Mechanical behaviour of breast tissue: an in-depth systematic review

The breast holds significant importance in women's lactation process. The breast has diverse tissues such as glandular, Cooper’s ligament, lactiferous ducts, adipose, muscles, and skin with various mechanical properties. Most soft tissues exhibit nonlinear, viscoelastic, and anisotropic mechanical behaviour. Stiffness is one of the commonly used mechanical properties for measuring mechanical behaviour in soft tissues. However, this is typically used in simplifying cases where analysis is limited to within the linear elastic region. Young’s modulus is the prevailing measure for quantifying stiffness in tissues. This systematic review examines commonly used techniques for mechanically characterizing breast soft tissues to close the gap in the literature. Additionally, this systematic review summarizes the mechanical behaviour of the breast tissues available in the literature and highlights the uncovered areas to fully understand the mechanical behaviour of breast tissues. These include a) more mechanical behaviour studies, allowing more accurate mod-elling for other applications, b) viscoelastic analysis studies, c) mechanical analysis on other breast tissues, such as the lactiferous duct, also known as the milk duct. The data obtained in the review can be used as inputs in computational models to analyze the behaviour of the breast tissues.