Hope you try this out and it helps a few peeps out with the maya to zbrush pipeline. Leave feedback;)
For a better read version http://www.jasonwelsh.com/zbrushtuts/blendshapes3.pdf
Its all very small when writing a tutorial please consider doing an html page, or at least a pdf file 
ya was going for forum friendly jpg, the 200kb limit was making it a bit tuff on size. anywho I’lll change it tomarow at work.
welp anyway heres a little render to give you an idea.
wacky idea I’m working on
I used zbrush to pump the geometry in the arms and added the morph to a set driven key on the elbow. Its not perfect but a little more work and it won’t be to bad.