Thirteen Points for Performance: The Essentials for Functional Conformation

Introduction

As creators of equine realism, we often draw inspiration from the horse industry through field study and reference photos. Being so, we learn to realize our visions with greater authenticity, variability, and panache. Undoubtedly then, the quality of our references helps to predetermine the quality of our creative outcomes.

However, if we're unable to determine between what's beneficial and what's deleterious, our studio can become unwittingly infiltrated by misinformation, problematic aesthetics, and propaganda. This can compromise not only our creative prerogatives, but also our value judgements. If we aren't very careful then, we can end up validating harm to this animal we so love when we could have created a much more positive visual with just a bit more objectivity. Truly, we can learn a lot about an artist's values by studying which structural aspects they imbue in their work and which ones they leave out.

The Challenge

We start the groundwork for this discerning understanding by having a firm grasp on equine anatomy and biomechanics. Not just a working one, but an in-depth one that also incorporates biology, evolution, and physics. Nature designed the animal a very specific way for very specific reasons, therefore the equine blueprint doesn't have a whole lot of fudge-factor for our aesthetics and fancies. And make no mistake—the horse world is awash in structural fads and problematic ideas about structure so we have to understand, through our knowledge base, which is positive, which is neutral, and and which is negative.

This is because how a horse looks isn't about aesthetics. It's about function. It's a biomechanical issue, not one of taste. The equine blueprint as nature intended doesn't allow us to simply construct a horse any which way we want—we have biomechanical rules to follow that ensure his well-being. This is because, above all else, the equine is a creature of motion and stamina. He's not a lap pet. The animal's mass and forces of motion introduce complications when his structure is thus compromised—he's simply too big and movement-oriented to give a pass to introduced structural problems. It's a matter of physics and biology. Truly there's no other animal like him—he's absolutely unique in his qualities and abilities. So anything that compromises these crucial, species-specific characteristics can automatically be thought of as bad, even inhumane in some cases.

Then the second phase of laying the groundwork for this understanding is recognizing that there isn't just one kind of conformation, but three! In order of importance, they're as follows:

1. Functional conformation: Structures consistent to the equine blueprint that ensure his well-being and sound performance.
2. Type conformation: The structures that differentiate breeds.
3. Aesthetic conformation: The structures within a breed that define variations, personal taste, fancies, or fads.

In this discussion then, we'll be exploring the most important one—functional conformation. Indeed, this category is so critical that it trumps the other two in all situations. At no time then should type or aesthetic conformation be given more weight than functional conformation. This is a non-negotiable rule for sculpting equines responsibly.

Common to all three, however, conformation entails the angles, lengths, dimensions, and other structural features of the equine skeleton and flesh that define phenotypic structure, type, or performance disciplines. Conformation is simply the variations on the anatomical blueprint that characterize individuals, breeds, or types. 

(For more information on the crucial differences between anatomy and conformation—they aren't the same thing—please refer to the previous blog post 4-part series Anatomy and Conformation, Part 1, Part 2, Part 3, and Part 4. Also refer to the previous important blog post Viability and Functionality: The Umbrellas.) 

This means conformation is subjective unlike anatomy which is objective. Truly, ask five different people about what they consider to be good conformation and we'll get many different answers in varying degrees. Likewise, ask five different people to evaluate an individual horse's conformation, and we'll get a plethora of different opinions. It's even caused battles and loaded debates. Everyone has their own idea of what constitutes "good conformation" and especially what's more aesthetically pleasing.

This means that conformation has an emotional component as well: we can end up liking a horse more and another less simply because of which we deem as "better." We can even label a horse as "ugly." But don't we have enough body image issues with ourselves? Should we, as artists and horse enthusiasts, really heap this negative baggage onto this noble and gracious animal? Shouldn't our sensibilities be broader and more generous especially for those of us who seek to explore his soul, personality, and autonomy?

If you have seen nothing but the beauty of their markings and limbs, their true nature is hidden from you.

~ Al Mutannabbi, 9th Century AD

This observation helps to inspire introspection and re-evaluation of our artistic decisions and perspectives. Horses are so much more than our value judgements and while we do need to weigh them when working in this genre, we should do so with more thoughtfulness and empathy than many tenets of conformation or fashion would have us believe. Just like with us, it's what's inside that matters most, doesn't it? And equine motion, performance, and soundness is far more complex that the logic fallacy of "false cause."

Because we have to be particularly careful with conformation. Indeed, the issue of conformation is often plagued by misinformation due to its nuance and relativity. Partly to blame are mistaken ideas being repeated in conformation books and clinics. Honestly, if we aren't keenly aware of the influence of biomechanics and horsemanship, we can get duped rather quickly. Conformation is also used as a marketing tool to feed propaganda and peer pressure to increase sales and status while also creating conventional tastes that may miss the mark with biomechanics. Conformation is also vulnerable to mercurial fads and changing fancies that make certain points fashionable and unfashionable. Often times, these predilections compromise his biological functions to the point of turning out herds of "lawn ornaments." Indeed, many fads deemed "desirable" are actual physical liabilities, often being gross exaggerations of type that cause suffering and further deterioration to structure. Sometimes even euthanasia. In turn, this can cause a confusion between what's a matter of taste and what's a matter of biological honesty, allowing people to promote those fashionable aspects of structure that actually cause harm. This is a serious issue for the realistic equine artist. What do we want to validate with our chosen visuals?

