Finite element investigation of the loading rate effect on the spinal load-sharing changes under impact conditions

Marwan El-Rich, Pierre Jean Arnoux, Eric Wagnac, Christian Brunet, Carl Eric Aubin

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147 Scopus citations


Sudden deceleration and frontal/rear impact configurations involve rapid movements that can cause spinal injuries. This study aimed to investigate the rotation rate effect on the L2-L3 motion segment load-sharing and to identify which spinal structure is at risk of failure and at what rotation velocity the failure may initiate? Five degrees of sagittal rotations at different rates were applied in a detailed finite-element model to analyze the responses of the soft tissues and the bony structures until possible fractures. The structural response was markedly different under the highest velocity that caused high peaks of stresses in the segment compared to the intermediate and low velocities. Under flexion, the stress was concentrated at the upper pedicle region of L2 and fractures were firstly initiated in this region and then in the lower endplate of L2. Under extension, maximum stress was located in the lower pedicle region of L2 and fractures started in the left facet joint, then they expanded in the lower endplate and in the pedicle region of L2. No rupture has resulted at the lower or intermediate velocities. The intradiscal pressure was higher under flexion and decreased when the endplate was fractured, while the contact forces were greater under extension and decreased when the facet surface was cracked. The highest ligaments stresses were obtained under flexion and did not reach the rupture values. The endplate, pedicle and facet surface represented the potential sites of bone fracture. Results showed that spinal injuries can result at sagittal rotation velocity exceeding 0.5°/ms.

Original languageBritish English
Pages (from-to)1252-1262
Number of pages11
JournalJournal of Biomechanics
Issue number9
StatePublished - 19 Jun 2009


  • Bone fracture
  • Finite-element analysis
  • High-speed impact
  • Injury
  • Lumbar spine
  • Stress


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