It is filled with detail, discussion, illustrations, and practical advice for spines of all types. This emphasis on variety is welcome and necessary: no two spines are exactly alike, and no two people have the same biology and biography.

What your spine is able to do may be vastly different from what other yoga students' or teachers' spines can do. The human spine is unique in its structure and function. Primarily, it provides stability through the core of our body, allowing forces to be transmitted from the upper body (arms and shoulders) to the lower body (pelvis and legs) and vice versa.

Secondarily, the spine allows tremendous range of movement. Unfortunately, in modern yoga practice we find the primacy of these two functions reversed, with flexibility prized over stability. This focus on spinal mobility comes at a grave cost to many students.

Stability is lost, and when that happens, dysfunction and pain often follow. Just as all tissues and areas of the body need a healthy amount of stress to regain and maintain optimal health, so too our spine needs the appropriate levels of stress to remain functional throughout our lives. How we choose to exercise the spine makes a difference, though.