot are ungular cartilage and hoof horn: They are avascular structures (have no blood supply or nerves). Ungular Cartilage forms the foundation of the palmar (rear) two-thirds of the foot, meaning that the confirmation of the cartilage determines the confirmation of most of the hoof capsule. The ungular cartilage and coronary band work together to suspend the internal foot within the hoof capsule. A soft vascular network of blood vessels, or ‘dermis’, sits between the internal foot and the hoof capsule. The dermis has many important functions in the foot, one of which is nourishing the horn of the hoof capsule. Confirmation and health of both the hoof capsule and the underlying cartilage, along with the application of stimulus determines how effectively the dermis is able to supply the horn with nutrients.

The dynamic hoof capsule is the vehicle for delivery of the stimulus to the foot within. The confirmation of the hoof capsule and health of the horn affects both how the dermis is stimulated and how pressure is delivered to the cartilage and coronary band throughout the stride of the horse. Ungular cartilage cannot be nourished by the dermis, it requires appropriate pressure in order to develop healthily. If at any point the horse feels pain in his soft tissues, he will alter the loading of the foot to avoid the pain. This may be very subtle and if left undetected, the result will be an improper development of the ungular cartilages and improper horn growth.  Physiological sequencing tells us that these changes will eventually affect the static tissue, the bones of the foot. 

Static tissue, bone, we understand is always in a constant state of flux, modeling, and remodeling, however, these changes can take longer for physical change to be seen. The changes are less immediately obvious than the other tissues in the foot. The pedal bone, P3, is unable to remodel due to it lacking a medullary cavity so modeling of this foundation bone of the foot is irreversible. Wolff’s Law states that cells will align themselves directly with the line of force. Using a radiograph the line of force can be seen in the density of bone cells where modeling has taken place, for instance in cases where the foot has been chronically imbalanced. Examination of the dynamic structures of the foot, together with the application of Physiological Sequencing, will point to why the Static tissue changes have occurred and how the dynamic tissues can be addressed in order to prevent further changes to bone.

All tissues of the foot are in a constant state of flux. Observing change and understanding what is correct structure and function allows us to ensure tissues are developing healthily. In his article ‘Did I do that?’, KC La Pierre describes how he identified a rider imbalance by noticing a lateral flare in one hind foot of each of her dressage horses. A rehabilitation program was put into place for the horses and the rider. This prevented the cause of the change to the Dynamic tissue of the horses from becoming the cause of bone change.

ETB Pegasus Gait Analysis technology accurately pinpoints where and when any asymmetry or irregularity of gait occurs. Soft tissue needs to be free of pain in order for the horse to move and develop as symmetrically as possible.

Early identification and treatment of pain and close observation of dynamic tissue whilst being mindful of Physiological Sequencing can increase our chances of preventing pathologies.

About the author: Penny Thorpe, DAEP came across Applied Equine Podiatry whilst working for two trainers who were clients of Trevor Jones DAEP. Curiosity to know a 'bit more about feet' led to a fascinating journey of study with the Institute, graduating as a DAEP in 2013 and starting second level study in 2014. She lives in Brighton with her family and is privileged to have a small practice of dedicated owners and lovely horses.

Wednesday, February 8, 2017

Re-writing the book on Chronic Laminitis

     It has been some time since I has last posted to this blog and I apologize to my followers. I have been working on my new book "Chronic Laminitis" and my research has taken me to distant shores and far away places in the virtual world of academia. The title of this blog post is Re-writing the book on Chronic Laminitis and that is precisely what I have been tasked with. I recently presented glimpses of my work during a lecture I presented at the University of Paris. In that talk I call for a change in perspective and a shift in paradigm. I suggested that research into the causes of chronic laminitis may be flawed because of the model that researchers subscribe to. The model that I am referring to is that of suspension. For decades research has been done following the premise that the lamellae attachment and subsequent loss of suspension of the distal phalanx was due to this tissue's degradation and that this loss defined the disease.
      Entertaining a new model for the suspension of the distal phalanx is.... A real game changer!
Over the past fifteen years we have proposed that the lamellae in and by themselves are not capable of suspension, this due to the fact that they have little to no elastic potential. It was back in 2002 that we conducted a study to define a hoof model that we have since used for research and teaching at the Institute, ultimately allowing us to literally re-write the book on chronic laminitis.
Adopting a new model for suspension has allowed us to develop studies that have provided evidence to support exploration of new treatments, both pharmacological and practical.
Our latest study, a histological comparison study has opened up new possibilities and shows great promise in helping to change the focus of current research.
If you have not viewed this latest lecture please take the time to do so. It is posted on our Facebook school page https://www.facebook.com/AppliedEquinePodiatry/
Also, subscribe to this blog or follow us on Facebook to receive notice of the release of my new book, I promise you it's a real game changer!






