Here is some information Pegasus asked me to share from a PM. I learn a lot of what is below from him nudging me in the right direction in my progress log. Basically, the conclusion is that a tight pelvic floor can impede one’s ability to do a RK.
I have direct experience with a tight pelvic floor keeping me from RK.
In the first two weeks of my training, I did a series of stretches for my pelvic floor (Hindi squats, happy baby pose, etc), and I was learning at the same time to RK. I didn’t understand what a tight pelvic floor felt like - because I couldn’t reference it to a loose pelvic floor. I only guessed that I had a tight pelvic floor because I had the symptoms: PreE, IKs, etc.
After stretching for two weeks for 10-30 mins each day, I started to feel my pelvic floor loosen and expand when I did a RK. Then, I started having success with my RKs during real sex.
Because everything was so new, I didn’t see the connection between stretching and me having the ability to do an actual RK. I just thought that RKs were a big part of my stamina getting better. So, I stopped doing the stretches. Well, the next time I tried to have real sex, I went back to lasting only 30 seconds. I could not do a RK. I felt like my pelvic floor was hard as a rock. I could not get it to expand.
It took me a few days to realize that if I tried to RK right at after doing the happy baby pose - it was super easy. My pelvic floor would expand with very little effort. It felt very natural.
Then, after a few hours, my ability to RK would fail again. That’s what made me realize that stretching was was what allowed me to do RKs. And, RKs are what lower my arousal and help increase my stamina. It’s all interconnected.
I’ve been playing around with a theory that RK effectiveness can be measured by how easily you can make your erection go away when doing RKs. For me, that was a good test, because at first when I tried to RK I could not make my erection go down. Now, I can make my full erection go down (maybe to a 2-3) in about 10-15 seconds. I have not gotten enough feedback to know if that really is a good test or if there are other confounding factors involved.
With other range of motion issues, a PT moves a body part around and can determine what the range of motion is. For the pelvic floor, I’m not sure how to do that. I suppose that some PT’s who specialize in pelvic floors have some diagnostic routines (maybe depth of a squat or how much you can butterfly the legs open, or something).
After loosening my pelvic floor with lots of stretching and doing a 100%RK routine for a few weeks, I then understood what a loose pelvic floor felt like. Even now after another month, I have to say that I have a constant awareness of how loose my pelvic floor is because it feels so different than it did for my whole adult life. It is hard to describe, it just feels loose. It doesn’t feel all bound up. This is an exaggeration, but it just feels like it hangs. I know it doesn’t literally hang, but it feels like it. Also, when I RK, my pelvic floor feels like it is expanding a lot. There is little resistance. It freely gets pushed down and out.