Biomechanics and Gait Analysis

By Nicholas Stergiou

Biomechanics and Gait Analysis presents a comprehensive book on biomechanics that focuses on gait analysis. It is written primarily for biomedical engineering students, professionals and biomechanists with a strong emphasis on medical devices and assistive technology, but is also of interest to clinicians and physiologists. It allows novice readers to acquire the basics of gait analysis, while also helping expert readers update their knowledge. The book covers the most up-to-date acquisition and computational methods and advances in the field. Key topics include muscle mechanics and modeling, motor control and coordination, and measurements and assessments.

This is the go to resource for an understanding of fundamental concepts and how to collect, analyze and interpret data for research, industry, clinical and sport.

• Details the fundamental issues leading to the biomechanical analyses of gait and posture
• Covers the theoretical basis and practical aspects associated with gait analysis
• Presents methods and tools used in the field, including electromyography, signal processing and spectral analysis, amongst others

• Language: English
• Publisher: Academic Press
• Release date: Mar 25, 2020
• ISBN: 9780128134405

Nicholas Stergiou

Dr. Nick Stergiou is the Chair of the Department of Biomechanics and the Distinguished Community Research Chair in Biomechanics and Professor as well as the Director of the Biomechanics Research Building and the Center for Research in Human Movement Variability at the University of Nebraska at Omaha where his primary appointment is. He is also a Professor of the Department of Environmental, Agricultural, and Occupational Health of the College of Public Health at the University of Nebraska Medical Center. His research focuses on understanding variability inherent in human movement. Dr. Stergiou’s research spans from infant development to older adult fallers, and has impacted training techniques of surgeons and treatment and rehabilitation techniques of pathologies, such as peripheral arterial disease. He has received more 30 million dollars in personal funding from NIH, NASA, NSF, the NIDRR/US Department of Education, and many other agencies and foundations. He has also several inventions and has procured a private donation of $6 million to build the 23,000 square feet Biomechanics Research Building that has opened in August of 2013. This is the first building dedicated to biomechanics research in the world. It is also the first building on his campus exclusively dedicated to research. He is an international authority in the study of Nonlinear Dynamics and has published more than 200 peer reviewed articles. He has written 2 books already, one for CRC Press.

Book preview

Biomechanics and Gait Analysis

Nick Stergiou

Department of Biomechanics, University of Nebraska at Omaha, Omaha, NE, United States

Table of Contents

Cover image

Title page

Copyright

Dedication

List of Figures

List of Contributors

Preface

Chapter 1. Introduction to biomechanics

Abstract

Contents

1.1 Introduction

1.2 The history of biomechanics

1.3 Areas of biomechanical inquiry: examples of diverse and unique questions in biomechanics

1.4 A quick look into the future of biomechanics

References

Suggested readings

Chapter 2. Basic biomechanics

Abstract

Contents

2.1 Introduction

2.2 Analysis of movement

2.3 Basic terminology for analyzing movement

2.4 Basic bio considerations

2.5 Basic mechanics considerations

2.6 Summary and concluding remarks

References

Further readings

Chapter 3. Advanced biomechanics

Abstract

Contents

3.1 Injuries and biomechanics

3.2 Biomechanical statistics

3.3 Final considerations

References

Chapter 4. Why and how we move: the Stickman story

Abstract

Contents

4.1 Briefly introducing Stickman

4.2 The Stickman’s evolution of movement

4.3 The Stickman’s performance of movement

4.4 The Stickman learns how to move

4.5 The Stickman’s mechanics

4.6 The Stickman’s goodbye

References

Chapter 5. Power spectrum and filtering

Abstract

Contents

5.1 Introduction

5.2 A simple composite wave

5.3 Spectral analysis

5.4 Fourier series

5.5 Discrete Fourier analysis

5.6 Stationarity and the discrete Fourier transform

5.7 Short-time discrete Fourier transform

5.8 Noise

5.9 Data filtering

5.10 Practical implementation

5.11 Conclusion

References

Chapter 6. Revisiting a classic: Muscles, Reflexes, and Locomotion by McMahon

Abstract

Contents

6.1 Introduction

6.2 Fundamental muscle mechanics

6.3 Muscle heat and fuel

6.4 Contractile proteins

6.5 Sliding movement: Huxley’s model revisited

6.6 Force development in the crossbridge

6.7 Reflexes and motor control

6.8 Neural control of locomotion

6.9 Mechanisms of locomotion

6.10 Effects of scale

6.11 Conclusion

References

Further reading

Chapter 7. The basics of gait analysis

Abstract

Contents

7.1 Introduction

7.2 The concept of skill

7.3 The skill of gait

7.4 Periods and phases of gait

7.5 Spatiotemporal parameters of gait

7.6 Determinants of gait

7.7 Conclusions

References

Further reading

Chapter 8. Gait variability: a theoretical framework for gait analysis and biomechanics

