Various Articles & Responses

~ The following is a response to an article written in 1997 by Tom Stovall, CJF - The Famous (or Infamous) Four-Point (Natural) Trim - http://web.wt.net/~stovall/4-point.htm

Response by Gene Ovnicek, RJF - Copyright © 2002

I am responding to a 1997 copywrited article by Tom Stovall because it is brought up occasionally and refreshed in bulletin board discussions among farriers, horse owners and equine professionals who are curious about Natural balance and 4 point trimming . I think it is safe to say that we all think differently on the subject. A quick five years have passed since that article was written. If we (meaning me and you) haven't been able to see the concept more clearly based on the test of time and scientific research, an opportunity to see the foot and its biomechanics more clearly has been missed.

I am responding in reference to Natural Balance, which is not to be confused with 4 point , Strasser, Jackson, Bergy, Savoldi, et al. I am however going to make note that all of these approaches have one thing in common, with diverse opinions on other issues of the foot. I will only talk about the positive aspects of other people's work. I have not walked in their shoes, to appreciate the various debatable aspects of their individual philosophies. And I offer similar suggestion to those who are concerned about these issues.

As I review British shoeing standards, I find trimming the heels to the widest part of the frog to be common language. This does sound foreign to many farriers who are taught to never trim heels, and trim the toe to a point where it yields to thumb pressure. It is also confusing to many who try to align the pastern to the dorsal hoof wall while trimming the heels to the widest part of the frog. I sympathize with farriers who are educated in a certain concept of old school, new school, or no school. This is compounded with the demands of the horse owner who pays their wages and whose demands are based with no experience or knowledge of anatomy or hoof biomechanics, just what they perceive Suzie's feet should look like.

Since 1997 much has been learned about the domestic hoof, based on research directed by the foot model of the feral horses. I will list some of the findings before I address the concerned statements made by Mr. Stovall. It is well known that the frog buttress or callous grows back rapidly when it is trimmed away or is exfoliated naturally. Science (R. Bowker DVM, PhD) has noted proprioceptors in the caudal region of the foot in that exact area of the frog buttress. Dr. Barbara Page has published repeated radiographic results showing that a breakover point placed ¼" anterior to the tip of the bone, combined with caudal frog contact to the ground created substantial improvement in alignment of the distal phalanges. The same position of breakover anterior to the tip of P3 along with the caudal frog contact is found in feral horses.

In a separate study Dr. Bowker discovered a link to the cause of Navicular disease based on presence and amount of fibro cartilage in the digital cushion. This important finding links perfectly with the importance of frog to ground contact upon hoof landing and loading. At the same time, even more important information about energy dissipation through the arterial and venous plexus is learned from studies directed by the wild horse foot, such as how to gain better efficiency of the foot by improving the quality of the back of the foot.

Improving the back of the foot is that one common denominator in all the various so called trimming methodologies. To bring the frog in contact with the ground by trimming the heels near the level of the sole fits perfectly with the new science.

How to trim the front part of the foot is debated by all traditional as well as new age trimmers. It is not a secret to those who have been aware of barefooted horses which have a natural lifestyle, or domestic horses with activity ample enough to keep the hoof well worn to a point that does not require trimming. If activity is not restricted by box stalls, continually soft ground, or small paddocks, all horses will wear the hoof wall to the level of the sole ahead of the widest point of the foot. Many domestic horses can be ridden aggressively with the hoof worn to the level of the sole. I am not suggesting that horses can walk entirely on the sole, but I am fully aware of the fact that the rim of sole on the inside the hoof wall stops the wall from wearing into the coffin bone. That rim of sole mimics the shape of the distal border of the bone, it hardens and softens quickly in response to environmental changes, and it is stronger than the hoof wall as it stops the wall from wearing beyond that level.

Please be aware of the fragile nature of the distal border of P3 and of the ventral position of the circumflex artery and vein, and therefore their close proximity to the ground creating vulnerability to damage when the sole ridge (sole callus) is minimized by removing toe as a method of aligning the distal phalanges. The importance of the hard adaptive sole ridge that mimics the shape of the distal border of P3 is paramount to the lifestyle of the foot. Russell, at the turn of the century used strong language instructing to preserve this structure as well as the frog, without knowing the now available scientific reasoning behind it. Common sense gained through practical experience has been the basis of our views of the foot and how it works.

