ABSTRACT
Determination of the constitutive properties and failure tolerances has been a principal activity of solid biomechanics for many years. Unlike engineering materials, however, the tissues and cellular structures of the body demonstrate uniquely challenging material behavior making the measurement of constitutive and failure properties difficult. In the face of these challenges a large experimental effort has occurred which has resulted in an increasingly accurate determination of the tensorial quantities upon which tissue properties and tolerances are dependent. In particular, the ability to measure stain in compliant, nonlinear, hydrated, biologic tissues has become particularly refined. Yet, the selection of the appropriate formulation of strain, and the techniques used to measure strain vary widely. In this chapter, we present an overview of these techniques with particular reference to the measurement of strain in muscle.
