I'll add one small comment on the whole SubD thing and then disappear.

SubDs, especially sub-dividing the entire form as DS4 proposes as best, is not the sole way to get smooth joints in a humanoid manikin.  Usually you need more geometry where the body's soft tissues can distort more in relation to its bones or where muscles might tend to bulge.   These also tend to be spots where joints offer the greatest degress of freedom such as elbows and kness.   Judicious application of additional geometry in those spots can go a long way to creating a smooth, skin-like surface deformation.

Simply solving smoothing issues by subdividing everything burns resources that could be more judiciously applied to dynamics, rendering the next frame in animation, etc.

-K