Equine Anatomy and Biomechanics: A Primer of Equine Engineering for Advanced Students Part XVI - Myths

Introduction

Hello! This is part sixteen of this 17-part series on equine anatomy and biomechanics for the intermediate student. Refer back to Part 1 to start. Truly, we've covered a lot of material to get here and we have just a bit more to go. Specifically, we'll be discussing myths now, a subject that's just as important as the truths we've already discussed. Why? Well, because there exist many myths regarding the equine form and unless we're aware of them, we risk parroting them in our work...and that can compromise it.

Myths abound in the horse world largely because science hasn't really taken a hard, objective look at the animal until relatively recently. It's so odd that an animal so pivotal and ingrained in human civilization could be taken for granted so profoundly! Indeed, modern science is revealing just how much we didn't know about horses, and how much we've assumed quite wrongly. No wonder horses are notorious for going lame! It's a miracle any remain sound at all. It only proves what a sturdy, adaptable animal he truly is. But thanks to new thinking and new technology, we're starting to better understand this complex and fascinating animal we've worked with for so long. Who knows what future studies will reveal! Whatever it is, it will help us better preserve and foster the well-being of this incredible creature.

So without further adieu...let's get to it!

Jibbah

The Arabian "jibbah," or bulged forehead, is often claimed to be a function of a larger braincase, supposedly explaining the breed's keen intelligence. But we have to remember where the breed originated: the desert. And many desert mammals have domed foreheads from the donkey to the hemonids. Even foals often have domed foreheads. In other words, the jibbah isn't something unique to horses, or Arabians. It's simply a function of the sinus, an expanded cavern to add moisture and coolness to the incoming hot, dry air to protect the lungs. That's it. Nothing fancy. Simply a dry environment adaptation.

The jibbah also shouldn't be extreme, but at most only moderate. It also shouldn't be accompanied by a "crunched down" nasal bone, as we so often see with extreme, "classic" Arabian heads, or "seahorse heads," or "dolphin heads." Instead, the jibbah should only be a slight bulge of the forehead accompanied by that concave axis of the head, everything else being normal. This is because an "extreme" Arabian head causes pain, and seriously impairs performance by causing inflammation of those sinus tissues as well as causing bad dental and biting-up problems. These are things that severely compromise a breed renown for its vitality and endurance, so why exalt them? Remember how fast the air comes rushing into and out of the head at speed? Well, when that air hits the "ledge" caused by a strong dish, that causes the tissues to become painfully irritated and even bleed. This is why Arabians with "exotic" heads aren't typically seen doing anything but being "lawn ornaments" or at best, doing the "softer" types of performance like Western Pleasure rather than more energetic forms such as endurance racing, flat racing, and sporthorse discplines. It's also why the incidence of wheezing and gruntling has been on the rise, especially with Arabian halter horses, a sad testament to how far off-track Arabian ideals have become. This means validating such a head becomes an ethical question for sculpture, not an aesthetic one.

Arabians can show a great deal of "type" even with a straight profile, so a moderate or little bit of a dish is more than enough to get the point across yet still remain honest to this magnificent, athletic breed.

Bone Density

It’s a common misconception that certain light breeds don’t require a lot of "bone" since theirs is somehow intrinsically denser due to the historic, rougher conditions in which they were developed, such as the Arabian. As a result, these breeds are suffering from a diminishment of their bone in the belief they can "lose some" and still remain sound, creating legs that are too slender and fine. But the truth is that it’s not a good idea to have bone denser than normal since this is actually a disease that results in brittle bones prone to breakage or fracture. What we want is a normal bone density adequate for the animal's mass, right?

And that's where the confusion comes in...mistaking density for mass. Biologically speaking, nature designed the equine to be basically no larger than an Arabian, about 15hh. There are exceptions here and there during evolution, but overall, this is about the size that works best for the equine blueprint. Why? Well, because bone density decreases with each unit of mass in the equine. That's to say, the more massive the horse, the more bone density they need, so if it doesn't adequately increase as the horse becomes more massive, then bone density goes down in relation to the mass of the horse. And this is exactly what happens with the larger or taller breeds, which is why they have a tendency towards unsoundness in comparison to smaller-stature breeds. They simply need more bone to accommodate their greater mass. This is also why the Arabian and pony breeds are famous for their soundness...they have enough bone for their mass. They're exactly what nature intended for the equine blueprint. They don't have greater bone density then...they have normal bone density! They just have less mass. It's the larger breeds that have abnormal density, being too low for their increased mass.

In actuality, all breeds should have ample bone of normal density that’s proportional to the individual’s weight and height. That's about 8 inches of bone per 1,000 lbs. On the drafter in particular we see a great disparity between the required bone and their actual bone. Can you imagine 16 inches of bone for a 2,000 horse? Those are some huge legs, ones that we have yet to find in most drafters. This is one of the reasons why drafters are designed to walk to do their work. But it's also why it's so alarming to have inadequate bone on sport horses, especially those over 15hh. Bigger size doesn't necessarily mean better.

Small Dainty Muzzle

In Arabian breeding, the want of a small, delicate muzzle is a common standard. The idea is that the muzzle should fit inside a teacup, or the "teacup muzzle." However, the original meaning of the "teacup" idea was that the muzzle be delicate and dainty enough to sip from a teacup, not fit into one.

The horse requires a muzzle of adequate size to make room for all the big teeth he'll need to survive. He also needs large nostrils and large nasal passages to provide adequate air during exercise. Yet too many modern horses possess muzzles that are far too small, a particular fault with draft horses as breeders try to prettify their heads, or as artists misinterpret correct drafter construction. So artists should avoid sculpting tiny muzzles on their sculptures in order to validate correct biological structure. There's nothing coarse about a biologically sound muzzle.

Crest

Some folks confuse the crest with the cervical vertebrae column, as though the column laid beneath the crest, forming it. However, the equine neck, as we've learned, is an S-shaped curve starting deep within the neck about mid-shoulder and snaking its way through the neck up to the back of the skull. This gives the neck a tremendous ability to compress or stretch, something that wouldn't be possible with a cervical column laying beneath the crest.

With this understanding we can avoid many of the errors we see in equine sculpture regarding the neck. For example, we can avoid creating "crane necks," where the neck is unnaturally elongated in an arch more like a mechanical crane than an actual equine neck. Or when the neck starts at the tip of the wither rather than exhibiting that dip where it connects to the wither. We can also avoid the similar "rainbow neck," that common way to arch a neck that creates a rainbow-like even tube rather than the nuanced curves and angles correct for an actual arched neck. We can also avoid the "giraffe" neck that's far too long when we understand the nature of the S-shaped curve that elongates and compresses the neck depending on posture.

Long Toe-Low Heel (LT-LH)

When we understand how the horse moves and how his feet are supposed to be structured, we come to see that the many trimming philosophies are misguided. One of the most common is the idea of the LT-LH trim. Here the toe is left long and the heel is trimmed short, creating a "flipper-like" foot. The belief here is that this configuration creates a long and low "grass-clipper" stride, or that it increases speed for a race horse (the LT-LH trim is ubiquitous in racing, and also in the Quarter Horse and draft horse industry, even with halter horses).

However, as many studies done by Hillary Clayton have demonstrated, this trim does none of its purported benefits but actually causes unnatural stresses on the foot that eventually lead to lameness or gait or hoof problems. Tendon problems and contracted heels are common results, for example. It's also been strongly implicated in navicular syndrome. Instead, the toe should be short with enough heel to support the animal. With this type of foot, we actually achieve a longer, lower, freer stride, since the horse is allowed to move normally rather than wearing a pair of "flippers." It also improves the stride of a race horse. With this knowledge then, we can therefore avoid sculpting LT-LH feet on our sculptures to advocate healthy feet.

