A Way to Shorten Labour
By Tony Crisp
Published: June 25, 2012.
The main statement in the book is that energy moves in straight lines unless it meets a resistance. When contractions occur the baby's body is pushed in a certain direction. If you imagine a line running through the baby's body and head, then the contractions push along that line to the head.
The important point made is that the head is often pressing, not into the birth canal, but into the back.