Hello I`m using Iphone Xs to live animate an avatar on an event . Head is quite in one place and the rest of the body is not moving . I would love to have an option of some sort of body following by head movement from the capture 
something like Head driven body movements in LIVEmotion 2D https://manual.reallusion.com/Motion_LIVE_2D_Plugin/Resources/CTA_4/Plugins/Motion_Live_2D/Body_Motion_Strength_Settings.htm
how it could be possible ?

Same could be with connected Leapmotion , hands could drive the rest of arm not be stick where elbow is , like inverse IK 

any help is very appreciated