Learning Tools. This time about the famous Green Line. The green line does represent the correct lowering of the center of gravity (COG) while the dancer is preparing for a step (during it’s initial part). The red line represents the movement of COG when the lowering is at the end of the step. Examples: Green Line – lowering during first step of Natural Turn in Waltz. The Red line – the lowering at the end of the last step of Chasse. If you would like to read more about COG and balance – please click the link: http://www.physio-pedia.com/Centre_of_Gravity