Abstract

Contents

8.1 Introduction

8.2 Conceptual approaches to gait variability

8.3 Gait analysis and biomechanical measurements for gait variability

8.4 Examples from clinical research

8.5 Future directions

References

Chapter 9. Coordination and control: a dynamical systems approach to the analysis of human gait

Abstract

Contents

9.1 Introduction

9.2 Hallmark properties of a dynamical system

9.3 A dynamical systems approach to gait analysis

9.4 Applications of relative phase dynamics to human gait

9.5 Summary and concluding remarks

References

Chapter 10. A tutorial on fractal analysis of human movements

Abstract

Contents

10.1 Introduction

10.2 Fractal theory and its connection to human movement

10.3 Fractal analysis of time series data

10.4 Applications to laboratory data

10.5 Conclusion

References

Chapter 11. Future directions in biomechanics: 3D printing

Abstract

Contents

11.1 Introduction

11.2 Lower extremity applications

11.3 Upper extremity applications

11.4 Methods for three-dimensional printing assistive devices

11.5 Anatomical modeling for surgical planning

11.6 Fracture casting

11.7 Upper extremity three-dimensional printed exoskeleton for stroke patients

11.8 Implementation of a three-dimensional printing research laboratory

11.9 Current Food and Drug Administration recommendations of three-dimensional printed medical devices

11.10 Limitations

11.11 Future perspectives

References

Index

Copyright

Academic Press is an imprint of Elsevier

125 London Wall, London EC2Y 5AS, United Kingdom

525 B Street, Suite 1650, San Diego, CA 92101, United States

50 Hampshire Street, 5th Floor, Cambridge, MA 02139, United States

The Boulevard, Langford Lane, Kidlington, Oxford OX5 1GB, United Kingdom

Copyright © 2020 Elsevier Inc. All rights reserved.

No part of this publication may be reproduced or transmitted in any form or by any means, electronic or mechanical, including photocopying, recording, or any information storage and retrieval system, without permission in writing from the publisher. Details on how to seek permission, further information about the Publisher’s permissions policies and our arrangements with organizations such as the Copyright Clearance Center and the Copyright Licensing Agency, can be found at our website: www.elsevier.com/permissions.

This book and the individual contributions contained in it are protected under copyright by the Publisher (other than as may be noted herein).

Notices

Knowledge and best practice in this field are constantly changing. As new research and experience broaden our understanding, changes in research methods, professional practices, or medical treatment may become necessary.

Practitioners and researchers must always rely on their own experience and knowledge in evaluating and using any information, methods, compounds, or experiments described herein. In using such information or methods they should be mindful of their own safety and the safety of others, including parties for whom they have a professional responsibility.

To the fullest extent of the law, neither the Publisher nor the authors, contributors, or editors, assume any liability for any injury and/or damage to persons or property as a matter of products liability, negligence or otherwise, or from any use or operation of any methods, products, instructions, or ideas contained in the material herein.

British Library Cataloguing-in-Publication Data

A catalogue record for this book is available from the British Library

Library of Congress Cataloging-in-Publication Data

A catalog record for this book is available from the Library of Congress

ISBN: 978-0-12-813372-9

For Information on all Academic Press publications visit our website at https://www.elsevier.com/books-and-journals

Publisher: Mara Conner

Acquisitions Editor: Fiona Geraghty

Editorial Project Manager: Lindsay Lawrence

Production Project Manager: Nirmala Arumugam

Cover Designer: Victoria Pearson

Typeset by MPS Limited, Chennai, India

Dedication

This book is dedicated to my mentors and all those people who helped me become the person I am.

List of Figures

List of Contributors

Barry T. Bates,     University of Oregon, Eugene, OR, United States

James T. Cavanaugh,     University of New England, Portland, ME, United States

Janet S. Dufek,     University of Nevada Las Vegas, Las Vegas, NV, United States

Aaron D. Likens,     University of Nebraska at Omaha, Omaha, NE, United States

Douglas A. Rowen,     University of Nebraska at Omaha, Omaha, NE, United States

Luis M. Silva,     University of Nebraska at Omaha, Omaha, NE, United States

Andreas Skiadopoulos,     University of Nebraska at Omaha, Omaha, NE, United States

Nick Stergiou,     University of Nebraska at Omaha, Omaha, NE, United States

Jorge M. Zuniga,     University of Nebraska at Omaha, Omaha, NE, United States

Preface

When you start on your journey to Ithaca, then pray that the road is long, full of adventure, full of knowledge. Do not fear the Lestrygonians and the Cyclopes and the angry Poseidon…

Always keep Ithaca fixed in your mind. To arrive there is your ultimate goal

From the poem Ithaca by Konstantinos Kavafis (1863–1933) who was an Egyptiote Greek poet, journalist, and civil servant.

