Meeting Abstract
Extracellular connective tissues surround muscle fibers, fascicles, and whole muscles. They are arranged in complex, roughly helical patterns, and this arrangement allows them to play important roles transferring force between muscle fibers and facilitating whole muscle shape changes. The prevalence and organization of connective tissue varies considerably in different muscles, both within and across species, but the functional consequences of these structural variations are not well understood. A means of simplifying and modeling connective tissue morphology is needed, and we suggest that an appropriate theoretical framework for this already exists within the field of biomechanics. Helically-reinforced hydrostats represent a class of structures occurring in a huge variety of species; in the bodies of worms and sharks, in the tube feet of starfish, and in the roots of trees, among many other examples. Helical hydrostats have been thoroughly modeled, and share a number of structural characteristics with skeletal muscle. Both incorporate helically-arranged connective tissue fibers which surround and reinforce constant-volume fluid-filled structures, and both utilize alterations of collagen fiber geometry to accommodate changes in length and shape. Can mathematical models and theory developed for the study of helically-reinforced hydrostats be applied to the study of intramuscular connective tissue? We provide empirical support for geometric models of connective tissue which incorporate hydrostat-like elements, and explore the potential for these models to increase our understanding of passive tension and other fundamental mechanical properties of muscle.
