People participate in a greater measure when we stand. It seems to be easier to sing while standing, perhaps because the diaphragm is not restricted. It also seems that when people follow the scriptural pattern, worship is not restricted. And the Levites, of the children of the Kohathites, and of the children of the Korhites, stood up to praise the LORD God of Israel with a loud voice on high. Nevertheless, if anyone is unable, weary or just doesn't want to stand, it is perfectly fine to sit during worship.
Worship is more a posture of the heart than of the body anyway.
The personality and culture of each church is very distinct. In some churches, you would never see anyone dance before the Lord. In others, it is very common. In our church, on occasion, people do dance before the Lord. We encourage every scriptural mode of worship.