Is there any precendent for this in Scripture?

I've known of some who say they believe it is wrong to do this in public worship and yet do it in private worship.

I can also see that there are two ways one could (rightfully or wrongfully so) raise their arms in worship. They could do it in a charismatic way and flail them about, or they could do it as a sign of surrender and humility before God.

So how do we tell what is permissible (like David prostrate before God) and the present emotionalism of charismania?

Further, is there a regulative principle to private worship, as there is one to public?

True godliness is a sincere feeling which loves God as Father as much as it fears and reverences Him as Lord, embraces His righteousness, and dreads offending Him worse than death~ Calvin