On Sat, 10 Dec 2016 08:58:20 GMT, DerbyBorn
wrote:

I was hoping to find out how the torque reaction of the body is dealt with.
I didn't want a view on whenther to buy one or to hear the merits of a
spoon.
The mechanism as seen on the video raised the questions

The loud music that covers the demonstration video should have given
you a hint, it must make a noise and the most logical conclusion is
that it vibrates its away around making a racket that some would find
irritating .

Often these things are sold under different names and a quick gander
at you tube shows them being used without the soundtrack.
This is just one I found in about 30 seconds.
https://www.youtube.com/watch?v=FbproR1neNw

G.Harman