Rigging a 2D NURBS human arm

Support Animation and Rigging
1

Hello,

I’m trying to create a two-dimensional human-figure out of NURBS curves, and I’m having a some trouble with rigging the first arm (as shown).

curve_points.jpg1024×232 16.7 KB


After moving the lower-arm bone about 45 degrees, the arm starts to collapse on itself or over-pinches from the elbow downwards.

Can anyone offer any advice on how to improve my arm rig?

Thanks,
Aidan