Monday, March 7, 2016

Flat foot? Concavity and Health

Concavity, Conformation or Health?

By KC La Pierre
We often receive emails from horse owners exhibiting frustration over their inability to aid their horse in achieving concavity to their horses' hooves. Usually it is said that their horse is footie (tender over rough or hard ground) after months or even years of being barefoot. They go on to explain that they are frustrated, because they feel that they have been doing all the right things; created a natural environment, provided exercise, have addressed nutrition and done all of the other things that are said to achieve concavity and health to the hoof. Why then is my horse still footie over rough ground and why can't I get concavity!
The first objective when attempting to answer such an email is to determine the true conformation and the state of health of their horses' foot. Lack of concavity is not something that can be corrected by trimming, and a lack of concavity is not always the cause for a horse being footie (stay with me here). Concavity defines conformation and not health. Taking a simplistic view of the sole does not serve the horse. The sole, like the hoof wall cannot be viewed or treated as homogeneous (having the same make-up throughout). The sole is divided into two distinct structures, the Primary Sole and the Terminal Sole. Each is defined by its conformation and the property of its horn (tissue). The Primary Sole is the horn that has a foundation of bone (that part of the sole that covers the coffin bone). The Terminal Sole is that which has a foundation of cartilage and forms around the perimeter of the coffin bone. Being familiar with the "Hoof Wall Matrix" will help you to determine the current state of health of both the primary and terminal sole. As the health of the sole increases a matrix is formed creating a healthy transition from terminal sole to primary sole. This matrix is important to overall performance.
Terminal sole consist of horn that is made up of terminal tubules (tough horn that distorts without failure) and intertubular horn, terminal sole allows for needed distortion. Primary sole consist of primary tubules (hard horn that provides stability, resisting distortion) and intertubular horn. The function of each is determined by its foundation. The chief function of the primary sole is to protect the coffin bone (its foundation), not from concussion, but rather from torque (twist). The primary function of the terminal sole is to allow for distortion (also protecting the coffin bone from torque), and to provide protection from blunt trauma. In both instances the horn needs to be healthy, have depth, and have a strong matrix.
Lack of concavity to the primary sole in truth defines the conformation of its foundation, the coffin bone. It is not possible to increase this concavity. If there is little concavity to the distal dorsal (bottom) surface of the coffin bone, there will be little concavity to the primary sole. The Unified Sole Theory by Mike Salvoldi describes uniform thickness of the sole. However, concavity of the hoof capsule is not defined by the concavity of the primary sole. Concavity of the solar (bottom) aspect of the hoof does increase with an increase in the depth of horn of both the primary and terminal sole. Why? Take a look at the illustrations presented here. 



You will see that as the diameter and height of a concave structure increases the depth of the concavity increases (its center is further from its perimeter). The concavity (conformation) of the primary (center) sole does not change, but the conformation of the overall solar aspect does. The internal foot is in effect further away from the ground surface and better protected by healthier thicker horn.
Many of the hooves presented with lack of concavity are in fact exhibiting a lack of depth in solar horn and poor matrix to both the sole and hoof wall.
Is lack of concavity to the primary sole a cause for concern? Because function is determined by conformation and the property of a structure's tissue, a lack of concavity to the coffin bone can result in a diminished ability to dissipate the energies created during the stance (load) phase of the stride. Some horses can handle higher levels of energy and cope well with a flat conformation (within limits), where others are more sensitive to the energies resulting from a flat conformation. If your expectation is for high performance where the foot is exposed to high levels of energy, then conformation of this sort does become a concern.

How can we help the horse with such conformation? After all concavity cannot be returned to the coffin bone. As I mentioned earlier in this article depth of sole can be increased, that is if the conditions are right. Following two principles of Applied EquinePodiatry can help in developing a treatment protocol that can help in the development of a stronger hoof capsule (including Sole).

1.       Accepting that the horse does have the natural ability to heal itself, this provided the environment is conducive to healing.
2.       That correct force is the stimulus for correct growth

When examining environment you must take into consideration not only terrain, but also nutrition, exercise, and how the hoof is treated (balanced, trimmed/shod). 

Starting with a balanced hoof and exercising within the defined Spectrum of Usability for the horse are paramount to success. 

If you are dealing with less than ideal conformation of the coffin bone do your homework on foot function.










It is not possible to increase the concavity of the foundation, but it may be possible to increase the health of those structures that will supplement foot function.   






Monday, February 22, 2016

Expanding on Expansion, Hoof Function

A new twist on things.

It's not about going barefoot or being shod.

