This is one of those martial arts techniques that requires tendon strength, flexibility and good balance just to execute it correctly. Great as a fitness exercise on its own. If you set yourself a goal of doing a few hundred of these in just one session you are guaranteed a tough workout. 

What's involved: Quads, front hip flexors, lower abs, glutes, hamstrings. lateral abs, adductors.

Powered by: Quads (primarily), hamstrings. 

Tip: Raise your leg in the chamber position (almost like you're ready to execute a front snap kick), then pivot on your standing foot changing the orientation of your body so you can execute what is essentially a turning kick in reverse.