A medical navigation system is provided for detecting movement of a subject, the system having an optical tracking system including a camera, a display, and a controller electrically coupled with the optical tracking system and the display. The controller has a processor coupled with a memory and is configured to receive a data signal from the optical tracking system and recognize and continuously monitor optical tracking markers on the subject within a field of view of the camera, and provide an alert on the display when movement of the optical tracking markers on the subject falls within predefined parameters.