Fig. 12

FEA of the lumbar spine under extension loading. (a) Displacement contours highlight greatest deformation at the superior vertebrae and least at the constrained L5. (b) Stress distribution reveals peak values in the posterior elements, especially pedicles and facet joints. (c) The strain distribution (in MPa) highlights areas of high deformation in the posterior ligaments and the posterior annulus fibrosus, indicating their critical role in limiting the range of motion during extension. Color scales indicate the magnitude of the respective variables, with red representing peak values and blue representing the lowest.