Are the influences for the muscles? I wouldent use them for every joint.
I use non smoothed polys, skinning with smooth polys is a right paint in the ass, hence the paint in there, use the low then add the smooth later or use a wrap an hide the low.
I generally use smooth all the time but depending on your project rigid is good, but I would say for this just use smooth.
"No pressure, no diamonds" Thomas Carlyle