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Structure: Detail drawing of
forequarter angulation.
The keystone of the forequarter assembly is the Scapula (shoulder blade) although it has no skeletal linkage with the Vertebrae (back-bone) but is held in its flexible position by sheets of muscles
and a few ligaments. (The dog has no collar bone.)
Approximately 67 to 70%
of a Collie's weight is supported by and distributed equally between his
forequarters-being directed to and concentrated on the "Vertical
Center of Gravity" (shown on drawing by a solid line which
intersects the axis of the shoulder and the center of the heel pad as it
touches the ground when the dog is standing at ease.) When the dog
moves, the blade rotates through a small arc upon an imaginary pivot or
axis. (The blade does not have an actual pin upon which to rotate: the
axis being that point which remains stationary when the pull of the
muscles controlling the forward and backward movement is equalized.)
The Scapula should
be set on the Collie at an angle of 45 degrees (X) to the Horizontal
when viewed from the side, and should slope downward from the highest
elevation (d) to the shoulder joint (a) which is the junction of the
shoulder blade with the upper arm, or Humerus. All that is meant
by the expressions, "a good layback" or "Shoulders well
laid back," is the slope of the shoulders should not be less
than 45 or more than 50 degrees with reference to the Horizontal line.
(Imaginary) An imaginary line extended from the top of the shoulder (d)
and continuing through, or passing over, the Olecranon (elbow)
should intersect the plane of the shoulder at 90 degrees to form angle
"Y". This line is theoretical because the Humerus (upper
arm) is not a straight bone, but the axis are parallel to each other and
therefore parallel to the line shown.
The length of the Scapula (a-b) should equal the length of the Humerus (a-c). The angle of
the attachment of the Radius-ulna (lower arm) is not important,
provided the bones are straight and stand vertically as observed from
either side or front. The pastern is sloped in order to place the heel
pad directly under the center of gravity and to provide additional
length of reach of foreleg and increase the gripping power and leverage of
the foot.
It is difficult to measure the value of
forequarter angulation when neither the bones or angles can be seen, so
the "Visional Approximation of the Center of Gravity"
can be judged along the dotted line (d-e). The highest point of the
shoulder should be in line with the rear section of the elbow joint and
the line should strike the ground behind the heel pad as shown on the
drawing.
In action, Collies conforming to these
basic principles of forequarter angulation when observed from the side
move correctly. (Assuming, of course, that the rear assembly is also
correctly put together.) The reach, or stride, is long; the feet are
lifted only far enough to clear the ground; and the gait
smooth and even; and the ground covered with a minimum of muscular
effort.
Basic
Forequarter | Detailed
Forequarter | Actual Forequarter
Basic
Hindquarter | Detailed
Hindquarter | Actual Hindquarter | Correct
Front Superficial Muscles of
Front | Skeleton of Front | Correct
Rear
Superficial Muscles of Rear | Skeleton of Rear | Narrow Front
Front
Too Wide | Out At Elbows | "East-West" | "Fiddle-Front"
Bowed Hocks | "Cow-Hocks" | Weak
Rear | Superficial Muscles | Skeleton |
