indent from turnout muscles

[swan#7]

This was orginally posted by someone else under the title "cutt butt" but there wasn't a lot of info there so I wanted to start another thread. What is that line that loops through the hips? I've heard teachers say it's from using the correct turnout muscles, but what muscles does the line go through, what muscles are worked to get the indent?

[Victoria Leigh]

The gluteous maximus muscles, in conjunction with the other rotators and the tops of the thighs under the glutes. Of course none of these work is one is not aligned and well placed in terms of weight placement.