Hoof care practitioners are asked to perform maintenance on horse's feet. Generally this consists of trimming the hoof wall near (or to) the level of the sole which I believe is a universal guide. Mr. Stovall compared trimming the hoof to a natural wear pattern to rasping the rubber of your car tire. I find no resemblance or comparison to hoof wear with wear on a tire, and find that comparison of the two is strongly like comparing apples and spaceships.

Regular trimming is advocated by most farriers, veterinarians and equine professionals. The fact is that if the hoof wall is left long, as a tread on a tire, hoof imbalance and distortion are likely to occur. The performance and soundness of the horse is then in jeopardy. (In short, it is good to trim horse's feet).

For the quarters to break away is normal in many environments. Domestic horses fit well in that category as they are seldom used on hard surfaces barefooted. That is the way all feet wear in most environments, feral or domestic. The author made a statement about a 'cone' working better at load bearing. Without the scientific information and common sense to support isolating the caudal region for optimal function, it would be easy to make a statement saying that purposely 'whacking' away the quarters to mimic natural wear is counterproductive. It is only in the laboratory where a "cone" works better. Again the comparison of apples and spaceships should be considered. Look at what science has offered as to how the back part of the foot functions to accept forces which are directed into the foot under all phases of the stride.

Phalangeal alignment has always been important for as long as horse feet have been trimmed and shod. That concept is still at the top of the agenda for most farriers and I believe that is good. Hoof distortions are often created by trimming the toe and leaving heel in the process of aligning the pastern with the dorsal hoof wall. It has been discovered that when the sole at the toe is thinned repeatedly to raise the hoof angle, P3 descends within the hoof capsule, the dorsal hoof wall at the distal border loses some of its ability to remain attached to P3 and therefore the dorsal wall migrates forward, stretching the thinned sole and frog apex with it.

At the same time, to assist in pastern and dorsal hoof wall alignment, the heels are left with some length or height above the live sole. In cases where pastern alignment is an issue, low angled forward heels are usually involved. When that type of heel is left untrimmed to try to improve the pastern alignment, the heels are forced even more forward and to a flatter angle. The heels turn inward as the bars become curled or bent to a similar configuration as the outer wall of the heel buttress. The most available literature for farrier reference is the book used by most farrier schools. It clearly states that to align the pastern with the dorsal hoof wall, trim the toe and leave the heel. This is with no regard for the resulting distal displacement of P3 from sole thinning , or the dorsal wall migration from compromising the attachment of the wall at the distal border, and is in fact promoting under run and contracted heels by leaving them grossly extending beyond the sole.

The latest scientific information demonstrates that caudal frog contact, with breakover placed close to the tip of P3 improves distal phalanges alignment. This is accomplished by including all caudal components of the foot. These include the frog, the digital cushion, lateral cartilages, bars, and heel buttress, all working together through frog contact.

When treating Navicular syndrome, experienced veterinarians and farriers who keep up with current technologies have found that raising the hoof angle by keeping the heels high occasionally helps for a very short time, until the heels later contract and the bars curl, thus increasing the heel pain and discouraging the horse from landing heel first.

The most recent helpful information that addresses Navicular syndrome comes from the research directed by the wild horse hoof patterns and Natural Balance trimming protocol, as it clearly addresses the needs of that syndrome. When the principles are applied correctly, the Navicular bone is positioned in a more vertical relationship with the coffin joint. The distal end of P2 is placed properly in the coffin joint, which reduces unreasonable strain on the impar ligament and proximal suspensory ligament to the Navicular bone. This is in light of Bowker's findings on how stress to the impar ligament causes poor blood flow to the Navicular bone combined with trauma to the coffin joint from loading toe first and poor support through the back of the foot from hoof distortion related to leaving heels high or under-run, and trimming the toe short to align the pastern with the dorsal hoof wall.

Mr. Stovall's refers to tenets from O.R Adams' "Lameness in Horses". That text has been revised numerous times to keep up with current technology changes. I believe that periodic revision is important for a text which is frequently referenced by hoof care professionals whether they are veterinarians or farriers. The most recent "Lameness in Horses" (Fifth Edition) contains a section on Natural Balance principles as well as other respected reference journals.

Bowker has commented based on his histological studies indicating that all horses are born with the same quality of hoof components. They then become either durable, optimal, or deficient based on their environment and lifestyle.