Success in science is not easy. A scientist has to face many adversities, exactly like Odysseus, the hero of Homer’s epic poem the Odyssey, on his trip to Ithaca. The road to success will be laid with many Lestrygonians and Cyclopes. The sea will be rarely calm, and you may feel that Poseidon is always angry with you. However, the biomechanist has to face even more adversities than Odysseus, more adversities than other scientists, that make success even more difficult to achieve. This arises from the fact that biomechanics is a new science that the public does not fully understand. When I started at university in 1996, the term was not even in existence. The course that I was asked to teach was called applied kinesiology. It was I who changed its name to biomechanics a few years later to better reflect what was being taught. Just recently, I have seen the term being used in the scientific journal Science to describe a discipline and related articles. Often, I found myself describing my career under a different professional title (i.e., ergonomist and engineer) to help the other person to understand what I do. Even in the American Society of Biomechanics, we are not just members of the society, but we also declare where we come from (i.e., kinesiology and engineering). Despite its obscurity, biomechanics increasingly contributes many benefits to everyday life. A good example is the plethora of gait analysis laboratories found in hospital around the world. Gait analysis laboratories provide instrumental information regarding movement disorders in terms of diagnosis, treatment, progression of interventions, proper selection of an intervention, etc. The knowledge provided by these laboratories is exclusively based on biomechanics. Many of my former students work in gait analysis laboratories or perform gait analysis evaluations on their jobs, almost daily.

Therefore the first goal of this book was to assist readers to better understand my discipline, which I have served and loved for more than 30 years now. Of note is that I drive frequently on my vacations in Greece by the birthplace of the great Aristotle, who was born about an hour away from my hometown. The next time that I will do so, I will be able to stop by and, while I pay my respects, I could say to the father of our discipline that, through this book, I have done a small part in further building on his initial efforts. The second goal was to enhance communication between biomechanics and one of its major applications, namely, gait analysis. Many times, as we move from theory and education to practice, information is lost. This book makes an effort to bridge this gap and better assist the professionals and practitioners of gait analysis to better understand their scientific realm, as it relates to biomechanics. It also provides them with an arsenal of knowledge tools to improve their invaluable work. This is why every chapter has numerous examples that translate knowledge to the application of gait analysis.

The organization of our book is as follows.

The first chapter is an Introduction to Biomechanics. For the reader, it is Biomechanics 101. We define biomechanics as the study of forces that act on a body and the effects they produce. We describe how, in biomechanics, we study movement because we want to understand the underlying mechanisms of movement and to improve our understanding of the acquisition and regulation of skill. However, the uniqueness of biomechanics, as an area of study, evolves not from the unique body of knowledge but from the uniqueness of the questions we ask relative to understanding human movement. In this chapter, we also provide a historical perspective, as biomechanics can trace its origins to Aristotle who wrote the first textbook in biomechanics, but during the 20th century biomechanical research witnessed a scientific explosion fueled by the availability of appropriate technology. As such, it has influenced applications in industrial, medical, and other practical areas. Biomechanics evolved as a necessary science-based method for the study of human and animal movement.

In the second chapter, we present Basic Biomechanics. Completing Biomechanics 101 entitles you now to move to Biomechanics 201. In this chapter we cover the basic principles of biomechanics. We discuss the anatomical and mechanical principles that provide the basis for understanding and analyzing the various forms of human movement. We don’t intend to replace, with a single chapter, the large volume of biomechanics textbooks that have been published mostly for undergraduate courses. However, we want to introduce the reader to a fundamental understanding on how to develop the ability to link the structure of the human body with its function from a biomechanical perspective.

In the third chapter, we move beyond the basic principles of biomechanics and cover various special topics. This is Advanced Biomechanics or, in our reader’s curriculum, Biomechanics 301. We continue our journey into the understanding of anatomical and mechanical principles, and we take a closer look at analyzing the various forms of human movement through various examples and problems from biomechanics research.

