Genuflection or genuflexion is the act of bending a knee to the ground, as distinguished from kneeling which more strictly involves both knees. From early times, it has been a gesture of deep respect for a superior. Today, the gesture is common in the Christian religious practices of the Anglicanism, Lutheranism, the Catholic Church, and Western Rite Orthodoxy. The Latin word genuflectio, from which the English word is derived, originally meant kneeling with both knees rather than the rapid dropping to one knee and immediately rising that became customary in Western Europe in the Middle Ages. It is often referred to as "going down on one knee" or "bowing the knee". In Western culture, one genuflects on the left knee to a human dignitary, whether ecclesiastical or civil, while, in Christian churches and chapels, one genuflects on the right knee when the Sacrament is not exposed but in a tabernacle or veiled.

Prostration is the gesture of placing one's body in a reverentially or submissively prone position. Typically prostration is distinguished from the lesser acts of bowing or kneeling by involving a part of the body above the knee, especially the hands, touching the ground.