A system (10) to track human locomotion by relative positional tracking of body parts (21, 22) of a user (20) comprises at least two sensors units (11, 12) at each limb (21, 22) as body part for obtaining the relative position of each limb (21, 22) over time to determine the position of the user (20) in space. One sensor at each limb (21, 22) is an electromagnetic sensor detecting signals issued by a central emitter, here integrated in the head unit (13), or localized at a different place at the user (20). The global position of a foot (21, 22) is determined based on its local position, whenever a foot (21 or 22) enters a stance phase, determined by a zero-velocity of that foot (21 or 22).
