A computer readable storage medium for determining a normalized mean axis of rotation (MAR) of a cervical spine in a patient is provided, having stored thereon instructions executable by a processor to perform steps of providing a flexion trace and an extension trace of each of cervical spine vertebrae C2 to C7 by detecting a start position, drawing a line concurrently as the pointing device follows the margin from the start position to a finish position and detecting the finish position； superimposing the flexion trace on the extension trace； providing for a user to correct an error in a trace； determining a MAR datum； and normalizing the MAR datum.
