Thursday, March 26, 2015

Steppin' Out: Hooves From An Artistic Perspective Part I: Overview

Let's talk about feet. Horse feet, that is. The hoofie is an important concern, and so the adage "no hoof, no horse" rings everywhere when it comes to this critter. That being so, the practice of farriery is as much an art as a science, and a good farrier is worth their weight in gold. Yet modern sciencearmed with new technology and new ideasis discovering that much of traditional management may be fundamentally flawed, in direct contradiction to the biology of the foot. There may be consistent reasons why domestic horses go lame so often, which implies that for any horse to remain sound under conventional conditions is testament to his hardiness. 

Now it may seem odd for an artist to concern herself with the science of equine podiatry. Sculpting hooves is simply a matter of logistics, right? Just slap some hoof walls onto our sculpture and call it a day, right? Any old hoof is a good hoof, right? And who's going to notice anyway.

Wrong. Whether just making it up or mimicking what we see, either way, that's precisely the wrong way to approach sculpting feet. The reason being most domestic feet are pathological. It also seems that many traditional ideas about the foot are being proven wrong as science advances. So unless we know what a sound, normal foot looks like—according to current sciencewe'll simply fail to filter through what life presents and be ill-equipped to recreate a sound foot sculpture. Just like the body, we need to know the equine foot from the inside out, since feet should never be treated as an afterthought.

Because it does matter. Our sculptures may not be real, living horses, yet our work functions as a validation, an endorsement of the visuals we recreate. That is to say, the visuals we choose to portray can advocate for the animal or unwittingly endorse harm—which do we want to do? If we detest the Big Lick, for example, shouldn't we also detest deleterious foot structures as well? Pain is pain, regardless of how it's inflicted. 

And it's said "the Devil is in the details," and feet are a classic example. At first impressions, they seem like an easy enough body part to duplicate, but step back and really start dissecting it and we find a consummately complex, nuanced biological marvel, one that appears to have some pretty strict parameters of construction to remain sound to boot. That means we can't simply sculpt them any which way nor can we just fudge them. They aren't inert blocks of keratin at the ends of our subject's legs, allowing approximations to suffice. No. These are precision-made, fundamentally critical features that demand great care in their recreation if we wish to not only pull off a convincing rendition, but a responsible one as well.

Being so, we'll find a passel of value judgments attached to them. Ideas about good and bad, about proper management and farrier technique, about what's ideal and everything in between, all roiling around the humble foot. Debates can get heated and disagreements intense, and new technology is shedding fresh light on this ancient, finely-tuned mechanism to hopefully offer more clarity over time.

For all these reasons, much can be revealed about an artist's gumption and mindset simply by studying how they sculpt feet. In fact, one of the first things I inspect on a sculpture are the feet to peer into the sculptor's savvy and depth of the intention. In order to sculpt good hooves, a sculptor needs to be precise and detail-oriented, illustrating discipline and diligence. But when it comes to feet, there's a lot more to it than just precisionno amount of exactitude can compensate for flawed construction. So studying the value judgments a sculptor applied to their sculpted feet speaks volumes about their knowledge base, skills, and prerogatives. Indeed, the feet are very much our "canary in a cage."

This is because feet are beguilingon the surface, they look simple enough to sculpt right? And we might be tempted to assume that people will be more enthralled by the glamour of our sculpted horse rather than fixate on the feet we recreate. But the fact is feet are a complicated structure fine-tuned by 65 million years of evolution into a biological miracle of natural engineering. No other animal has feet like an equine! As solipeds, their feet are absolutely unique and rank among evolution's greatest achievements. The genius and economy of nature cannot be expressed any better than with the equine hoof, a masterpiece of horn, hide, bone and flesh, forming a complex structure full of nuance, narrative, and detail. And so there's a lot more to them than just the hoof wall and anyone worth their salt when it comes to horses will pay attention to how we sculpt them. Why? Because when it comes to equine realism, there's no difference between how we sculpt our heads, our bodies, our manes and tailsand our feet. Realism channels even the tiniest detail into clay!

For this purpose then, this twelve-part series will explore the equine foot from an artistic point of view in an effort to bolster awareness. Only aspects of direct relation to sculpture will be presented, so this series should be thought of as a springboard for one's own proactive research. For that, recommended reading will be offered as the last installment, along with all the references used to compile this series. The point is to stay informed because an informed artist is a responsible artist. If there's one feature more or less unique to realism is its accountability to the subject, even when it comes to ethics. Because once we understand the true importance of the foot, simply sculpting an approximated "hoof-like" appendage will hardly seem justified.

