The reverse planche is not nearly as popular as the planche, though it use to be more so than it is today. This has also been called a hollowback, but that may be confusing with the hollow position from gymnastics.
In this video you can see Peto Pavelka go into a great position, although it’s not held for long.
This video shows a man working towards the full move. It’s pretty good (meaning far better than most people could possibly do), but there is room for improvement in getting more bend going.
Finally, we have a video of a little girl in gymnastics showing the difference between a planche and reverse planche. What I like about this video is it shows a variation with a single leg that you can try, in building up to the full stunt.
The key thing to do when working on this exercise, is to open up the shoulders as much as possible. Having a flexible spine is important, but to get the legs low, you must counterbalance by bringing your chest through. Go ahead and try it if you’re up to it.
And lastly here was my attempt at the skill from this morning. I did manage a couple better ones but missed the pictures with the timer on my camera. Oh well! I’m going to start working on the reverse planche more and I’ll have more about it for you in the future.