The first quarter was useful. Such as finding out speed of movement is determined by balance fitness. I like sports so I liked the details of athletic balance -- up to the point I realized the book was never going to talk about regular person balance in walking and hiking...much. I skipped a big section of the athlete stuff. I learned some things about how to use my balance cushion that were useful, however this author is also trying to sell the slackbow, which I can't afford. Overall an enjoyable read that helped me understand my own balance physical therapy right now. I have neuropathy and I guess I'm mostly affected by my feet but I still don't know the mechanisms of my disease as it relates to balance. Book goes into depth on concussions but not much on neurological disorders.