FORM FOLLOWS FUNCTION
Figure 9. The Seven Lumbar Vertebrae
THE LUMBAR AREA AND THE LAST THORACIC VERTEBRAE PLAY A MORE IMPORTANT ROLE IN MOVEMENT WHEN THE DOG IS AT A GALLOP.
Figure 10. Pelvic Girdle from Above
vertebrae, whereas the shoulder blade is attached to the body with only muscles and ligaments. This is one of the main reasons that we can see much more lateral movement in the forequarters than we can see in the rear, as there is a less rigid connection to the body in the forequarters (so there is space for “wiggle” room). The croup is that area between the rim of the pelvis, which includes the fused sacral ver- tebrae, and the first four or five of the tail verte- brae. These vertebrae form a slightly curved area that can be fairly easy to feel through a physical examination on a dog in correct weight (not fat)! The angulation of the croup determines tail set. A fairly level croup indicates a higher tail set, and a more angled croup indicates a lower tail set. It is important to note that the angulation of the croup and the angulation of the pelvis are two separate and distinctly different parts of the body, and are independent of each other. You can have a dog with a flat croup and a flat pelvis, and one with a steep croup and a steep pelvis. But you can also have a flat croup and a steep pelvis as well as a steep croup and a flat pelvis. The final set of vertebrae are the tail (coc- cygeal) vertebrae that can number from no tail at all through a full tail of approximately 20-23 vertebrae. If you have any questions or comments, or would like to schedule a seminar, you may con- tact me via email: jimanie@welshcorgi.com.
THE LUMBAR VERTEBRAE The seven lumbar vertebrae support the organs of the abdomen and the pelvis, and offer protection of the abdominal organs and the spinal cord. They are vital in the movement of the dog. The loin area of the spine rises upward in a curve that then slopes downward toward the pelvis and then on to the three sacral vertebrae and the first several tail (coccygeal) vertebrae that form the croup. The lumbar vertebrae gradually increase in width from the first to the seventh, with bodies that are longer and heavier than the thoracic vertebrae, and increase in length from the first through the sixth. The last lumbar vertebra is shorter than those that precede it, making it about the same length as the first lumbar vertebra. In the average dog, the first nine thoracic vertebrae are about equal in length to the seven lumbar vertebrae. The spinous and transverse processes of the lumbar vertebrae are massive, to allow for strong muscle and ligament attachments that are vital for the transmission of power from the rear of the dog. (See Figure 9.) Because of the shape of the lumbar area and the position of the articular facets of the individual lumbar vertebrae, free flexion and extension and a slight rotation are allowed, though this inhibits much lateral movement. Because of this special formation of the lumbar spine, it is not unusual for a dog to show a slight roach over the lumbar area that is temporary and does not affect the dog in motion. The lumbar area and the last thoracic vertebrae play a more important role in movement when the dog is at a gallop. They begin to “roach” as the dog brings both rear legs forward under the body, which causes more forward reach, and then the same vertebrae begin to straighten out, increasing the rear extension and adding power to the force of forward propulsion through the powerful back muscles. The reach of the spinal cord ends at the fourth lumbar vertebra. SACRAL VERTEBRAE AND CROUP The sacral vertebrae consist of three vertebrae that are fused together. (See Fig- ure 10.) The important function of the sacral vertebrae is that on either side, it is joined by a cartilaginous joint with the pelvis. This forms a firm union that allows the transfer of forces from the hindquarters to the vertebral column. It is extremely important to understand that the hind limbs are attached to the pelvis with a ball and socket joint, and that the pelvis is firmly attached to the spine via the sacral
102 | SHOWSIGHT MAGAZINE, OCTOBER 2021
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