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.

The objective of this work is to study the effect of obesity on the intervertebral discs and provide system analysis of the spine between multiple configurations of people, and know the risks due to this eccentric load (Big Belly). The results show that in all three previous loadings (obese people), the distributions of stress and strain are high in both D1 and D10 intervertebral discs. This shows that the distance between the point of load application and the spine axis has an important role in solicitation increasing and therefore its deformation: as main conclusion is that the concentration of the mass of stomach fat is a risk factor that leads to pain problems, deformation and herniated disc.

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.