Spine model

[daverudolf]

Hi folks,

I am not really a biomech eng, but am an animation researcher who is looking to build a model of the human spine (and surrounding tissue as necessary). Really, I have position and orientation information for the pelvis, cranium, and two humerus bones (and the position of their attached joints). I then want to be able to estimate positions and orientations for the vertebrae. Can anyone point me to some literature that might help me out?

Thanks,

Dave

 

[ProbaSci]

Not sure what you want to animate exactly, but as a first attempt, you could assume the spine is just a rigid connection between the head and pelvis.

http://www.probasci.com

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Implantable FEA for medical device manufacturers

 

[daverudolf]

Ya, the assumption that the whole spine is rigid gets violated pretty quickly. If the subject even slouches a little bit, then the model is overconstrained. That simple case we can handle, but if the subject twists their torso or goes into the fetal position, etc, then things get ugly. We tried to represent the spine as a chain of rigid objects that essentially have ball-and-socket constraints between them, and then we add forces to try and drive the chain toward a rest configuration. That mostly works, but there are cases where the spine moves in very unnatural ways. So, I was wondering what other people had done to represent the curvature of the spine during arbitrary movement.