this video may be of interest to you:

http://deansomerset.com/side-plank-internal-rotation-question-answered/

note that many problems are related to core stability, and its precursor to proper stability which is proper diaphragmatic breathing. i would study those as well as working on soft tissue.

but also related to what you and i are working on, are the 21st century problems like overactive anterior chain, inhibited posterior chain which will move the femur head out of socket during certain movements. you can see some discussion on that in that post.

it is fascinating stuff and very complex as you dig deeper, but still very interesting.

i feel very fortunate that i live in the SF Bay and can drive up to see Roop every now and then. i usually work on something until i hit some roadblock, then i go up to see Roop who gives me a ton more things to do and think about. no substitute for his experience or training.

good luck on it and yes it can take a long time. it took me 4-5 months before i could get ass to heels in squat and then it’s taken twice that long to get there nearly without warm up and then it’s still not consistently perfect.