0
Research Papers

Material Properties of the Axillary Pouch of the Glenohumeral Capsule: Is Isotropic Material Symmetry Appropriate?

[+] Author and Article Information
Eric J. Rainis, Patrick J. McMahon

Musculoskeletal Research Center, Department of Bioengineering, University of Pittsburgh, Pittsburgh, PA 15219

Steve A. Maas, Heath B. Henninger, Jeffrey A. Weiss

Musculoskeletal Research Laboratories, Department of Bioengineering, and Scientific Computing and Imaging Institute, University of Utah, Salt Lake City, UT 84112

Richard E. Debski

Musculoskeletal Research Center, Department of Bioengineering, University of Pittsburgh, Pittsburgh, PA 15219genesis1@pitt.edu

J Biomech Eng 131(3), 031007 (Jan 06, 2009) (7 pages) doi:10.1115/1.3005169 History: Received October 22, 2007; Revised August 18, 2008; Published January 06, 2009

Inconclusive findings regarding the collagen fiber architecture and the material properties of the glenohumeral capsule make it unclear whether the material symmetry of the glenohumeral capsule is isotropic or anisotropic. The overall objective of this work was to use a combined experimental and computational protocol to characterize the mechanical properties of the axillary pouch of the glenohumeral capsule and to determine the appropriate material symmetry. Two perpendicular tensile and finite simple shear deformations were applied to a series of tissue samples from the axillary pouch of the glenohumeral capsule. An inverse finite element optimization routine was then used to determine the material coefficients for an isotropic hyperelastic constitutive model by simulating the experimental conditions. There were no significant differences between the material coefficients obtained from the two perpendicular tensile deformations or finite simple shear deformations. Furthermore, stress-stretch relationships predicted by utilizing the material coefficients from one direction were able to predict the responses of the same tissue sample in the perpendicular direction. These similarities between the longitudinal and transverse material behaviors of the tissue imply that the capsule may be considered an isotropic material. However, differences did exist between the material coefficients obtained from the tensile and shear loading conditions. Therefore, a more advanced constitutive model is needed to predict both the tensile and shear responses of the material.

FIGURES IN THIS ARTICLE
<>
Copyright © 2009 by American Society of Mechanical Engineers
Your Session has timed out. Please sign back in to continue.

References

Figures

Grahic Jump Location
Figure 1

(a) Anterior and (b) posterior view of the glenohumeral capsule. The following structures are shown: (1) anterior band, (2) axillary pouch, and (3) posterior band of the inferior glenohumeral ligament.

Grahic Jump Location
Figure 2

Mechanical testing setup for (a) tensile and (b) shear loading conditions showing the load cell and clamp relationships

Grahic Jump Location
Figure 3

Flowchart of the inverse finite element methodology (9) utilized to determine the material coefficients for the isotropic constitutive model

Grahic Jump Location
Figure 4

Representative load-elongation curve of tensile loading condition

Grahic Jump Location
Figure 5

Representative load-elongation curve of shear loading condition

Grahic Jump Location
Figure 6

Average stress-stretch curves for tensile loading conditions

Grahic Jump Location
Figure 7

Average stress-deformation curves for shear loading conditions

Tables

Errata

Discussions

Some tools below are only available to our subscribers or users with an online account.

Related Content

Customize your page view by dragging and repositioning the boxes below.

Related Journal Articles
Related eBook Content
Topic Collections

Sorry! You do not have access to this content. For assistance or to subscribe, please contact us:

  • TELEPHONE: 1-800-843-2763 (Toll-free in the USA)
  • EMAIL: asmedigitalcollection@asme.org
Sign In