Mechanical Sinker

The pointed tip of the coffin bone (at the front) should be level or slightly above the coronet. This is the proper biologically-designed intention for a healthy foot. However, farriery has routinely carved the sole to be too thin when it actually should be quite thick (up to 1") to push the coffin bone upwards into this configuration and allow the hoof capsule to "sink," creating a short foot. When the sole is too thin, however, the coffin bone sinks into the foot because it has no support, its tip sinking below the coronet band, sometimes markedly so. This inhibits this joint from properly functioning inside the foot, and it causes lameness, bruising, and pain.

We can see a mechanical sinker by its long hoof capsule, and in X-rays. Many times the horse's foot will become "numb" and that interferes with proprioception, or the way the horse feels the ground and keeps track of where his feet are, which can cause the horse to become less nimble and light-footed.

Many sculptures have mechanical sinker feet, most commonly seen in their long hoof capsules with long heels. Keep the feet short, the toe short, and the heel of moderate length to help ensure sculpting a sound foot.

Hoof Size

It's often believed that hoof size is measured by the length of the hoof capsule, but science has proven this is an error. Instead, hoof size is measured by the circumference of the coronet band, i.e. the overall size of the hoof capsule, not its length. 

As for its length, generally speaking there should be a basic length (measured from coronet to toe) of the hoof capsule per pound of horse to maintain a healthy foot:

• 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 show and pads.

As for size, science has provided a formula we can apply to our sculptures:

(12.56 x W) = R
       (C2)

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

This is how we apply the equation:

1. Measure the circumference of the hoof at the hairline, right below the coronet, in inches.
2. Multiply the horse's weight in pounds by 12.56 and hit the "equals" sign.
3. Divide this first number by the hairline measurement in inches, and hit the "equals" sign.
4. 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 is too much for the feet. Scaled down, we can use this ratio by estimating how many inches our sculpted coronets are and then estimate the weight of our sculpted horse as if he were alive, and then plugging the numbers into the equation.

This means that hooves with long hoof capsules may not represent large hooves if their circumference is too small (as well as being a mechanical sinker). It also means that hooves that have short hoof capsules but with a sizable circumference to their coronets are good hooves, so we shouldn't let length throw us off. Indeed, a quality foot has a short hoof capsule, large circumference, and a short, rounded toe with adequate heel. The sole should be thick, vaulted, and smooth, and the frog large, wide, and extending to about 1" from the toe. For more information on quality hooves, please refer to my blog series, Steppin' Out: Hooves from an Artistic Perspective.

The Modern Horse

The horse of yesteryear, when he was a utilitarian animal as opposed to a sport, show, or recreational partner, was very different in build. Necks were shorter, heads were bigger, bone was more ample, hooves were bigger, and he was overall studier in build. In short, he was "coarser" by modern standards, but he was a "using" animal nonetheless.

It's been the pressures of art that has contributed to the shaping of modern standards of beauty. Indeed, we see the exact opposite of the everyday working horse exalted in many popular paintings and in the works of many popular artists. Long necks, small heads (sometimes markedly small), light bone, and small hooves are almost characteristic of art work in the past and present. The Victorian age, with its ideas of the eugenic "purebred" standards of beauty and social class put an inordinate amount of pressure in the modern age to adhere to these standards of beauty and purity, too. Indeed, it was a mark of "high blood" that a horse approach these troublesome ideals.

As a result, we've seen the results in the breeding shed. Necks have gotten longer, heads smaller, bone lighter, and hooves smaller, all of which compromise the working nature of these animals. It's no wonder so many are "lawn ornaments."

As artists we hold the grail in how this animal is portrayed. We shape the ideals many breeders aspire to as they shape their particular herds. Unless we understand biological functionality, we risk perpetuating problematic messages, and end up contributing to the ongoing problem of unusable horses. We have a responsibility. We can't just recreate what we see since what we see may be pathological, even if the animal has won great awards, is popular for breeding, or is regarded as an ideal standard. We need to know the difference between what's popular and what's functional. And there's nothing ugly about functionality!

Less Vertebrae

It's often believed that Arabians have one less vertebrae, as a point of breed uniqueness. However, many Arabians have a normal number of vertebrae despite being purebred. So this is a myth. And the truth is that many breeds derived heavily from Arabians, such as the Thoroughbred, can also have one less vertebrae, so it's not something unique to Arabians.

Wry Tail

We find in many conformation books the idea of a "wry tail," or a tail bone held off to the side, sometimes clenched to the buttock. The idea purported here is that this is a conformational fault, as though this posture was something bred into the animal.

However, in reality, a wry tail indicates bad posture brought on by poor riding technique. The animal is clenching his back and is moving crooked, and that manifests as a tail held and clenched to the side. It indicates bad riding, not bad conformation. And even when the animal is rehabilitated, he can still hold his tail this way, it having become habitual.

Big "Buggy" Eyes

We find in many Arabian circles the desire for a big, bulging eye, thinking this means the eye is bigger and more beautiful. However, while a big eye is desirable, it shouldn't "bug out." This indicates hypothyroidism, and it's no mistake then why this condition has been growing in the Arabian population as a result.

We want horses with a normal protrusion of their eyes despite size, so attending to this in sculpture helps to promote healthy visuals.

Pulled Manes and Tails

It's been a common belief that horses don't feel the process of "pulling" manes and tails to thin them out, such as we see when the mane is cropped short. However, modern studies have demonstrated that horses do, indeed, feel the entire process, and that it's quite painful. This might give us pause when we depict such types of manes and tails. It's also hoped that grooming practices switch to clippers and razor-cutting to achieve similar results and stop with the "pulling."

The Big Lick

Many in the Tennessee Walking Horse industry involved with Big Lick Showhorses try to convince us that the results they get are natural; that the resultant movement is a natural way of moving. However, recent court cases have revealed under oath that all horses demonstrating such movement have been "sored." This is something every equine anatomist already knew, knowing that equine biomechanics cannot produce such movement without coercion. And all those contraptions on their feet from chains to "packages" only serve to deliberately cause more pain by acting on the chemically burned skin to compel the horse to lift his feet even higher. Big Lick Showhorses often have big beefy chests, too, due to overdevelopment of the Shoulder Sling caused by the weight of those packages.

That means that every artistic representation of The Big Lick is a depiction of flagrant cruelty, and that may compel us to think twice before validating it in our work. It's not natural. It's not normal. It's not bred-in. It's flat-out abuse, plain and simple. If only horses reacted to hoof pain by dragging their feet instead of lifting them higher. *sigh*

Cat-Clock Eyes

The horse's eyes can move in unison (for example, eye whites at the front of both eyes), but contrary to common belief, they can also move like a "cat clock" (where eye white is at the front of one and and in the back of another). The horse is predominantly dependent on vision for survival, so it makes sense that his eyes could move in various ways. Yet this doesn't mean he can move them like a chameleon, but that they have a greater range of options than previously thought. 

Horses also have a special muscle connecting the orb to the back of the socket, which they contract when experiencing great fear or medical distress (like convulsions caused by tetanus). This muscle pulls the eye back further into the socket, creating a distinctive sunken-in look to the eye compared to the surrounding lids. So we need to be very careful when sculpting our eyes to make sure we aren't representing something we'd rather not.

Even Curve To The Spine

As we see in many horsemanship books, the horse is said to be able to bend evenly around a turn, as though his entire spine could curl around in an even half-circle. However, this isn't the case as the equine is mechanically incapable of such a bend as we've learned in this series.

Lateral bend of the torso occurs between T9 and T16, the front aspect of the spine. The loins aren't designed to laterally bend, but to coil, so minimal, if any, lateral bend occurs there. In turn, the horse shifts his ribcage to the outside of the bend, to "ride the rim" so to speak. We also learned that the pelvis cannot articulate with the spine laterally, but only as a hinge joint with the LS-joint. So all this, with the lateral bend to the neck, creates the illusion of an even curve. However, the horse actually bends as a series of kinks at the neck and the front of the torso, consistent to his structural biomechanics as we learned in the torso section of this series. 

