My flat feet seem to cause my knees to become sore if I do a lot of
walking or stairs. I got custom made orthotics, which helped, but I
still have the problem. I am afraid my knees will get too sore if I
go on hikes more than 4 miles or so.

I wonder if my shoes could be a problem. I wear wide width shoes even
though my feet are not really wide. Regular shoes rub against one of
my little toes. Since my shoes are a little loose, maybe my orthotics
can't work as well as they should. Anyone know anything about this
kind of problem?