It's difficult to reach the leg with upper body striking weapons. You need to move a big mass of your body a whole lot of distance (to reach the opponent and then to reach downwards). This can only be done with utmost commitment to the technique and a good lunging motion.
I was happily striking our orange belter in the leg with a flat hammer fist. Before I did, I stepped on her lead foot so that she couldn't pull away (nice). And then I proceeded to hammer fist the outside of her thigh muscle and allow her to feel the pain as the strike penetrated into hit points.
The flat hammerfist is generally a good non-discriminating weapon. It serves my purpose well. But to really make a different, I modify the 'end-tackle' and proceeded to strike her with the corner of my fist - using the point of the smallest knuckle. The difference is significant and you can see the shockwave literally travel up her body into her face.
The strike I used was a variation hardly seen in any book but an extremely legitimate taekwondo technique. This leads us to the question "What is the role of the basics?"
My take is that the basics teach parameters of what should be done. This means that they are also encouraging you think of what also *could* be done. Adaptation and innovation need to occur so that you are more successful in accomplishing your objectives. Slight variations (some less overt than others) are not only encouraged, but highly prized when it hits the mark!
Dan Gun: Defence Against a Front Kick