A little light reading:

http://www.urosource.com/fileadmin/u...3804005627.pdf

http://pudendal.info/node/pdf/intrac...renialpain.pdf

The vast majority of studies about perineal and pudendal nerve compression and entrapment are about men... cuz men really worry when their pee-pees don't work. But the general idea is the same.

If you've got the time, do some searches on scholar.google.com You can find some pretty neat stuff.

(and yes, numbness on the outside is what happens when the sensory nerve gets compressed on the inside on its way out, just like your hand gets numb when you sleep on your shoulder. numbness that lasts for days means the nerve running to that area was compressed so horribly that it took days for it to rebound and recover)