Leg stiffness is an important factor in human walking. Understanding the ways in which stiffness impacts walking could lead to improvements in gait rehabilitation, exoskeleton design, and exoskeleton control. Three studies were conducted to better understand the effects of stiffness on walking. The first study investigated how changing stiffness of the foot itself affects walking. To do this, a rigid foot plate was attached to the foot of 16 subjects in order to increase the stiffness of the foot. This is because many exoskeletons and orthoses use a rigid foot plate, but this may affect the natural mechanics of the foot. The resulting spatiotemporal parameters, kinematics, and kinetics were compared with normal walking. It was found that the foot plate did not have an effect on spatiotemporal parameters, but did decrease the ankle range of motion and decreased the intersegmental motion of the different parts of the foot. It was also found that a foot plate that ends before the toes has less of an effect than a foot plate that extends to the end of the toes. Therefore, exoskeletons and orthoses should implement a jointed toe segment or a shorter foot plate in order to increase the transparency of the device. For the second study, an ankle exoskeleton was developed with the requirement that it was capable of a versatile range of control modes, and was robust. Versatility is important for an exoskeleton because the type of rehabilitation a person may require can vary due to a number of factors. The exoskeleton must also be robust in uncertain environments because humans undergoing rehabilitation may act unpredictably. Therefore, a pneumatically powered exoskeleton was designed and controlled using sliding mode control. This exoskeleton is capable of position, force, and impedance control. Four subjects were used to test the performance of these controllers while following position and force trajectories. The tests showed that regardless of the behavior of the wearer, the exoskeleton acted appropriately and under an acceptable degree of error. This demonstrates that sliding mode control can be used to make exoskeletons capable of the versatility required for rehabilitation. Lastly, in the third study, the control of leg stiffness while walking was investigated. This was done by using human data from 12 subjects to extract system models and leg stiffness controllers for walking using three different methods and informed by the spring-loaded inverted pendulum model. The first method used ordinary least squares to linearize the system about a Poincaré section; the second linearized the spring-loaded inverted pendulum model and combined that with the results from the first method. The third method used the sparse identification of nonlinear dynamics procedure to identify linear combinations of nonlinear functions that describe the system. These methods were evaluated based on how well they predicted experimental data, and based on how well they controlled a spring-loaded inverted pendulum model walker in simulation. Results showed that all three methods resulted in similarly accurate models and controllers. Therefore, using human data in conjunction with data driven identification techniques may be used to reveal the mechanics of gait or to design robotic controllers for walking.

Paediatric Biomechanics and Motor Control brings together the very latest developmental research using biomechanical measurement and analysis techniques and is the first book to focus on biomechanical aspects of child development. The book is divided into four main sections – the biological changes in children; developmental changes in muscular force production; developmental changes in the biomechanics of postural control and fundamental motor skills and finally the applications of research into paediatric biomechanics and motor control in selected clinical populations. Written by a team of leading experts in paediatric exercise science, biomechanics and motor control from the UK, the US, Australia and Europe, the book is designed to highlight the key implications of this work for scientists, educators and clinicians. Each chapter is preceded by a short overview of the relevant theoretical concepts and concludes with a summary of the practical and clinical applications in relation to the existing literature on the topic. This book is important reading for any sport or exercise scientist, health scientist, physical therapist, sports coach or clinician with an interest in child development or health.

The revised edition of the definitive book on the mechanics, mysteries, and methods of upright walking The ability to walk upright on two legs is one of the major traits distinguishing us as humans, and yet the reasons for its development remain a mystery among scientists. In Born to Walk, author James Earls explores the mystery of walking's evolution by describing the complex mechanisms enabling us to be efficient in bipedal gait. Viewing the whole body as an interconnected unit, he explains how we can regain a flowing efficiency within our gait--an efficiency which is part of our natural design. Based on Thomas Myers's Anatomy Trains model of human anatomy, as well as the latest science in paleoanthropology, sports medicine, and anatomy, Earls's work demonstrates how the whole body collaborates in walking, and distills the complex actions into a simple sequence of "essential events" that engage the myofascia and utilize its full potential. The second and revised edition of this book provides bodyworkers, physical therapists and movement teachers with new research on assessment, diagnosis, and treatment approaches. Earls offers a convenient model for understanding the complexity of movement while gaining a deeper insight into the physiology and mechanics of the walking process. This book is designed for movement therapy practitioners, physiotherapists, osteopaths, chiropractors, massage therapists, and bodyworkers hoping to understand gait and its mechanics. It will also appeal to anyone with an interest in evolution and movement.

The ability to walk upright on two legs is one of the major traits that define us as humans; yet, scientists still aren't sure why we evolved to walk as we do. In Born to Walk, author James Earls explores the mystery of our evolution by describing in depth the mechanisms that allow us to be efficient in bipedal gait. Viewing the whole body as an interconnected unit, Earls explains how we can regain a flowing efficiency within our gait--an efficiency which, he argues, is part of our natural design. This book is designed for movement therapy practitioners, physiotherapists, osteopaths, chiropractors, massage therapists, and any bodyworker wishing to help clients by incorporating an understanding of gait and its mechanics. It will also appeal to anyone with an interest in evolution and movement. Drawing on recent research from paleoanthropology, sports science, and anatomy, Earls proposes a complete model of how the whole body cooperates in this three dimensional action. His work is based on Thomas Myers's Anatomy Trains model of human anatomy, a holistic view of the human body that emphasizes fascial and myofascial connections. Earls distills the complex action of walking into a simple sequence of "essential events" or actions that are necessary to engage the myofascia and utilize its full potential in the form of elastic energy. He explains the "stretch-shortening cycle"--the mechanism that is the basis for many normal human activities--and discusses how humans take advantage of isometric contractions, viscoelastic response, and elastic recoil to minimize calorie usage. This streamlined efficiency is what enabled our first ancestors to begin to migrate not only seasonally but also permanently to new lands, thereby expanding the natural resources available to us as a species.

Now part of a two-volume set, the fully revised and updated second edition of The Wiley-Blackwell Handbook of Infant Development, Volume 1: Basic Research provides comprehensive coverage of the basic research relating to infant development. Updated, fully-revised and expanded, this two-volume set presents in-depth and cutting edge coverage of both basic and applied developmental issues during infancy Features contributions by leading international researchers and practitioners in the field that reflect the most current theories and research findings Includes editor commentary and analysis to synthesize the material and provide further insight The most comprehensive work available in this dynamic and rapidly growing field

Biomechanics in Sport is a unique reference text prepared by the leading world experts in sport biomechanics. Over thirty chapters cover a broad spectrum of topics, ranging from muscle mechanics to injury prevention, and from aerial movement to wheelchair sport. The biomechanics of sports including running, skating, skiing, swimming, jumping in athletics, figure skating, ski jumping, diving, javelin and hammer throwing, shot putting, and striking movements are all explained.