Victor R. Claveau, MJ
If you cannot genuflect because of physical limitations, a profound bow (90º bend at the waist) is appropriate.
GIRM 275. A bow signifies reverence and honor shown to the persons themselves or to the signs that represent them. There are two kinds of bows: a bow of the head and a bow of the body.
a. A BOW OF THE HEAD IS MADE WHEN THE THREE DIVINE PERSONS ARE NAMED TOGETHER AND AT THE NAMES OF JESUS, OF THE BLESSED VIRGIN MARY, AND OF THE SAINT IN WHOSE HONOR MASS IS BEING CELEBRATED. (This is during Mass).
b. A bow of the body, that is to say a profound bow, is made to the altar [as the altar represents Christ]; during the prayers Munda cor meum (Almighty God, cleanse my heart) and In spiritu humilitatis (Lord God, we ask you to receive); in the Creed at the words Et incarnatus est (by the power of the Holy Spirit . . . made man); in the Roman Canon at the words Supplices te rogamus (Almighty God, we pray that your angel). The same kind of bow is made by the deacon when he asks for a blessing before the proclamation of the Gospel. In addition, the priest bows slightly as he speaks the words of the Lord at the consecration.
A bow of the head is always appropriate whenever you speak or hear the name Jesus. The tradition of reverencing the name of Jesus takes its origin from St. Paul, who wrote in his Letter to the Philippians 2:9-10: “God greatly exalted him and bestowed on him the name that is above every other name, that at the name of Jesus every knee should bend … and every tongue confess that Jesus Christ is Lord. …”
The custom was formalized at the Second Council of Lyons in the 13th century, which decreed the special honor due, “that at the name of Jesus every knee should bow; whenever that glorious name is recalled, especially during the sacred mysteries of the Mass, everyone should bow the knees of his heart, which he can do even by a bow of his head.”