Now while it’s true that certain conformational packages lend themselves better to certain disciplines, it’s equally true that the more quality horsemanship dominates, the less conformation is an issue. This means a good horseperson, one who is thoughtful, informed, and “works deep" can get a good, happy, and healthy performance out of any horse and keep that horse sound despite the animal’s “unsuitable” build. For instance, long, sloping pasterns aren't the cause for springy, smooth rides! It's the suppleness of the Serrati complex, part of the Shoulder Sling, that's responsible for this effect. Absolutely, with the right conditioning and horsemanship, a horse with short, upright pasterns can provide a wonderful ride. In short then, the concept of “suitability” isn't such a pivotal one since all horses can do all horse movements. It's simply their different builds—their different conformation—that lends a different style to those movements. And make no mistake, movement is as vulnerable to fads as physical structure. For example, a Clydesdale can do a piaffe just like a Swedish Warmblood. It's simply the different style in which he does so that causes one to judge which is "better," i.e. more fashionable.

We should also remember that the original intent of evaluating conformation wasn't to determine which horse was "better" than another. Nope! Originally, conformation evaluation was meant to determine a tailored training and conditioning program for an individual horse to allow him to perform to his full potential. In other words, it wasn't meant to demean and denigrate, but to elevate!

The Goal

All this in mind, the issue of conformation is a complex one for the artist who wishes to validate positive messages. Yet we can clarify our prerogatives and refine our creative decision-making by focusing on functional conformation first to set the stage for responsible promotion of the animal's well-being. Indeed, once we understand these points of functional conformation, we can then better gauge our type and aesthetic tastes to ensure they're aligned to our convictions.

So while the finer points of conformation are open to debate, in this discussion we'll consider the thirteen most basic conformational factors that are essential for functional well-being which are applicable to all horses, of all types, in all situations. Being so, they’re also the sculptural prerequisites for portraying a happy, healthy, "using" horse—a horse as nature intended. This is because these thirteen points are based on biology rather than fashion; they're consistent to the equine anatomical blueprint rather than subjective tastes.

So let's get to it!...and not in any particular order...

(Note: To learn more about equine evolution, biology, and anatomical function, refer to Bio-logic: Equine Anatomy 101 and then the more advanced and in-depth 17-part series Equine Anatomy and Biomechanics: A Primer of Equine Engineering.)

Thirteen Points Of Functional Conformation

1. Adequate Muzzle Size

The horse is what he eats, literally. It was the eating of grass that made the horse what he is today. But to fully understand this requires knowledge of his evolutionary development, an important subject that squarely puts conformation (and type) in thoughtful and informed perspective. But the short version is this: the consumption of grass, on the open plain, essentially created the horse. Sounds simplistic? Well, it’s actually rather complicated. The horse’s ancestors dined on soft forage of forest habitats, but as he ventured onto the new grassy plains, many changes had to occur for him to flourish there, one of them being his skull. Because grass is a low nutrient and abrasive foodstuff, due to the silica it contains within its structure, the horse had to evolve a battery of large, long, continuously growing teeth which shaped his skull to be long and large by stretching the head forwards from below the eyes. In order to extract the most nourishment from grass, the horse must grind his mouthfuls into the texture of fine cornmeal (it's also necessary to avoid blockage in his intestines, or colic). The grass is nipped with the incisors, pulverized by the molars, and then onward it goes into the digestive tract. And that's a lot of nipping and chewing. To illustrate, he'll eat about 1.5 to 3% of his body weight in dry feed, depending on his athletic and conditioning needs. In other words, a 1,000 pound (about 454 kg) horse will eat about 10 pounds (4.5 kg) of dry forage per day. What's more, he also obtains his necessary water exclusively through is muzzle, and that's a big job, too. The average horse drinks about 5 to 10 gallons (about 19-38 liters) of water each day (a bit less if he eats wet, pasture forage). 

But it doesn't end there—he also obtains air exclusively through his muzzle. And that's definitely no small matter. The average horse takes about 1.25 gallons (about 5 liters) of air with each breath. He takes about 12 breaths per minute which means he'll inhale and exhale about 16 gallons (about 60 liters) of air per minute. And that's at the resting stage! During exertion, the air volume per breath can increase to between 3 to 5 gallons (about 12 to 15 liters), taking over 150 breaths per minute. That means about 500 gallons (about 2,250 liters) of air is moved per minute with less than a half a second for each breath. Add into this that the speed at which that breath rushes in and rushes out is the fastest recorded wind on the planet, being about 400 mph (about 644 kph)! Compare that to the fastest wind thus recorded of 318 mph (about 512 kph) in an F5 tornado. Those nostrils are truly important, aren't they? 

In other words, all elements necessary for life are accomplished by his muzzle. All that boils down to this: not only should a horse have a skull of adequate size, breadth, and length to accommodate those big teeth and large activating muscles, but even more, it must be paired with a muzzle of adequate substance to process what he needs from food, air, and water. For this reason, a muzzle that’s too small and “dainty” will have problems with the rooting and growth of the teeth along with sinus problems and reduced volume, greatly compromising his ability to derive the basic requirements for his health. It also means he’ll have a harder time with the bit, and therefore can be difficult to put to work because he’s uncomfortable. 

Yet unfortunately, a small, dainty muzzle has become fashionable and even exaggerated in the domestic horse, most notably in the Arabian and stock horses. Indeed, the idea of the "tea cup" muzzle didn't mean a muzzle small enough to fit inside a tea cup, but delicate enough to sip from one. The issue is even more pronounced with horses over 1100 lbs (about 499 kg), who need skulls and muzzles even larger to process the nutrients they need for their larger bodies. This brings into question the “prettifying” of heads of certain large breeds, particularly stock horses and drafters. As such, artists can make the mistake of putting small muzzles on their sculptures not knowing what it is they're compromising.

So when evaluating our sculpture, we should be sure its skull and muzzle size are consistent to biological functionality—are they big enough? Do we want to promote the health of our subject or pander to our aesthetics? Do our stylistic habits predispose us to creating small muzzles and heads? Is our sculpting technique flawed? Is there a creative method that needs updating?