As to the article's referenced book "Horseshoeing Theory and Hoofcare" (Emery, Van Hoosen), it was an important introduction to the need for change in the hoof care industry. It challenged some traditional views and supported others. This publication was without a doubt a catalyst for a deeper look at the horse's foot, hence the search goes on.

Those "jumpers on the feral bandwagon" are drawn this direction primarily because of the commonsense approach with scientific backing. The view is certainly not clear in the forest of information as we have to sort through antiquated doctrine and old, previously learned ideas that have now been proven different. This is progress. This is "not being stuck". Yet for many it is scary.

Since the introduction of the feral horse hoof information, there has been heated discussion about it's usefulness for under saddle performing disciplines consistent with domestic horses. It is apparent that those with doubt about the success of the feral horse performing sound when placed in a domestic arena have not visited with those who do this. Keeping in mind that the most successful results are those with the animals left barefooted and trimmed regularly in a manner consistent with the way they were raised. The others perform very well and stay extremely sound until they are shod in a manner which allows more ground surface of the foot to migrate forward of the widest part of the foot. This is the same criteria domestic horses are confronted with when they become lame.

The wild horse study published and presented at AAEP in 1995 showed clearly and consistently that the bottom of all feet had more ground surface behind the widest part of the foot than in front of it. Farriers and veterinarians who treat lame horses find that hoof preparation combined with shoe placement which maximizes the length and width of the ground surface in the back of the foot, while shortening the leverage arm in front (breakover) are generally more successful. This same principle is also practiced by many farriers as a means to prevent lameness, improve performance, overcome gait faults, and avoid weak hooves that are easily distorted.

I ask you to look at a horse standing and in motion. You will see the importance of the feral horse hoof design, shaped by the environment for thousands of years for good reason.

In regard to the bold print statement quoted in the article concerning extra weight of rider, tack and work "Since these factors are not considered, observations on the foot wear of feral horses without regard for the relationship of anatomical form to efficient function become meaningless because they can not be logically applied to domestic horses". With this statement I find it difficult to be diplomatic when information was readily available at the time the article was written which supports the biomechanical efficiency of the wild horse foot. If the author disagrees with the fact that the foot is more efficient with more foot mass behind the widest part of the foot than forward of that point, with relatively straight heel buttresses and bars, large frogs and no contracted heels, I honestly do not know what to say.

The assumed parallel relationship of P3 to the dorsal hoof wall in domestic horses is not reliable as a reference to phalangeal alignment and this factor has been demonstrated many times and presented at many venues in the U.S. and abroad at respectable veterinary functions. The unreliability of the parallel relationship is the reason for increased phalangeal leverage, as a result of increasing distance anterior to the distal border of P3. Bowker shows that pathologies to the impar ligament and coffin joint are directly related to delay in breakover and a toe first landing due to an excessively long leverage arm. Equally important in this equation is the heel height when the time of breakover is an issue, with regard to length of stride and the hoof contacting the ground. Heels that are allowed to grow beyond the sole more than 1/ 2" are directly related to a shortened stride. These parameters are all governed by tension in the deep flexor tendon below the inferior check ligament. Efficiency of motion appears to be a result of the equilibrium around the flexor and extensor tendons.

Mr. Stovall concludes his article with the following: "In my opinion, one can learn a great deal from feral equids in abrasive environments, but what one learns must be evaluated in accord with what one knows about the anatomy and physiology of the equine foot, as well as the physics of efficient motion". It would be difficult to disagree with that statement.

A very productive five years have passed since that was written. During that time, continuing scientific research has provided a lot of new information about the biomechanics of the feral hoof and how the environment shapes and develops it to provide pure efficient function, perfect for survival. The domestic horse on the other hand is subjected to an incredibly unnatural environment and isolated from the forces which shape the efficient feral hoof. Through deeper research, especially in comparing the tissues and structure of feral and domestic hooves, there are now more answers to the questions about anatomy, physiology, physics of efficient motion, and what forces affect those things.

Perhaps we should ask ourselves a couple of questions. Does a domestic hoof need to be efficient? And how important is efficient function when considering the added demands of rider weight, tack and discipline? And if "form to efficient function" is the goal, now that we have been provided with more of the answers as to what forces help shape feral horse function and efficiency, can we use some of that information to help achieve efficient function in domestic hooves? Some food for thought...

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