Intervertebral disc flexibility is influenced by lifestyle, loading history, trauma, preexisting conditions, age and degeneration. With regard to degeneration, intervertebral discs become less flexible and stiffer. In...Intervertebral disc flexibility is influenced by lifestyle, loading history, trauma, preexisting conditions, age and degeneration. With regard to degeneration, intervertebral discs become less flexible and stiffer. In this study, a testing protocol using bending and torsion loading was developed to gain the flexibility curves and stiffness often cadaveric lumbar discs. Measurements of rotation in the sagittal plane （flexion-extension）, coronal plane （right-lefl lateral bending） and transverse plane （torsion） due to a 5 N-m load are reported. Results show that overall normal discs are more flexible and behave in a nonlinear fashion. The testing results were used in a develop t＇mite element model of an intervertebral disc to investigate the stresses and strains in the disc components： annulus fibrosus and nucleus pulposus with regard to degeneration. Simulation of bending and torsion loadings show large strains in the annulus and nucleus from a normal disc, in contrast higher stresses develop in the annulus from a degenerated disc. The proposed methodology is novel, versatile, functional and economic with implications in bioengineering, medical sciences and the clinical field.展开更多
文摘Intervertebral disc flexibility is influenced by lifestyle, loading history, trauma, preexisting conditions, age and degeneration. With regard to degeneration, intervertebral discs become less flexible and stiffer. In this study, a testing protocol using bending and torsion loading was developed to gain the flexibility curves and stiffness often cadaveric lumbar discs. Measurements of rotation in the sagittal plane （flexion-extension）, coronal plane （right-lefl lateral bending） and transverse plane （torsion） due to a 5 N-m load are reported. Results show that overall normal discs are more flexible and behave in a nonlinear fashion. The testing results were used in a develop t＇mite element model of an intervertebral disc to investigate the stresses and strains in the disc components： annulus fibrosus and nucleus pulposus with regard to degeneration. Simulation of bending and torsion loadings show large strains in the annulus and nucleus from a normal disc, in contrast higher stresses develop in the annulus from a degenerated disc. The proposed methodology is novel, versatile, functional and economic with implications in bioengineering, medical sciences and the clinical field.