2. Normal Size of the Eye

Sight is an important element to equine biology and, indeed, horses have the largest orbs of any land mammal. The equine eye also isn't round like a ping-pong ball, but oblong like an egg. We humans are also a visual species, so this makes the equine eye instinctively appealing to us as we gravitate towards it naturally. It's no wonder why we pay it so much attention to it.

Yet many breeders have sought to enlarge the equine eye to "improve" the beauty of the head, which is fine given it remains within biologically sound parameters. However, when they become too large, in particular too bulging, this can invite serious diseases such as hypothyroidism or ASD (Anterior Segment Dysgenesis). We should remember that it’s actually the differences in the skull’s orbital or fleshy structures that makes one eye appear larger than another since all breeds possess orbs of similar size and shape.

Now when it comes to art, artists can stylistically make the eye way too big, and that compromises not only a realistic look, but a conscientious visual as well. So we should take care to avoid sculpting eyes unnaturally too large or too bulging. Taking measurements, using good references, engaging in field study, and building a solid mental library of healthy eyes is smart for thoughtful sculpture.

3. Good Bone

Domestic horses have been loosing substance for some time as the breeding for finer, more delicate legs has become fashionable. We've seen this effect in the Arabian, stock breeds, Saddlebreds, and some drafters and Warmbloods. Some circles even claim this is acceptable because their breed has denser bone than normal and can, therefore, withstand this continuing loss of substance in the pursuit of "refinement" such as the Arabian. However, this is a gross misinterpretation of equine biology that threatens long-term viability. The truth is that “fine bone” never meant thin, delicate legs, but legs with clean, crisp anatomy, lacking pathology and puffiness; a refined leg is one in which we can see the clear, crisp underlying anatomy. We also can't ignore, too, that denser-than-normal bone is actually a disease and highly undesirable because it’s more brittle and prone to breakage and fractures.

Nature designed the horse to be relatively small in both stature and mass, say not much more than 15hh, the size of the average Arabian. Density is measured as mass (or weight) per unit volume, and with horses, bone density decreases as mass increases. In other words, bone density doesn't scale up in kind with mass when it comes to equines. So horses below 1100 lbs typically have normal bone density whereas horses heavier than 1500 lbs have abnormal or lower bone density. That means Arabians don't have denser bone, they have normal bone density. Horses more massive than 1500 lobs also often have trouble processing enough calcium (and so usually require supplementation), complicating matters. As a result, the bone density of horses between 1100 and 1500 lbs, who comprise the bulk of riding and sport horses, teeters on the low side simply because of this biological ratio. Even more, the bone density of drafters is significantly abnormal, being even lower in comparison to their mass. This is why the drafter is designed to walk as his primary means of work. For these reasons, the bone of horses below 1100 lbs are stronger and sounder than those above it, which confirms the typical claim of the hardiness of smaller breeds such as Arabians and ponies.

We're also probably aware of the concept of “good bone” or "ample bone" as measured on the foreleg right below the knee; it's actually a pretty good indicator of predicted soundness. Like bone density, "good bone" doesn't scale up in synch with size either, particularly when breeding pressures can select against it. Yet horses require a minimum of 8 inches circumference per 1000 lbs of body mass, a ratio derived as a statistical average. Nature never intended the equine to have less than this ratio. For example, in wild populations, such as Zebras and the Takh, they naturally average about 10 inches of bone, with some having as much as 14 inches. Thus, the more massive the horse, the more bone he’ll need to remain sound. For instance, a 1200 lbs horse will need at least 9.6-10 inches of bone. However, very few individuals can be found with this measurement now, unfortunately. It also means that a 2000 lbs drafter will need at least 16 inches of bone to remain sound as a riding horse, but finding such individuals is a rare thing today, particularly with the "hitchy" types. 

Now while "good bone" tends to diminish with increased size, it tends to improve with decreased size since this is consistent to what nature calculated. In other words, as the body mass decreases, the bone circumferences tends to stay about the same, which is why horses of Arabian size and smaller are known for their sturdiness and soundness. This is because they have at least the 8 inch measurement, but with less massive bodies.

What's more, as "refinement" of the leg has been occurring, the size of the joints has been diminishing as well. But as points of articulation, joints should be large and robust to endure the years of work the horse will be asked to perform; small joints are never desirable. They should also be “clean," appearing as only bone and hide, free of puffiness, inflammation, deformation, or calcification that would indicate injury or pathology.

So when sculpting, it’s wise to regard bone in biological terms and not just on or fashion and aesthetics. Being able to gauge mass as compared to bone, and knowing the biological consequences, helps us to make more informed creative decisions about what we want to validate. We do run into complications however if we're duplicating an actual individual with inadequate bone such as a "hitchy" drafter. All we can do is our best and apply our knowledge with as much savvy as we can, given the circumstances.

4. Straight Forelegs

Many in the horse industry, particularly in America, have forgotten what constitutes a proper, straight foreleg. Instead, breeding decisions are often skewed by misinterpretations, often found in conformation books, which can also be inadvertently parroted and even artistically exaggerated in the studio. 

Functionally speaking, a correct, straight foreleg has a radius tipped slightly forward at the distal end to set at 90˚ to the carpus. Therefore, a plumb line will bisect the radius and bony column (know your boney landmarks!) to emerge at the bottom of the bisected cannon bone and behind the coffin bone, onto the frog. This is the only acceptable foreleg alignment that applies in all situations, with all types and uses.

