Effects of Vertebral Body Changes on Cervical Spine Load Sharing

2002 ◽  
Author(s):  
Jiangyue Zhang ◽  
Narayan Yoganandan ◽  
Frank A. Pintar
Keyword(s):  
Cervical Spine ◽  
Young’S Modulus ◽  
Vertebral Body ◽  
Modulus Of Elasticity ◽  
Young's Modulus ◽  
Compressive Force ◽  
Axial Compressive Force ◽  
Inferior Surface ◽  
Biomechanical Behavior ◽  
Young’S Modulus Of Elasticity

The objective of the study was to determine the effects of changes in the Young’s modulus of elasticity of the cancellous bone that occur due to the ageing process on the biomechanical behavior of the cervical spine. An anatomically accurate three-dimensional (3-D) nonlinear finite element model of the C4-C5-C6 cervical spinal unit was used. The inferior surface of the C6 vertebrae was fixed in all degrees of freedom, and external loads were applied to the top surface of the C4 vertebra. The model was exercised under an axial compressive force of 754 N. In addition, flexion and extension bending moments of 3.44 Nm were applied individually to the model. The effects of ageing on bone strength were simulated by decreasing the Young’s modulus of elasticity from 100 MPa in the healthy spine to 40 MPa in the degenerated spine. The degenerated spine was found to be more flexible than the healthy spine. In addition, the degenerated spine responded with increased forces in the outer anterior and posterior regions of the vertebral body. Furthermore, forces in the facet joints increased in the degenerated spine. In contrast, the middle region of the disc showed decreased forces. These increases in the forces leading to stress risers may explain the occurrence of osteophytes in the spine with age.

Biomechanics of Cervical Spine Ligaments

1999 ◽  
Author(s):  
Narayan Yoganandan ◽  
Srirangam Kumaresan ◽  
Frank A. Pintar
Keyword(s):  
Cervical Spine ◽  
Young’S Modulus ◽  
Modulus Of Elasticity ◽  
Ligamentum Flavum ◽  
Young's Modulus ◽  
Posterior Longitudinal Ligament ◽  
Biomechanical Properties ◽  
Cross Sectional ◽  
Interspinous Ligament ◽  
Young’S Modulus Of Elasticity

Abstract The purpose of the present study was to determine the geometrical and biomechanical properties of human cervical spine ligaments from the axis to the first thoracic level. A total of 33 human cadavers were used. Geometrical data included the length and cross-sectional area measurements. Biomechanical properties included force, deflection, stiffness, energy, stress, strain, and Young’s modulus of elasticity. These data were obtained for the anterior longitudinal ligament, posterior longitudinal ligament, joint capsules, ligamentum flavum, and interspinous ligament. Geometrical characteristics were determined using cryomicrotomy techniques and biomechanical properties were obtained using in situ failure tensile testing. Force-deformation responses of each ligament type and at each spinal level were normalized. The joint capsules and ligamentum flavum exhibited the highest area of cross-section (p < 0.005). The longitudinal ligaments responded with the highest length measurements. The strain parameters were higher for the ligaments of the posterior complex, i.e., interspinous ligament, joint capsules, and ligamentum flavum, than for the ligaments of the anterior complex, i.e., the anterior and posterior longitudinal ligaments. In contrast, the failure stress and Young’s modulus of elasticity were higher for the anterior and posterior longitudinal ligaments compared to the ligaments of the posterior complex. These findings delineate the relative contribution of the anterior and posterior ligaments in the human cervical spine.

THE INFLUENCE OF SEX HORMONES ON THE BONY CHANGES OCCURRING IN PARALYSED LIMBS

1954 ◽  
Vol 11 (1) ◽  
pp. 66-70 ◽  
Author(s):  
J. A. GILLESPIE
Keyword(s):  
Young’S Modulus ◽  
Sex Hormones ◽  
Modulus Of Elasticity ◽  
Young's Modulus ◽  
Bending Moment ◽  
Breaking Point ◽  
Total Weight ◽  
Breaking Stress ◽  
Young’S Modulus Of Elasticity ◽  
Ash Weight

SUMMARY 1. Paralysis, produced in young male rats by avulsion of peripheral nerves, resulted in a highly significant reduction in the total weight, ash weight, ash percentage, X-ray density and bending moment at the breaking point, of the bones of the affected limb. The breaking stress was significantly reduced, but Young's modulus of elasticity was unaltered. 2. Certain of these changes were modified by treatment with sex hormones. Both oestradiol and testosterone significantly reduced the difference between the bones of the normal and paralysed limbs in respect of total weight, ash weight and bending moment at the breaking point. 3. Treatment with oestradiol significantly increased both the ash percentage and Young's modulus of elasticity, the increase affecting equally the bones of the normal and paralysed limbs. Testosterone treatment did not significantly affect either of these properties, and neither hormone affected the breaking stress.

scholarly journals Young’s modulus of elasticity of Schlemm’s canal endothelial cells

2009 ◽  
Vol 9 (1) ◽  
pp. 19-33 ◽  
Author(s):  
Dehong Zeng ◽  
Taras Juzkiw ◽  
A. Thomas Read ◽  
Darren W.-H. Chan ◽  
Matthew R. Glucksberg ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Young’S Modulus ◽  
Modulus Of Elasticity ◽  
Young's Modulus ◽  
Schlemm’S Canal ◽  
Schlemm's Canal ◽  
Young’S Modulus Of Elasticity
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