Then those who were freed of all venial sin, had not broken the fast and had been absolved of mortal sins, if these had been committed, humbly approached the altar with heads bowed, hands folded and kneeled at the altar railing in humble anticipation of their Savior who alone saves them.
Kneeling for Holy Communion is the most humble acknowledgement that "I am a sinner" and in Christian humility showing it by the bodily posture of kneeling, which is of humble acknowledgement of one's sinful status and seeking God's forgiveness. Standing is not. Especially at Holy Communion standing in the Latin Rite is a sign of the haughtiness of those who wanted to diminish our sense of sinfulness after Vatican II by its false "spirit" and our "right" to Holy Communion would be emphasized. "I'm okay, you're okay" of the 1970's isn't served well by kneeling for Holy Communion! To say that only Christ saves us and not our own abilities and haughtiness goes against the spirit of the 1970's when standing for Holy Communion was shoved down the throats of the collective Catholic Church of that time and by denigrating the 1500 year tradition of kneeling for Holy Communion in humble acknowledgement of the truth of whom we are: SINNERS!