However, this correct alignment often appears over-at-the-knee to the unaware, and in this misinterpretation of a “straight foreleg," calf-knees have become prevalent, particularly in America such as we often see in the Arabian, stock horses, Saddlebred, American Iberian, and Morgan. And predictably, unaware artists copy what they see, making calf-knees far too common in artwork as well, sometimes markedly so. Some media even cause a calf-kneed stance or exaggerate it a pre-existing occurrence. For example, fine bone china almost always causes calf-knees unless the greenware sculpture has had its cannons bend slightly back to compensate before firing. This is because the media shrinks along the longest axis, pulling the foreleg forward along the front seam. Now we shouldn't confuse a calf-knee with a leg under stress such as we often see in racing when the planted foreleg appears bent back. A proper foreleg will withstand these pressures whereas a calf-knee won't, so we need to understand the difference. For reference, racing Thoroughbreds and European breeds make a better reference for sculpting the correct alignment.

Yet calf-knees are a serious functional fault, even in small measure, because this misalignment of the boney column causes bone fractures or chips in the carpus and is prone to tendon injuries. Just studying the photos of equine athletes who possess correct forelimbs, and the stresses their forelimbs endure, is enough to clarify the issue. On the other hand, however, genuine over-at-the-knee structure is actually an injury to the foreleg’s tendinous check system that allows the carpus to pop forwards without support. Certainly, a horse with genuine over-at-the-knee alignment shouldn’t be ridden, and absolutely should never be jumped, until his injury is healed. So it's imperative to understand what constitutes a calf-knee, correct foreleg, and an over-at-the-knee stance so we can make informed creative decisions.

Also regarding straight forelegs, the correct anatomical alignment of the equine foreleg, when seen from the front, is a knock-kneed stance just like our own femur with our radius. In other words, the femur and the radius of the equine forelimb shouldn't be aligned straight up and down like a rod, but angled-in at the knee, towards the median. It's a subtle alignment, but it's a necessary one nonetheless. In truth, when there's a straight line between the femur and the radius the horse is actually bow-legged, a serious fault. Yet many conformation books illustrate a straight, rod-like structure and many artists, not recognizing this anatomical alignment, put such forelegs on their sculptures.

So before deciding a sculpture is finished, we should double-check our foreleg structures and alignments to confirm we’ve created a piece that depicts a functionally sound foreleg.

5. Straight Hindlegs

Similarly, the idea of a “straight” hindlimb has been misconstrued, now meaning straightness in a literal sense. We also find this mistake in nearly every conformation book so it's no surprise that we'd find this mistake repeated so often in sculpture. We have to be careful with conformation books and labels of "champion" when it comes to our references. They can be very wrong. Just because it won a ribbon or is in a book means that it's sound information (pun intended, ha ha ha).

So, for starters, a good rule of thumb for a proper hindlimb as measured from the side is a plumbline from the point of hip, to the point of hock, and down the back, or in some breeds, the center of the hindcannon. This plumb line should be consistent whether the hind limb is under the body, articulated and planted forwards, or articulated and planted backwards as when standing. Keep in mind, however, that balance shifts can influence these articulations away from the plumbline, depending on the moment. Nevertheless, an experienced eye can usually extrapolate what’s happening if the sculpture is done well such as correctly shifting weight not just in the legs, but throughout the whole body, too.

Post-legs occur when the hindleg is placed in front of the plumbline whereas camped-out occurs when the hindleg is placed behind it. Sickle-hocks occur with undue angulation of the hock to orient the hindcannon away from the plumbline. It’s handy to think of hindlimbs as lengths and angulations that influence the reach of the limb as well as its long-term durability. To illustrate, the standing hindlimb is really a series of bends in a fixed space, between the croup and the ground. So between two horses of equal croup height, the one with post-legs will have a comparatively shorter hindlimb with more open angles whereas the horse with a camped-out stance will have a longer hindlimb with more acute angles. Subsequently, post-legs don’t have much reach and are prone to involuntarily locking the stifle and that irreparably injure the stifle joint. On the other hand, camped-out legs have more reach under the body, but are unstable, weak, wobbly, and are often prone to spavins.

However, because they move primarily in non-suspended gaits, gaited breeds can be regarded a little bit differently. Specifically, acceptable angulation lies within a range from the ideal plumbline to one that touches the front of the hindcannon. Nevertheless the hindlegs shouldn’t be more angled than this or be sickle-hocked either. Yet, unfortunately, the role of coiled loins in quality gaitedness isn’t largely recognized in the modern showring anymore and, therefore, long, crooked hindlimbs are becoming prevalent to artificially increase reach. (On another side note, post-legs in gaited horses are a significant fault because this can lead to ESAD over time, particularly with improper riding.)

Now inspecting from behind, the hind cannons should be parallel to each other. If they divert away they're cow-hocks and if they converge, they're extremely bow-legged. What's more, some draft breeds should be "close-hocked" which shouldn't be confused with cow-hocks. Instead, "close hocks" is when the cannons are properly parallel to each other, but are situated very close to each other, sometimes almost touching.

Also inspecting from behind when the horse is standing, the proper hindlimb should be oriented on an outward plane from stifle to toe, with all the bones aligned on the same plane. That means hind hooves should point outwards at the toe. This orientation is often consistent in motion, too. Yet this isn’t to be confused with cow-hocks, which misinformation would have us believe. Genuine cow-hocks have hindcannons angled away from each other whereas correctly planed hindlegs have parallel hindcannons (just like a drafter's "close hocks"). The truth is that a standing hindlimb should never be planed straight forwards, it actually being bow-legged. The biological reason for the outward plane is that the hindleg must clear the broad posterior portion of the belly, a biological imperative that has influenced the evolution of the hindlimb for standing and motion. (On an aside, granted, sometimes in certain movements the hind limb will orient on a forward-facing axis, but this is momentary and also caused by the mechanics of the body and balance.) Yet many sculptors create standing hind limbs with this erroneous forward-facing axis, inadvertently creating bow-legs, a rather bad fault.

Ellie shows us the correct outward plane to the hind limb with her left hind leg.

