Finite element simulation of daily activities held by the intervertebral disc

The spine is a complex system, capable of maintaining stability and simultaneously performing movements and the lumbar region is fundamental for this ability. The present work aims to validate a Finite Elements (FE) model of a lumbar motion segment, through numerical simulation of the required mobility on the intervertebral disc, accordingly to some daily activities. For this study, only the simplest motion on the spine was simulated: flexion, extension and lateral bending. The biomechanical response of the FE model has proved to be suitable for predictions on flexion, but on extension and lateral flexion unexpected extension angles were obtained. These results showed the need of improvements in the mesh geometry, along with the introduction of a model considering of the external ligaments restraining effect, in order to get a more reliable and closer to reality simulation of the all biomechanical system

Characterisation of microbial attack on archaeological bone

As part of an EU funded project to investigate the factors influencing bone preservation in the archaeological record, more than 250 bones from 41 archaeological sites in five countries spanning four climatic regions were studied for diagenetic alteration. Sites were selected to cover a range of environmental conditions and archaeological contexts. Microscopic and physical (mercury intrusion porosimetry) analyses of these bones revealed that the majority (68%) had suffered microbial attack. Furthermore, significant differences were found between animal and human bone in both the state of preservation and the type of microbial attack present. These differences in preservation might result from differences in early taphonomy of the bones. © 2003 Elsevier Science Ltd. All rights reserved