Cavalier Movement, the Front Assembly – Let’s Talk Anatomy By Dr John Ioia

Cavalier Movement, the Front Assembly – Let’s Talk Anatomy

I spend a good amount of time around dogs and the show ring, watching, listening, reading and thinking. I hear much about movement in our breed, the way they should move and the way they should be constructed. I hear terminology but sometimes I question what exhibitors and judges really understand, especially as I watch some selections. I thought that we might start with a discussion of the Cavalier front end, it’s anatomy, how it works and why some dogs have a smooth stride with good reach and seem to float around the ring while others have a choppy gait and can’t cover ground. The reader should remember that I have a special interest in anatomy from my education and my work as an orthopedic surgeon, as well as my love of dogs.
We hear much about shoulder layback, front assemblies and proper movement but what constitutes a good front and why. Let’s start with the anatomy and begin with the shoulder and upper arm. I was interested many, many years ago listening to a respected group judge Dr. Sam Draper, educate a number of judges on the anatomy of the shoulder assembly. He was an expert and a good teacher. I continue to be amazed at the number of judges and exhibitors who don’t understand basic anatomy, like the point of the shoulder or what constitutes layback or even where the prosternum is and why they are important to movement.
Shoulder anatomy is similar in name in dogs and humans but vastly different in form and function. The shoulder in a human is suspended or hangs from a cage created by the clavicle or collar bone and the scapula or shoulder blade. It is further secured by attachment to the sternum or breastbone. This is an excellent arrangement for an arm that is used for grasping or hanging from trees as our ancestors may have but it is not suited to running or carrying weight, as a quadruped requires. The human shoulder allows for 180º of motion while the canine requires just 90º.
The shoulder blade of the dog doesn’t hang like the human’s but floats on the chest wall, with bony attachment to the breastbone and stabilized by strong muscles which do well to cushion the front legs when moving. These muscles also pull the upper arm forward and then help to pull the arm back, propelling the dog forward. Interesting point to consider, while the human’s point shoulder is obvious, the canine point of shoulder is the forward projection of the shoulder blade and where the upper arm meets it. So, if asked for the point of shoulder and you placed your finger on the base of the neck or withers, you are dead wrong.

Now, why is this important, what is angulation or layback and how does it affect motion? The forward projection of the scapula and the dish within which the head of the humerus rests is called the glenoid. The range of motion or how far a dog’s arm can extend will depend on the angle of the scapula and the surrounding muscles plus some other factors. Simply put, a flatter scapular will lead to greater reach. There is an additional 15º of forward extension, produced by shoulder rotation. So in the Cavalier, a layback of 40º or so will result in a very attractive and functional reach. Of course, one must also consider the depth of chest as well as the positioning of elbows and lower legs. Contrary to this, a dog that is “Upright” in the shoulder will have a choppy or short reaching gait that won’t cover ground effectively. In addition, an upright shoulder will give the appearance of a shortened or Ewe-neck, which is very unattractive. Additionally, appropriate layback will result in the “Forelegs…being well under the dog….”

There is much to consider in evaluating a Cavalier while the Cavalier Standard simply states “Forequarters: Shoulders well laid back. Forelegs straight and well under the dog with elbows close to the sides.”

There are several excellent resources on canine anatomy and movement. The best in my opinion is Rachel Page Elliott’s – Dogsteps or any of the various reprintings, like Dogsteps – A New Look, 3rd Edition and the Cineradiology that can also be purchased. Another excellent source on anatomy is Claudia Orlandi’s ABC’s of Dog Breeding. No dog library is complete without these.
There is much more on anatomy and movement but we will save that for another time.

- John V. Ioia, MD, PhD, This email address is being protected from spambots. You need JavaScript enabled to view it.
- American Cavalier King Charles Spaniel Club, http://www.ackcsc.org/