Artists who sculpt a laterally bending rear thoracic section, loin, or pelvic sections, or even a bend at the LS-joint or sacrum, are actually creating a broken back, so we need to be careful when we sculpt our pieces to avoid this common mistake.

Sickle Hocks

Sickle Hocks aren't always genetic! Sometimes they're caused by poor riding technique that compels the animal to move with a hollow back. This can cause a misalignment in the hindlegs, causing them to assume sickle hock angles. With proper rehabilitation, those hocks can be made to straighten out to attain the natural, proper alignment of having the back of the metatarsal being plumb with the point of buttock.

A Good Foot

The adage, "no hoof, no horse" remains true today as it ever did. However, science is revealing just how much we've gotten wrong about it! It's imperative then for an equine artist to understand what constitutes a good foot in order to promote responsible visuals in artwork. 

Also, a horse's foot will customize itself to its lifestyle and natural habitat which is why the desert feet of Mustangs are different from the marsh feet of Camarque horses which are still different from the sandy feet of beach ponies. Or even more subtly, why the feet of horses worked on roads is different from the feet of horses worked on groomed footing. There isn't "one size fits all" foot, but a spectrum of possibilities. This means we need to take the imagined lifestyle and habitat of our sculptures into account in order to sculpt an accurate foot.

It's a complex subject, but one important to understand. For more detailed information then on what makes a good foot, please refer to the blog series, Steppin' Out: Hooves From An Artistic Perspective.

Close Hocks

Being "close hocked" isn't the same as being "cow-hocked." Being cow-hocked is where the metatarsals are oriented away from the median, when seen from the rear and standing square. In contrast, "close hocks" have metatarsals going straight down, in plumb and angled outward with the rest of the leg. In fact, many drafters, especially the Clydesdale, are expected to be close hocked to accommodate walking within the crop rows. Don't confuse the two.

"Straight Legs"

Many people confuse the issue of straight legs when it comes to evaluating the conformation of the horse. Indeed, some confuse them so much as to favor calf-knees and post-legs over correct ones.

For example, in the forelimb, the carpals should align to the metacarpal at 90˚, creating a look that appears "over at the knee" to many who don't understand this proper alignment. Likewise, the back of the metatarsal should be plumb with the point of buttock, regardless of standing stance, being neither post-legged or behind the plumb, or "camped out."

What's more, many believe "straight legs" has a literal connotation for the hindlimb, meaning that the entire limb from stifle to toe should be oriented straight forwards when standing, as seen from the back. Instead, the normal, correct orientation is an outward angle from stifle to toe, away from the median, to allow the stifle to pop around the wide barrel better. 

These flaws are quite common in equine art, so avoiding them promotes more responsible messages.

Growth Plates

In the immature horse, bones contain growth plates, zones of cartilaginous “bone” not yet ossified and still containing living osteoblasts. They’re located behind either end, between the diaphysis and the epiphysis of the bone. These are the only places where the bone can grow longer as the horse matures. The bone must also grow in diameter to maintain a strong proportion to the increasing length and this is achieved by the periosteum. Therefore, length is added by the growth plates and width by the periosteum in a lamellar fashion, like growth rings on a tree. 

A common fallacy is that only the radius has a growth plate, one that closes at about two years old, making the horse presumably ready to ride. But in reality, all the bones in the horse have growth plates that mature at rather predictable rates. In fact, the most important bones mature the last! Ultimately, this means that despite the rhetoric, there’s no horse of any breed at any time that's mature at two years old. All horses mature at six years except those who are very tall or have very long necks, maturing more around eight to nine years old. The closure schedule of the growth plates starts first on the lower limbs then ends in the spine. However, the coffin bone has full closure at birth and although it will gain width as the horse matures, it has all the height it will ever have as an adult. 

Anyway, the ossifying schedule is as follows:

• Birth to six months: the top and bottom of the short pastern bone. 
• Six months to one year: the top and bottom of the long pastern bone. 
• Eight months to a year and a half: the top and bottom of the cannon bones.
• One and a half to two and a half years: the carpus
• Two to two and a half years: the bottom of the radius and ulna.
• Two and a half to three years: the top of the radius and the top and bottom of the tibia.
• Three to three and a half years: the top and bottom of the humerus.
• Three and a half to four years: the bottom of the scapula.
• Four years: the tarsals.
• Three to three and a half years: the bottom of the femur.
• Three and a half to four years: the neck of normal length. This can be up to eight years for long-necked types.
• Three to four years: the growth plates in the pelvis.
• Six to eight years (six months more for a male horse): the vertebral spine, with the last cervical vertebrae maturing the latest. 

Actually, the incremental growth in height in the limbs is only approximately 20% more between birth and age six. A horse will grow upwards until about three or four years old, but will continue to grow lengthwise until about six years, or even eight years with tall or long-necked types. So, really, foals aren’t long-legged, they're short backed!

The spine matures last, making its bones and plates vulnerable to slippage or disjoining if the youngster is ridden too young. The data with ridden two year olds or pre-two year olds (such as in futurities for racing, cutting, reining, etc.) doesn’t indicate much problem with the legs at that point (though it may show up when the horse is older since there isn’t much long-term follow-up data yet). But slipped vertebrae and growth plates can permanently injure the horse. Sometimes therapies can help the situation, such as with loin slippage, but slippage at the sternum is nearly impossible to fix. Yet only about 2%-4% of these ridden youngsters suffer from slippage, a relatively low number. In reality, the biggest problem with riding a horse too early is to teach him early on to automatically brace his back and neck muscles the instant he’s mounted because he'll instinctively protect his vulnerable spine. So there’s no good reason ever to ride a two year old horse. It’s much wiser to wait until after four and ideally six years when his spine has matured. And those preliminary four or six years are the ideal time to teach him all about manners, lounging, driving, therapeutic tricks, clipping, trailering, washing, and all those other things he’ll need to know. 

The location of the growth plates in mammals (and birds) is actually a revolutionary development that might have given mammals an evolutionary edge. Because the mushier growth plates are sandwiched in bone, the joints are precisely formed at birth, resulting in immediate motion, agility, and speed. However the trade-off is that growth is stopped after a period of time so the mammal cannot grow indefinitely. In contrast, the ends of dinosaur bones were mushier since their growth cartilage was immediately behind the hyaline cartilage of the joint. So while a dinosaur could grow almost indefinitely to tremendous statures, his joint design was imprecise. So it’s hypothesized by some that most dinosaurs really couldn’t move fast or be terribly agile, otherwise they would’ve crushed their joints under their own weight. 

Some bones in the horse may also fuse with wear or maturity such as the splint bones and some in the hock or lumbar. They may also fuse because of poor horsemanship, such as with "kissing spines" of the spinal column. Any which way, bones are rarely straight, but are typically curved to accommodate forces of mass, torque, and the mechanics of motion. A bone certainly isn't a cold, static piece of anatomy, but is organic, adaptive, and alive. It’s important to remember that every aspect of the bone has evolved for a functional reason whether for flesh attachment, protection, or support of fleshy structures or to act as lever-like mechanisms. It also changes shape and characteristics depending on the forces visited upon it. To understand the nature of his bones is to establish a good basic understanding of his motion, his evolution, and how it affects his lifestyle.

Conclusion to Part XVI

Understanding the nature of myths and misinformation surrounding horses arms us with knowledge that informs our art work. Informed art is powerful art...it's an advocate for this animal rather than just a superficial admiration. When our art has this kind of authority, it transcends simply being something "pretty" and becomes something provocative and meaningful. The horse is unable to speak for himself, and as artists, we can think of ourselves as his voice, his conduit for connection beyond superficiality. We can dig beneath the surface to get to the gist of the matter. Approach our work in this light, and we gain a new insight not only into our own motivations, but empower of our own sculptures.

