Awesome link! Thanks for the contribution. Suhaila and her chiropractor introduced me to this fun roller thing about 4 years ago and it really made a difference in my hip flexibility. For me the best part is to lay where the muscles insert around the inner and outer hips and hip flexor. Then regular yoga focusing on lung and hamstring stretches will help release your psoas, hip flexors, and hamstrings. These are what's pulling you into a kind of crunch when you are sitting in spread eagle on the floor. Especially if the psoas is too tight it will make that small hump in your lower back. Once these muscles have relaxed then the glutes will have a broader range to move, but you still have to work on glute strength and dexterity. Having a big beautiful butt doesn't insure strong glute work, strangely enough, because most women walk by powering through their legs, so isolating the glutes is like waking up a zombie sometimes. Regular practice is what does it. Lifting half up and half down helps with dexterity and breaks up the monotony of single glute squeezes, and then squeezing them both together as tight as possible with out engaging any of your, um, pelvic floor, builds strength. And the whole gluteus minimus/maximus/medius labeling thing doesn't match the action of squeezing half way and then all the way. So an anatomy chart might confuse things because your minimus is actually your outer/side glutes, what gives hott men that really nice concave flex in their side booties. So it's your good ole gluteus maximus that you want to focus on and when it contracts in the lower areas it's just building strength to finally make it half way and then all the way up to the top of the pant line. It's just 3 different areas of the same muscle that strengthen over time. Lemme know if you have anymore questions about this stuff. Best!