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Genuflection on Left Knee
How:
Kneel on your left knee for a moment, bringing the left knee all the way to the floor and keeping the back straight. Hold for a moment, then stand. (The word is pronounced “jen-you-flek’-shun”)
When:
When greeting or leaving the Pope or other hierarchs with the rank of Bishop or above and who have jurisdiction over you (only when the Pope is not present) – e.g., to the Bishop or Archbishop of your diocese, not of a neighboring diocese. During the left-knee genuflection, a kiss is given to the hierarch’s ring. Then stand.
Genuflection on Right Knee
How:
Looking at what you are genuflecting toward, kneel on your right knee for a moment in the manner of a man proposing to a woman, bringing the right knee all the way to the floor, close to the heel of the left foot, keeping the back and neck erect. Hold for a moment, then stand.
When:
Genuflect toward the Tabernacle where the Blessed Sacrament is reserved, and each time you pass in front of it (except when you’re in procession, such as standing in line for Communion, or returning to your seat afterward). While this should, on one level, be a matter of habit, it shouldn’t be done thoughtlessly. Remind yourself when genuflecting toward the Tabernacle that you are kneeling before God. Praying mentally, “My Lord and My God” is a good habit to get into while genuflecting on the right knee. If the Tabernacle is not on the Altar, genuflect toward the Altar and the Altar Crucifix.
Before a relic of the True Cross when it is exposed for public adoration.
On Good Friday to Holy Saturday, after the ceremony of the Adoration of the Cross, genuflect when passing in front of the exposed Crucifix on the Altar.