The Challenge

The unfortunate fact is that nearly every aspect of domestication exists in direct opposition to the way this animal evolved. Unnatural rich foods fed sporadically, confinement in stalls, social disruption, exaggerated and repetitive gaits, dramatically varied and different terrain, rigorous training, structural abnormalities in the name of "type," competitive stresses and a host of other impositions all conspire against the species on a biological level. It’s surprising how this inherently ancient animal has held up so well, and performed so admirably, under the divergent conditions of our modern world. 

In American Farriers Journal (vol. 26, Nov. 2000), the article, Most Of Your Income Comes From Shoeing Lame, But Still Used Horses, claims that of the estimated 122 million domesticated equines (at that time), no more than 10% are thought to be actually sound and healthy-footed, while another 10% are completely lame and unable to be used. More alarming, it goes on to state that a staggering 80% of all domestic equines actually are lame to some degree, yet are still used. These figures imply that something is terribly wrong with the management of domestic feet. Could it be that traditional equine care actually is producing herds of unsound and unhappy horses and forcing farriers to work at a continual disadvantage?

Consequently, we artists should be aware that domestic equines probably don't always provide reliable examples of sound feet. This means many of our references may depict unhealthy feet and foot function as examples, which we risk duplicating in our work. Above all, we should remember that the horse has a heartbreaking ability to bear and mask pain, being a prey animal. That means we really have no idea of the comfort level our domestic population! And during a study that used a "grimace" index to decipher and codify equine expressions of pain, they found that a horse would avoid grimacing in the presence of his owner! That means horses actively try to hide their discomfort from the one person in the best position to help them.

Now add into this our unfortunate human tendency to only notice things when the situation becomes critically obvious plus our use of hurtful tactics to achieve certain results (such as soring, false collection, other abusive training techniques), all of which are probably inflicting unacknowledged levels of suffering onto this animal. Yet as artists, we have the rare privilege of operating outside of the horse industry’s fishbowl, and in doing so, we can work to promote responsible representation of equine podiatry and management. Why denigrate when we can elevate? Why mimic when we can be proactive?

Let's Backtrack

First, let’s go back in time into equine evolution to gain a more complete perspective of the foot. Undeniably, there can be no genuine understanding of anatomy without knowing some of the evolutionary factors that shaped it.

Around 65-54 million years ago, in the Cenozoic Tertiary’s Paleocene era (“Ancient Recent Life”), early mammals burst into the niches previously left by the dinosaurs. They were quite small, only few the size of a small bear. All had short legs with plantigrade stance with five toes on each foot (all vertebrates with four limbs are based on the same blueprint, one of those features being five digits on each limb from our common fish ancestor about 360 million years ago). "Planta" means “sole of the foot” and gradus means “to walk”, hence “to walk on the soles of the hand” like a rat, bear, or human. Among the dominant animals at the time were the “primitively” hooved and omnivorous Condylartha, 75 million year old animals currently believed to be the progenitor of all modern hooved animals.

Now unlike plantigrade stance and the later digitigrade stance (where the foot is supported on fibrous pads with elevated digits, like a dog or elephant), a hoof is a specialized claw or toenail that lifts the telescoped toe structures into a “perched” position. Hooved mammals include the Orders Artiodactyla (from the Greek ratios meaning “even,” and daktulos, meaning “finger,” hence “even toed” or “cloven hooved,” such as camels, giraffes, cows, sheep, swine, deer, antelope, etc.) and Perissodactyla (from the Greek perissos, meaning irregular or uneven and hence “odd toed,” such as horses, zebras, asses, half-asses, tapirs, and rhinos).

But the modern equine’s story really begins about 55-60 million years ago, in the Eocene with Hyracotherium (or hyrax-like beast, a hyrax being a rabbit-like wee critter). Appearing in North American forests, this little animal was only about two feet long and approximately 8-9 inches at the shoulder, with four toes on the forefoot and three on the hindfoot, each bearing a little “hoofie” with footpads, like a dog. The major bones in his legs weren’t fused and his joints were designed to rotate freely to maneuver on the cluttered forest floor. He had a flexible spine, rather like a cat or rabbit, and his build was suited for a forest life, nibbling on soft leaves and sprouts while dodging, scampering and sprinting around tree trunks and branches to escape danger. His upwardly curved spine also suggested he had a rump-high, “popping” gait, like a bunny. 

