title: Mechanical properties of lumbar spine motion segments under large loads.
abstract: The mechanical behavior of fourteen fresh human lumbar motion segments taken at autopsy from males with an average age of 29 yr was studied. Forces up to 1029 N were applied in anterior, posterior and lateral shear; and moments up to 95 Nm were applied in flexion, extension, lateral bending and torsion. In response to these loads endplate displacements up to 9 mm and rotations up to 18 degrees were measured. Stiffness values ranged from 53 to 140 N mm-1 in response to the shear forces and 6-11 Nm degree-1 in response to the moments. Lumbar motion segments can develop significant passive resistances to loads in situations where they are allowed to undergo substantial deformations.
mesh_terms: D000293:Adolescent; D000328:Adult; D001696:Biomechanical Phenomena; D006801:Humans; D007403:Intervertebral Disc / Q000502:physiology; D008159:Lumbar Vertebrae / Q000502:physiology*; D008297:Male; D009068:Movement; D005082:Physical Exertion