All that aside, you'll also need to consider the JCMs... which in V4, AFAIK, are magnet deformers, which were created for a specific range of rotation. I don't think I've ever seen JCMs designed for forearm side to side motion. Those things are set at limits for expected ranges of rotation. I'd have to agree with SamTherapy here, and the fact that his instructions about how to pose a figure within it's expected limits produced a result that worked.