Finite element modeling and experimental verification of lower extremity shape change under load

P. K. Commean, K. E. Smith, Michael W. Vannier, B. A. Szabo, R. L. Actis

Research output: Contribution to journalArticle

24 Scopus citations

Abstract

Prediction and measurement of residuum shape change inside the prosthesis under various loading conditions is important for prosthesis design and evaluation. Residual limb surface measurements with the prosthesis in situ were used for construction of a finite element model (FEM). These surface measurements were obtained from volumetric computed tomography. A new experimental method for modeling the shape of the in situ lower residual limb was developed based on spiral X-ray computed tomography (SXCT) imaging. The p-version of the finite element method was used for estimating the material properties from known load and displacement data. A homogeneous, isotropic, linear constitutive model with accommodation of the constitutive soft and hard tissues of the residuum was evaluated with static axial loading applied to the in situ prosthesis and compared with experimental results obtained in a human volunteer. Two FEMs were created for similar coronal cross sections of the below knee residuum under two loading conditions. Agreement between observed (from SXCT) and predicted (from FEA) residual limb shape changes inside the prosthesis were maximized with a single modulus of elasticity for the residuum soft tissue of 0.06 MPa, consistent with previously published results. This methodology provides a framework to predict and objectively evaluate FEMs and determine residuum material properties by inverse methods.

Original languageEnglish
Pages (from-to)531-536
Number of pages6
JournalJournal of Biomechanics
Volume30
Issue number5
DOIs
StatePublished - May 1 1997

Keywords

  • Anthropometry
  • Finite element modeling
  • Lower limb prosthetics
  • Material properties determination
  • Spiral computed tomography

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