Mechanical response of human female breast skin under uniaxial stretching

Abstract

Skin is a complex material covering the entire surface of the human body. Studying the mechanical properties of skin to calibrate a constitutive model is of great importance to many applications such as plastic or cosmetic surgery and treatment of skin-based diseases like decubitus ulcers. The main objective of the present study was to identify and calibrate an appropriate material constitutive model for skin and establish certain universal properties that are independent of patient-specific variability. We performed uniaxial tests performed on breast skin specimens freshly harvested during mastectomy. Two different constitutive models – one phenomenological and another microstructurally inspired – were used to interpret the mechanical responses observed in the experiments. Remarkably, we found that the model parameters that characterize dependence on previous maximum stretch (or preconditioning) exhibited specimen-independent universal behavior.

Characterization of human female breast and abdominal skin elasticity using a bulge test.

“…Several of these models treat the skin as an isotropic elastic material with a nonlinear response. Although, some of these models were capable of predicting the stiffening effect observed in experiments, they fail to represent the anisotropic behavior widely observed in experiments (Evans and Holt, 2009;Flynn et al, 2011b;Hendriks et al, 2006;Kumaraswamy et al, 2017). In previous work, our group examined the mechanical properties of female breast skin, but under uniaxial loading conditions (Kumaraswamy et al, 2017).…”

“…Mechanical properties of skin have been studied by a number of authors [see for example, porcine: (Khatam and Ravi-Chandar, 2013;Shergold et al, 2006); murine: (Muñoz et al, 2008); human: (Agache et al, 1980;Bischoff et al, 2000;Clark et al, 1996;Dunn and Silver, 1983;Hendriks et al, 2003;Kumaraswamy et al, 2017;Kvistedal and Nielsen, 2009;Reihsner and Menzel, 1996;Silver et al, 2001;Tonge et al, 2013aTonge et al, , 2013c; Wan Abas and Barbenel, 1982;Ní Annaidh et al, 2012b, 2012a; and rabbit Fung, 1974a, 1974b)]. These studies were motivated by different objectives such as understanding the mechanics of stabbing (McCarthy et al, 2010(McCarthy et al, , 2007, planning plastic surgery, dermatology, impact biomechanics (Gallagher et al, 2012;Ní Annaidh et al, 2012a), and designing devices that interact with the skin, such as shaving blades (Evans et al, 2013).…”

“…Although, some of these models were capable of predicting the stiffening effect observed in experiments, they fail to represent the anisotropic behavior widely observed in experiments (Evans and Holt, 2009;Flynn et al, 2011b;Hendriks et al, 2006;Kumaraswamy et al, 2017). In previous work, our group examined the mechanical properties of female breast skin, but under uniaxial loading conditions (Kumaraswamy et al, 2017). Two different constitutive models -one phenomenological (Hart-Smith, 1966) and another microstructurally inspired (Rausch and Humphrey, 2015) -were used to interpret the mechanical response observed in these experiments.…”

Do static and dynamic activities induce potentially damaging breast skin strain?

“…25 26 It is this collagen failure (occurring due to defibrillation) that signifies skin damage. 27 In healthy breast skin samples, Kumaraswamy et al 28 identified up to 58% strain without fibril damage. However, strain assessment was performed in vitro using a testing rig restricted to 58% strain.…”

“…In healthy breast skin samples, Kumaraswamy et al 28 identified up to 58% strain without fibril damage. However, strain assessment was performed in vitro using a testing rig restricted to 58% strain.…”