One of the best things about this book is the realization that when we take responsibility for our own health we will be far better off. This is not to denigrate the medical profession, but not to expect them to do everything for us, or simply give us a pill that will fix what's wrong. The back is a complex and crucial part of our bodies. MacKenzie explains in lay language the anatomy of the back and why we have back pain. Basically he says a lot of lower back pain is the result of losing the 'lordosis' in the lower spine (the curvature). When this happens (through poor posture or other causes) pressure results on the nerves, especially the sciatic nerve that cause pain down the leg. The exercises in the book help to keep the shape of the spine in its proper curvature, resulting in the relieving of pressure on the nerves. In my own experience this cured my problem, and I continue to do the exercises because they keep everything in place. I have given this book to more people than I can remember, and also his companion book "Treat your own Neck."