I hate to say it, but a lot of people out there are getting bossed around by a big butt muscle (you knew that, right?). What I mean is that the big ol' gluteus maximus tries to override a lot of things another special little group of hip muscles called the deep six should be allowed to do.
The deep six hip muscles have to do with hip integrity, stability and decompression; as well as turning the leg out and opening the hip. You really need them to work well. In honor of the double meaning of "deep six" at Halloween (nerd that I can be), I've written an article introducing the where and how of the deep six hip muscles.
By the way, you might consider the result of a lack of balance between the deep six and the big butt muscle, i.e. an overly tight butt (firm is good, perma-squeeze is bad) and weak inner thighs. Got your attention? Get into the deep six.