This dissertation investigated the role of biomechanics in two physiological systems, the heart and bone. Biomechanics motivates the study and characterization of how cells sense external forces and convert these signals into an intracellular response in a process called mechanotransduction. Three independent studies were designed with the goal of applying mechanical forces that mimic the in vivo microenvironment of either the heart or bone. The aim of these studies was to better under the mechanisms driving cellular processes, including cardiac myocyte differentiation and osteoblast mechanotransduction. The first study presents the design and implementation of tissue engineering approach to stem cell-based myocardial therapy. Three dimensional engineered heart tissue was formed by suspending human embryonic stem cell-derived cardiac myocytes isolated from beating embryoid bodies in a soluble extracellular matrix, and an in vitro mechanical conditioning regimen was applied at physiological levels of myocardial strain. The viability of the engineered stem cell tissue was monitored in vitro and in vivo for up to 8 weeks using molecular imaging of reporter gene activity. The application of cyclic mechanical strain in vitro resulted in cellular alignment along the axis of strain and an elongated cellular morphology with a high nuclear to cytoplasmic ratio, typical of neonatal cardiac myocytes, as well as increased expression of cardiac troponin I, in comparison to static controls. Analysis of the in vitro and in vivo bioluminescence imaging data demonstrated the viability of engineered heart tissue constructs; however, histology results showed immature cells within the implanted constructs, suggesting an inability of the stem cell-derived cardiac precursors to maintain a cardiac phenotype in vivo, as well the inherent inefficiency of the beating embryoid body method to identify and isolate cardiac myocyte precursors. The functional shortcomings exhibited by the embryoid body-based differentiation of embryonic stem cell-derived cardiac myocytes in the first study motivated further refinement of cardiac myocyte differentiation techniques. Therefore, the second study executed the design and fabrication of a microelectromechanical platform to study the role of electrical and mechanical stimulation in cardiac myocyte differentiation. The fabrication process used a combination of soft lithography and traditional microfabrication techniques to pattern thin film metal electrodes on an elastomeric polymer membrane. The completed device enabled coupled characterization and imaging of cardiac myocytes precursors, and the ability to assess the range of mechanical forces, up to 10% equibiaxial strain, that may induce or maintain a cardiac fate. Electrical continuity was demonstrated under static conditions but not under strain, and improvements in metal deposition and adhesion could address this performance defect. Beating clusters containing human embryonic stem cell-derived cardiac myocytes were plated on fabricated membranes, uncoated and coated with Matrigel, and cell viability was monitored using contrast microscopy. The third study transitioned to a different mechanical model of physiological forces, which was the application of oscillatory fluid flow-mediated fluid shear stress generated by the loading and unloading of bone. Specifically, the role of focal adhesion kinase, a protein tyrosine kinase recruited at focal adhesions and a major mediator of integrin signaling pathways, was studied in osteoblast mechanotransduction. The biochemical and transcriptional response of focal adhesion kinase mutant osteoblasts to physiological levels of shear stress induced by oscillatory fluid flow was impaired as measured by prostaglandin E2 release and cyclooxygenase-2 gene expression. Restoration of focal adhesion kinase expression with site-specific mutations at two tyrosine phosphorylation sites demonstrated that phosphorylation events play a role in prostaglandin release following oscillatory fluid flow. In conclusion, the role of mechanical forces, including the effect of cyclic mechanical strain in human embryonic stem cell-derived cardiac myocyte tissue engineering and the fluid shear stress-induced response of focal adhesion kinase mutant osteoblasts, was successfully demonstrated and quantified in this dissertation.

Every year workers' low-back, hand, and arm problems lead to time away from jobs and reduce the nation's economic productivity. The connection of these problems to workplace activities-from carrying boxes to lifting patients to pounding computer keyboards-is the subject of major disagreements among workers, employers, advocacy groups, and researchers. Musculoskeletal Disorders and the Workplace examines the scientific basis for connecting musculoskeletal disorders with the workplace, considering people, job tasks, and work environments. A multidisciplinary panel draws conclusions about the likelihood of causal links and the effectiveness of various intervention strategies. The panel also offers recommendations for what actions can be considered on the basis of current information and for closing information gaps. This book presents the latest information on the prevalence, incidence, and costs of musculoskeletal disorders and identifies factors that influence injury reporting. It reviews the broad scope of evidence: epidemiological studies of physical and psychosocial variables, basic biology, biomechanics, and physical and behavioral responses to stress. Given the magnitude of the problem-approximately 1 million people miss some work each year-and the current trends in workplace practices, this volume will be a must for advocates for workplace health, policy makers, employers, employees, medical professionals, engineers, lawyers, and labor officials.

