Biomechanical Properties of Skin

Epidermis has a thickness of 0.07 to 1.4 mm and serves to protect the body surface against physical and ultraviolet injury, to provide a barrier to water and chemicals, and to resist microbial penetration. The presence of disulfide bonds within the keratin layer and the desmosomal attachments between the epithelial cells give the epidermis mechanical strength and relative water impermeability. Studies of the effects o f water and emollients on skin indicate that epidermal hydration has a significant effect on maximum skin disten­ tion and accommodation to tension (1,2). Protective effects of melanin in maintaining skin extensibility and viscoelasticity have also been proposed (3).