A Comparison of the Torsional Stiffness of the Lumbar Spine in Flexion and Extension

Tissue loading created during spinal manipulation in comparison to loading created by passive spinal movements

“…Additionally, the estimated stiffness of the L3/L4 spinal segment arising from SMT application was also smaller in magnitude when compared to the magnitude of stiffness observed to occur immediately before spinal injury48495051. Specifically, our data allows us to estimate L3/L4 spinal stiffness during SMT to be 0.33 Nm/deg in extension and 1.51 Nm/deg in axial rotation; values that are smaller than the extension stiffness described by Garges et al 49.…”

“…Specifically, our data allows us to estimate L3/L4 spinal stiffness during SMT to be 0.33 Nm/deg in extension and 1.51 Nm/deg in axial rotation; values that are smaller than the extension stiffness described by Garges et al 49. of 10 Nm/deg and torsion stiffness described by Bisschop et al 50.…”

Vertebral Bodies or Discs: Which Contributes More to Human-like Lumbar Lordosis?

“…Because posterior and posterolateral disc herniations can impinge on the spinal cord and spinal nerve roots, causing substantial neurologic impairment, the enhancement of posterior disc integrity may confer protection from herniation. If in the course of evolution, however, the posterior margin of the intervertebral discs became very thin, as would be required for the discs to contribute to lumbar lordosis, the ROM between adjacent vertebrae could have been diminished and the ability to withstand compressive and torsional loads altered [6,8,20,29].…”

Finite element investigation osteoporotic lumbar L1 vertebra buckling in a presence of torsional load

“…Due to the lack of the transversal bonds the vertical trabeculae collapse and lose stability under the impact of the axial force. The studies of spinal torsion state analysis [12], [13] predicted fractures applying mechanical criteria of plasticity and decomposition, but the correlation between the loss of spinal stability and vertebral fractures occurrences was not included. Polikeit et al [14] suggested imitating osteoporosis by adjusting only the properties of the necessary material.…”