In the next part, the final Part XVII, we'll wrap up this lengthy series with some additional observations. More than anything, it's hoped this series has given us pause to rethink what we know and assumed, and perhaps inspired us to take up the torch of pro-active education to learn even more. The horse is an unfolding mystery today thanks to renewed scientific research, and what science has been revealing is both fascinating and troubling. We artists stand in a unique position to spearhead these new discoveries freely and without hinderance of obsolete convention through out work, and so learning about them and infusing them into our clay becomes an exciting and enlightening proposition.

So until next time...bust those myths!

"It is better to have knowledge, even if the knowledge endures only for the moment that comes before destruction, than to gain eternal life at the price of a dull and swinish lack of comprehension of a universe that swirls unseen before us in all its wonder."

~ Isaac Asimov

Equine Anatomy and Biomechanics: A Primer of Equine Engineering for Advanced Students Part XV, Physics

Introduction

Welcome back to this 17-part series that explores equine anatomy in a bit more depth than Anatomy 101, which was designed for beginners. We can therefore think of this series as one for the intermediate student since there's more to it than discussed, which is good...it keeps us learning. 

In this installment, we'll discuss physics as it relates to our clay. But what is physics in this regard? Is it the workmanship that goes into the construction of our sculpture? No, not really. Does it pertain to the materials we've used in its creation? Nope. Is it how our sculpture is designed from an artistic perspective? Kinda. Actually, what it relates to is how the natural laws of our physical world are expressed in the design of our sculpture...what forces would a real horse undergo in the real world and how are they expressed in our piece? Are they accurate to life or made up? Are they overlooked? Are they consistent throughout the body? Do they further the narrative or impede it?

It's not enough to simply sculpt his body accurately, in every conceivable detail. Unless we instill the natural laws that govern his existence, our sculpture simply won't come across as very convincing despite anything else that may be accurate. The horse doesn't exist in a "reality vacuum" and so neither should our sculpture.

So let's get to it!...

The Physical Forces

The horse is a living, breathing animal and not a simple, artificial abstraction. The animal is movement personified, with motion that's living, fluid, changing, often shifting and spontaneous, and always thrilling. Imbued with life, energy, power, and "spark," equine motion is irresistible to be sure. It's important then to be aware of these qualities in order to express them in our sculpture accurately and dynamically, and we do so in part by infusing the physical world into our clay.

To that end, the forces affecting equine motion can be broken down into thirteen basic factors: mass, balance, momentum (with inertia), centrifugal force, impulsion, tension (with tork), chaos, "bounce," "slump," "snap," "float," "kick up," and natural coordination.

1. Mass: Horses are a bulk of bone and flesh subject to the effects of gravity. Mass should therefore be imparted in the body through indications of shock absorption, muscle exertion, and the sculpture's posture to best impart the impression of the effort required to move or position such mass. For example, mass can be expressed through the flexion of the fetlocks during impulsion or weight-bearing, or the effort expressed in the muscles such as increased definition, 3D pooching, or muscle striations. Even the exertion depicted in the spine's posture helps the idea along. Expression can even be used to denote the effort required to move himself forcefully. It takes a great deal of power and coordination to move such a large herbivore, and our sculptures do best when conveying it.
2. Balance: Horses are constantly adjusting their balance, with their skeletons and muscles making accompanying adjustments which can change the posture and body alignments, sometimes rather radically. For instance, when one hindleg is square under the body while the other is drawn backwards, the pelvis will often tip down on that leg as it "follows the leg to the ground." Another example is when his neck is cranked sharply to one side, so he's looking behind himself, the front aspect of his thoracic column with often bend along the curve as that side "pooches out." Other examples are "tracking down the middle," "barrel swing," and "body snaking." “Tracking down the middle" is how horses tend to naturally move; they usually place their hooves towards the median, especially at speed. That's to say, horses typically don't place their hooves directly straight down, but slightly, and sometimes markedly, towards the median. This isn't to be confused with moving crooked. As for "barrel swing," that's when the forces of movement and balance swing the barrel over the supporting hindleg, like a pendulum. The effect can be clearly seen or subtle, but is a natural function of shifting weight and mass. This is referred to as "schwung" in German. Remember, there's a huge weight of viscera inside the animal's torso, and it sloshes around. So a horse moving naturally with a relaxed body will have barrel swing whereas a horse with a tense body won't as much. Now regarding "body snaking," that occurs when the horse curves his body in resonance with motion to aid balance and compensate for the force of the motion. For example, when a walking horse, when seen from above, will undulate his spine to alternately bring one side of his pelvis forward with each hindleg step forwards. In addition, when standing, the horse is constantly adjusting his balance, and so may lean, or move his shoulders, neck, or hips, even his pasterns, to accommodate. A standing horse doesn't just stand "straight up," but exhibits all these small corrections constantly. Therefore, our "standing" sculpture is brought to life when we imbue it with these ongoing movements.
3. Momentum (with Inertia): With all that mass moving around, momentum (and inertia) becomes a significant factor for movement. It distorts the flesh and can create wobbling, jiggling effects in loose or relaxed body parts, or it can cause tension and stress in activated body parts. In addition, momentum (and inertia) affects joints and other body aspects as often seen with wobbling hooves or ears (often seen on mules with their wibbly-wobbly ears). Momentum also propels the animal forwards as he pole-vaults over his forelimbs, an important quality to capture in clay. We have to get the sense that our sculpture is moving in a way that it would take power to cease or turn it. Momentum and inertia play a big part in how we design the mane, tail, and feathers, too, since they're passive aspects at the mercy of physics. For instance, perhaps we created a sliding stop sculpture. To drive home the idea of an instantaneous stop of momentum, we can have the mane still "catching up" to the stop by having its tips still oriented backwards rather than all of it swooshed forwards. Or maybe the long, silky feathers on our sculpted feet show parts and flowing bits in synch with how the leg is being moved. Indeed, hairy bits can go far in helping along this aspect of physics.
4. Centrifugal Force: Associated with momentum, it entails momentum in a spin. For instance, such things can include a lifted front hoof that's flung laterally outward in a sharp turn, or how genitalia, lips, ears, loose skin, hair, and relaxed muscles are pushed outward in a spinning or abruptly turning horse. Or perhaps his spine is curved into a turn and his barrel is markedly swung to the outside of that turn. Maybe his muscles are more tense on the outside of the turn than they are on the inside of it. And again, the mane, tail, and feathers can do much for conveying this feature. Truly, every time the horse turns, pivots, or spins, he's subject to centrifugal force and adding small indications in how his flesh and hair reacts help to plant our sculpture in a real universe. What's more, horses lean in motion a lot more than people realize such as around turns. The lean can be slight, or it can be pronounced, depending on the speed and angle of the turn. Horses don't just move up and down, keeping their bodies perpendicular to the ground at all times...they lean!
5. Impulsion: The original meaning of "impulsion" wasn't forwards movement, but upwards movement, such as we see with the lightness of self-carriage, or how the legs cause the body to "sproing up" with lightness. We can help along this idea with posture and through the strategic relaxations of the legs and body, even the wobbling of the ears and jiggly bits of the body such as the "plumbing" in the groin area, the underline of the neck, and relaxed aspects of the bodywaz. Plus, the mane, tail (and feathers) are very useful to forward this concept as they try to "catch up" with the upwards and downwards motion of every stride.
6. Tension: As muscles are activate they tense up, as they deactivated they relax. We can really amplify (and duplicate) the look of effort then by showing tension in those muscles that would be working and relaxing those that wouldn't be. For instance, tensing the triceps on a supporting foreleg while relaxing the triceps on a lifted foreleg at the trot. This also relates to tork, or the forces that "gear up" or "gear down" the animal's efforts. If we're able to catch how the body braces itself when it slows down or when it compresses in certain circumstances, such as a tight turn, we're that much closer to a faithful duplication of equine motion.
7. Chaos: This term applies to everything that just happens; that moment when things just occur and react. Maybe the horse has heard something and flicked an ear, maybe the breeze has brushed his mane a certain way, maybe he's excited about something and chomps on the bit, or perhaps his mood lends him to laziness, or perhaps he's momentarily tensed an area of the body, changing his posture or balance. Chaos happens all the time in a myriad different ways, so look for it and consider those touches for sculpture. Plus, being passive, the mane, tail and feathers are also elements of chaos as they're whipped around by the forces they undergo. Don't be afraid to design "wildly" moving hairy bits! And that even includes a hairy coat because perhaps a breeze has caused a section of his winter coat to part and billow. There are lots of little touches.
8. Bounce: Horses have springy motion, thanks to their many systems that give them agility and lightness to their movements. They essentially move as a series of different kinds of "bounces." For this reason, our sculpture should appear to have that same quality and not appear overly weighted down (unless that's our intention). There should be a freedom in our sculpture's movement, a kind of energy that helps to explain how such a heavy, large herbivore could move so gracefully and lively. For example, we can help this along is through posture with strategic areas being stressed and others relaxed, such as a weighted hindquarter and a relaxed, free forehand. Or how we express musculature's definition over various areas of the stressed or relaxed areas can help this idea along, too. There are many options once we start looking for these things in field study. 
9. Slump: Sometimes horses are lazy or exhausted, and so move in a distinct way that's plodding, or slumped. 
10. Snap: Equine motion is quick and often "flighty," for lack of a better word. Hooves can snap into flexion or snap forwards in extension, tails can be snapped into curious curves as the tailbone is flitted around, heads can be snapped up and down with their lips flipping up and down, or heads can be tossed from side to side, or ears can be snapped forwards in alert attention. Capturing the quickness and abruptness of equine motion can go far in bringing out sculpture to life.
11. Float: The animal's movement is graceful, often appearing as though he's floating along such as with a trot with a long suspension phase. How we design the body and place the legs can go far in mimicking this effect, with beautiful results. For example, in the suspension phase, placing the legs a little bit farther apart with snappy hooves, and sometimes those peculiar braced shoulders we often seen in this motion, can do much to forward this idea.
12. Kick Up: Remember there's more to motion than just his body, in particular his feet. There's the ground, too! Because of this, if on a base, if we can indicate the force of his impact with the ground through thrown dirt, "fans" of sand or snow, torn turf, tousled or stomped grass, shoved-aside pebbles, thrown rocks, and perhaps even previous hoof prints, we've captured a unique "detail of the moment." Sometimes these features can even be used as supports to further along the idea of the motion rather than stopping it such as a clear perpendicular rod often does.
13. Natural Coordination: Horses move in ways that express the natural orientations or postures their blueprint adopts when standing or in motion. They relate to all these factors, incorporating them all. Field study is a great way to learn them, as is the astute study of reference photos (when you know what to look for, many of these orientations become obvious). For example, horses tend to keep their heads perpendicular to the ground, when seen from the front, even when leaning or turning. Or the torso will "see-saw" up and down, when seen from the side, based on how far out from under the body the forelegs or hindlegs are. What's more, their tails often express what their spine is doing; if curving around a turn, they tend to hold their tails in line with that curve. Or, for example, when a horse is about to turn on his forehand, say to turn left, he tends to lean his forequarter in that direction, into the turn. More still, when seen from the top, the pelvis rocks from one side to another, bending the spine thusly, at the walk when each hindleg is alternately brought forward under the body in the landing phase of the gait. Even more, when the neck is raised high, the spine tends to hollow out in the thoracic span, causing more a dip in that section. And finally, when coming to a stop, the horse will naturally engage his LS-joint and curl his spine to curl his hindquarter to plant those hindlegs under the body. When he spins from that stop, he'll rock back onto those hindlegs and swerve his forequarter in the direction of the turn, leading with his head. These are just some of the natural coodinations to look for, so pay attention to how horses move under natural conditions.

