I am a former TKD practitioner myself, and this was always one of my favourite techniques. It enables you to develop a lot of power and momentum in a short period of time and can be used as a pushing technique or a snapping technique. In addition it can be used to deliver devastating body blows, though some practitioners also use it to strike to the face or knees.

Sometimes it is useful to first step forward with your back foot and then pivoting on it to strike with you other leg. This allows you to use it from greater distance or to feint and disguise it.

Here is Cung Le using the technique in a kicking combo, using a rear turning kick first.