the position of bending over and allowing the fingers to eventually touch the floor.
1. one of the only times in life when the knees are supposed to be locked.
2. for 30 years i did this and my quads would be bunched up over my knee, the kneecaps lifted, i noticed but never imagined relaxing them. then i did, took about 2 weeks to get the quads to relax.
3. just hanging, allowing the low back fascia to stretch and the muscles to relax, the fingers at my age do not touch the floor immediately the first time, takes me about 30 seconds, leave the palms-on-floor for last, if feel like it.
4. one gets different results with mulabandha open or closed (that is the asshole, that is what that is).
5. Because of this aspect probably every human will have some psychology to deal with in regard to this position. It is about as unprotected as one can get in vertical. Of course there's bending over backwards, but that's a different story.