Fig 5. Stance-neutralization with waypoint method.

The blue trajectory represents the actual horizontal movement of the center of mass (COM). In the example shown, the athlete moves from south to north and briefly stops in the center. Even if the athlete is standing still (both feet on the ground for a certain time), the COM trajectory would lead to artificial accumulating distances that are measured. The waypoint method (red trajectory) suppresses the micro movements that are not relevant for the gross motion.