Posterior gluteal line
The posterior gluteal line, the shortest of the three gluteal lines, begins at the iliac crest, about 5 cm in front of its posterior extremity; it is at first distinctly marked, but as it passes downward to the upper part of the greater sciatic notch, where it ends, it becomes less distinct, and is often altogether lost.
Behind this line is a narrow semilunar surface, the upper part of which is rough and gives origin to a portion of the Gluteus maximus; the lower part is smooth and has no muscular fibers attached to it.