I am having a bit of trouble setting up this rig to the mesh. I have fiddled with the Vertex groups and weights to make the sleeve cuff not deform except inline with the sleeve but for some reason is continues to deform. The Cuff seems to deform with the hand rotation but it shouldn't. The sleeve has no vertex' in the hand deform or any of the finger bone deforms but still it deforms.
The vertex group for the Bicep area was for some reason also including the cuff region which is not very helpful. So there was an extra deform to the cuff that was messing things up.