Work

Comparison of intervertebral disc and nucleus pulposus stresses under different lumbar curvature configurations

Year: 2026

Type: article

Abstract: Background To compare the intervertebral disc and nucleus pulposus stresses under different lumbar curvature configurations. Methods Finite element models of a healthy lumbar spine were established for eight postures: standing with a forward inclination position, standing in a neutral position, standing with a backward inclination position, relaxed sitting with a forward inclination position, upright sitting in a neutral position, relaxed sitting with a backward inclination position, relaxed sitting in a neutral position, and relaxed sitting in a neutral position with lumbar support. After assigning different material properties, the model of the standing in neutral position was selected for validation. Following the application of a 400 N physiological load, the lumbar intervertebral disc and nucleus pulposus von Mises stresses were analyzed for each posture. Results Among the three standing postures, the peak von Mises stresses in the L3-L4, L4-L5, and L5-S1 discs were higher than that in the L1-L2 and L2-L3 discs. The smallest peak von Mises stresses in the L3-L4, L4-L5, and L5-S1 discs were observed in the neutral standing position. The nucleus pulposus stresses were minimal in the L3-L4 and L4-L5 discs in the neutral standing position, while the nucleus pulposus stresses in L5-S1 disc was minimal in the backward-inclined standing position. Among the five sitting postures, the smallest peak von Mises stress and nucleus pulposus stresses in the L4-L5 and L5-S1 discs were found in the upright sitting in a neutral position and the relaxed sitting in a neutral position with lumbar support. Across all postures, the nucleus pulposus stresses was the lowest. Conclusion Lumbar curvature configurations significantly influences both the distribution and magnitude of von Mises stress in the L4-L5 and L5-S1 intervertebral discs and nucleus pulposus. Maintaining proper spinal alignment and avoiding postures that reduce lumbar lordosis are generally more favorable for lowering stress levels at these two segments.

Source: Frontiers in Bioengineering and Biotechnology

DOI: 10.3389/fbioe.2026.1969400