An inverse finite-element model of heel-pad indentation

Ahmet Erdemir, Meredith L. Viveiros, Jan Ulbrecht, Peter R. Cavanagh

Research output: Contribution to journalArticle

103 Citations (Scopus)

Abstract

A numerical-experimental approach has been developed to characterize heel-pad deformation at the material level. Left and right heels of 20 diabetic subjects and 20 nondiabetic subjects matched for age, gender and body mass index were indented using force-controlled ultrasound. Initial tissue thickness and deformation were measured using M-mode ultrasound; indentation forces were recorded simultaneously. An inverse finite-element analysis of the indentation protocol using axisymmetric models adjusted to reflect individual heel thickness was used to extract nonlinear material properties describing the hyperelastic behavior of each heel. Student's t-tests revealed that heel pads of diabetic subjects were not significantly different in initial thickness nor were they stiffer than those from nondiabetic subjects. Another heel-pad model with anatomically realistic surface representations of the calcaneus and soft tissue was developed to estimate peak pressure prediction errors when average rather than individualized material properties were used. Root-mean-square errors of up to 7% were calculated, indicating the importance of subject-specific modeling of the nonlinear elastic behavior of the heel pad. Indentation systems combined with the presented numerical approach can provide this information for further analysis of patient-specific foot pathologies and therapeutic footwear designs.

Original languageEnglish (US)
Pages (from-to)1279-1286
Number of pages8
JournalJournal of Biomechanics
Volume39
Issue number7
DOIs
StatePublished - May 3 2006

Fingerprint

Heel
Indentation
Materials properties
Ultrasonics
Tissue
Pathology
Mean square error
Students
Finite element method
Calcaneus
Finite Element Analysis
Foot
Body Mass Index
Pressure

All Science Journal Classification (ASJC) codes

  • Biophysics
  • Orthopedics and Sports Medicine
  • Biomedical Engineering
  • Rehabilitation

Cite this

Erdemir, A., Viveiros, M. L., Ulbrecht, J., & Cavanagh, P. R. (2006). An inverse finite-element model of heel-pad indentation. Journal of Biomechanics, 39(7), 1279-1286. https://doi.org/10.1016/j.jbiomech.2005.03.007
Erdemir, Ahmet ; Viveiros, Meredith L. ; Ulbrecht, Jan ; Cavanagh, Peter R. / An inverse finite-element model of heel-pad indentation. In: Journal of Biomechanics. 2006 ; Vol. 39, No. 7. pp. 1279-1286.
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Erdemir, A, Viveiros, ML, Ulbrecht, J & Cavanagh, PR 2006, 'An inverse finite-element model of heel-pad indentation', Journal of Biomechanics, vol. 39, no. 7, pp. 1279-1286. https://doi.org/10.1016/j.jbiomech.2005.03.007

An inverse finite-element model of heel-pad indentation. / Erdemir, Ahmet; Viveiros, Meredith L.; Ulbrecht, Jan; Cavanagh, Peter R.

In: Journal of Biomechanics, Vol. 39, No. 7, 03.05.2006, p. 1279-1286.

Research output: Contribution to journalArticle

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