We also have to consider two crippling diseases: ESAD and DSLD. ESAD (Equine Suspensory Apparatus Dysfunction) is a term for a crisis in the suspensory apparatus, which inhibits the horse from properly supporting himself through the lower leg. It appears to be caused by several things ranging from injury, overstress, peculiar conformation to genetics. Similarly, DSLD (Degenerative Suspensory Ligament Desmitis) is a painful, bilateral degenerative condition of the suspensory ligaments, usually in the hindlegs, which hinders their supportive properties. As DSLD progresses, the fetlocks sink increasingly downwards, causing the pasterns to become progressively parallel to the ground while straightening the stifle and hock; think of a post-legged horse with sloping hindpasterns. The causes of DSLD are also suspected to be genetically based, but can be brought on by overstress or peculiar conformation as well. Unfortunately, however, many sculptors don't realize what ESAD and DSLD look like in life so they parrot these alignments in their work. As such, we see many sculptures with too-sloping hind pasterns paired with straight hocks and sometimes post-legs, or sculptures with too-sloping pasterns with a broken axis at the hoof.

6. Deep Heartgirth

A "using" horse should have a heartgirth—the depth of the torso right behind the wither and the elbow—that's a head's length or longer (such as with stock horses, Thoroughbreds, and Warmbloods). Yet as certain breeds, particularly halter horses, have become more "refine," heartgirths have been shrinking such as in the Arabian, Tekes, Saddlebred, and Morgan. As a reflection, some sculptures sport shallow heartgirths, a serious fault that compromises the ability of that horse to process enough oxygen for exercise.

It's always smart to use calipers to make sure our sculpted bodies have adequate heartgirths. To do so, we apply the head length to the span running from the back of the wither to the bottom of the torso, behind the elbow. It's an easy fix.

7. Healthy Foot

(Note: For an in-depth, detailed exploration of what constitutes a good and bad foot, refer to the 12-part blog series Steppin' Out: Hooves From An Artistic Perspective. It's highly recommended to digest this series because sculpting a healthy foot really is that important.)

Sculpting a healthy foot on our sculptures is of paramount importance, yet finding a good set of feet in artwork can be a challenge. There simply aren't enough artists who take the time to educate themselves on the subject and so chronically sculpt pathological feet and continue to validate undesirable visuals. Feet aren't an afterthought! It cannot be overstated enough how important it is to take care in sculpting quality feet on our sculptures. And to do so, we have to keep up with modern science which is only now unraveling its true secrets and discovering just how wrong we've been this whole time! It's important to take the time to be informed.

Now contrary to popular opinion, the correct angle of the foot isn’t strictly 45˚. Furthermore, the shoulder or pastern angles aren’t sensible comparative measurements, either. Truthfully, based on recent research and observations of farriers, the normal range for domestic horses is 48 - 58˚ for the forefeet and 52 - 60˚ for the hindfeet. Actually, the normal range seen in feral horses can be as acute as 60˚ for the forefeet and 63˚ for the hindfeet. What's more, a horse's feet customize themselves to the lifestyle and habitat of the animal, meaning we need to take such things into account when we sculpt feet on our sculptures.

Actually, the accurate means to evaluate anglulation is the Foot-Pastern Axis (FPA), also referred to as Dorsal-Palmar Balance (DPB), a line that should bisect the first, second, and third phalanxes with the anterior (or dorsal) and posterior (or palmar) surfaces of the hoofwall parallel to this line regardless of the foot angle.  What's more, a correct FPA is more important than if the foot is structurally too upright or too sloping—there should never be a break in the axis. Be particularly mindful then of sculpting stock breeds. Many halter specimens sport a broken axis on the front feet which is implicated in the occurrence of navicular syndrome. Always keep that axis straight!

Then studied from the front or back, another critical angle is the Medial-Lateral Balance (or MLB), which refers to the relationship between the medial and lateral walls and the boney column. The two sides of the hoof wall should be equal in length and the ground surface of the hoof should be centered beneath the boney column, creating even weight distribution. This means, practically speaking, that a line should bisect the large metacarpal (cannon bone), the first, second and third phalanxes and down through the hoof. That said, the medial side of the hoof is typically slightly steeper than the lateral side since mass is directed more down the inside of the limb. Nonetheless, DPB and MLB must be in proper alignment since deviations are largely responsible for most structural lameness. 

Shape is also essential for a healthy foot. The Toe-Heel Tubule Alignment (THTA) should match, meaning that the angle of the heel should parallel the anterior angle of the wall when seen from the side. The wall should also be free of bulges, dishes, or flares. The hooves of the forefeet are more sloping and rounder than those of the hind feet which are slightly steeper and have a pointed toe (and sometimes are slightly more narrow), often with slightly flared quarters. This is due to the pressures of tork on the hind feet. Indeed, a foal will be born with feet the same shape, but in as little as 24 hours, those feet will take on these characteristic shapes (something in mind for sculpting foal feet). Feet that are all the same shape in an adult is a common mistake in sculpture. Indeed, many popular artists, and therefore many popular sculptures, have feet all the same shape which is a serious flaw in realism.

Proper shape should also have a rounded toe, or "rolled back" toe, that allows rapid break over and shortens the leverage of the foot that avoids a contracted foot. This is why hooves with long toes are typically contracted whereas those with short, rolled toes are properly shaped. Yet many artists create crisp, sharp pointed toes in the belief this shape is the correct one. However, this represents a pathological foot. Also many collectors expect this shape for the same reasons, making the same mistake.

Even so, shape variation between limb pairs can occur, caused by different limb conformation, poor horsemanship, irresponsible trimming, or actual pathology so we want to avoid this in sculpture. Interestingly, the mismatched phenomenon usually affects the forefeet, tending to show itself as one foot with a long toe-low heel and the other tending towards a short toe-long heel, and is often attributed to chronic leaning in a horse who hasn’t been schooled to carry himself straight. Mismatched foot pairs are a common fault in sculpture.

