Mounted skeleton of an Arabian horse, showing underlying structure of breed characteristics including short back, high-set tail, distinction between level croup and well-angulated hip. This specimen also has only 5 lumbar vertebrae.
Skeletal analysis
Mounted skeleton of an Arabian horse, showing underlying structure of breed characteristics including short back, high-set tail, distinction between level croup and well-angulated hip. This specimen also has only 5 lumbar vertebrae.Some Arabians, though not all, have 5 lumbar vertebrae instead of the usual 6, and 17 pairs of ribs rather than 18.[9] A quality Arabian has both a relatively horizontal croup and a properly angled pelvis as well as good croup length and depth to the hip (determined by the length of the pelvis), that allows agility and impulsion.[4][10] A misconception confuses the topline of the croup with the angle of the "hip" (the pelvis or ilium), leading some to assert that Arabians have a flat pelvis angle and cannot use their hindquarters properly. However, the croup is formed by the sacral vertebrae. The hip angle is determined by the attachment of the ilium to the spine, the structure and length of the femur, and other aspects of hindquarter anatomy, which is not correlated to the topline of the sacrum. Thus, the Arabian has conformation typical of other horse breeds built for speed and distance, such as the Thoroughbred, where the angle of the ilium is more oblique than that of the croup.[11][12][13] Thus, the hip angle is not necessarily correlated to the topline of the croup. Horses bred to gallop need a good length of croup and good length of hip for proper attachment of muscles, and so unlike angle, length of hip and croup do go together as a rule.[