Artistic Aspects to Consider about Physics

Awareness of physics for our clay is a learned skill. When we sculpt from anatomy charts and focus on structure, type, color, posture, and the other everyday aspects that go into our craft, it's easy to overlook the physical forces that influence all that. The bend of a fetlock, the wobble of flesh, the flinging of the mane, the weight visited onto a hindlimb, and the posture of the animal can all escape us if we aren't paying close attention.

And physics aren't just expressed in the joints and the mane and tail, but the entire body from the posture to the expression, so we need to be aware of that as well. The entire being and body of the animal participates, including his emotions, and learning to see how it does gives us more information to inject into our clay.

Common Artistic Faults With Physics

Sculpture often lacks immediacy and "moment" in their motion, and so appear static and rigid, and artificial. Yet equines are defined by dynamic, fluid, energetic motion and postures...these are large herbivores moving at great speed and energy with tremendous agility and power, or they're bearing weight in constantly changing balance. Unless our sculpture can convey these qualities, it'll continue to appear as an inert tabletop model rather than a depiction of a living, breathing animal living in the real world. Our sculptures need that "inner energy," that "spark of movement." We do this by paying attention to and infusing all those little touches that drive the "feel" home regarding motion. Every little thing counts.

Horses do a lot of leaning in motion, especially around turns, even standing as balance shifts and posture changes. It's a mistake to always orient our sculptures up and down, especially when depicting motion and turning. On a side note, n the top photo, notice that the hock's calcaneum creates a distinct bulge, not being the same width as the back of the cannon or the Achilles Heel?

On the other hand, we can have a preponderance of physical expression to the point where it "stops" the motion, too. Equine motion is elastic so if we convey too much weight and gravity, our depicted gaits won't appear very light and energetic, but weighted down and plodding. It's a delicate balance. For instance, during the extension phase of the gallop, when one foreleg is planted on the ground and placed in a straight upright position, perpendicular to the ground. This design can "stop" the sense of forward motion by "rooting" the sculpting too strongly to the base. Instead, it's often a better idea to make that planted foreleg oriented a bit forwards or backwards to keep the sculpture visually "moving forwards."

Similarly, we should be careful how we design supports or bases. Many times clear rods or how the sculpture is attached to a base will "stop" the sense of motion, too. Instead, a more integrated or different approach could have helped that visual along better. For instance, perhaps placing the clear rod at an angle to trail the motion, or putting flourishes of kicked up dirt under the hooves as supports could prove better options. When we design a sculpture that really conveys the sense of motion beautifully, it's a shame to "stop" that motion with a poorly conceived support system.

Conclusion to Part XV 

Now that we've discussed all these topics and how they relate to realistic equine sculpture, we can begin to process it all together. It's a lot to take in, isn't it? And this is just a start! There's always something new to learn, so approach all this in that spirit and keep moving forwards.

Nonetheless, in the next and final installment, we'll take a look at some myths regarding these subjects so we can learn to filter through them for our work. So much about being a responsible equine artist is about being a responsible horseperson, so problematic myths are worth ferreting out to keep them from compromising our work.

So until next time...may the force be with you!

"Energy is an eternal delight."

~ William Blake

Equine Anatomy and Biomechanics: A Primer of Equine Engineering for Advanced Students Part XIV, Details

Introduction

We've covered a lot of ground since Part I, haven't we? And all that's just the tip of the ice berg! Not only is there more information for the advanced student, but it's also a matter of application. It's not enough to know, we also have to do, right? And in that respect, a lot can go haywire. When we're dealing with the creation of fallible human hands, we can divert away from accuracy quite easily if we aren't careful. So translation is another matter entirely.

