Testing a New Hip Stretch

My left hip's psoas/hip flexor has been bothering me again lately. I am really tired of this! My lateral flexibility isn't good at the hip joint. I suddenly recalled a moment I had with the gymnastics coach at U. Az back in my post-doc days, who showed me what it meant to really get a stretch to achieve new levels. He had me bend over on the floor, legs spread wide, and he pushed on my back - hard. Hard enough to hurt, and only just a bit less than the point where my body would involuntarily contract from perceived damage. It was far beyond the comfort point. Those incredibly flexible young gymnastics ladies got that way with a fair amount of pain, it seems. So with new determination, I got a heavy ankle weight, wrapped my left knee, laid on my back, opened my hip wide, and let the weight stretch my hip for ~10-15 minutes. The word these days is that you need to hold a stretch for at least 5 minutes before it really makes for the possibility of a new level being "permanent". It was just a stab in the dark, if this might help alleviate how quickly I've been getting inflammed psoas and hip flexor. I was quite happy to be able to run 9 hilly miles yesterday in Nicene Marks without the inflammation (but still getting tired and a bit overworked on some of those hip muscles, but that's a different sensation than inflammation). Then I ran 2 + 2 + 8 miles today. So that's 21 miles in 24 hours, and no hip inflammation! This is intriguing!