Perhaps this can be simplified as a discussion of Component Vectors
V-> = (Vx, Vy)

The wrap-around(-the-heel) cable has to be under tension or it would fall off.
The heel-pivot is higher than it's connection to the frame.
Hence there is a downward component vector resisting the raising of the heel,
which becomes larger as the heel is raised.



How to affect how much the heel is "anchored" or "locked" versus "free" seems well-established.
The component vectors should be easy to visualize, as well as how the following system functions.
Source: http://www.smhc.co.uk/objects_item.asp?item_id=33040 (<-- short read)


If you've read this far and would like more of a rabbithole, check this out. It's in German, but even scrolling through the photos gives an idea of this paper's scope.
https://docplayer.org/18680858-Alpiner- ... en-at.html