It tends to happen to people who are right footed. Do you play soccer? Most soccer players have bigger quads on their weaker leg. It's because you kick with the dominant leg, and the weaker leg has to support your entire body. Over years and years of soccer, my left quad is bigger than my right. Not some grotesque amount, but enough to where you notice if i point it out.
A good way to even out is to do everything with the weaker limb. My quads are way more even now that i've spent a good couple of years practicing with my left kicking and such. It also makes you better at whatever caused you to become like that.
i actually thought it was from raising my hi hats... but now that you've explained it... it could be my vibes playing...
