Table 1 Mechanical properties of poroelastic materials in the FE models for all L2-L3 segments

a. Elastic properties of the lumbar except nucleus pulposus

Material property

Poisson^’s ratio (μ)

0.2

0.3

0.1

0.3

Neo-Hookean C₁₀ = 0.315, D = 0.688

Fitting from test data

The linear-elastic properties of cancellous bone, cortical bone, and cartilage endplates were based on Schmidt et al. [19]. The linear-elastic properties of annular fiber were based on Xu et al. [10]. The hyper-elastic properties of annulus ground substance were based on Schmidt et al. [20], Schmidt et al. [21], and Galbusera et al. [32]. The hyper-elastic properties of ligaments/facet were based on Sharma et al. [33].

b. Porous properties of the lumbar spine except nucleus pulposus

M (Eq. (1))

10

12

The porous properties of cancellous bone, cortical bone, cartilage endplates, and annulus ground substance were based on Argoubi and Shirazi-Adl [34].

c. Poroelastic material properties of all the nucleus pulposus

The hyper-elastic properties of nucleus pulposus for Grade 0 to 3 were based on Schmidt et al. [13], Schmidt et al. [20], and Schmidt et al. [21]. The porous properties of nucleus pulposus for Grade 0 to 3 were based on Johannessen et al. [6], Massey et al. [11], and Argoubi and Shirazi-Adl [34].