Most of the times when we defend ourself we have disadvantage against the attacker(s). We might not know the place, the attacker(s), his/her strength, strategy, weapons, direction and also the surprise might block us for a little time.
We cannot be prepared for everything, however situational awerness might be our friend. Also if we need to use physichal contact it is generally a good idea to know what part of the body we should attack. As well we should… we must keep in in our mind that there are consequences for our actions and accessive force is a very serious expression front of the judge. We don’t want that.
When we practice we should do it with proper techniques. Our targets are the vulnerable points of a human body. Remember, when you are in a real life situation you react how you practiced during trainings, therefore we should practice properly.
In the great book, Fighting fit, Col. David Ben-Asher described perfectly the most important vulnerable points and the physuchal effects when they are being attacked. I cannot express this subject more clearly and easier, so… (page 77 and 78)