Book One -- The things that sustain and support the entire body, and what braces and attaches them all. [the bones and the ligaments that interconnect them] | Chapter 29 On the Bones Which Are Attached to the Sides of the Sacrum

The line on the back of the ilium and the muscles which occupy it 44

From the back of the ilium or its wide outer area, which is rougher than the bone’s interior surface, three muscles (the first: P in the 9th table of muscles; second: S in the 10th; third: S in the 11th) [m. gluteus maximus, medius, et minimus] chiefly originate, occupying the entire back of the ilium with their beginnings. The first [m. gluteus maximus] will be counted the first of the muscles that move the femur, filling most of the posterior surface of the iliac dorsum with its origin. Two lines (one is Z, Y [linea glutealis anterior], the other a, b [linea glutealis inferior] in fig. 2) projecting quite obscurely on the back of the ilium indicate how great a portion of this surface it occupies; they run like a semicircle and mark off the back of the iliac bone into three areas. The first, located outside the first line [Y, Z], is occupied by the first of the muscles [m. gluteus maximus] that move the femur. The second, visible between the first line and the second [a, b], puts forth the muscle [m. gluteus medius] which will be counted the second of those that move the femur. The third area, which extends from the second, shorter line to the hip joint, provides the starting place for the third of the muscles [m. gluteus minimus] that move the femur. This is the way the wide part of the bone attached to the sacrum, which is called the iliac bone, is arranged; the middle part, which is called the hipbone [os ischii], has also been explained to a great degree. We have said that the bone in that area is made thicker and stronger so that it may better support the entire body when resting on one leg, and become a fit place for a socket [acetabulum] suitable to articulate the femur to be incised.



Book One -- The things that sustain and support the entire body, and what braces and attaches them all. [the bones and the ligaments that interconnect them] | Chapter 29 On the Bones Which Are Attached to the Sides of the Sacrum