Biomechanics is often defined as “mechanics applied to biology” (Fung 1993). Although this is certainly true, it is hoped that the reader now appreciates that biomechanics can and must be much more. Because of the complexity of tissue structure and behavior, there is a need for new, sophisticated theoretical frameworks; because of the continuing lack of data, there is a need for new, clever experiments; because of the geometric complexity of cells, tissues, and organs and their interactions, there is a need for robust computational methods; and because of the significant morbidity and mortality that results from disease and injury, there is a need for improved biomechanically based modalities for diagnosis and treatment. Clearly, we must continue to expand the scope of biomechanics to seek new concepts, postulates, technologies, and techniques upon which rigorous understanding can be based. Biomechanics is thus better defined as the development, extension, and application of mechanics to answer problems of importance in biology and medicine. Biomechanics is a vibrant field—one with continuing promise.