To that end, let's now discuss details, or those little touches we can add to our sculpture that infuse interest and believability. Details are neither easy to do nor should they be considered afterthoughts. Instead, they should be integrated into our sculpture with equal attention since they can make or break a piece. 

We should also understand that many details are fleshy or cornified and so their texture comes into play when we recreate them. We can't just approach them all with the same technique, but need to find those that reproduce how they would feel and look on the real animal. The flesh should appear gooshy and the cornified should appear rough or polished, depending on what they are. For instance, the difference between chestnuts and hoof horn, respectively.

So enough gab...let's go!

Veins

Veins are patterned and bilaterally symmetrical on either side of the horse, lengthwise. Smaller and finer capillaries obey certain patterns of their own, but are much more random and spontaneous. Both can be very prominent on thin-skinned horses, especially on hot days, or during exercise. Some such horses are the Arabian, Teke, and Thoroughbred.

Since arterial and vein structure is so complex, this section distills the veins into those most obvious on most horses. These primary subcutaneous veins are: 

• Facial vein (or submaxillary vein): The “Y” vein that comes from the front tip of the teardrop bone (facial crest) that splits and then branches towards the eye and nostril. It also goes under the jaw, to enter the jugular, and this portion is referred to as the Glosso facial vein; it can produce a subtle visible effect in the throatlatch area.
• Internal subcutaneous vein of the forearm: This major vein of the forelimb is a continuation of the internal metacarpal vein. It passes over the anterior top part of the subcutaneous shaft of the radius and travels to the back of the knee.
• Internal and External saphena vein: A major vein of the hindlimb, it erupts from the groin around the Gracilis and Sartiorus muscles and then branches. The larger anterior branch crosses over the top of the tibia and follows the groove between the front of the tibia and the Tibialis cranialis (Deep flexor metatarsi), over the front of the hock, crossing the top of the metarsal and becoming the internal metacarpal vein. The smaller posterior branch goes towards the Gastrocnemius muscle.
• Internal metacarpal vein: Major vein of the hindlimb and a continuation of the saphena vein.
• Digital veins of the limbs: Pass along the caudal aspects of the limbs into the foot and with two branches, reaches to the front of the limbs. They can be a visible aspect on the horse.
• Spur vein: A major vein of the torso, it often branches into two aspects, an inferior and superior branch. The parent branch lays along the top border of the Posterior deep pectoral muscle and goes into the armpit.
• Subcutaneous abdominal vein:  Passes along the posterior of the abdomen and into the posterior of the sternum. It's very distinct on a broodmare, often referred to as the "milk vein" when nursing. 
• Capillaries: A series of webbings or "chicken scratches" networking over a region of the body; they are subcutaneous and often very distinct during hot weather or exercise, or on thin-skinned horses. They most commonly manifest on the neck, shoulder, chest, lower haunch, gaskin, and forearm, groin area going up to the anus, with some appearing on front and rear portions of the barrel, or the barrel itself.

Landmarks and Reference Points for Veins

The teardrop bone is a good landmark for the facial vein, as is the front canthus of the eye. The internal malleolus of the radius is a handy reference for the internal vein of the forearm whereas the hock is a good landmark for the internal saphena vein. The top of the Posterior deep pectoral and the back of the elbow is a good start to trace the spur vein. The bag or sheath is a good reference for the abdominal vein.

Artistic Aspects to Consider about Veins

Veins should appear squishy and soft, with a rounded surface to blend with the surrounding flesh. They can also have bulbs where they're wider, as often seen with capillaries. The more veins and capillaries we apply, the more we imply heavy exertion or heat dissipation, so we need to make sure our sculpture warrants a heavy or light application of them. Certain breeds with thin skin and "dry" features also tend to exhibit more veins and capillaries such as Tekes, Thoroughbreds, and Arabians. The deft application of veins and capillaries can create a lovely contrast to firm muscle or hard bone, and really drive home the appearance of "living flesh."

Common Artistic Faults

Veins on sculptures are often structured improperly such as being randomly branching when they should be bilaterally symmetrical on either side of the body. This isn't to say they should mirror each other perfectly, but they should present the same general idea in terms of placement and intensity. They also tend to be misplaced, not following their anatomical patterns. For instance, a "Y" vein placed too low on the head or a spur vein placed too high or too low in the elbow area.

They can also be incorrect in structure being indicated as either simply grooves in the clay or flat. They may be clumsily executed and messy, too, due to a shaky hand or poor technique. Size is also a common problem as they can be too big in size or width. The veins and capillaries should also be smooth, and not pebbly, streaky, or rough in texture.

Genitalia

The vulva forms the external opening slit of the urinary and reproductive tracts of the mare. It's approximately four to five inches long and fleshy. The anus is at the top, immediately under the dock, and the vulva is a descending slender oval or hourglass shape. Between the hindlimbs, at the termination of the abdomen, the mare has a fleshy udder comprised of two dangling triangular portions of flesh with a teat on each.

Between the thighs, at the back of the abdomen, the stallion has a penis, sheath, and two testicles. The penis is enclosed in a double fold of skin called the prepuce that forms the visible sheath outside the body. A normal testicle is egg-shaped or round and about three to five inches long. The size of the testicles vary with individual stallions, but the left is sometimes larger than the right. The testicles are suspended in the scrotum and can be raised or lowered simultaneously or independently.

The vulva, anus, scrotum, and penile sheath are fleshy and relatively hairless.

Landmarks and Reference Points

In both the stallion and mare, the underside of the dock is a good point to gauge where to place the anus. Likewise, where the Gracilis muscles meet along the median seam of the body is a handy reference for placing either the udder or sheath and testicles.

In the mare, the vulva begins about where the points of buttock occur. It can be shaped like a soft oval, more like a rectangle, or have a slight hourglass shape, depending on the natural variation between mares. It should also be straight up and down, and not slanted outwards.

Artistic Aspects to Consider about Genitalia

All genitalia should appear soft and fleshy, not hard. They are passive aspects of flesh (when relaxed) and so are subject to the effects of physics. For example, the udders, sheath, and scrotum jiggle and bounce with motion, or are shifted from side to side. The anus can also pop in and out in synch with the gaits or movements.

Common Artistic Faults

Genitalia is commonly faulted by incorrect size, structure, and placement, even a lack of detail. Many times they're sculpted too harshly, blockish, or blobbish, too, obliterating their soft, fleshy nature. Sculpted vulvas are often slanted, which is a conformation fault. It's not enough to simply pop on blobs of roughly-shaped clay to indicate these features...they need careful shaping and detail just as any other part of the body.

Chestnuts

Chestnuts are small masses of cornified tissue (essentially, horn) on the internal aspect of the forearms and the hock. It's believed they're remnants of one of the digital foot pads lost during equine evolution. On the forearm they occur above the knee and on the hindlimb they occur on the back and bottom of the hock. They tend to be larger and more oval-shaped on the forearm and more slender and smaller on the hindlimb. Those of the forearm also tend to be placed on a forwards angle whereas those of the hindlimb tend to be more perpendicular to the ground. 

Each chestnut is distinctive and can sometimes be used to identify animals. They're rough in texture, often having ridges or a pebbly surface. However, they can be softened with oils or lotion, and peeled away to be flatter and smoother, a common practice in show grooming. Sometimes they're oiled for show, which darkens their coloration.

Landmarks and Reference Points

The internal "bump" of the knee is a good point to reference when placing the forearm chestnut whereas the top of the internal splint bone is a good landmark for placing the hindlimb chestnut.

Artistic Aspects to Consider about Chestnuts

Duplicating the cornified texture of a chestnut is important for believability just as much as getting then placed, oriented, and sized correctly. For painting, they can either be a grayish tan, tan, dark brown, dark grey, or nearly black (when oiled), depending on individual variation and the underlying coat color. Often, they're pink or light tan when in a white marking.

