ABSTRACT
Musculoskeletal mechanics occur over many length scales, from macroscopic muscle extension and weight-bearing bone compression to microscopic muscle bers, down to the cytoskeleton that supports the bone cell structure and facilitates muscle cell contraction. At each length scale, the surrounding environment can play a critical role in modulating the mechanical behavior; this is especially true at the cellular and the subcellular length scales wherein the intrinsic properties of the environment, that is, composition, structure, and elasticity of adjacent extracellular proteins, can modulate cell behavior and the transduction of their signals. Passive properties “felt” by cells via actomyosin contractions occur using many varied mechanisms and invoke a wide range of cell responses, that is, the induction of gene expression through calcication. This area has been a signicant focus of research in musculoskeletal cell mechanics over the past decade. However, the inverse case in which solid and shear stresses are actively applied to these systems has also been a source of much enthusiasm. To appreciate the breadth of the understanding of musculoskeletal cell mechanics as well as the open questions in the eld, this chapter provides an introductory review of musculoskeletal structures, followed by a presentation of the recent literature on mechanotransduction, for both bone and muscle.
