Lucid Dreaming | Could somebody explain vibrations ?

Im asking because when Im relaxing (for wild), I often get these vibrations in legs. I gues they arent HH or OBE vibrations (is that same ?), because they dont stop when I change position to sleep, even when I get up and than again lay down after few seconds they start again, I don't understand what are they, so I would be thankful if somebody could explain this (and vibrations in lucid dreaming generally).

via Lucid Dreaming - Dream Views - Attaining Lucidity http://www.dreamviews.com/showthread.php?t=146416&goto=newpost