Lightning Shift is a 6th Level Sorcerer Utility Encounter Power that is a move action.
Effect: You shift your speed. You ignore difficult terrain during the shift.
If the sorcerer is knocked prone can she use this power before standing up?
Part of the definition of ProneDDI is:
Lightning shift does not use one of the forms of movement that can allow a creature to move while prone.
In order to use Lightning Shift while prone, you need to take one of a number of feats or items:
In rough order from least onerous to most: