Often it has been said that as human beings, "we are almost helplessly self-centered." This of course is due to what we call "original sin". The "fall" of man was at the point of his deciding to go it his own way instead of God's way.
This self-centeredness is also found in our worship. We may be right as to the object of our worship - we all know that we are to worship the One True God, the Creator, the Father of All. But our self-centeredness still gets in the way, because we want to worship God the way we want to worship Him.
There is a simple invitation in the Bible which suggests to us the way we are to worship in respect to our position. It's found in Psalms 95:6 - "O come, let us worship and bow down: let us kneel before the LORD our maker."
To worship is to bow down.
Right away, someone will respond, "It certainly doesn't mean that the only way to pray or to worship God is in the kneeling position! If I want, I can sit, I can stand, I can worship while walking, jogging, driving my car (with my eyes open, of course) - I can even worship while laying down." I once had an Indian friend by the name of Thomas Matthew - at the time I knew him he was serving as a Chaplain Intern in a state hospital. He said that if he ever would become a Pastor, he would program his answering machine to respond to late night callers with this message, "Thank you for calling Pastor Matthew. Unless your call is an emergency he should not be disturbed - he's lying prostrate before the Lord."
So no, we're not going to argue the point that the only possible worship is that kind which happens while we're on our knees. But the Bible does say it, "let us kneel before the LORD our maker". You see, the problem isn't so much that we don't do it, but that we don't want to do it. Perhaps we've become so used to singing the song "Just As I Am", that we've forgotten that He only accepts those who come to him "bowed down." It may not matter too much to God what our physical position may be when we worship, but He is very concerned about our inner posture.
Do you remember the story of the little boy who was told to sit down? After repeated commands, pleas and even threats, the boy finally sat down. And then he said, "I may be sitting down on the outside, but on the inside, I'm still standing up."