BTW, I am mortified of heights. My sons scared the living daylights out of me at Zion. I don't know how people can dangle from those heights. Not for me...uh, uh....nope.
You may be interested in researching this topic. Pressure Neuropathies. It may not be the kind of thing you want to hear, but, it bears looking at.
http://www.ncbi.nlm.nih.gov/omim/162500