U is for Under eights
Under eights aka loop of infinity
This movement is usually done with the hips, but can be performed with the upper body too.
Imagine an eight, on its side, and as if drawn on a wall. This is the shape you will make with your hips, no forward backward twist. The emphasis is on the downward action - focus on your right hip; push it down, out and up and back to centre; now repeat action to left hand side
U is for undulation
Undulation is a movement which fits with its descriptor! It is sometimes known as a backward camel, sometimes a body wave. The upper body moves forward, up, back & bottom half catches up. Quite often performed whilst stepping backwards, or diagonally.