A thought...
In the second image the chains go from wrist, through the elbow cuffs to the collar..
The idea.
Same basic setup, but have an electro magnet on the collar. Pass rope from wrist as in image up to a ratchet/TRD (1 per side)
As you pull the rope with the opposing hand, the wrist will be moved to the elbow and the elbow will be pulled into the back by the shortening of the dimension to the collar. Do both sides and you are stuck until the 9v battery degrades enough to weaken the electromagnetics.
You know, the elbow cuffs don't have to be tight.
The only reasion for the elbow cuffs are to keep the arms in place.
How do you get out from that bondage webbing? Seems like there is no escape when alone?
They have a one-way latch sorta thing. It's like loosening a backpack strap.