A coupling apparatus allows anti-phase movements of inertial sensor element frames along parallel axes but substantially prevents in-phase movements of the frames. The coupling apparatus includes a bar coupled between first and second sensor element frames and at least one supporting structure supporting the bar. The at least one structure is coupled to a substrate underlying the frames. The structures allow the bar to rotate at a pivot point when the frames move in anti-phase to one another along substantially parallel axes but substantially prevent in-phase movements of the frames.