As much as I am open to experimentation I would never try this without first getting my spine flexible and mobile. Mine actually is extremely healthy, very mobile and if I may say "educated", as I have learned to segment each vertebrate when I move it. What I mean is, I can move my spine one vertebrae at a time with almost full control. Multifidus muscles in my back are quite very healthy and strong. Yet, I would still not do this exercise since I believe is so threatening to the body, that the body will lock itself elsewhere, at a level that is too deep to understand or prevent. The chance I believe, of a serious injury with this hack, out weight any possible advantages.