Biology is the study of living things; mechanics is the study of motions and the applied loads that cause them. Biomechanics could be defined, therefore, as the study of motions experienced by living things in response to applied loads. Herein, however, we consider that biomechanics is the development, extension, and application of mechanics for the purposes of understanding better the influence of applied loads on the composition, structure, properties, and function of living things and the materials with which they interact. Applied loads can be chemical, electrical, and thermal, not just mechanical, which incorporates so-called chemomechanics, eletromechanics, and thermomechanics among other combinations. Thus, the domain of biomechanics is broad. It includes studying the effects of wind loads or gravity on the growth of plants, the mechanical properties of foodstuffs, the silk generated by spiders to weave a web, the drag-reducing properties of the skin of dolphins, and human athletic performance. Additionally, biomechanics addresses many issues of health as well as disease, injury, and their treatment in both humans and animals. These latter topics shall be our primary motivation herein; thus, it is easy to see that biomechanics is fundamental to biomedical engineering.