While they break off with growth, chestnuts can grow long under natural circumstances to stick out quite a ways from the surface of the arm or hock. This can be commonly seen on wild or feral horses.

Common Artistic Faults

Chestnuts are often misplaced, being placed too high or too low. Or they may be placed bilaterally asymmetrical. They can also be indicated simply by dollops of smooth clay, like smooth buttons, rather than as cornified tissue. They can be too big (often on the hindlimb), too, or not angled correctly (often on the forearm). Sometimes they aren't even present. Mules tend to only have chestnuts on the forearms and not the hind limbs.

Ergots

Like chestnuts, ergots are cornified flesh forming dime-sized peaks or "buttons" on the back of the fetlock joints. Usually hidden by hair, they're placed a bit lower on the fore fetlocks than on the hind fetlocks, and vary in size depending on individual variation. They're also though to be remnants of the ancient foot pads of eohippus.

Landmarks and Reference Points

The flatter aspect of the posterior fore fetlock makes for a useful landmark as does the pointier posterior aspect of the hind fetlock.

Artistic Aspects to Consider about Ergots

Ergots form a gentle, discreet point at the back of the fetlock joint, something especially obvious on a clipped lower leg. They tend to be smoother in texture than the chestnuts. However if allowed to grow, they can become quite pronounced, especially under feathers.

Common Artistic Faults

Ergots are often misplaced or too big.

Whisker Bumps

Whisker bumps or moles occur on the muzzle and around the eye. They vary in size, intensity, and number between individual horses. They can occur a bit randomly or in patterns, again, depending on individual variation and location.

Landmarks and Reference Points

The nostrils and mouth are good landmarks for placing moles on the muzzle. The lower lid is a handy reference for placing those around the eye.

Artistic Aspects to Consider about Moles

Moles are small raised buttons of flesh from which a whisker grows. They're fleshy, squishy, and not hard. They can vary in size on the same horse, or between horses. Those around the eye tend to be smaller than those on the muzzle.

Common Artistic Faults

Moles are most typically flawed by a clumsy rendition that does not make them appear fleshy and soft. They can also be too large and pronounced, lacking a discreet nature. They can also have sunken pits, like a collapsed souffle, or too pointy rather than being smoothly rounded. They can also lack the randomness or pattern indicative of an individual's variation.

Wrinkles

Wrinkles are soft folds of flesh caused by the compression or flexing of skin, or areas of skin that experience a great deal of stretching and movement such as the muzzle. When the animal is standing, wrinkles are most common between the ears, around the eyes, around the muzzle and nostril, in the throatlatch area, at the junction between the neck and the wither, and between the forelegs. In motion, however, wrinkles proliferate as movement dictates. 

Wrinkles can vary in size and intensity between individuals. Sometimes certain unusual regions of the body are predisposed to wrinkles, too, such as on the haunch during certain movements, the throatlatch area, or on a heavily crested neck along the crestline or span of the neck. Furthermore, if the animal is laterally bent, large wrinkles on the ribcage may appear on the barrel. Similarly, if the neck is cranked to one side, wrinkles will be apparent on the neck inside the turn, often fanning out onto the shoulder and sometimes the wither area.

Landmarks and Reference Points

Wrinkles occur wherever the flesh is compressed or an articulation has caused the skin to fold. So pay attention to the flesh around articulated joints, or on those areas that are subject to squishing and goo-ing.

Artistic Aspects to Consider about Wrinkles

We should sculpt our wrinkles so they appear as soft, folded flesh. We should also notice that they vary in width and intensity within a "bundle"; they aren't a clone of the one previous. Wrinkles can even wrinkle as clusters wrinkling on each other, such as we often seen in the throatlatch area of a tightly tucked head. Wrinkles also softly fade out into the surrounding skin and don't end abruptly with a definite border.

Wrinkles occur on the muzzle and around the eye, too, with great delicacy and softness. The amount of wrinkling here can vary between individuals, however, with some having few wrinkles while others having a dense proliferation of them.

Common Artistic Faults

Wrinkles are most typically faulted by a clumsy rendition that doesn't make them appear fleshy and soft, but hard and literal. They can also suffer from regimentation, like the folds of an accordion, rather than varying in depth, width, folding, and orientation. They can appear as gouged-out grooves, too, rather than rounded folds of flesh. Wrinkles can end too abruptly as well, rather than softly fading into the surrounding skin.

Secondary Sex Characteristics

Horses have a distinct difference between the genders so a stallion should look like a stallion and a mare look like a mare. Sure there are some exceptions, but on the general scale this works to our advantage in sculpture. 

For instance, stallions appear more compact and muscular, often sporting more of a crest and stronger jowls. On the other hands, mares appear "lower to the ground" and longer, with less pronounced jowls. Their necks also tend to be finder and their ears longer. 

Geldings, on the other hand, are a bit of a mixture of the two since the full expression of masculinity wasn't allowed to develop. They also often have some eccentricities that disqualified them from being a breeding stallion, and they're fun to inject into clay.

Common Artistic Faults

These characteristics can be overlooked in sculpture so we have a homogenized "horse" rather than a distinct gender. In other words, we can't just swap out "plumbing" and expect to pull off a convincing piece. 

Flesh and Hide, or "Goo"

The term "flesh" entails the muscles and fat beneath the skin. In turn, "hide" refers to the fascia and skin of the animal. Both express themselves, resonating and reacting to motion and articulation.

When it comes to flesh, the novel depressions and concavities of muscles during movement, the amebic absorption of boney parts during certain phases of motion, muscle resonance in response to movement, buckling caused by articulation or force, and the general jiggling and wriggling of flesh are all indicators of gooey flesh that need attention. In terms of hide, the sliding or rippling of skin, its stretched and compressed distortions during movement, and its wrinkles, bumps, stretches and pooches, and soft ridges are also good indicators of "living flesh."

So we can't simply sculpt correct anatomy...we also have to duplicate the nature of flesh as well as express the hide. Being so, it's a common oversight in equine sculpture in lieu of the underlying anatomy. Remember, the hide has been stripped away to reveal the muscular structures in an anatomy chart, but we have to reinstatel it for our sculpture to look real. Truly, a masterly artistic expression of flesh and hide and muscle...goo...is one of the most important ingredients for creating a convincing equine sculpture. What does that mean in practice? It means we should only use our anatomy charts as guides, not gospel. Life presents us with so much more to anatomy than a static chart.

Look how each pectoral is changed away from its resting state simply by walking. Unless we pay attention to muscle morphiing, our sculptures are going to appear artificial and formulaic. Horses don't move like articulated anatomy charts.

Artistic Aspects to Consider about Flesh and Hide

Flesh is soft and inviting, and it depresses and pooches with movement. That means it has a 3D quality, an in and out quality as it goos. Unless we capture this in our sculpture, our muscles will appear flat, contrived, and artificial, more like an articulated flat anatomy chart rather than "living flesh." Similarly, unless we understand and denote the nature of the hide, we're going to create a stylized piece of work that's too polished-looking and hyper-smooth to be truly believable. No horse is smooth like polished metal, but rich in the little imperfections of skin and fascia. Imbuing all this into our sculpture will go far in duplicating a life-like appearance.

Note all the hide and fleshy details to the skin. Horse's aren't "polished" smooth. The smooth finish on Maureen Love pieces is certainly pretty, for example, but it's not realistic. It's a manifestation of artistic style.

Common Artistic Faults

Sculptures are often faulted by a static, formulaic, or stylized rendition of flesh and hide. For example, we cannot apply standing anatomical configurations to a sculpture depicting motion just as much as we cannot apply the anatomy changed by motion onto our standing sculpture. Horses don't move like articulated anatomy charts, with the same configurations occurring over and over again despite anything else, like a "sculpt by numbers" formula. Instead, motion and physics can radically change the nature of the flesh and hide, and we need to capture these changes in our work.

