This is the hand of the arm that is on the same side of the body as your Front Leg. For example, if your right leg is back then your left leg is the Front Leg and your left hand is the Front Hand. It remains the Front Hand as long as the left leg remains the Front Leg. It does not matter if your right hand is currently placed forward and closer to your opponent than the left hand. The left hand, in this circumstance, remains the Front Hand.