Here's the first verse one of tongue-in-cheek rewrites of a class gospel favorite:
Stand Up, Stand Up, for Jesus:
For Praise Time
Though legs be tired and sore
We stand up for a praise song
Then stand for fourteen more
With arms and hands uplifted
So when we look around
We know who loves our Jesus
The rest are sitting down
Well, the problem with my little soap box is that standing in worship, for three-fourth's of the history of the church, was universal. People in Europe stood in worship until the fourteenth or fifteenth century. In some traditional Orthodox services, everyone still stands. Since there are no seats, it's not exactly optional.
Introducing pews (a word for benches that is ironically rooted in the Latin word for podium) for people in church came only very late in the Medieval Era. Since the great stone church buildings of Medieval Europe were not heated, standing, at least in winter, would have been a very good idea.
In reality, standing was the normal and expected position students took throughout the ancient world. To sit was to assume authority. To stand was to mark yourself as a learner. Jesus sits to teach (Matthew 5:1-2). Pilate sits to pronounce his judgment (John 19:13). If the Pope were to speak ex cathedra (from the chair), then Catholic doctrine asserts he would be speaking with the infallible authority of the Apostle Peter.
Of course, I also think we need to make room in our understanding of worship for people who simply cannot or do not want to stand during the music. If we claim to offer some freedom in regard to what people can do (you can raise your hands without being Pentecostal or kneel without being Catholic), then surely we must graciously allow the sitters to be among us without being the subjects of our secret evaluations. It is also simple kindness to recognize that standing for an extended period is painful and difficult for some.
Like all patterns of expected behavior, standing in worship has evolved from spontaneous to expected to assumed. In that, it is true that it is lost some of its original fervor, and may be on its way to becoming just another meaningless ritual some future generation will challenge and reject. But, much as I hate to admit it, the claim that the practice is something new in worship doesn't really have a leg to stand on.