Modeling L4-L5 and intervertebral disc

Hello all,

I want to do a finite element analysis on the intervertebral disc between L4 and L5 vertebrae for a given motion-capture data. Now, I have the geometry and the material properties of the disc and the vertebrae. I can also individualize the L4 and L5 vertebrae in Anybody and run the MOCAP model, however, the Anybody model doesn’t include the intervertebral disc. So, my question is how can I use the loading and the boundary condition from the Anybody output for a finite element analysis of the complete L4-L5 segment. Can I export the forces for the L4 and L5 segment and use that as a boundary condition and insert a disc (with geometry and material property) between the L4-L5 vertebrates and run the FE analysis? Any advice would be helpful.


Hi @ap21

Yes, you should be able to dump the boundary conditions and use in your FE model.
Depending on you scenario you could implement new nodes corresponding to your FE model.
You can find a few details in this older thread: AnyBody-Ansys Interface - #13 by victorwambugu

Best regards,

Just to confirm, should I use the AnyFe2Abq converter for L4 and L5 separately using their respective reference frame and get 2 loading files? Then, merge those two loading files with the new mesh file that contains the L4 vertebrae, L5 vertebrae, and disc geometry? I am using Abaqus for the FE analysis.

I am working on similar work, but I think discs should be modeled as body segments in anybody..

Hi Bjorn,

Or Should I use one of the local ref frame frame of L4 or L5 (AnyRefFrame) and use both the segments (AnySeg: L4 and L5) to output the AnyMechOutputFileForceExport (.xml file)? Also generate the mesh file that contains all the geometry (L4,L5, and disc). Then combine those two files (.xml and mesh file) to generate the final input file using AnyFE2Abq converter. I have some confusion regarding understanding using one ref frame to export multiple segments in AnyMechOutputFileForceExport. Any assistance would be helpful.