Cowin (New York Center for Biomedical Engineering) and Humphrey (biomedical engineering, Texas A&M U.) present seven papers that discuss current research and future directions. Topics concern tissues within the cardiovascular system (arteries, the heart, and biaxial testing of planar tissues such as heart valves). Themes include an emphasis on data on the underlying microstructure, especially collagen; the consideration of the fact that both arteries and the heart contain muscle and that there is, therefore, a need to quantify both the active and passive response; constitutive relations for active behavior; and the growth and remodeling of cardiovascular tissues. Of interest to cardiovascular and biomechanics soft tissue researchers, and bioengineers. Annotation copyrighted by Book News, Inc., Portland, OR.

Biomechanics is concerned with the response of living matter to forces, and its study has taken long strides in recent years. In the past two decades, biomechanics has brought improved understanding of normal and patho physiology of organisms at molecular, cellular, and organ levels; it has helped developing medical diagnostic and treatment procedures; it has guided the design and manufacturing of prosthesis and instruments; it has suggested the means for improving human performance in the workplace, sports, and space; it has made us understand trauma in war and in peace. Looking toward the future, we see many more areas of possible development such as: reduction in heart diseases and atherosclerosis improved vascular assist and replacement devices, including a permanent artifical heart enhanced oxygen transport in the lung understanding and control of growth and changes mechanics of neuromuscular control and robotics prevention of joint degeneration permanent total joint replacements prevention of low back pain workplace designs to enhance productivity ambulation systems for the handicapped fully implantable hearing aids improved understanding of the mechanisms for permanent disability injuries identification of factors such as alcohol use and disease influence on impact tolerance improved cellular bioreactor designs mechanics of DNA and its application in biotechnology. * Obviously, the attainment of these prospects will greatly improve the quality of human life and reduce the costs of living. * This list is from a report by the U. S. National Committee on Biomechanics, April, 1985.

The motivation for writing aseries ofbooks on biomechanics is to bring this rapidly developing subject to students of bioengineering, physiology, and mechanics. In the last decade biomechanics has become a recognized disci pline offered in virtually all universities. Yet there is no adequate textbook for instruction; neither is there a treatise with sufficiently broad coverage. A few books bearing the title of biomechanics are too elementary, others are too specialized. I have long feIt a need for a set of books that will inform students of the physiological and medical applications of biomechanics, and at the same time develop their training in mechanics. We cannot assume that all students come to biomechanics already fully trained in fluid and solid mechanics; their knowledge in these subjects has to be developed as the course proceeds. The scheme adopted in the present series is as follows. First, some basic training in mechanics, to a level about equivalent to the first seven chapters of the author's A First Course in Continuum Mechanics (Prentice-Hall,lnc. 1977), is assumed. We then present some essential parts of biomechanics from the point of view of bioengineering, physiology, and medical applications. In the meantime, mechanics is developed through a sequence of problems and examples. The main text reads like physiology, while the exercises are planned like a mechanics textbook. The instructor may fil1 a dual role: teaching an essential branch of life science, and gradually developing the student's knowledge in mechanics.

This is a comprehensive and accessible overview of what is known about the structure and mechanics of bone, bones, and teeth. In it, John Currey incorporates critical new concepts and findings from the two decades of research since the publication of his highly regarded The Mechanical Adaptations of Bones. Crucially, Currey shows how bone structure and bone's mechanical properties are intimately bound up with each other and how the mechanical properties of the material interact with the structure of whole bones to produce an adapted structure. For bone tissue, the book discusses stiffness, strength, viscoelasticity, fatigue, and fracture mechanics properties. For whole bones, subjects dealt with include buckling, the optimum hollowness of long bones, impact fracture, and properties of cancellous bone. The effects of mineralization on stiffness and toughness and the role of microcracking in the fracture process receive particular attention. As a zoologist, Currey views bone and bones as solutions to the design problems that vertebrates have faced during their evolution and throughout the book considers what bones have been adapted to do. He covers the full range of bones and bony tissues, as well as dentin and enamel, and uses both human and non-human examples. Copiously illustrated, engagingly written, and assuming little in the way of prior knowledge or mathematical background, Bones is both an ideal introduction to the field and also a reference sure to be frequently consulted by practicing researchers.

