being a christian doesn't exclude us from doing what we like. it just means we are more responsible for what we like. and by that i mean, do we like music that pleases God? in that case, it's really the song you are dancing too that gives Him the glory or not. you can dance however you want without that particular song, so your body movement is not relevant to the song in any way. however, are you repeating those lyrics? that is when you draw the line and are not glorifying God if it's secular. but if you change the lyrics and make it please God, than you are now worshiping Him. God made our bodys, why would a particular movement be any less blessings for Him than lifting our hands in church?
"know ye not that your body is the temple of the Holy spirit and that you were bought at a price?"