Introduction to the Symposium: Muscle Properties and Organismal Function: Shifting Paradigms

Movement is fundamental to survival and reproduction of all animals. Most animals must possess the machinery to support and move organelles, cells, parts of the organism, and the entire organism. In multicellular animals support and movement are accomplished by specialized tissues, including, muscles, bones, tendons, and other connective tissues. These tissues must operate as integrated components to provide appropriate functional capabilities to the system. The symposium from which the following several papers are drawn focused on muscle. However the basic philosophy that brought the participants together was that muscle function must be integrated into the context of the multiple systems that are needed to accomplish movement. Only with an integrated approach can we hope to understand the specialization of muscle by natural selection to suit its function in vivo. We are now the beneficiaries of several centuries of investigation into the details of muscle function, with particularly important insight coming in the past 70 years. A change in our understanding of muscle function began in the early part of this century with the pioneering experimental analyses of A. V. Hill. This work denned the basic contractile properties of muscles at a phenomenological level (Hill, 1922, 1938, 1949, 1951, 1965, 1970). In the middle of this century, the understanding of underlying cellular and molecular aspects of muscle function was altered substantially with the introduction of the sliding-filament model (Huxley and Niedergerke, 1954; Huxley and Hanson, 1954). The perspective 1 From the symposium Muscle Properties and Or