This is excerpted from Chapter 9 of Yoga Therapy, "Kinesiology and the Biomechanics of Movement."

The trouble with the fast lane is that all the movement is horizontal. And I like to go vertical sometimes.

—TOM ROBBINS

YOGA ASANAS ARE TYPICALLY DEPICTED in the yoga anatomy literature in the same static form that we find presentations of human anatomy more generally. We are given idealized perfect forms showing the precise position of the bones (and occasionally ligaments) in various asanas, with muscles added to show how the skeleton is held in that position. These portrayals help us understand the basic form of the asana and which muscles are doing what in support of it, sometimes including identification of the role played by each muscle. Many of the best of these published works on yoga anatomy are written by teachers with a primary background in Iyengar-style yoga, which emphasizes, in the words of B. K. S. Iyengar, the “perfect pose.”

The American yoga teacher Erich Schiffmann...