Title: Predicting pressure distribution between transfemoral prosthetic socket and residual limb using finite element analysis

Authors: Rajesh Surapureddy; Alexandra Schönning; Stephen Stagon; Alain Kassab

Addresses: Mechanical Engineering, University of North Florida, Room 2500 Building 50, 1-UNF Drive, Jacksonville, Florida-32224, USA ' Mechanical Engineering, University of North Florida, Room 2500 Building 50, 1-UNF Drive, Jacksonville, Florida-32224, USA ' Mechanical Engineering, University of North Florida, Room 2500 Building 50, 1-UNF Drive, Jacksonville, Florida-32224, USA ' Mechanical and Aerospace Engineering, University of Central Florida, Room 381 Building Engr. 1, P.O. Box 162450, Orlando, FL 32816-2450, USA

Abstract: A static implicit nonlinear finite element model (FEM) was created and analysed to determine the pressure distribution between the residual limb and the prosthetic socket of a transfemoral amputee. This analysis was performed in an attempt to develop a process allowing healthcare providers and engineers to simulate the fit and comfort of transfemoral prosthetics to reduce the number of re-fittings. The FEM considered the effects of donning and body weight and included geometric nonlinearity due to large deflections, nonlinear contacts due to friction, and nonlinear hyper-elastic material properties for the residual limb's soft tissue. The results attained can provide prosthetic fitting clinicians customised information on where the prosthetic fits too tight, and how stress concentrations would change as a result of geometric modifications to the prosthetic. This knowledge can improve patients' comfort levels by providing well targeted and more accurate modifications to the prosthetic, minimising the need for numerous refittings.

Keywords: transfemoral prosthetics; pressure distribution; finite element analysis; FEA; nonlinear modelling; contact analysis; hyper-elastic material properties; transfemoral prosthetic socket; residual limbs; transfemoral amputees; stress concentrations; patient comfort; deflections; friction; body weight.

DOI: 10.1504/IJECB.2016.081746

International Journal of Experimental and Computational Biomechanics, 2016 Vol.4 No.1, pp.32 - 48

Available online: 23 Jan 2017 *

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