Abstract: A motion sensor for monitoring the activity of a body in motion includes a pair of force detecting sensors capable of detecting both magnitude and direction of an applied force. These sensors are configured to enable translational or rotational motion resulting from travel in a vehicle to be suppressed from any general motion signal leaving only a rotational or translational component. The active compensation of an electrical circuit is provided to aid in the calibration of a non-ideal sensor pair and reduce the leakage of translational motion into rotational motion or rotational motion into translational motion due to any differences between the pair.