Shape may also be a function of type. For example, small ponies tend to have narrower and more upright walls with longer heels while some drafters tend to have either boxy or “pancaked” hooves. Similarly, Arabians tend to have rounder hooves while, conversely, many Thoroughbreds tend to be wide across the quarters. Mules, exotics, and donkeys tend to have narrower, more upright walls and a coffin bone placed higher in the hoof capsule, often creating a slightly longer heel.  

Size is important too, and should be adequate for the mass of the animal; it should never be too small. However, contrary to common artistic interpretation, foot size isn't measured by the length of the hoof capsule. Instead it's measured by the circumference of the coronet band—the bigger, the better. In the past, identifying a foot that was “too small” was rather subjective, but science has now provided a real measurement we artists can use...

 The equation can be calculated on a calculator, as follows: 

• Measure the circumference at the hairline, right below the coronary band (in inches). 
• Multiply the horse’s weight (in pounds) by 12.56 and hit the “equals” sign. 
• Divide this first number by hairline measurement (in inches) and hit the “equals” sign.
• Divide this number again by the hairline measurement (in inches) and hit the “equals” sign. The answer should be between 68 and 78. If the number is higher than this range, the horse’s mass (or the sculpture’s depicted mass) is too much for the feet.
• Or as the equation: (12.56 x W) ÷ C2 = R

The sum (R) is the ratio of the body size to foot size, described in pounds per square inch. In results, (R) should amount to no more than 78, or 78 pounds per square inch, the maximum loading for an average performance horse (Turner, 2003). Statistically, ratios higher than 78, particularly those higher than 83, tend to develop lameness issues. 

Scaled down, we can use this ratio by estimating how many inches our sculpted coronets are and then estimating the weight of our sculpted horse if alive, and then plugging the numbers into the equation. Handy, huh?

But unfortunately, in life, foot size is a common victim to the trend and fashion of "refinement" as clearly seen by the tiny feet of many breeds nowadays, especially with halter stock horses, Thoroughbreds, and now some Arabians. And since many artists don't understand the importance of a a foot of adequate size and often seek to "refine" the legs even more, the hooves on many sculptures are alarmingly too small as a function of artistic exaggeration.

More still, science has discovered that the hoof wall was never meant to support the horse's weight. When the foot is trimmed so that the wall is made to do so, it's called "peripheral loading" and it can cause all sorts of lameness issues, which contributes to the regular occurrence of lameness in the domestic horse. Instead the wall is merely meant as a protective wall for the internal foot structures. In reality, the frog, bars, sole, and "waterline" are the structures meant to bear the horse's weight and impact forces, working as an interconnected system. Think of a rhino's foot with a protective hoof—that's how the equine foot is supposed to function. That means our sculptures should have a proper structure of the palmar foot and walk on the "waterline" rather than the rims of the hoof wall.

Now coming back to a long hoof capsule, as many artists create thinking this increases the size of the foot, such a foot is termed a "mechanical sinker," a condition that shares some characteristics with the sinking associated with laminitis. Contrary to convention, the horse's sole should be thick, up to one inches thick. Yet convention regularly pares down the sole to even within one-sixteenth of an inch! The thought is to "clean up" the sole and to help the hoof flex despite silence showing that the hoof flexes just fine with a thick sole. So because the sole is so thin, the coffin bone sinks within the hoof capsule, which is then pushed up on the second pastern bone, causing the hoof capsule to lengthen. In reality, the proper foot has the top of the hoof capsule at or below the anterior point of the coffin bone so as not to "house" the joint between the second phalanx and the coffin bone. As a result, this correct alignment has a short hoof capsule, not a long one! Because many artists don't understand this syndrome, the hoof capsules on many sculptures are too long, indicating this pathology of the foot. Keep those hoof capsules short! A good rule of thumb for hoof length is (measured from coronet to toe):

• 3 inches for an 800-900 pound horse
• 3.25 inches for a 950-1,050 pound horse
• 3.5-4 inches for a 1150-1,250 pound horse

(Also keep in mind that certain registries regulate hoof length. For example, the Arabian registry prohibits a toe that's longer than 4 1/2", including the shoe and pads.)

Hoof length is important because a hoof that’s too long will have a breakover point too far forwards, reducing the overall base of support for the foot and that can cause pathological hoof shapes to develop such as a contracted foot. A long toe also creates a longer lever-arm for the limb to rotate over, therefore delaying breakover, stressing the posterior areas of the limb and risking lameness. Imagine running a marathon in clown shoes! Unfortunately, many breeds don't reflect the science of the foot and are deliberately trimmed to have long hoof capsules such as the Arabian, Saddlebred, and Morgan. We need to make better decisions for our sculptures.

Furthermore, there exists in certain circles the unfortunate yet persistent belief that manipulating hoof angles will improve flight patterns, speed, and stride length. This manipulation is usually the long toe-low heel trim (LT-LH) which is thought to create long, low, sweeping strides and greater leverage for breakover, in the pursuit of increased stride length (riding) or speed (racing). What's more, since this is an artificial trim, it typically creates a broken axis in the DPB, which then causes a host of lameness issues to surface. However, a Canadian study done in the 1980's by Hilary Clayton at the Western College of Veterinary Medicine found that stride length was increased only by a minute and insignificant amount with this trim and didn’t get the horse from point A to point B any faster than his normal foot angles. But alarmingly, the study did find that this trim subjected the horse to a greater incidence of unnatural limb stress, unsoundness, and compounded lameness. Nonetheless, the pathological LT-LH hoof is common in sculpture since artists simply parrot what they see without an adequate knowledge base. Keep those toes short and those heels of adequate length! And don't forget to create a straight DPB axis!

