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Structure:
Hindquarter Assembly
Detail drawing of the
correct hindquarter assembly which will provide the Collie with a
maximum drive, lift and power for propulsion. The mechanical efficiency
depends upon several features of angulation which experience has shown
to be correct for the breed.
The hind leg is firmly
attached to the skeletal framework through an articulated attachment to
the Illium (pelvis). The pelvis should be sloped at an angle of
30 degrees (Angle X) to the Horizontal as shown on the line (a-b). The
axis of the Femur (thigh or upper leg) should intersect the
pelvic slope at 90 degrees (Angle Y) as indicated by the typical axis
line (c-d). The stifle, consisting of two bones, the Tibia and
the Fibula, is articulated with the Femur and should be
distinctly angled at the "stifle joint." (This is referred to
as "Good bend of stifle".) At the lower end, where it meets
the hock "joint", the line of the stifle (o-f) should
intersect the vertical line of the Hock-Metatarsus (g-h) at an angle of
45 to 50 degrees. (Angle Z). The overall length of the stifle should at
least equal the length of the thigh bone, and preferably should exceed
it. ("Hocks well let down" is indicated by the shortness of
the hock-i.e., close to the ground- in relation to the long stifle
bone.)
Leverage exerted by the
stifle and a short, straight hock, in action with the tendons and
muscles, produces lifting action and, with the Femur the power to
move the Collie smoothly and without wasted muscular effort. (Assuming,
of course, that the front quarters are also correctly
"angulated".) When moving at a fast trot the combined forces
reach maximum thrust along line "A" and not over the Center of
Gravity "B" as might be supposed.
Line "A"
dropped vertically from the Ischium (buttock) should parallel the
inside of the hock and bisect the foot. This is the position assumed
when the Collie stands "four square" at attention. When at
ease, a Collie will often shift one or both feet up to the normal center
of gravity. This is not to be confused with a bent or "sickle"
hock which is an anatomical defect due to an abnormal curvature of the Metarsal bones below the Os Calcis, "hock joint". A "Sickle
Hock" can not be straightened by the dog when in action and is faulty
because it opposes the principles of leverage.
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 |
