Front Leg

The leg that is forward and closest to your direction of focus. For example, if you are standing in Heiko Dachi facing an opponent at angle 1, then stepping back with the right leg will move it further away from your opponent and make your left leg the Front Leg.

There is neither a Front Leg nor Back Leg if you are in a parallel stance such as Heiko Dachi (unless an opponent is positioned somewhere other than directly in front or behind you).