Table Of Content

Other books by Theodore Dimon, Jr. The Elements of Skill: A Conscious Approach to Learning The Undivided Self: Alexander Technique and the Control of Stress Anatomy of the Moving Body, Second Edition: A Basic Course in Bones, Muscles, and Joints Your Body, Your Voice: The Key to Natural Singing and Speaking 2 3 Copyright © 2011 by Theodore Dimon, Jr. All rights reserved. No portion of this book, except for brief review, may be reproduced, stored in a retrieval system, or transmitted in any form or by any means—electronic, mechanical, photocopying, recording, or otherwise—without the written permission of the publisher. For information contact North Atlantic Books. Published by North Atlantic Books P.O. Box 12327 Berkeley, California 94712 Cover art © iStockphoto.com/Comotion Design Cover design by Brad Greene Illustrations by G. David Brown The Body in Motion: Its Evolution and Design is sponsored by the Society for the Study of Native Arts and Sciences, a nonprofit educational corporation whose goals are to develop an educational and cross-cultural perspective linking various scientific, social, and artistic fields; to nurture a holistic view of arts, sciences, humanities, and healing; and to publish and distribute literature on the relationship of mind, body, and nature. North Atlantic Books’ publications are available through most bookstores. For further information, visit our website at www.northatlanticbooks.com or call 800-733-3000. The Library of Congress has cataloged the printed edition as follows: Dimon, Theodore. The body in motion : its evolution and design / Theodore Dimon Jr. p.; cm. eISBN: 978-1-58394-691-6 1. Musculoskeletal system—Anatomy. 2. Musculoskeletal system—Evolution. 3. Human locomotion. 4. Human locomotion. I. Title. [DNLM: 1. Musculoskeletal System—anatomy & histology. 2. Biomechanics. 3. Movement. 4. Musculoskeletal Physiological Phenomena. WE 101 D582b 2010] QM100.D563 2010 611’.7—dc22 2010021590 v3.1 4 To Walter Carrington, with gratitude and appreciation 5 Contents Cover Other Books by This Author Title Page Copyright Dedication List of Illustrations Preface Introduction 1. The Origins of Movement Bones, Muscles, and Movement The Head and Its Central Role in Movement Four-Footed Animals and the Role of Posture in Movement Our Upright Design Upright Posture and the Evolution of Intelligence 2. Upright Support—Part I: The Extensors The Extensors Stretch Reflexes The Head and Spine Head Balance 3. Upright Support—Part II: The Flexors Flexors and Our Basic Body Design The Suspensory Function of the Flexors Front Length and Head Balance 6 4. Upright Support—Part III: The Spine The Central Column Origins of the Human Spine Upright Posture and the Spinal Curves The Spine as Lengthening Device 5. The Shoulder Girdle The Mobile Cross-Piece The Yard-Arm From Fins to Limbs The Floating Shoulder Girdle 6. The Upper Limb The Basic Limb Pattern Modes of Positioning the Hand The Rotation Mechanism of the Forearm The Hand The Opposable Thumb The Relation of the Upper Limb to the Shoulder and Trunk 7. The Pelvic Girdle The Design of the Pelvis The Upright Compromise The Arch Design of the Pelvis The Pelvis in Relation to Lengthening in Stature 8. The Lower Limb The Weight-Bearing Limb The Ankle Joint The Foot Joints The Arched Foot The Toes Length in the Legs Our Two-Footed Poise 9. Breathing Why and How We Breathe 7 The Anatomy of Breathing The Suspensory Support of the Trunk Widening the Back Breathing and Our Upright Design 10. The Voice How We Produce Sound Closure of the Vocal Folds The Suspensory Muscles of the Larynx The Larynx and the Breath The Larynx and the Brain 11. The Suspensory Muscles of the Throat The Suspended Throat Depressing the Larynx The Throat and Upright Poise The “Open Throat” The Jaw Head Balance Revised 12. The Spiral Musculature Rotational Movement and Our Upright Design The Evolution of Spiral Muscles Rotational Movement and the Use of the Arms Anatomy of the Spiral Musculature Postural Twists The Suspended Trunk: Our Fishy Ancestry Our Double-Helix Architecture Lengthening into the Spirals 13. The Miracle of the Human Form Our Upright Suspension System Our Unique Design Features Our Higher-Order Design About the Author and Illustrator 8 Illustrations 1. The Origins of Movement 1-1. A primitive fish (amphioxus) 1-2. Lateral flexion in a fish 1-3. Early amphibians coming onto land 2. Upright Support—Part I: The Extensors 2-1. Extensors of trunk and legs 2-2. Diagram showing where muscles are needed to keep a structure from falling down 2-3. Extensor muscles of the back: a. deep postural muscles; b. erector spinae 2-4. Muscles on front of spine that support the cervical and lumbar curves 2-5a. Forward balance of the skull 2-5b. Head balance in relation to the extensors of neck and back 2-6. The sub-occipital muscles are crucial indicators of posture and balance in the body 2-7a. Head balance in a cat 2-7b. Head balance in a human 2-8. Disruption of head balance 3. Upright Support—Part II: The Flexors 3-1. Spine as a bridge 3-2. The upright human spine 3-3. Flexor muscles on the front of the body 3-4. Flexor muscles on the front of the spine 3-5. Tent pole and guy wires 3-6. Sternocleidomastoid muscles supporting the rib cage 3-7. Backward pull of sternocleidomastoid muscle on head 3-8. Head balance 4. Upright Support—Part III: The Spine 4-1. The spine 4-2. Vertebrae of the spine 9 4-3. Notochord and neural tube 4-4. Developing arch and body of vertebra 4-5. Evolutionary development of the spine 4-6. The thoracic curve in a four-footed animal 4-7. The balanced curves in the human spine 5. The Shoulder Girdle 5-1. The shoulder girdle 5-2. Shoulder girdle with immobile socket vs. mobile socket 5-3. Muscles from entire length of spine converging into shoulder 5-4. Muscles moving the scapula 5-5. Evolution of pectoral fin to the forelimb of an early amphibian 5-6. Suspensory muscles of the shoulder girdle 5-7. Pectoral muscle attaching to coracoid process 5-8. Muscles attaching to the upper arm 5-9. Pectoralis major 5-10. Widening of the shoulder girdle 6. The Upper Limb 6-1. Bones of the left upper limb 6-2. Action of the hand at the wrist 6-3. Rotation of the radius around the ulna 6-4. Rotation mechanism of the forearm 6-5. Bones of the hand 6-6. Action of the lumbrical muscles 6-7. Bones and joints of the thumb 6-8. Distal joints of the thumb 6-9. Action of TM joint showing the movement of the thumb pad in relation to the hand 6-10. TM joint at base of movable column 7. The Pelvic Girdle 7-1. Bones of the pelvis 7-2. Front view of the pelvis 7-3. Relationship of the pelvis to the spine in a fish and amphibian 7-4a. The “scapula” of the pelvis transmits force to the spine 7-4b. The scapula of the shoulder girdle absorbs force 10