Bi-pedaling motors move predominantly by hand-over-hand, i.e. while the leading head remains attached to its track the lagging head detaches from its rear position, advances alongside the attached head, and becomes the new leading head following filament rebinding.
A motors ability to walk hand-over-hand and to retain motility under heavy load, i.e. to move processively, require that at any given moment at least one of the heads stays tightly bound to the filament, or put differently, that each of the head remains attached at least 50% of the motors chemomechanical cycle.
The stepping mechanisms for myosin V and VI provide good examples for how processivity can be achieved by way of inter-head communication and chemomechanical coordination.