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Gaits of the Quadrupedby Erica Liszewski
Quadrupeds move themselves around in different ways, but their body movements are not random. Most quadrupeds follow similar patterns of limb and body movements. There are, of course, variations between different species as well as smaller variations between individuals within a species. Even a single individual can exhibit a wide range of movements. Despite these variations, most of these movements can be mapped to a handful of basic gaits.
A gait is a repetitive pattern of leg movements used by an animal to move around. Gait patterns are based the order of footfalls, push-offs, and suspensions (although not all gaits have suspension). Keep in mind that while the basic pattern of limb movement is similar, gaits can vary widely. Any gait can be done extended (where the feet are thrust far from the body), collected (where the feet are kept under the body), or somewhere in between. The feet can be lifted high, or lifted just enough to clear the ground. Gaits can be fast and energetic, or slow and meticulous. A gait describes only the pattern in which the limbs are moved, not the entire limb action.
The basic gaits covered in this article are the walk, amble, trot, pace, canter, transverse gallop and rotary gallop. These are roughly ordered by speed, but any gait can be done at a variety of speeds, so a fast walk might be faster than a slow canter. These gaits are common to many mammalian quadrupeds, but this is not an all-inclusive list.
Lateral - "Lateral" in anatomical terms refers to either the left or right side of the body. As we are specifically interested in limbs, "lateral" refers to limbs that are on the same side of the body. Thus the right hind and right fore make the right lateral, the left hind and left fore are the left lateral.
Diagonal - Diagonal refers to a fore limb and a hind limb from the opposite sides of the body. Diagonals are named after the involved fore limb. The right fore and left hind are the right diagonal, the left fore and right hind are the left diagonal.
Suspension - Suspension occurs when the animal thrusts itself forward, and none of the limbs are touching the ground.
Symmetrical - In a symmetrical gait, the movements of the left and right limbs mirror each other.
Asymmetrical - In an asymmetrical gait, the left and right limb movements do not mirror each other. There will be a "left" and a "right" version.
Lead - A lead is used when describing asymmetrical gaits, like the canter and gallop. Leads are named for the foreleg that extends the furthest forward, and is the last to leave the ground. The "right lead" is usually used for circling right, and the "left lead" for circling left. An animal will usually have a preferred lead when moving in a straight line, and can change leads as needed to avoid fatigue and change direction.
Collected - This can refer to an animal having all limbs gathered under them, as in collected suspension, or to a gait done with less movement and smaller steps.
Extended - This can refer to a animal having all limbs extend away from the body, as in extended suspension, or to a gait done with large steps and lots of movement.
About the Animations
In order to give you a better visual picture, each gait will be demonstrated by Farah, the bone dog. Farah was modeled, rigged, and animated in Blender 2.5. The gait animations are fairly basic, demonstrating only the core actions of each gait. When you're actually drawing or animating you'll probably want to include more "personality" in your gaits.
The walk is a four-beat gait, characterized by triangular (three-leg) support. The body is usually supported by three limbs, with one limb in the air. There may be short moments where only two legs are touching the ground. The pattern of foot movements is: right hind, right fore, left hind, left fore. The feet move in a regular rhythm, with even spacing between beats. The fore leg is usually lifted just before the lateral hind leg is placed, allowing the hind footprint to overlap the fore footprint.
The head moves up with the forward swing of each foreleg, and down in between. The chest moves up and down slightly, with the high corresponding to the support phase of each foreleg. The pelvis rocks from side to side, with the higher side being with the supporting hind leg. The spine also oscillates laterally, bulging towards the extended fore leg. The head and tail usually point away from the extended fore leg. This gait is common among most quadrupeds.
The amble is a four-beat gait, and is effectively a sped-up walk. The footfall pattern is the same as the walk, but there is less support. The amble will usually have two supporting limbs, or alternate between one and two supporting limbs. The amble is the fastest gait of very large animals like the elephant. The "gaits" of the various gaited horses are also usually variants of the amble.
The trot is a diagonal, two-beat gait. The animal moves a fore limb and the opposite hind limb in unison. The pattern of foot movements is: left diagonal (right hind and left fore), right diagonal (left hind and right fore). There may be a moment of suspension between the steps, especially at higher speeds. The pattern with suspension is: left diagonal, suspension, right diagonal, suspension. The rhythm of the trot is regular, with even spacing between beats.
The head and body remain fairly rigid during the trot, with the head raised from it's usual position at the walk. The body will usually move up during the suspension phase, and down when either pair of hooves is on the ground. Slower trots usually have less up and down oscillation, and faster extended trots have more up and down movement. This gait is common to many quadrupeds.
