I thought a genuflection was merely a Catholic thing: cross yourself and touch one knee to the floor as you keep your body otherwise erect. Maybe there is such thing as an Orthodox genuflection.
The AWRV does that. However, the term genuflection originally meant a bow rather than kneeling. A medieval
genuflectio is crossing oneself with a 'profound bow' - same way as the normative English customs, and Russian customs. There was a form known among the Anglo-Saxons where they would kneel on both knees, then trace a cross on the floor in front of them, prostrate and kiss it. It was a controversial practice, however, for tracing a cross where people stepped with their feet.
The Parson's Handbook, IIRC, has a discussion of the history of
genuflectio - though it might also be in other Alcuin Club publications. (I think Daniel Rock DD might have discussed it as well.)