Would it be possible for a rigger to look at Yoops thumbs. Maybe the splines are bad (there seems to be enough) but it's like only the end joint bends when you rotate the thumb bone in the z axis. I tried it on other characters and they get more of a "square" bend rather than an "L" one.
Cheers.

The "right/left_thumb_knuckle_1_curl" pose needs adjusting. I'm sure David will take care of it, but if not, I'll fix it.

Thanks fellas.

I'll take a look at it tonight.

Mrs. Yoop's thumbs and hand clench poses should work alright now.