In many Asian and Middle Eastern cultures today, the act of bowing has tremendous significance both religiously and politically. Here is a scholarly insight that helps us to appreciate the symbolism of that posture.
"For much of the Old Testament, whether in Hebrew or in the Greek of the Septuagint, "bowing down" and "worship" are linguistic equivalents. Thus, according to George E. Mendenhall:
The symbolic action denoted by the Old Testament Hebrew term consists of kneeling before the god or person having power, and then leaning forward until the face rests on the ground, or sometimes becoming completely prostrate. Sometimes the act is completed and acknowledged by the god’s or the king’s placing his foot on the head or neck of the worshiper. The symbolisms should not be difficult to understand. The situation is that typified by a captive of war. The man has been rendered powerless by a superior power, and henceforth his fate is completely in the hands of the mighty one. He is in a state of absolute dependence upon the will of the victor, and this is the first basic significance of the act."
From such a perspective, incidentally, it is worth noting that the Islamic term "mosque" derives from an Arabic word masjid, meaning "place of prostration."
Burkhart, John E. 2002. Worship: A Searching Examination of the Liturgical Experience. Eugene, OR: Wipf and Stock Publishers (reproduced with permission from the Westminster Press, pg 103)