An A320 First Officer reported the Captain; as pilot not flying; nudged the rudder pedals while level with the autopilot engaged. Contends the practice is common among a significant percentage of company pilots and constitutes a violation of the airline's FOM.

Narrative

While level at 7000 FT with autopilot on; the pilot not flying (Captain) put their feet on the rudder pedals causing a minor input. This is a constant problem with 10-15 percent of company pilots who believe it is OK to touch the controls of an airplane they are not flying; and it is in contrast with the Flight Operations Manual. I do not know where they developed this unprofessional and unsafe tendency. The pilot not flying should be at the ready position to take control should an autopilot malfunction; or if the pilot flying becomes incapacitated; but not actually touching the controls; which causes a distraction; causes the aircraft to react in a way the pilot flying was not expecting and then must correct the situation. I do not believe having such distractions is the best course of action on a commercial airplane; especially when IFR. If the FAA searches their accident database it may be interesting to learn how many incidents of catching a wingtip on landing because the pilot not flying made an input has occurred. It may also enlighten the FAA if the inspectors decided to notice how many of our pilots as the pilot not flying are violating the FOM.