Genuflection is the placing of your right knee on the floor while keeping your back straight. This Roman custom was a sign of reverence and humility toward the Lord or Emperor. Since there is only one LORD Jesus Christ, Catholics use this practice when in the presence of the Eucharist or facing the Tabernacle. When you enter a Catholic Church you should always face the Tabernacle and genuflect whether you are passing the Altar or entering your pew.