Accuracy enhancing systems, devices and methods are provided using data obtained from inertial measurement units (IMUs). IMUs are provided on one or more of a patient, surgical table, surgical instruments, imaging devices, navigation systems, and the like. Data from sensors in each IMU is collected and used to calculate absolute and relative positions of the patient, surgical table, surgical instruments, imaging devices, and navigation systems on which the IMUs are provided. The data generated by the IMUs can be coupled with medical images and camera vision, among other information, to generate and/or provide surgical navigation, alignment of imaging systems, pre-operative diagnoses and plans, intra-operative tool guidance and error correction, and post-operative assessments.