Principles of Animal Locomotion (ebook)

Argumento de Principles of Animal Locomotion (ebook)

"The lack of a comprehensive text has been the source of substantial frustration to those who teach courses in animal locomotion. It is a great pleasure, then, to see the publication of this book. It is poised to become an instant classic and will undoubtedly serve as the central source of distilled wisdom on the subject for many years to come."--Mark Denny, Stanford University

"One of the major gaps in the literature of biomechanics is a general textbook on animal locomotion, and it is difficult to imagine anyone better suited to write one than Alexander. He is a leading researcher, and his books always convey the interest and excitement of his field to a broad audience. I look forward to using this book in my own classes."--Robert Dudley, University of California, Berkeley

"This is unique, important, and useful synthesis that brings together an analysis of locomotion on land, in water, and in the air. There is no other contemporary book on animal locomotion that is as broad in scope, and I expect that it will become a classic in the field."--Thomas J. Roberts, Oregon State University

"A remarkable volume that simply must be read by anyone contemplating any kind of work on, or in imitation of, muscle-driven motion. This is no ordinary summing up but rather a synthesis, an explication of principles--the title needs no disclaimer. . . . [O]ne should read it in short bouts separated by intervals of contemplation."--Steven Vogel, American Scientist

"The book will be a godsend for any lecturer looking for a course book about animal locomotion, and many a naturalist will find that it sheds a flood of light on the reasons behind the endlessly surprising things that animals do. . . . [A] 'must have' for anyone who thinks in terms of physics about the way animals work."--C. J. Pennycuick, Trends in Ecology and Evolution

"A valuable reference book written by a leader in the field."--Stephen Gatesy, Nature

"This is an important work that will be appreciated by anyone interested in animal biomechanics. . . . Alexander is gifted in his ability to choose or create models that are sufficiently simple as to be understandable and tractable, but not so simple that they stray far from biological reality."--Robert Josephson, The Quarterly Review of Biology0PREFACE ix

Chapter 1: The Best Way to Travel 1

1.1. Fitness 1
1.2. Speed 2
1.3. Acceleration and Maneuverability 2
1.4. Endurance 4
1.5. Economy of Energy 7
1.6. Stability 8
1.7. Compromises 9
1.8. Constraints 9
1.9. Optimization Theory 10
1.10. Gaits 12

Chapter 2: Muscle, the Motor 15

2.1. How Muscles Exert Force 15
2.2. Shortening and Lengthening Muscle 22
2.3. Power Output of Muscles 26
2.4. Pennation Patterns and Moment Arms 28
2.5. Power Consumption 31
2.6. Some Other Types of Muscle 34

Chapter 3: Energy Requirements for Locomotion 38

3.1. Kinetic Energy 38
3.2. Gravitational Potential Energy 39
3.3. Elastic Strain Energy 40
3.4. Work That Does Not Increase the Body's Mechanical Energy 42
3.5. Work Requirements 46
3.6. Oscillatory Movements 48

Chapter 4: Consequences of Size Differences 53

4.1. Geometric Similarity, Allometry, and the Pace of Life 53
4.2. Dynamic Similarity 58
4.3. Elastic Similarity and Stress Similarity 60

Chapter 5: Methods for the Study of Locomotion 68

5.1. Cinematography and Video Recording 68
5.2. Stationary Locomotion 70
5.3. Measurement of Energy Consumption 73
5.4. Observing Flow 74
5.5. Forces and Pressures 76
5.6. Recording Muscle Action 80
5.7. Recording Movement at a Distance 83
5.8. Properties of Materials 84

Chapter 6: Alternative Techniques for Locomotion on Land 86

6.1. Two-Anchor Crawling 86
6.2. Crawling by Peristalsis 88
6.3. Serpentine Crawling 90
6.4. Froglike Hopping 91
6.5. An Inelastic Kangaroo 93
6.6. A Minimal Model of Walking 95
6.7. The Synthetic Wheel 97
6.8. Walkers with Heavy Legs 98
6.9. Spring-Mass Models of Running 99
6.10. Comparisons 100

Chapter 7: Walking, Running, and Hopping 103

7.1. Speed 103
7.2. Gaits 109
7.3. Forces and Energy 114
7.4. Energy-Saving Springs 122
7.5. Internal Kinetic Energy 125
7.6. Metabolic Cost of Transport 128
7.7. Prediction of Optimal Gaits 133
7.8. Soft Ground, Hills, and Loads 136
7.9. Stability 139
7.10. Maneuverability 143

Chapter 8: Climbing and Jumping 146

8.1. Standing Jumps 146
8.2. Leg Design and Jumping Technique 150
8.3. Size and Jumping 153
8.4. Jumping from Branches 155
8.5. Climbing Vertical Surfaces and Walking on the Ceiling 159

Chapter 9: Crawling and Burrowing 166

9.1. Worms 166
9.2. Insect Larvae 170
9.3. Molluscs 171
9.4. Reptiles 176
9.5. Mammals 179

Chapter 10: Gliding and Soaring 181

10.1. Drag 181
10.2. Lift 183
10.3. Drag on Aerofoils 187
10.4. Gliding Performance 192
10.5. Stability 200
10.6. Soaring 201

Chapter 11: Hovering 209

11.1. Airflow around Hovering Animals 209
11.2. Lift Generation 213
11.3. Power for Hovering 221

Chapter 12: Powered Forward Flight 224

12.1. Aerodynamics of Flapping Flight 224
12.2. Power Requirements for Flight 228
12.3. Optimization of Flight 236

Chapter 13: Moving on the Surface of Water 240

13.1. Fisher Spiders 240
13.2. Basilisk Lizards 244
13.3. Surface Swimmers 246

Chapter 14: Swimming with Oars and Hydrofoils 249

14.1. Froude Efficiency 249
14.2. Drag-Powered Swimming 250
14.3. Swimming Powered by Lift on Limbs or Paired Fins 255
14.4. Swimming with Hydrofoil Tails 261
14.5. Porpoising 264

Chapter 15: Swimming by Undulation 266

15.1. Undulating Fishes 266
15.2. Muscle Activity in Undulating Fishes 277
15.3. Fins, Tails, and Gaits 282
15.4. Undulating Worms 284

Chapter 16: Swimming by Jet Propulsion 288

16.1. Efficiency of Jet Propulsion 288
16.2. Elastic Mechanisms in Jet Propulsion 296

Chapter 17: Buoyancy 301

17.1. Buoyancy Organs 301
17.2. Swimming by Dense Animals 303
17.3. Energetics of Buoyancy 307
17.4. Buoyancy and Lifestyle 311

Chapter 18: Aids to Human Locomotion 316

18.1. Shoes 316
18.2. Bicycles 318
18.3. Scuba 321
18.4. Boats 322
18.5. Aircraft without Engines 324

Chapter 19: Epilogue 327

19.1. Metabolic Cost of Transport 327
19.2. Speeds 328
19.3. Gaits 330
19.4. Elastic Mechanisms 331
19.5. Priorities for Further Research 331

REFERENCES 333
INDEX 367