To define finger floor contact for a character:
> Show/Hide > Finger Tips In the Character Controls to make the finger tip markers on the character visible. In order to see the finger tips markers, you may also have to temporarily hide the FK and IK markers on your character by disabling them in the Show/Hide menu.
These options let you decide how you want the fingers to react when they come in contact with the floor. If you have no floor defined for the hands, the fingers react to the plane at 0 on the Y-axis as the floor.