The texture of the wall should also be smooth and hard. Sometimes it can have tiny, shallow rings (often referred to as grass, fever, or growth rings) that evenly encircle the hoof, parallel to the coronet. They're created by nutritional, seasonal, climatic, or systemic changes to the animal's lifestyle. 

The frog and sole are integral to a quality foot, too. The frog should be symmetrical, broad and extend more than half the distance from the heels to the toe to about one to one and a half inches away from the toe. The sides of the "V" the frog makes should extend beyond the bulges of the heels so it's adequately broad. The sole should be firm, smooth, vaulted, and of adequate thickness, up to 1 inch. If the sole is too thin, the animal will suffer bruises  pain, sinking, and injury. Under natural conditions or barefoot, excess sole with slough off by itself to maintain an optimal thickness. Unfortunately, the frogs of a typical sculpture are often far too small, either too narrow or too short, and sometimes both, a serious fault. Soles are also often flat, uneven, or bulging, and typically too thin as exhibited by a hoof capsule that's too long.

Good lateral cartilages and coronets are also necessary for a quality foot. The lateral cartilages should be even, symmetrical, pronounced, and extend well back from the back of the pastern. Those of the forefeet are thicker and larger than those of the hindfeet. They should also be smooth and firm, free of bumps, dips, or other deformities that indicate injury or disease. Likewise, the coronet should be even, symmetrical, continuous and slightly rounded in front and flat at the heels. There should be no swellings, bumps, undulations, knobs, or any other sign of injury, infection, calcification, or imbalance. Lateral cartilages are typically treated as afterthoughts in sculpture being bumpy or too small. Likewise, coronets are often carelessly done in sculpture, having bumps, unevenness, dips, and rounded all the way around the foot.

When creating our sculpture, it’s crucial to pay close attention to the functionality of the feet. We can sculpt hooves how ever we wish—they have specific biological rules to follow for soundness. We also can't be careless in our sculpting since this typically leads to the creation of pathologies. It's just not enough to have hoof-like formations on the ends of the legs. Equine feet should be of a particular and specific nature to be healthy.

8. Neck Length

It’s been fashionable for some time to breed for longer necks, with some folks claiming a “neck can never be too long." But it most certainly can! When compared to ancestral, wild, and feral brethren, the modern domestic horse demonstrates just how influential this trend has been. The purpose wasn’t just for aesthetics, but to improve the horse’s agility with the weight of the rider since the neck is used as a balancing tool by the animal. But there’s a point where length becomes a physical liability, and this point is when the neck is longer than the length of the back. This is because all horses have seven cervical vertebrae, so to produce the extra length means these vertebrae have to elongate, which unnaturally stresses the fleshy attachments, structures, nerves, and connections of the cervical column. 

What's more, long necked horses take longer to mature (meaning that all the spinal growth plates have calcified), at about eight to nine years as opposed to six years for their average-necked friends. Also horses with overly long necks can be difficult to ride, often becoming "rubber necked" and so produce stiff, rigid movement, or tend to experience growth abnormalities, cervical dislocations, and problems with coordination when not in the hands of a thoughtful rider. And a long neck isn’t more flexible than a short one, but it’s the reverse that’s actually true! A shorter neck has more joints per given foot than a long neck, which is why long necked horses tend to brace, lean, or avoid bit contact since their necks are relatively less flexible. For all these reasons, it’s essential the neck be in harmony with the horse's body and not a fashion statement since it's an essential part of a horse’s balance and locomotion. 

That said, certain breeds are bred for longer necks such as the Saddlebred and Teke, so we have to account for that in our sculpting. And length neck doesn't seem to adversely affect the Saddlebred since his neck is rooted so high and upright. That's because we shouldn't get too hung up on length, especially if we think a neck is too short. That's because when it comes to the neck, it's the set and shape of the neck that are more important than length by directly impacting collection, balance, and performance. (So we need to be aware of the bony landmarks because these qualities are determined by the skeletal cervical column and not by the outline of the muscles.) In regards to this, the first, and most important, consideration of any neck is the root, or its location and set. In this, there are two types of ideal necks: the arched neck and the straight neck. Both share the same basic cervical structure, and both can easily telescope for bascule, even if relatively short. An arched neck has a root that’s shallow and set high. In other words, it's set at or above the middle of the scapula and quickly projects upwards, creating a neck that easily telescopes for bascule, even with horses with hammer-head structure (or an acute angle where the neck joins the head). Horses historically bred for riding such as the Arabian, Morgan, Saddlebred, Iberian, etc., typically have an arched neck. Now a “swan neck” is the same structure, but simply more slender in musculature, highlighting the shape of the cervical column. It shouldn't be faulted, being so. Likewise, a straight neck also has a shallow root and long, open turnover, but is set lower on the shoulder, appearing to shoot out from the body. Horses historically bred for speed or stockwork tend to have straight necks such as stock horses and the Thoroughbred. Drafters can have arched or straight necks, depending on their breed type.

In contrast, a root that’s deep and set low has great difficulty telescoping, and is characteristic of an “ewe-neck." This type of neck projects down from the torso, with a typical dip where the neck joins with wither, and usually attaches in a hammer-head fashion to the skull. Because these horses have such difficulty lifting the base of the neck, they tend to stiffen and brace, often resulting in star-gazing and resistance. 

Of secondary importance to a quality neck is the connection to the skull, often referred to as a “mitbah” in Arabian circles or “turnover” in Saddlebred or Morgan circles. The longer and more open the turnover, the greater ease the horse will have to flex at the poll without impediment, bracing, or stiffness. 

9. Shoulder Bed

It's essentially been one of the long-term goals of breeding to join the angle and shape of the "shoulder bed" with the actual angle and shape of the scapulae. When the two are in alignment, we get freer shoulder action and that translates into "better" shoulder motion. In contrast, wild or feral cousins can have a shoulder bed misaligned to the actual scapulae alignment, so comparing and contrasting them with domestic counterparts can be illuminating.

