After seeing yesterday's story in the LA Times about kneeling, I consulted Earthen Vessels, a little book by Gabriel Bunge, O.S.B. subtitled The Practice of Personal Prayer, According to the Patristic Tradition. The book doesn't deal with prayer during Mass, but it seems like it could lend a little insight into the role of kneeling, especially since the liturgists seem to dismiss it altogether, saying it doesn't comport with human dignity.
According to Bunge, standing is the "basic posture" of prayer, but it's "by no means the only posture." He then lists the importance of kneeling, citing over twenty Old Testament, New Tradition, and Patristic sources. When addressing whether a person should kneel or stand, he says, "The answer is not 'either-or,' but 'both-and.'"
Of course, the modern liturgists don't admit both. It's all standing, all the time.
