The American Medical Association has published a book titled Guide To The Evaluation of Permanent Impairment, 5th Edition consisting of approximately 400 pages. This publication is used by doctors in all 50 states. It shows doctors how to rate an injury by using various physical instruments to measure loss of range of motion and in some cases pain (a much more difficult concept to quantify). This book is generally considered the “bible” for impairment ratings. One item to remember is the Guide states that the percent rating cannot be given until and unless the patient is at maximum healing. The Guide also allows the doctor to rate two or more separate injuries in the Combines Values Chart at the end of the book.