Karate: The History and Practice of the Art/Hand Strikes
For self defence applications, hand strikes are the preferred technique. If delivered correctly using hip rotation a hand strike is fast, precise and effective. Both hands should always be in use - we'll discuss this later. In contrast, in sport karate, leg strikes are often favoured as they can be delivered at range. While circumstances may arise where a leg strike is the better technique, it is rather rare as real combat typically occurs at very close range and the last thing you want to do is lift a leg off the ground risking your balance.
A Note Regarding Young People
Children and young adults have much softer bones than adults. Compared to an adult, a child can easily break a bone when punching. Therefore, in general children are better training to use techniques like the Heel of Palm Strike that do not risk damaging the hands.