Can I make a suggestion for experimentation? I know C5's SSS assumes there are no interior objects - so if you were to put a bone model inside one of those fingers, it wouldn't have any affect. But what if you booleaned out the bone, creating a hollow in the finger? Depending how it does the scattering, that might create a fairly realistic shadow. I'd appreciate it if you'd pop a cylinder into one of the fingers and give it a try.