            Ever since someone decided horseshoes were a necessary evil, the debate over their effect on foot function has raged. Those advocating barefoot for the better of the horse, claim that horseshoes do not allow for expansion and contraction, resulting in a loss of foot function (read circulation), while those nailing on horseshoes loudly proclaim that expansion and contraction is not impaired, as nails should never be place behind the widest part of the hoof.
Several hundred articles and even a scarce few scientific papers have been produced to support the belief that horseshoes could be applied in a way that did not inhibit hoof expansion and contraction.
            Let me present a new twist on foot function that cast a stone upon the water, a stone that could, and should result in a tsunami.
            Expansion and Contraction are not enough. "Nearly all-new research into the functions of the frog, lateral cartilage, and digital cushion are flawed." This is a bold statement, but one that can be easily proven.
            Over the last decade there have been several papers published on the function of the digital cushion, and its function during footfall, and its relationship to overall foot function. In each of these papers the importance of frog contact with the ground has been stressed, or somehow referred to. Nowhere in theses studies has the importance of frog anatomical function been clearly defined. What am I talking about? The anatomy of the proximal internal frog surface (the surface that makes contact with the digital cushion), and the structure defined as the frog’s spine. As a horse person you may be more familiar with, and identify with its ground surface counterpart, the central sulcus, often seen as a deep crevice in the back, center of the frog.

            Our studies are proving that the health of the frog’s spine is crucial to the overall health of the caudal aspect (back half) of the horse’s foot. 
            The attached picture shows a healthy frog spine, and how distal and proximal (up and down) movement of the heels cause it to move either laterally or medially, directing the downward forces to the appropriate heel bulb and cartilage.
This action results in the correct distribution of pressure and force occurring at impact. This action is also responsible for directing the stimulus needed for correct growth of the heels, bars, digital cushion, and cartilage of the foot. When distortion of the hoof capsule is limited to expansion and contraction only, the frog spine remains centered and the forces created by the downward movement of the pastern and deep digital flexor tendon cannot be distributed to the advantage of the foot. Simply stated; expansion and contraction is not enough, the foot needs to be able to distort on all dimensions.
            Simply removing the ridgid horseshoe may be a step in the right direction (provided stability exist), but how the frog is addressed during the trimming process is of greater importance. A weak or unhealthy frog results in the foot’s inability to deal with force. A deep central sulcus is unhealthy, and is evidence of a weak spine (instability), the direct result of a lack of correct stimulus. Correct pressure is the stimulus for correct growth, and only with its application can the frog, and its spine become healthy. It is now clear that simply applying pressure to the frog is not enough to achieve true foot function, or a healthy frog for that matter. Dental impression materials, frog wedge pads, and any other attempt to apply pressure to the frog in a foot that can only expand and contract will not result in correct frog growth. We need to know how to apply the correct amount of pressure to the frog and heels, while allowing the foot to distort on all planes. The frog then becomes the vehicle for the distribution of energies to the back half of the foot.

            There is a simple protocol for treating an unhealthy frog, and helping your horse develop a strong frog spine. It involves treating any infection that might be evidenced in the central sulcus, the deeper the central sulcus the weaker the frog’s spine.  I suggest infection be treated with a non-necrotizing treatment (those that will not damage healthy tissue), Silvetrasol Hoof and Wound Wash is one such product. The frog should be trimmed by removing all dead or exfoliating horn, working to center it on the centerline of the foot. It is best to trim a slight angle to the sides of the frog, following its contour. This helps in distributing needed pressure to the correct underlying structures, resulting in healthy spine growth. You will then need to exercise the horse, exposing its feet and frogs to the proper environment (provided the hoof is stable enough), turnout is not enough. Hand walking a horse over uneven ground will cause the foot to distort, working the frog spine. Be sure to evaluate the frog and the health of the horse’s foot before you begin, a very weak foot cannot cope with excessive amounts of distortion. In such cases, you will need to work slowly, exposing the foot to less distortion in the beginning, increasing the work with the steady return of health to the frog, its spine, and to the stabilization of the caudal (back) foot. In cases where stability is in question it may be necessary to provide dynamic stability (stability by means of materials with elastic potential) by using Perfect Hoof Wear or a spring steel type of shoe.  Flexible horseshoes do not provide stability and often glue on shoes are too immobilizing, causing restrictions, which result in incorrect distortion.
            There you have it, expansion and contraction are not enough, and the argument that the conventional horseshoe when applied correctly allows for it, is no longer a valid argument. Foot function is complex, and the current trend of being “complacent with simplicity” can no longer be tolerated, not if our intentions are to serve today’s horse best. True foot function requires multi-dimensional distortion and dynamic stability, not simply expansion and contraction. The argument that the conventional horseshoe, dental impression materials, frog pads, or the host of other devices developed as a result of such beliefs support true foot function, is in my judgment no longer a valid one.

            For more of the latest information on foot function, please visit our website: www.equinepodiatry.com