We define clinical biomechanics as that body of knowledge that
employs mechanical facts, concepts, principles,  terms, methodol­
ogies, and mathematics to interpret and analyze normal and abnormal
human anatomy and physiology. Our purposes in writing Clinical
Biomechanics of the Spine are to advance that knowledge by present­
ing a comprehensive review and analysis of the clinically relevant
scientific data on the mechanics of the human spine, and to combine
clinical experience and observations with scientific data in order to
improve patient  care.
During the course of our study of the biomechanics of the spine, we
became aware of the  value of the tea!l1 approach, that of an ortho­
paedic spine specialist  interested in biomechanics working with a
mechanical engineer interested in clinical problems. This approach
was beneficial in the improvement of research techniques and the
application of engineering theory for a better understanding of clinical
problems in  the human spine. We recognize that  a considerable
amount of information concerning mechanical behavior of the spine is
based on reliable research that may be used to improve patient care.
There are engineering theories and principles that are crucial to the
basic understanding of the normal and abnormal functioning of the
spine. This information is useful in the understanding and treatment
of patients with diseases ofthe spine, provided that it is presented in a
clinical context. Our goal is to present this information in a manner
that is understandable and useful to the clinician who may not be a
student of biomechanics. In doing so, we hope to make some contribu­
tion toward a stronger scientific basis for the practice of medicine as it
relates to the spine.
Since the clinician increasingly employs biomechanical terms and
interprets problems with the assistance of the engineer,  and since
biomechanical engineers are showing more interest in the field  of
spine care and surgery, it is important to facilitate communication
between the two disciplines. This book is particularly designed to
improve the accuracy and effectiveness of communications between
the clinician and the engineer.