Abstract

The purpose of this book is to explore the mechanical bases of musculoskeletal injury in order to better understand the mechanisms involved in causing the injury, the effect of injury on musculoskeletal tissues, and ultimately, based on our current knowledge of biomechanics, how injury might be prevented. Chapter 1 gives an introduction to biomechanics as an interdiscipline and explores the mechanical aspects of injury, briefly assessing the prevalence of injury in the society and the physical, monetary, and emotional costs which result. Chapter 2 establishes the structural foundation necessary to appreciate both the normal function of the human musculoskeletal system and how injury may affect this function. Included is a brief discussion of embryology and tissue development and how these processes play a role in determining the morphology and mechanical behavior of the mature human structure. Highlighted are the details of particular connective tissues (bone, cartilage, tendon, and ligament) which are most often involved in injuries of the musculoskeletal system. Chapter 2 concludes with an examination of arthrology, or joint mechanics. Chapter 3 presents the basic biomechanical concepts essential for a greater understanding of injury mechanics. These mechanical parameters, such as force, stress and strain, stiffness, and elasticity, are examined in the context of connective tissue injuries. Although mathematics is inextricably intertwined with biomechanics, mathematical calculations are kept to a minimum, emphasizing instead the concepts on which the mechanics of the phenomena are based. Chapter 4 integrates the topics presented in earlier chapters and elucidates how connective tissues respond to mechanical loading, in both normal and abnormal environments, and how these tissues are tested experimentally to quantify their mechanical behavior. A multitude of factors affect the musculoskeletal systems responses when forces are applied to tissues. A collection of these factors, such as age, gender, nutrition, and exercise are discussed with emphasis on how an individual might, with an understanding of the responses involved, intervene to lessen the chance or severity of injury. With a foundation in the scientific bases of tissue structure and function in place, we progress, in chapter 5, to the exploration of injury mechanisms. Beginning with a general discussion of injury concepts (such as acute versus chronic loading, and modes of tissue failure), we continue with a regionally based sample of common injuries, emphasizing for each the mechanical aspects of the injury. We begin with the lower extremity (chapter 6), looking in detail at injuries such as inversion ankle sprains, stress fractures, compartment syndromes, and meniscal tears. Subsequent chapters examine injuries of the upper extremity (chapter 7) (e.g., rotator cuff tears, impingement syndrome, epicondylar stress syndromes, carpal tunnel syndrome), and head, neck, and trunk (chapter 8) (e.g., concussion, intervertebral disc injury). Understanding the mechanical responses of biological tissues and the associated injury mechanisms will assist our efforts in reducing the chances that we may fall victim to that third inevitability in life: physical injury. aus dem Vorwort