Hooves

Know it or not, hooves are rich in detail from the bars to the clefts to the frog, yet they're often overlooked in sculpture. Detailing the hooves is important to fully express realism. For a more in-depth look at hooves, please refer to the blog post, Steppin' Out: Hooves From An Artistic Perspective.

Common Artistic Faults

Many sculpted hooves are pathological since the artist didn't understand what constitutes a healthy, adaptive, balanced foot. Many sculpted hooves also lack detailing on their palmar side, and usually we're lucky if merely the frog is indicated. But there's so much more to the underside of the foot and we need to factor all those structures into the sculpting of our feet.

Ears and Nostrils

These features are typically hollowed out to enhance realism. 

Artistic Aspects to Consider about Ears and Nostrils

Ears are complicated structures, being delicately fluted with a bulbous base. Where the rims meet at the bottom forms a "V" constructed of subtle curvaceous, bulbs, and lip-like structures rather than a literal, simple "V." What's more, these structures change as the ear is rotated, forming rather complex curves, pooches, angles, and overlapping flesh.

The nostril is similarly complicated being so fleshy and gooshy. Being so, the lateral rim stretches and misshapes depending on how its manipulated by the muscles, tendons, and fascia which can distort it well away from its resting aspect. The anterior "comma cartilage" rim can be distorted as well, expanding quite a bit from its resting state. There's also the false nostril that can distort, too, and even form pronounced raised flutes of flesh on either side of the nasal bone. On the side, the flared nostril typically has hollows, curves, and depressions confident to the muscles and tendons that activate them. 

Complicating things still further, each nostril can move up or down, or back and forth in relation to its pair, adding to expression, character, and effect.

Common Artistic Faults

Errors in the nostril are common. Of particular note is the error of overdoing it with the drill tool. Specifically, the more rounded, bulbous front rim of the nostril may be too thinned as the nostril is hollowed, and sometimes so that front rim can be reduced to a sharp edge. The rims of the nostril can also be sculpted in a clumsy way, creating an uneven, pebbly texture rather than a smooth, fleshy one. On the other hand, the nostrils may be sculpted incorrectly altogether, or with flutes (especially when flared) that don't possess the complex curves and indentions imposed by the overlaying musculature. Nostrils aren't simple things on the horse, and so shouldn't be so straight-forward on a sculpture.

Similarly, equine ears are complicated. Too often, however, they're "scooped out" when hollowed, forming more of a spoon-shape than a fluted one. The bottom "V" is often too simply rendered as well, as though it was simply two rims pinched together (a common sculptural flaw with pre-formed ears). Yet that "V" is characterized by a complicated folding of flesh with bulbs, twists, and overlapping features peculiar to equines alone, and unless our sculpted ears have similarly complex "Vs," those ears don't actually belong to Equus. Just as cat ears and dog ears aren't simple flat triangles (they have those curious folds on their lower, outside rim, where the outer rim meets the head), so a horse's ears aren't simple flutes with a simple "V" on the bottom either.

Mane and Tail

Sculpting the mane and tail (and feathers) is arguably one of the hardest aspects of sculpting realistic equines. It should never be treated as an afterthought. And there are many ways to expressive, but regardless, hair is passive to physics and moves in often complicated, unpredictable, chaotic ways. Its texture also presents a challenge, it being wispy, weighty, striated, and complex.

Artistic Aspects to Consider about the Mane and Tail

The manes and tails on certain breeds can be quite fine and soft, such as on the Arabian. On the other hand, it can be quite coarse such as on the Takhi or Fjord. Similarly, feathers can be silky and wispy on some breeds such as the Clydesdale or Shire, or wiry and dense such as on the Ardennes and Brabant. All this means that different types of hair flow differently, something we should pay attention to. In short, not all hair is created the same.

Hair also has layers; the mane and tail (and feathers) aren't all one equal length. These layers can operate independently or in synch with the other layers, depending on the situation. So unless we think in terms of layers, our manes and tails (and feathers) will appear odd and artificial.

And there are many ways to sculpt hair, given we meet the criteria of its flow and movement, and texture. Some artists merely indicate texture, opting for a more impressionistic approach while others go for a highly detailed rendition, with lots of little striations indicating each hair. It all depends on what we like for our sculptures.

We may also choose to impart waviness such as often seen when manes and tails are taken out of braids that preserve its length. This can be a really appealing touch on a sculpture, especially on Morgans, Andalusians, and Friesians, or other breeds known for a long mane and tail.

Common Artistic Faults

Missteps here are common. Often we see hair rendered as dreadlocks, tentacles, or "ropes," especially with flowing tendrils. Likewise, we may find the mane sculpted like soft-serve ice cream rather than naturally flowing hair (a flaw I used to do in the past as I was learning). Here's a handy trick: make the tips as thin as possible to make them appear wispy instead of ropey. 

Other times, layers haven't been accounted for so we have hair all the same length which gives it an artificial look rather than a natural, flowing one. We also often see texture gouged into the mane and tail (or feathers), often being pill-ed or with torn ridges, as though it was sculpted with a fork. Instead, the hair should be smooth and silky. 

Hair is also 3D, so it should have areas of hollows and areas of bunched-up thickness. If we sculpt it all the same, like a 2D rendition, it won't look natural and real.

More still, we find that the sculpted hair lacks the passive, unpredictable movement characteristic of its flow, instead taking on a regimented "safe" expression. Remember, hair is passive to motion, so we need to keep the movements of the body and physics in mind when we design it. And often times, hair can move counter-intuitively to the motion as a result, so pay attention to life study and reference photos.

Even so, we may find that the sculpting of the mane and tail (and feathers) is inconsistent to the motion such as with "standing" feathers on a cavorting piece. Or we can find it "stopping" the sense of motion by not flowing in reaction to motion such as a trotting horse with a static mane. 

Sometimes we'll see an amount of hair inconsistent to a breed's characteristics. For example, profuse, thick manes and tails on Arabians or Tekes, or thin, sparse manes and tails on an Andalusian or Vanner are errors.

When it comes to hair weaving and braids, we often see more problems. For example, a hair weave with hair "tassels" hanging down often don't flow perpendicular to the ground, obeying the laws of physics. Remember hair is passive and will hang always perpendicular to the ground unless impeded by motion or a breeze. Yet we see many of these hanging bits askew, as though a breeze was slightly blowing them, but without that breeze expressed in the tail or forelock. As for braids, we often see them too big or too sloppy, crudely sculpted on. Instead, braids do best when in-scale, correctly textured, and neatly done.

Conclusion to Part XIV

The "devil is in the details" and realistic equine sculpture definitely proves this to be undeniably true. They can really take our sculpture to the next level of realism, but only if done correctly and carefully; otherwise they can bust our illusion rather quickly. And learning to see details is a learned skill...it doesn't come so naturally when there's so much else to concentrate on it seems. We can be easily distracted. Yet once we do start to pay attention to them, the easier it becomes to pick them out, adding interest and believability to our work.

One last note about details though: the nail clenches with shoes shouldn't be located at the quarters of the hoof, but away from them, well towards the toe. The hoof does its primary contraction and expansion at the quarters which would be uninhibited by nails. Too many times, however, the clenches on sculptures flow well into the quarters, which is a serious fault in farriery, and should be considered a severe fault in detailing. Clenches that are too big, or uneven in size and shape should also be similarly penalized.

So anyway...in the next installment, we'll discuss physics and how that pertains to realistic equine sculpture. We have to instill a real world in our work, and we do this by infusing the effects of physics into our clay. It's fun and highly effective!

So until next time...bedevil those details!

"I admit I'm enthusiastically demanding."

~ Brad Bird