0
Research Papers

A Female Ligamentous Cervical Spine Finite Element Model Validated for Physiological Loads

[+] Author and Article Information
Jonas Östh

Department of Applied Mechanics,
Chalmers University of Technology,
Gothenburg SE-412 96, Sweden
e-mail: jonas.osth@chalmers.se

Karin Brolin

Department of Applied Mechanics,
Chalmers University of Technology,
Gothenburg SE-412 96, Sweden
e-mail: karin.brolin@chalmers.se

Mats Y. Svensson

Department of Applied Mechanics,
Chalmers University of Technology,
Gothenburg SE-412 96, Sweden
e-mail: mats.svensson@chalmers.se

Astrid Linder

Statens väg-och Transportforskningsinstitut (VTI),
Gothenburg SE-402 78, Sweden
e-mail: astrid.linder@vti.se

1Corresponding author.

Manuscript received September 1, 2015; final manuscript received March 8, 2016; published online May 2, 2016. Assoc. Editor: Joel D. Stitzel.

J Biomech Eng 138(6), 061005 (May 02, 2016) (9 pages) Paper No: BIO-15-1432; doi: 10.1115/1.4032966 History: Received September 01, 2015; Revised March 08, 2016

Mathematical cervical spine models allow for studying of impact loading that can cause whiplash associated disorders (WAD). However, existing models only cover the male anthropometry, despite the female population being at a higher risk of sustaining WAD in automotive rear-end impacts. The aim of this study is to develop and validate a ligamentous cervical spine intended for biomechanical research on the effect of automotive impacts. A female model has the potential to aid the design of better protection systems as well as improve understanding of injury mechanisms causing WAD. A finite element (FE) mesh was created from surface data of the cervical vertebrae of a 26-year old female (stature 167 cm, weight 59 kg). Soft tissues were generated from the skeletal geometry and anatomical literature descriptions. Ligaments were modeled with nonlinear elastic orthotropic membrane elements, intervertebral disks as composites of nonlinear elastic bulk elements, and orthotropic anulus fibrosus fiber layers, while cortical and trabecular bones were modeled as isotropic plastic–elastic. The model has geometrical features representative of the female cervical spine—the largest average difference compared with published anthropometric female data was the vertebral body depth being 3.4% shorter for the model. The majority the cervical segments compare well with respect to biomechanical data at physiological loads, with the best match for flexion–extension loads and less biofidelity for axial rotation. An average female FE ligamentous cervical spine model was developed and validated with respect to physiological loading. In flexion–extension simulations with the developed female model and an existing average male cervical spine model, a greater range of motion (ROM) was found in the female model.

FIGURES IN THIS ARTICLE
<>
Copyright © 2016 by ASME
Your Session has timed out. Please sign back in to continue.

References

Figures

Grahic Jump Location
Fig. 1

Cervical spine model overview, from T1 to the base of the skull (left); lower cervical spine structure (middle); internal ligaments of the UCS (right). In the close-up views, some parts of the model have been blanked out for visibility.

Grahic Jump Location
Fig. 2

Flexion–extension ROM for all segments compared with experimental data from the study by Nightingale et al. [57]. Vertical bars indicate SDs for the experimental data. Lower row markers indicate FE model motion segment data. The C4C5 response is included in both (a) and (b).

Grahic Jump Location
Fig. 3

ROM at 1 Nm torque for (a) lateral bending and (b) axial rotation. All model segments in comparison with experimental data from Panjabi et al. [58]. Vertical bars indicate SDs for the experimental data.

Grahic Jump Location
Fig. 4

LCS segment compliance. Vertical error bars indicate SDs for the data measured by Panjabi et al. [59], representing the average of 18 functional spine units from the all levels of the cervical spine. AS, anterior shear; PS, posterior shear; LS, lateral shear; Tens, tension; Comp = compression.

Grahic Jump Location
Fig. 5

Flexion–extension ROM at 1 Nm for the female cervical spine model and of a 50th percentile male model [13,60,61]. The female model has larger ROM at all cervical levels except the C7T1 level.

Grahic Jump Location
Fig. 6

Flexion–extension response for OCC2, C3C4, and C7T1, showing the nonlinear segment response with low resistance around the initial position. For the C3C4 segment, one simulation with a linear elastic material model for the ligaments is included to visualize how the neutral zone is coupled to the toe-region of the ligaments.

Grahic Jump Location
Fig. 7

Verification of LCS ligaments in comparison with average characteristic curves derived by Mattucci et al. [45]

Grahic Jump Location
Fig. 8

Verification of UCS ligaments. Markers indicate experimental data (Exp.) from Mattucci et al. [46] and for the alar and apical ligaments average values scaled with failure force reported by Myklebust et al. [51]. The solid lines connecting markers are the curves fitted to the data. For the AAAM in panel (c), the AAOM curve was used as basis for the material model.

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