To be hung by one's heels for much longer than an hour was a common form of
corporal punishment here in the USA - 19th Century and earlier. I
know. My father used to threaten me with that punishment from time to time
though he never did it. He was born in 1880 - in the South where corporal
punishment of that kind was common. I don't perceive your dream to be in
thst fashion - as in a past life experience. Yes, we can and do have dream
experiences from past lives.
In today's world to be hung by one's ankles is evidently part of the BSDM
scene (do an Internet search) and because you say that the hanging was to be for
only an hour and the mechanism had pads for your ankles my suggestion would be
that it was meant to be some form of an erotic adventure - either yours, or
someone else's. We each have our own private dream/astral space and others
can invade that space and disrupt what we are experiencing in our own astral
world. That's possible too - for someone else to have those
thoughts/desires directed at you. You have the answer as to what it means
and by posting here you are getting suggestions but ultimately it is you who has
the answer.