Introduction
Charles Oxnard championed the use of statistical techniques to reduce a multitude of variables into a comprehendible pattern in order to demonstrate some aspect of primate behavior or evolution. In reality, Professor Oxnard's interests and writings have spanned an enormity and diversity of topics. By analogy, one might conclude that the “first principal component” of his work is reflected by the succinct statement on page 6 of his 1975 book, Uniqueness and Diversity in Human Evolution: “There is no doubt that the locomotor behavior of an animal is, on a gross level, controlled by the anatomy of the animal.” This point of departure for the research of many contributors to this volume, has influenced our own endeavor to understand how the internal morphology of a muscle itself, i.e., fiber architecture and histochemical fiber type composition, is associated with organ function and animal behavior. In this chapter, we consider the relationship of locomotor behavior, muscle function, and the fiber architecture of the gluteal and hamstring muscle groups.
Many classes of polymorphic variables determine the internal morphology of whole skeletal muscles. These include the relative composition of histo/immunocytochemical fiber types (see Chapter 7), neurological compartmentalization related to fascial partitioning (English, 1984) by the branching pattern of motoneurons (e.g., Herring et al., 1989, 1991), and the spatial arrangement of muscle fibers and tendons, otherwise known as fiber architecture (Gans and Bock, 1965; Gans, 1982; Richmond, 1998).