Systems and methods for soft tissue navigation

There are provided systems and methods for soft tissue navigation. A sensor unit provides tracking information to determine positional data for a patient's structural anatomy and gravity direction measurements to determine a direction of gravity relative to the anatomy. A computing unit, during a procedure, computes the direction of gravity and determines spatial information for soft tissues of the patient, responsive to the direction of gravity. Expected soft tissue movement may be provided by a computer model modelling the mechanics of the soft tissues responsive to the direction of gravity, or by other means such as look up table. Surgical navigation data is presented via a display unit. Medical images may be registered and navigation provided relative to the images. Tool positions may be tracked via the sensor unit. Spatial differences in soft tissues between orientations of the patient (relative to gravity) may be determined and presented.