Shore hardness is a more representative measurement of bulk tissue biomechanics than of skin biomechanics.

Chatzistergos, Panagiotis E.; Allan, David; Chockalingam, Nachiappan; Naemi, Roozbeh

Abstract

To support the effective use of Shore hardness (SH) in research and clinical practice this study investigates whether SH should be interpreted as a measurement of skin or of bulk tissue biomechanics. A 3D finite element model of the heel and a validated model of a Shore-00 durometer were used to simulate testing for different combinations of stiffness and thickness in the skin and subcutaneous tissue. The results of this numerical analysis showed that SH is significantly more sensitive to changes in skin thickness, relatively to subcutaneous tissue, but equally sensitive to changes in the stiffness of either tissue. Indicatively, 25% reduction in skin thickness (0.3 mm thickness change) or in subcutaneous tissue thickness (5.9 mm thickness change), reduced SH by 7% or increased SH by 2% respectively. At the same time, 25% reduction in skin stiffness (10.1 MPa change in initial shear modulus) or of subcutaneous tissue (4.1 MPa change in initial shear modulus) led to 11% or 8% reduction in SH respectively. In the literature, SH is commonly used to study skin biomechanics. However, this analysis indicates that SH quantifies the deformability of bulk tissue, not of skin. Measurements of skin thickness are also necessary for the correct interpretation of SH.

Citation

Chatzistergos, P. E., Allan, D., Chockalingam, N., & Naemi, R. (2022). Shore hardness is a more representative measurement of bulk tissue biomechanics than of skin biomechanics. Medical Engineering and Physics, 105, 103816. https://doi.org/10.1016/j.medengphy.2022.103816

• Journal Article Type: Article
• Acceptance Date: May 5, 2022
• Publication Date: 2022-07
• Deposit Date: Apr 9, 2024
• Publicly Available Date: Apr 10, 2024
• Journal: Medical Engineering & Physics
• Print ISSN: 1350-4533
• Publisher: Elsevier
• Peer Reviewed: Peer Reviewed
• Volume: 105
• Pages: 103816
• DOI: https://doi.org/10.1016/j.medengphy.2022.103816
• Keywords: Biomedical Engineering; Biophysics
• Additional Information: This article is maintained by: Elsevier; Article Title: Shore hardness is a more representative measurement of bulk tissue biomechanics than of skin biomechanics.; Journal Title: Medical Engineering & Physics; CrossRef DOI link to publisher maintained version: https://doi.org/10.1016/j.medengphy.2022.103816; Content Type: article; Copyright: © 2022 The Author(s). Published by Elsevier Ltd on behalf of IPEM.