Many investigators have performed studies on specific defect situations or determined the contribution on isolated structures. Investigating the contribution of functional structures requires obtaining the kinematic response directly on spinal segments. The purpose of this study was to quantify the function of anatomical components on lumbar segments for different loading magnitudes. Eight spinal segments (L4-5) with a median age of 52 years (ranging from 38 to 59 years) and a low degree of @entity1797 were utilized for the in vitro testing. Specimens were mounted in a custom-built spine tester and loaded with pure moments (1-10 N m) to move within three anatomical planes at a loading rate of 1.0 degrees /s. Anatomy was successively reduced by: ligaments, facet capsules, joints and nucleus. Data were evaluated for range of motion, neutral zone and @entity1515 angle. Transection of posterior ligaments predominantly increased specimen flexion for all bending moments applied. Supraspinous ligament also indicated to resist in extension slightly, whereas the facet capsules did not. @entity2720 contributed to @entity717 , but not in lateral bending. The anterior longitudinal ligament was found to slightly resist in @entity717 , but strongly in extension. Nucleotomy caused largest increase of all movements. The unloaded posture of the specimens changed after ligament dissection, indicating ligament pretension. The region of lumbar spine is interesting for finite element (FE) simulation due to the high evidence of @entity1797 . This study may help to understand the function of specific anatomical structures and assists in FE model calibration. We suggest to start a calibration procedure for such models with the smallest functional structure (annulus) and to cumulatively add further structures.

Stepwise reduction of functional spinal structures increase range of motion and change XXXX angle.

@entity1797 :: ('MESH:D055959', 'Disease') :: ['disc degeneration and injuries', 'disc degeneration'] @entity717 :: ('MESH:D009069', 'Disease') :: ['axial rotation'] @entity1515 :: ('MESH:D008141', 'Disease') :: ['lordosis'] @entity2720 :: ('MESH:D007592', 'Disease') :: ['Facet joints']
@entity1515 :: (MESH:D008141,Disease) :: ['lordosis']
