The Limits of Biomechanical Concepts

I'm just a little bit concerned that we're this far behind, as far as what is the basic science really say? I mean, what is it truly a big range of motion difference? Is that truly a torsion issue? And so if we can prove some of those biomechanical concepts, that would be great. Looking at some of the things that are like mental health,. There's been probably four or five of them by now, but the mental health coma biddies that these patients had before surgery and then they exacerbated after surgery.