Dynamic stiffness and damping of human intervertebral disc using axial oscillatory displacement under a free mass system.
The aim of this study was to analyse the dynamic response of the human intervertebral disc to vibration in a physiologically relevant frequency spectrum. Eight lumbar intervertebral discs were harvested. After preparation, each sample was subjected to a pre-loading and then dynamic compression (from 5 to 30 Hz). The dynamic compression was applied using an experimental set-up comprising a free weight loading from above and a driving oscillatory displacement from below (closest to the in vivo loading). A viscoelastic model enabled the calculation of stiffness and damping from the transfer function. From 5 Hz to 30 Hz the stiffness values are between 0.19 and 3.66 (MN/m) and the damping values between 32 and 2094 (Ns/m). The mean resonant frequency was found at 8.7 Hz. These dynamic characteristics of the intervertebral disc could be used in a three-dimensional finite elements model of the human body to study its response to vibration in the driving position.
Izambert
O
O
Laboratoire de Biomécanique, ENSAM-CNRS, 151 boulevard de l'Hôpital, 75013 Paris, France. olivier.izambert@wanadoo.fr
Mitton
D
D
Thourot
M
M
Lavaste
F
F
D000368:Aged; D019567:Back Injuries / Q000209:etiology / Q000503:physiopathology; D004548:Elasticity; D005260:Female; D006801:Humans; D007403:Intervertebral Disc / Q000033:anatomy & histology / Q000502:physiology* / Q000503:physiopathology; D017116:Low Back Pain / Q000209:etiology / Q000503:physiopathology; D008159:Lumbar Vertebrae / Q000033:anatomy & histology / Q000502:physiology* / Q000503:physiopathology; D008297:Male; D008875:Middle Aged; D008954:Models, Biological; D011187:Posture / Q000502:physiology; D013314:Stress, Mechanical; D016474:Weight-Bearing / Q000502:physiology