Dog Locomotion and Gait Analysis

book review by Jim Bradrick

Animation as we know it can generally be said to be a caricature of real-life movement; if it works, it is because it in some way resembles the familiar movements of everyday life. This is true even of animation with extreme exaggeration, which nevertheless must have some grounding in the physics of the real world.

Any serious student of animation should therefore always be on the lookout for good motion reference. The first useful works of motion reference, which pre-dated even motion picture film, were the glass plate images of Eadward Muybridge. His rather murky sequences -- showing horses and other creatures from dogs to tigers to elephants, plus an extensive and imaginative series of studies of human movement -- are still in use today, more than a hundred years since their creation.

More scientific in nature is the work of Muybridge's lesser known contemporary, the Frenchman, Etienne-Jules Marey, who was the first to develop a means of exposing a sequence of poses on a single plate. More recently, Harold Edgerton, inventor of the stroboscope and stroboscopic photography, found ways of capturing for us events of the briefest duration. His work includes such well-known images as a drop of splashing milk frozen as a perfect coronet, and bullets in the act of penetrating an apple, exploding a balloon and cutting through a playing card edge-on.

Motion pictures and videos viewed in slow-motion and stop-motion, while they would seem to be a wealth of information in the study of motion, are often frustrating. Material not created specifically for motion study is often flawed with the distortion of telephoto photography, framing that crops out lower limbs, or the confusion caused by such natural obstructions as grass and other features of terrain that obscure essential detail. Moreover, the material in films not designed for motion study is not organized for it, and therefore, the time and effort involved in research can be burdensome.

Dogs and Animators?
My own personal library of over a hundred books on animation and motion reference is as comprehensive in its field as I have been able to make it, so I was surprised recently to discover the existence of Dog Locomotion and Gait Analysis, by Curtis Brown. However, it was not through my interest in animation that I discovered it; it was because of my love of dogs. Searching the Internet one day for Websites on dog breeds, I opened the site of Hoflin Publishing. The book's title leapt out at me.

Dog Locomotion and Gait Analysis was created with the least thought of animators in mind. The target readership was simply serious dog people: breeders, trainers and dog show judges. Indeed, there is far, far more here than the animator as such could ever need or want, including discussion of such topics as the misguided standards specified by official kennel clubs and breeder associations to which show judges must adhere.

Yet there is plenty of material to satisfy the most exacting animator or CGI model builder. Although the trot is the gait given most coverage due to its extensive use in shows and breed judging, all the various gaits are shown and considered, including rarely heard-of ones such as pronk and pace-like walk.

How does a short-legged dog trot differently from a long-legged dog? How does the gallop of a dog differ from that of a cat or horse? How does a dog change over from one gait to another? What is a diagonal gallop? A double-suspension rotary gallop? What are the advantages of a flexible back [cat] as compared to a stiff back [horse] in a run?

The author, Curtis Brown, an engineer and surveyor by trade, answers these questions in clear, readable language. The text, although concerned with purebred dogs primarily, does also compare their movement with that of wild creatures, including wild dogs, wolves, jackals, and even elephants, bison and jackrabbits.

Best of all are the illustrations: photographs by the author and others, and drawings by Robert Cole. A relief from the dim imagery of Muybridge, many of Cole's lucid line illustrations show sequences of various gaits performed by a variety of breeds, from the long-legged saluki to the bandy-legged English bulldog. These sequential illustrations alone are worth twice the price of the book, and are a gold mine for anyone wanting reference for movement cycles, whether the intended use is realism or caricature.

A valuable resource long known among people of the dog breeding world, perhaps this book will now take its place as a standard reference on the shelf of every animator as well.

Dog Locomotion and Gait Analysis is in print and available for purchase.

Dog Locomotion and Gait Analysis by Curtis Brown. Wheat Ridge, Colorado: Hoflin Publishing, 1986. 160 pages. ISBN: 0-8666-7061-0 [trade paperback, US$25 + $4 s&h ($8 outside U.S. & Canada)].

Jim Bradrick is an animator with Humongous Entertainment near Seattle.