Biomechanics is a component of Encyclopedia of Physical Sciences, Engineering and Technology Resources in the global Encyclopedia of Life Support Systems (EOLSS), which is an integrated compendium of twenty one Encyclopedias. The enormous progress in the field of health sciences that has been achieved in the 19th and 20th centuries would have not been possible without the enabling interaction and support of sophisticated technologies that progressively gave rise to a new interdisciplinary field named alternatively as bioengineering or biomedical engineering. Although both terms are synonymous, the latter is less general since it limits the field of application to medicine and clinical practice, while the former covers semantically the whole field of interaction between life sciences and engineering, thus including also applications in biology, biochemistry or the many '-omics'. We use in this book the second, with more general meaning, recalling the very important relation between fundamental science and engineering. And this also recognizes the tremendous economic and social impacts of direct application of engineering in medicine that maintains the health industry as one with the fastest growth in the world economy. Biomechanics, in particular, aims to explain and predict the mechanics of the different components of living beings, from molecules to organisms as well as to design, manufacture and use of any artificial device that interacts with the mechanics of living beings. It helps, therefore, to understand how living systems move, to characterize the interaction between forces and deformation along all spatial scales, to analyze the interaction between structural behavior and microstructure, with the very important particularity of dealing with adaptive systems, able to adapt their internal structure, size and geometry to the particular mechanical environment in which they develop their activity, to understand and predict alterations in the mechanical function due to injuries, diseases or pathologies and, finally, to propose methods of artificial intervention for functional diagnosis or recovery. Biomechanics is today a very highly interdisciplinary subject that attracts the attention of engineers, mathematicians, physicists, chemists, material specialists, biologists, medical doctors, etc. They work in many different topics from a purely scientific objective to industrial applications and with an increasing arsenal of sophisticated modeling and experimental tools but always with the final objectives of better understanding the fundamentals of life and improve the quality of life of human beings. One purpose in this volume has been to present an overview of some of these many possible subjects in a self-contained way for a general audience. This volume is aimed at the following major target audiences: University and College Students, Educators, Professional Practitioners, and Research Personnel.

This textbook describes the biomechanics of bone, cartilage, tendons and ligaments. It is rigorous in its approach to the mechanical properties of the skeleton yet it does not neglect the biological properties of skeletal tissue or require mathematics beyond calculus. Time is taken to introduce basic mechanical and biological concepts, and the approaches used for some of the engineering analyses are purposefully limited. The book is an effective bridge between engineering, veterinary, biological and medical disciplines and will be welcomed by students and researchers in biomechanics, orthopedics, physical anthropology, zoology and veterinary science. This book also: Maximizes reader insights into the mechanical properties of bone, fatigue and fracture resistance of bone and mechanical adaptability of the skeleton Illustrates synovial joint mechanics and mechanical properties of ligaments and tendons in an easy-to-understand way Provides exercises at the end of each chapter

Traditionally, applications of biomechanics will model system-level aspects of the human body. As a result, the majority of technological progress to date appears in system-level device development. More recently, biomechanical initiatives are investigating biological sub-systems such as tissues, cells, and molecules. Fueled by advances in experime

This book provides a balanced presentation of the fundamental principles of cardiovascular biomechanics research, as well as its valuable clinical applications. Pursuing an integrated approach at the interface of the life sciences, physics and engineering, it also includes extensive images to explain the concepts discussed. With a focus on explaining the underlying principles, this book examines the physiology and mechanics of circulation, mechanobiology and the biomechanics of different components of the cardiovascular system, in-vivo techniques, in-vitro techniques, and the medical applications of this research. Written for undergraduate and postgraduate students and including sample problems at the end of each chapter, this interdisciplinary text provides an essential introduction to the topic. It is also an ideal reference text for researchers and clinical practitioners, and will benefit a wide range of students and researchers including engineers, physicists, biologists and clinicians who are interested in the area of cardiovascular biomechanics.