The pace is a lateral, two-beat gait. It's characterized by the animal moving both fore and hind limbs on the same side of the body in unison. The pattern of foot movements is: right lateral (right hind and right fore), left lateral (left hind and left fore). There may be a moment of suspension between each step, especially at higher speeds. The rhythm of the pace is regular, with even spacing between beats.
Like the trot, the body and head are held fairly rigid, with the head raised. The body moves side to side, moving the center line over the limbs that are currently touching the ground. There is little up and down oscillation of the body, but it will be similar to the trot (up during suspension, down during support). The pace uses less energy, and is usually faster than the trot. The pace is common in animals with very long legs, like giraffes and camels, as they can take larger steps without their legs interfering with each other. Some breeds of horse also pace naturally.
The canter is an asymmetrical, three-beat gait. It's characterized by a hind limb striking the ground, followed by the diagonal containing the other hind limb, followed by the opposite fore limb. The pattern of foot movements for the left lead is: right hind, right diagonal (left hind and right fore), left fore, suspension. The right lead is the opposite: left hind, left diagonal (right hind and left fore), right fore, suspension. The rhythm of the canter is three beats in rapid succession, followed by a pause (the suspension). The suspension phase may be absent in a very slow canter.
The body of an animal has a rocking motion during the canter. The front end is higher than the rear as the first hind leg hits the ground, then levels out as the diagonal impacts. The rear end is higher than the front as the last fore leg pushes off, then levels out again during the suspension. The canter is used mostly as a transition between trot/pace and gallop.
The Transverse Gallop
The transverse gallop is an asymmetrical, four-beat gait. The pattern is similar to the canter, except that the limbs in the diagonal pair hit the ground separately, with the hind limb striking first. The pattern for the left lead is: right hind, left hind, right fore, left fore, suspension. The pattern for the right lead is: left hind, right hind, left fore, right fore, suspension. The transverse gallop usually only has a single, collected, suspension phase. Thus the rhythm is four beats followed by a pause (suspension).
The body exhibits the same rocking motion as the canter, but there may be less up and down motion in the gallop. The head and neck will extend forward during the "down" phase of the front end, and back during the "up" phase, especially at higher speeds. The transverse gallop is preferred in larger herbivores with long legs and less flexible spines. It is seen in horses and other larger hoofed mammals such as cattle and bison.
The Rotary Gallop
The rotary gallop is also an asymmetrical, four-beat gait, but has a different footfall pattern than the transverse gallop. The pattern for the left lead is: left hind, right hind, suspension, right fore, left fore, suspension. The pattern for the right lead is: right hind, left hind, suspension, left fore, right fore. The rotary gallop usually has a double suspension, but is sometimes seen with either a collected or extended single suspension.
The rotary gallop requires more trunk flexion than the transverse gallop. The body is stretched out during the extension phase, and arched in during the collected phase. This allows shorter-limbed carnivores to extend their hind legs far in front of their fore legs to attain greater speed. The head is stretched out during the extended phase, and lifted up during the collection phase. The rotary gallop has the potential for more speed than any other gait. It's used by carnivores, pigs, and other small hoofed mammals.
The best way to learn about animal gaits is to study animals moving. Video is great, because you can rewind and re-watch, as well as being able to slow it down and move through frame by frame. The works of Eadweard Muybridge, Animal Locomotion, are also nearly indispensable for both human and animal movement. Pay attention not only to the footfall patterns, but the body movements, energy, and rhythm of the various gaits.
When drawing or animating a quadruped, think not only about what gait it's using, but the motivation behind that movement. Is the animal in a hurry, or is it just wandering around? Is it excited, or scared, or bored? Is this gait being done fast, or slow? Extended or collected? Is there a lot of energy, or does the animal plod along? Watch video of the animal (or similar animals) to get a feel for not only what gait to use, but how that gait is done. As you understand more about how animals move, it will be easier to see the differences in movement patterns. This, in turn, will make it easier to draw and animate both real, and fictional, animals.
Gait Footfall Patterns
This is a veterinary site, but has some excellent information, and interactive illustrations, on quadruped gaits. This site focuses more on footfall patterns than body movements.
Eadweard Muybridge's Animal Locomotion
Collection of sequential photographs that document animal movement. The complete works include humans, various mammals (particularly horses), and birds. Muybridge's work can be found in a variety of books, as well as online as both plates and animations. At the time of this writing the plates are available at the above link.
Erica Liszewski is an artist, programmer, and game designer, with way too many pets.
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