The shoulder bed, or that ledge connecting the neck to the shoulder.

Specifically, the "shoulder bed" is that plateau created where the neck meets the scapulae, that ridge that often catches the light. In turn, we measure the angle of the scapulae from the point of wither to the point of shoulder. Both the bed and this alignment should be the same, or as close as possible.

Sometimes misalignments show up in sculpture, so we keep to keep our eyes open when we sculpt. Happily, when we get in the habit of matching up their angles, it makes sculpting the shoulder that much easier by providing a good "landmark" of sorts to develop surrounding areas.

We should also keep in mind that different breeds require different shoulder angles. For example, those breeds traditionally bred for riding such as the Arabian, Morgan, Saddlebred, and Iberian do best with a shoulder angle of about 45˚. In contrast, many draft breeds are favored to have a steeper angle to better carry the collar and pull. So we need to pay attention to breed peculiarities when we sculpt our shoulders.

10. Loin and Wither

All horses require a strong, broad loin and back to carry or pull weight over long distances and remain sound. Classic riding horses such as the Arabian, Morgan, Saddlebred, and Iberian, for example, typically have good loins for this reason. Drafters should also have a short, broad loin since this is the interconnection between the "engine" of the hindquarter and the forequarter. 

However, racing types often don’t possess such a loin because their origins were founded wholly on speed. Such horses include the Thoroughbred and the Quarter Horse, for instance. So we may want to compensate if we're working from reference photos.

Horses should also have a good wither, not just to seat the saddle or collar, but to also act as an anchor for the neck and back, facilitating balance, collection, power, and agility.

11. Chest

Now we should note the peculiarity of chest width, easily one of the most difficult things to measure in equine sculpture. Remember that the fleshy Shoulder Sling attaches the scapulae to the torso; there's no bony attachment of the scapluae to the torso. That means the width of the chest isn’t constant and can be influenced by management, conditioning, and horsemanship. That means starving, unfit, neglected,  or underweight horses will have narrow chests not because they’re built that way, but because the flesh of the Shoulder Sling has deteriorated or atrophied. It can be re-conditioned back to a healthy width. In contrast, horses ridden with weighted feet such as Big Lick Tennessee Walkers will develop an unnaturally broad chest simply because the chest muscles are overdeveloped from the excess weight on the front feet. In contrast, athletic horses will have a robust, nicely broad chest because they’re fit, supple, and conditioned. So we need to keep fitness and condition in mind when determining the width of our sculpted chests.

12. Head Shape

Nature designed the horse's head not just for the points we've already discussed, but to process air. Indeed, the horse has a "fuel-injection" structure to direct the incoming air directly into the bronchial tube in an uninterrupted flow. So we have to consider the sinus cavities when judging what kind of head we're sculpting to ensure we're securing the integrity of this air pathway.

And we run into a particular problem with the Arabian in this regard. Over time, the desire for more "extreme," "classic" heads has been a steady pressure on the breed. Now we have Arabians with heads so extreme, the "bend" in the head caused by the deep dish and crushed nasal bones actually disrupts the sinus pathway, which is why wheezing has become more common in the halter show ring. Such horses have breathing and have chronic issues with sinus inflammation and pain. We have to remember the windspeed of the incoming and outcoming air when a horse is at excercise—400 mph. When this air hits the "bent" angles of an extreme head, that causes inflammation of the sinus tissue, and we now have a horse that's more a "lawn ornament" than a "using" horse. Isn't this contrary to the famed athleticism and stamina of the Arabian breed?

This is as extreme a head we can have without running into sinus and breathing problems.

For this reason, as artists we have to make some important value judgements when we sculpt the Arabian. Do we wish to pander to mercurial aesthetics or validate those points that made the breed renown in the first place? Do we falter to our tastes or create according to his well-being? Because, in this, "type" isn't a matter of taste. It's a matter of humane function. We don't get to put as extreme a head as we want on our Arabian sculptures because it suits our aesthetics—we're obligated to this animal, first and foremost. And that forces certain choices for our clay. Something to ponder. 

(Sidenote: The arched heads of Iberians and others, like Campolinas, don't cause sinus problems when it comes to air flow since they still maintain the unimpeded pathway.)

13. Tailbone

The tailbone is an extension of the spinal column and so should be of adequate thickness and robustness to reflect these qualities of the spine. It should never been too thin or too thick as we too often see with braided tails.

Conclusion

As artists, we have the opportunity to circumvent the validation of structural liabilities to create pieces that promote our subject's well-being. This affirmation of what’s good for the horse over what’s popular in mercurial taste has real potential for positive change by helping to alter desired visuals. 

What's more, when we create according to biology rather than fashion, we reaffirm our conviction to this animal and the responsibility in our work. It also keeps us honest and compassionate when we're creating from imagination. Research, reflection, and re-evaluation are always necessary and, in this manner, we can create work with distinction and thoughtfulness.

It also means we create work with an automatic advantage with those that are informed. When we demonstrate that we know what's what in our work, we create authoritative work and speaks well of our Voice. We show we're not careless and uninformed, and that reveals we care not only about our work, but our subject as well.

So it's important we take the time to educate ourselves and apply new knowledge to our work. It helps our body of work and our motivations evolve towards ideas that benefit our subject and that sends out a positive message. Owning the accountability to and responsibility for our subject puts us in a position of creative power, and that not only compels us to learn even more, but allows us to defend our work with confidence. And, in the end, that translates into more freedom in the studio—freedom from unwanted, unconscious visuals and freedom to create courageously to become an advocate for this animal. And that's a true blessing!

"I must take responsibility for my work. That word may be grandiose, but there's an ethic involved in creation."

~ Cecilia Davis Cunningham

Thirteen Points for Performance: The Essentials for Functional Conformation