I'm sorry that I may sound a bit harsh - it's just in my nature to be sceptical.

My point is that there are probably thousands of experts out there who claims to know how to cure or prevent lower back problems. Indeed, if one has problems with the back and follows the advises of any one of those experts, there is a big probability that the back will get better. Mine certainly did.

I see no reason to believe that Esther Gokhale cracked the nut better than everyone else. "Buy this book and everything will be better" - I don't like the sound of that. Thousands of quacks have already been doing that before - creating some theory based on anecdotal evidences, writing a book about it, finding some "clickbait" title for it and then finding some experts willing to recommend the book.

If she really did crack the nut, she should have her work published somewhere. The word would spread as wildfire, and her methods would become well-known and easily accessible. It should simply not be needed to buy a book to learn what exercises helps against lower back problems.

I try to stand most of my workday, and when I do slump down I use something like this:

... hence the exercise in the video is not something I can easily perform.