Properly aligning bone roll on relaxed mesh

Hi, I have a imported MakeHuman mesh that is in a relaxed pose.

I am wondering if there is a way to accurately set the bone roll, so that the joints deform in the proper direction on such a mesh, other than just eye-balling it from the perspective view?

On a T pose mesh this is easy as you can use the ortographic views and align to a global axis, but here obviously, that won’t give good results.

http://i60.tinypic.com/npl5wo.jpg

Hopefully you can see what I mean. Currently I am just setting the roll so that the main deform is on the X axis (for the forearm and such) and that the joints move generally in the right direction (forearm towards biceps and not off to the side for example) but I’m wondering if there is a “100% right” method of setting bone rolls on such a mesh.

Thanks