Biological process

Any process involved in maintaining the planar beating pattern of ciliary movement pattern. Connection between the outer doublets and the central pair via the radial spokes constrains ciliary movement to the planar beating pattern. Cilia that lack this connection, such as those in the embryonic node or Kupfer's vesicle, display radial movement.

Note that we deem cilium and microtubule-based flagellum to be equivalent.