Fatigue responses of the human cervical spine intervertebral discs
| Autor: | Narayan Yoganandan, Brain Stemper, Bryan Snyder, Sagar Umale |
|---|---|
| Rok vydání: | 2017 |
| Předmět: |
Materials science
Finite Element Analysis Biomedical Engineering Work hardening medicine.disease_cause Weight-bearing Weight-Bearing Biomaterials 03 medical and health sciences 0302 clinical medicine medicine Humans Posterior longitudinal ligament Intervertebral Disc 030222 orthopedics Viscosity business.industry Intervertebral disc Structural engineering Compression (physics) Low back pain Finite element method Biomechanical Phenomena Longitudinal Ligaments medicine.anatomical_structure Mechanics of Materials Cervical Vertebrae Stress Mechanical medicine.symptom business 030217 neurology & neurosurgery Cervical vertebrae |
| Zdroj: | Journal of the Mechanical Behavior of Biomedical Materials. 69:30-38 |
| ISSN: | 1751-6161 |
| DOI: | 10.1016/j.jmbbm.2016.11.026 |
| Popis: | Numerous studies have been conducted since more than fifty years to understand the behavior of the human lumbar spine under fatigue loading. Applications have been largely driven by low back pain and human body vibration problems. The human neck also sustains fatigue loading in certain type of civilian occupational and military operational activities, and research is very limited in this area. Being a visco-elastic structure, it is important to determine the stress-relaxation properties of the human cervical spine intervertebral discs to enable accurate simulations of these structures in stress-analysis models. While finite element models have the ability to incorporate viscoelastic material definitions, data specific to the cervical spine are limited. The present study was conducted to determine these properties and understand the responses of the human lower cervical spine discs under large number of cyclic loads in the axial compression mode. Eight disc segments consisting of the adjacent vertebral bodies along with the longitudinal ligaments were subjected to compression, followed by 10,000 cycles of loading at 2 or 4Hz frequency by limiting the axial load to approximately 150 N, and subsequent to resting period, subjected to compression to extract the stress-relaxation properties using the quasi-linear viscoelastic (QLV) material model. The coefficients of the model and disc displacements as a function of cycles and loading frequency are presented. The disc responses demonstrated a plateauing effect after the first 2000 to 4000 cycles, which were highly nonlinear. The paper compares these responses with the "work hardening" phenomenon proposed in clinical literature for the lumbar spine to explain the fatigue behavior of the discs. The quantitative results in terms of QLV coefficients can serve as inputs to complex finite element models of the cervical spine to delineate the local and internal load-sharing responses of the disc segment. |
| Databáze: | OpenAIRE |
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