Switch Direction
Reference
Mode:
Edit Mode
Menu:
Armature ‣ Switch Direction
Shortcut:
Alt-F
This tool allows you to switch the direction of the selected bones (i.e. their root will become their tip, and vice versa).
Switching the direction of a bone will generally break the chain(s) it belongs to. However, if you switch a whole (part of a) chain, the switched bones will still be parented/connected, but in “reversed order”. See the Fig. Switching example..