The effect of the eccentric loading on the components of the spine

Abstract

The objective of this work is to study the effect of the backpack on the components of the spine system of a child, know the effect of an eccentric load on the intervertebral discs, the creating a 3D model of the spine of child of 80 kg overall weight under the effect of three eccentric load (P2, P3, P4) plus P1 compression load and calculated by the element method ends, For the boundary conditions we fixed the sacrum (Embedding the sacrum). We propose in this section to draw up a comprehensive study of the distributions of stresses and normal elastic strain of Von Mises in the intervertebral discs based on loads supported. The results show that the stress and strain of Von Mises are highest and concentrated in four intervertebral discs (D1, D15, D16 and D17), which causes a problem that calls (herniated disc). We concluded that the cause of the posterior load, a 350 mm lever arm with a 200N load present maximum Von Mises stresses concentrated in four intervertebral discs (D1,D15,D16,D17), which justifies the distance between the load which is the point of application of the load and the axis of the spine plays a very important role in increasing the solicitation of the latter.

Computed tomography osteoabsorptiometry for imaging of degenerative disc disease

“…This assumption is further supported by studies that looked at stress distribution on the vertebrae and IVDs under different physiological movements using the finite element method (FEM) [46][47][48] . This work showed that the maxima of stress and strain were localized at the dorsal lateral region and in the ventral median region of both IVD and vertebra.…”

Finite element analysis of the influence of three‐joint spinal complex on the change of the intervertebral disc bulge and height

“…Because of the fact that collagen fibres embedded in AF lamellae play the greatest role in the IVD, the structures of the NP and of the AF matrix have also been simplified. Modelling of these structures as linear elements is also proposed by authors of other studies …”

“…The bone tissue of the vertebrae and endplates and the interspinous cartilage was described by isotropic, linear‐elastic material properties . The IVD was modelled in accordance with the vertebral model proposed by Schmidt et al, who modelled the structure of the AF as a matrix strengthened with layers of collagen fibres.…”

“…The IVD was modelled in accordance with the vertebral model proposed by Schmidt et al, who modelled the structure of the AF as a matrix strengthened with layers of collagen fibres. The matrix of the AF surrounding the NP was described by isotropic, linear‐elastic material properties . Six cylindrically arranged layers of collagen fibres were modelled in the AF matrix, which were radially placed between successive annuli fibrosis (lamellae).…”

“…The fibres were tilted at a 30° degree and arranged alternately, ie, to the right or to the left . Ligaments (ALL, PLL, ISL, ITL) were also described by isotropic, linear material properties with theoretical defined cross‐sectional area . The articulating facet surfaces were modelled using surface‐to‐surface contact elements (with a penalty algorithm and a friction coefficient of 0.1).…”