Non-Catholics are amazed at the workout they get whenever they come to a Catholic Mass.
Sitting, standing, kneeling, genuflecting, bowing, beating your breast, making the sign of the cross, shaking hands, going to Communion—it is a lot of movement and gesture for one hour. So why all the hustle and bustle?
Human beings are both body and soul. We are not trapped souls imprisoned in bodies until released at death, as Plato speculated. We are a union of matter and form, of body and soul, more like what Aristotle proposed. Our bodies connect to the material world and our souls to the spiritual, and since both body and soul are united into one human person, we are citizens of both worlds, living in both realms simultaneously.
Catholic worship engages the whole person, body and soul. We hear the Word of God preached, we verbally respond and sing, we sit, stand, kneel, bow, and genuflect depending on what is happening or where we are located. We smell incense burning or the aroma of chrism oil perfumed with balsam. We taste the consecrated bread (called the Body of Christ or the Blessed Sacrament or Holy Eucharist) and we taste the consecrated wine (called the Precious Blood of Christ).
Kneeling in the Western Church is the most profound sign of reverence, whereas in the Eastern Church it is standing and bowing. A genuflection is a quick kneel on the right knee, while bending the left. It is a gesture of adoration and worship and is given to God alone. Since Jesus is God, His real presence in the Blessed Sacrament (the consecrated hosts in the tabernacle) demands a gesture reserved for God alone. Bowing is done before symbols like the cross or crucifix, the altar, the person of the bishop or priest (during Mass they act in the Person of Christ, in persona Christi, and as another Christ, alter Christus). A bow of the head is done whenever the Holy Name of Jesus Christ or the Holy Spirit are mentioned.
Parishioners sit during the Old Testament and Epistle reading from Scripture, but everyone stands at the Gospel to show its preeminence as the words and deeds of Christ. Catholics strike their breast during the Confiteor (I confess) as a sign of humility and admission of fault. The sign of the cross is the most prevalent and identifiable gesture of Catholicism (and maybe genuflection, too). The right hand is used with fingers together.
First the forehead is touched and the person says simultaneously, “in the name of the Father.” Then he or she touches the chest in the middle with the same hand, moving downward from the forehead, saying “and of the Son.” Next, the right hand reaches over and touches the left shoulder and says “and of the Holy” and moves across to touch the right shoulder and says “Spirit, Amen.”
That one gesture reaffirms two doctrines, the Holy Trinity (One God in Three Persons: God the Father, God the Son and God the Holy Spirit) and our redemption by the cross of Christ.