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Form Follows Function – Up and Down and All Around

Illustration of Directional Terms in Dog Anatomy

 

I was recently asked to further explain the importance of energy conservation in canine movement and delve more into vertical and horizontal movement. In the simplest of terms, vertical means up and down (perpendicular or at right angles to the plane of the baseline), and lateral means towards the side of the body or even outside of the body; specifically, going away from the medial line.

The best way to determine the structure and condition of a dog is to observe the dog in motion from the side. A dog in top condition with firm muscles will present the most valid proof of structure. Dogs that are flabby or weak will show some of the basics but will have wasted motion even if the dog’s structure is excellent. One can compare the skeletal structure of a dog to a blueprint for a building. The basics are there, but one must consider much more before you have a complete picture of the dog.

Before going much further, we should learn a bit about some of the directional terms used when discussing canine anatomy.

 

The principal planes of motion for dogs are as follows:
  • The sagittal or median sagittal plane divides the dog into right and left portions.
  • The dorsal plane divides the dog into ventral (towards the belly) and dorsal (towards the back) portions.
  • The transverse plane divides the body into cranial (towards the head end) and caudal (towards the tail end of the body) portions.
dogs in motion
Figure 1. Directional Terms in Dog Anatomy

See Figure 1.

Motion may occur in any of the three planes of motion or some combination. We will mainly be concerned with the median (or sagittal) plane that divides the dog into right and left portions. The dashed line shown in Figure 2 (centerline or midline) divides the dog into right and left portions (median plane). Lateral indicates the side or outside, and specifically, it denotes a position away from the median plane or midline of the body.

dogs in motion
Figure 2. The Medial Line from Above

 

Vertical Motion

You want to see a seemingly effortless, smooth forward motion when a dog moves at a trot. In most breeds, the dog’s topline should look the same when standing and in motion. (See Figure 3.) The topline should be “quiet” in that the observer sees no up and down motion, referred to as “vertical” motion. If this dog bounces over the withers when in motion, it is pouring much of its energy into vertical instead of forward motion.

dogs in motion
Figure 3. Medial Axis (Center or Midline) of the Body from the Front

Robert L. Vandiver, a fellow South Carolinian and judge, took an engineer’s approach to describe a bouncing topline. It is the best explanation I have ever encountered concerning this common fault. With his permission, I will quote from his article, “Doberman On The Move.”

Mr. Vandiver’s comments are concerning the Doberman Pinscher, but they are relative to all breeds even though the measurements may vary:

A Doberman that bounces over the withers has a serious handicap. Let’s try to quantify the effects of a bouncing front due to a combination of structural deviations. If a male Doberman has a stride of 28 inches at the trot (2,263 steps per mile), and the withers move up and down 1/2 inch with each step, then the dog’s front will expend the energy equivalent of lifting it 94 feet while traveling that mile. Since the dog’s front is about 60% of the dog’s total weight, then the dog would have expended 60% of the energy to raise his entire body the 94 feet.

In other words, after trotting for a mile, the dog will have also expended the energy equivalent to climbing a 6-story building (60% of the 94 feet). The extra work expended in an hour of trotting (typically at 5 miles per hour) would be the equivalent of climbing 30 stories. After a day’s work, this dog will be far more exhausted than one that moves without bounce over the withers.

You may find Mr. Vandiver’s entire article on movement in the Doberman on his website, under the “other information” button. I would urge you to read this article no matter which breed you may have.

The red rectangle shown in Figure 5 seems like such a small amount that it is hard to realize how it can cause many problems for a dog. This bouncing action is usually caused by an upright shoulder that restricts the forefoot’s reach. The driving force of a well-angled rear assembly acts much as the pile driver that is used to drive a support into the ground. Any motion that draws attention to one part of the body (such as bouncing over the withers) signals that the dog is out of balance in some area of its structure.

dogs in motion
Figure 4. Australian Cattle Dog with Correct, Balanced Side Gait
dogs in motion
Figure 5. The red rectangle approximates a one-half-inch rise.

The most significant problem with vertical motion over the withers is that this constant stress on the shoulder assembly of the dog will eventually cause the dog to break down in front. How many of you have watched a Veteran Class at a National Specialty and noted that some of the dogs that were top winners in their day seemed to be high in the rear—and your recollections of this dog were that there was no evidence of this fault. The dog is not high in the rear. The dog most often breaks down in the front, sagging down at the wither, giving the illusion of being high in the rear.

The most significant problem with vertical motion over the withers is that this constant stress on the shoulder assembly of the dog will eventually cause the dog to break down in front.

Vertical motion can also be observed below the dorsal plane in the motion of the legs. Faults observed in the movement of the legs are an attempt by the dog to put itself in some semblance of balance so that its footfall (when each foot strikes the ground in the typical sequence of a trot) lands without the interference of the feet and legs with each other as they move forward.

The most common example of this is when the dog is upright in shoulder, but with a correctly angled rear assembly. The dog can lift the front legs higher (vertical motion), or the feet can form a circular motion such as paddling or winging (lateral motion) to keep the front feet in the air (wasting time) long enough for the rear assembly to finish the driving and follow-through action, which propels the dog forward. Another method to balance the foot timing can be achieved by kicking up the hind leg far beyond what is needed to drive the dog forward.

 

Lateral Motion

Any lateral motion in the dog is another significant waste of energy. The body can sway laterally from side to side with a rolling motion in the front or rear of the animal. This action can be due to many different reasons. Sidewinding is also somewhat of a lateral motion, as can be a rolling in the hindquarters. For most breeds, any lateral movement is a waste of energy and can lead to an eventual physical breakdown.

The dilemma for most of us is that there are so many different compensatory actions for an unbalanced dog to take, often for the same mechanical problem, that it can be quite confusing to determine precisely why the dog is doing so.

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