I just happened to come across this video on my recommended, and thought I would share since it could possibly help someone.

I've been practicing yoga nidra for a couple weeks now, and within the relaxation driven session, the guide will often instruct you to let your jaw relax completely as well as your tongue. I didn't think much of it, just felt nice to completely let the jaw and tongue relax, but then after a number of sessions, I began to notice by relaxing my jaw and tongue, other areas of my body would relax, in particular my cranium, my pelvis, and hip area. Interestingly, ever since being more mindful of keeping my jaw relaxed during the day, intuitively I felt the need to stretch my hip flexor more. And then this video popped up in a timely manner explaining the physiological connection between our jaw and our pelvic area.

I've only just started to dig a bit deeper into this, so will most likely follow up on this post, but for now wanted to get the information out there!