Our beloved Stickman is the topic of our fourth chapter. The Stickman lives in every biomechanics laboratory. He is a simple man that is generated in biomechanical processing software. In this chapter, we offer Biomechanics 401, and, because our reader is now a senior, we use the Stickman as a model to overview selected aspects of human movement and performance in order to gain an appreciation of their complex interactions. We wish to assist the reader in developing skills in conceptual thinking and reasoning.

The fifth chapter focuses on a topic that is a common source of errors in biomechanics; filtering and smoothing. This was even acknowledged by the great David Winter, one of the modern pillars of our discipline, in terms of a book on signal processing. This chapter marks a departure from core courses of our sequence in biomechanics. The rest of our chapters will complete our reader’s curriculum with other fundamental courses. One is a solid understanding on Fourier transform, data sampling, spectral leakage, noise, digital filtering, smoothing, and time series processing. We strongly believe that biomechanists and gait analysts must understand the basic concepts of digital processing in order to be responsible users of commercial equipment and software.

In the sixth chapter, we revisit a classic as we provide a protracted summary of McMahon’s (1984) text entitled Muscles, Reflexes, and Locomotion. This text has educated several generations of biomechanists. Thus revisiting this foundational text allows our reader to reconnect with the classics and develop a strong historical background to the research performed in biomechanics. It is important that we educate ourselves, both in breadth and in depth. The reader will also note that, despite not being updated since the 1980s, the material we summarize broaches a number of topics with strong contemporary appeal, including coordination dynamics and robotics. The scope of McMahon’s book and his clear mastery of deep topics such as mathematics, biology, and mechanics of animal locomotion are difficult to summarize within the pages of a single chapter. In many instances, we refer the reader to the original text for richer historical context and more in-depth treatments of difficult topics. Although the content of the book is exceptional, many important scientific discoveries have been made in the time since this book was last published. Therefore, when possible and space allows, we point the reader to recent discoveries made in the intervening years.

Next, we cover the basic principles of gait analysis. In the seventh chapter, we discuss gait as a skill, along with the definition of motor skill, more generally; we define gait analysis; present the periods and the phases of gait; and identify the most important spatiotemporal parameters to evaluate during gait analysis. We explore two special cases, the first being step width and lateral stepping, and the second being stride/step time and gait variability; and we examine the determinants of gait. In addition, we present a few more advanced principles with respect to modeling, such as the dynamic walking method and the inverted pendulum.

Starting with Chapter 8, Gait variability: a theoretical framework for gait analysis and biomechanics, and continuing with Chapter 9, Coordination and control: a dynamical systems approach to the analysis of human gait and Chapter 10, A tutorial on fractal analysis of human movements, we provide the reader with a theoretical foundation and plenty of tools to ask important questions in the gait analysis laboratory and to supplement evaluations with essential knowledge of human movement variability. My mentor, Barry Bates, considers variability in human movement as one of the great mysteries of biomechanics and one domain that deserves much more attention in the laboratory. Thus in the eighth chapter we view gait as a variable and necessarily adaptable behavior. We quantify gait variability in terms of its amount and complexity, two distinct yet complementary facets of human gait that are associated with the health status of the performer, their stage of learning, the demands of a particular walking task, and the environmental conditions in which walking occurs. We also present measures of gait variability derived from theoretical assumptions about motor control that could provide rehabilitation professionals with a new generation of gait assessment tools and intervention approaches for clinical populations with walking limitations.

In the ninth chapter, we present the application of dynamical systems theory to the study of human movement and gait analysis. Our efforts focus on presenting both theory and practical suggestions regarding the analysis and interpretation of results. Moreover, we have demonstrated a major benefit in applying dynamical systems theory to human gait—simplicity. Our intention in constructing this chapter is to facilitate research in those domains, as we feel there is much revolutionary science yet to come from applying dynamical systems theory to the analysis of gait. Furthermore, we strongly advocate the use of this powerful investigative approach by scientists and clinicians that work in gait analysis laboratories or utilize gait analysis to understand the effects of various pathologies on human gait.

Moving into the tenth chapter, we present an introduction to fractal analysis of human movement data. Our approach avoids heavy mathematics and confusing jargon. Instead, we present the material in plain language and take care to define terms unique to fractal theory and analyses. To that end, we present basic ideas related to fractal theory and translate those ideas to fractal characteristics typical of human movement variability. In addition, we present an in-depth tutorial on one of the most common methods of fractal and multifractal analysis. We supplement our presentation with two complete examples demonstrating how to use these techniques in laboratory studies. We believe that our presentation will provide gait