Skin Cage

Create SliderJoints from SkinCurve positions for sliding or volume-preservation motion.
Deform Skin Cage Sliders
This creates SliderJoints. SliderJoints are placed from the positions of the SkinCurves. First select the SkinCurve, then Create Slider.
The SliderJoint moves based on rotation of a nearby joint.

SliderJoints made from green SkinCurves move outwards for volume preservation.
SliderJoints made from red SkinCurves move along the skin for a skin-sliding effect.