As he started to adapt to the encroaching grasslands, however, among other necessary changes to his body (such as to his spine, teeth, head and digestive system), evolution markedly changed his legs and feet. Indeed, the footing on the plains was quite different from that found on the forest floor, being abrasive and rough with rocks, hard surfaces and coarse plants (such as grass and scrub), heightening the need for tough horn rather than soft footpads for an ever-larger, herbivorous animal that came to depend more and more on roaming and sustained speed. Put another way, his escape strategy from predation became ever more about running, and running fast for a long time in a straight line (more or less) to avoid becoming someone’s lunch. 

Consequently, his limbs modified and around 22 million years ago, with Parahippus, they began to elongate through a lengthening of the leg bones, particularly those of his “hand” and “foot.” This made his upper limbs (scapula, humerus and femur) comparatively shorter than his lower limbs, thereby changing his limb proportions from those of a browser to a runner, a typical characteristic of speed animals that require leg structures made of long levers with high fulcrums. In other words, his became a limb based on a short upper ratio to a longer lower ratio, with leverage oriented about one-third up the leg column (from the scapula to the elbow) to act upon the remaining two-thirds (from the elbow to the toe), resulting in a great deal of leverage and stride length achieved by the upper limbs with only minimal effort. Think of it this way—the equine scapula and humerus are about the same length as a human arm bone, but the lengthening of his distal limb far exceeds this, increasing stride length to achieve great speed with relative ease.

Likewise, his limb structure became simplified, removing the muscles below the knee and hock to turn the distal limbs into passive levers activated by tendinous servos whose muscle bellies are located high on the limb (above the knee and hock), thus reducing the weight of the distal limb to further maximize energy efficiency and speed. The plane of limb motion also narrowed to eliminate gross inward or outward instability that could compromise speed, coordination and efficient energy use. For instance, people can turn their palms upwards or downwards, known as “supination of the manus,” since the human radius isn’t fused to the ulna. However, as the equine evolved for speed, his ulna became fused to the radius to keep the toe permanently pointed forwards. Similarly, even his leg joints became structurally oriented on the same plane so that each time he articulated his legs, his toes would point forward automatically. 

As for his feet, they also simplified and streamlined to serve the cursorial lifestyle. Greater dependence was placed on his middle, or third, toe, gradually leading to atrophy and eventual loss of the other digits. In the lineages leading to the modern equine, it’s believed the first digit lost was the first (or thumb), then the fifth (or pinky), later the second (pointer finger) and finally the fourth (wedding finger), the latter two turning into dew claws before morphing into the splint bones. In fact, the digital toe pads (or central pads) are thought to have become the frog and digital cushion in the sole, while his old distal metacarpal pads became the ergots and his ancient proximal metacarpal and wrist pads became the chestnuts. 

Although the horse isn’t the fastest mammal on the planet, elite racing Thoroughbreds can achieve bursts of speed for about 547 yards up to 38-46 mph, and elite racing Quarter Horses have been clocked at 50 mph during sprints. However, these breeds have been artificially developed for higher speeds at shorter distances and on groomed footing, whereas evolution designed the genus for slower speeds over much longer distances and on varied terrain. In other words, nature engineered the equine as a “running machine,” which doesn’t translate necessarily into being the fastest. Therefore, while most average horses cannot achieve the high speeds of our modern equine athletes, they’re still quite fast and possess a high cruising speed for long distances, over all sorts of terrain. Even newborn foals are able to keep up with the herd at a full gallop within hours of birth since their joints are already precisely formed for a nearly immediate ability to run. That is to say the average equine’s abilities are more than adequate to outrun and outlast just about any predator large enough to bring them down, such as a wolf with a top speed of about 25-30 mph, or a lion with a top speed of about 35 mph. A predator’s best bet for bringing down an equine is ambush, with that chance significantly increasing within 50 yards or less. Yet in response, equines evolved a highly sophisticated sensory system designed specifically for early detection for that essential head start. Indeed, once a horse starts running, it’s unlikely any large predator can catch him. 

Overall then, when it comes to combining a sizable herbivore with reaction time, speed, endurance, maneuverability and durability, the equine easily can be regarded as the finest running machine today. To think of such a large, heavy animal running at the speeds and duration they can achieve is astonishing. And on single hooves! Truly a marvel of evolutionary engineering!

Sum Up

Now that we have this general overview under our belts, let's get down to the nitty gritty of things! We have a lot of ground to cover, so in Part II-III then, we'll delve into detail about foot structure and take it from there. So until next time, keep puttin' your best foot forwards!

"We are not what we know but what we are willing to learn." ~ Mary Catherine Bateson

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