1. A method comprising: tracking movement of two occluded hands during an occlusion period, the two occluded hands being tracked as a unit; determining a type of synchronization characterizing the two occluded hands during the occlusion period based on the tracked movement of the two occluded hands; and determining, based on the determined type of synchronization, whether directions of travel for each of the two occluded hands change during the occlusion period.