For full keyboard accessibility (as needed for example by users of screen readers) it should be possible to move between the body of a document and the text of footnotes/endnotes via keyboard commands. There is code in http://cgit.freedesktop.org/libreoffice/core/tree/sw/source/ui/docvw/edtwin.cxx (see the comments and code starting at line 1454) which is apparently supposed to assign this functionality to alt-ctrl-pgup/pgdown, but in my testing, this key combination does nothing. Also, it isn't clear from the comment how this feature is supposed to work. What is wanted is a mechanism to move from the footnote anchor in the body of the document to the footnote text with a keyboard operation. Pgup (with no modifiers) exits a footnote in my testing. I'm running Gnome with the default Gnome 3.4 window manager.
Please open the dialog to customize keyboard. Choose "Navigate" as category. Look in the command list for the command, e.g. "Edit Footnote/Endnote" or "To Previous Footnote". Select the command. In the field "Keys" you can see, which short cut is actually assigned to the command. Use the list in field "Shortcut keys" to assign or modify a shortcut. Please keep in mind, that a shortcut cannot be uses by LO, if it is caught by the OS.
Thanks. It turned out to be ctrl-shift-pgdown on my system. I would say that it's a low-priority documentation issue at this point.
Accordingly to comment #2 set to enhancement. Best regards. JBF
The keyboard shortcut for switching to edit Endnote/Footnote is Ctrl+Shift+PgDwn in my system (Windows 10) as well. Pressing the keys, has no effect.
Seth Chaiklin committed a patch related to this issue. It has been pushed to "master": https://git.libreoffice.org/help/commit/609d466f02d63c43d42636627ee3b35e26df4661 tdf#65991 improve help for keyboard navigation with footnotes and endnotes
Verified as fixed in the help page for both 7.2 and 7.3.