The objective of this study is the development and testing of a quantitative optical model of striated muscle for the purpose of distinguishing between different mechano-chemical transduction mechanisms. The birefringence properties of striated muscle will be determined under a variety of experimental conditions in which the constituent components of muscle are either organized, constrained or removed in a well defined manner. The optical model will then be used to interpret the birefringence properties of muscle in terms of parameters which are important for a quantitative description of the mechano-chemical transduction process. The extension of these studies to smooth muscle is also contemplated. A full understanding of how chemical energy is converted into work during muscle contraction is important in many areas of physiology and medicine.