Human skin as an elastic membrane

The equations governing the deformation of human skin are derived. First, the equations of an anisotropic, elastic membrane undergoing large deformations are recorded. Next, the kinematical condition is derived which restricts the skin to slide over the surface of a rigid foundation. Last, stress-strain relations are proposed which fit the known experimental data for skin. As a special case of this theory, the equations of a simple model for the flexure of a joint are solved. In another special case of the theory, the equations of a homogeneous, isotropic, elastic membrane lying in a plane and undergoing small deformations are solved by complex variable techniques for the case of a large sheet having a circular hole and subject to biaxial tension at infinity. Finally, some problems of interest to physicians and plastic surgeons are discussed.