6. The Spine: This is what is called FK ( Forward Kinematics) . A lot of stop motion animators opt for an FK spine because it mimics what they do with stop motion puppetry. Basically you setup a rotator ( in this case a null bone) and a deformer. A standard bone that is usually rotated 90 degrees in a given direction. You then attach a controller object ( in this case a spline cage) and tell it to control the global rotation of the null bone. I use the same type of system for the shoulders ( FK).

You can then just copy and paste these little guys and parent them to get a realistic , simple and calculationally light spine system. The benefits to this setup are you can animate the progressive breaking of joints and also have concise global control over any section of the spine at any time.

I think that this setup coupled with a more procedural spine setup would make for a pretty formidable spine solution. Basically a procedural spine system can get unwieldy and can be no fun to animate. If you drop the controllers into the boxes you will have the simplicity of the FK control system I outlined with the procedural complexity of the detailed spine system. I have yet to try it but I know it will work.