[NYFriend]

The article is misleading. The Elbow, specifically the forarm portion, is the hardest or most solid part of the human body. You're right that a forearm shot dosn't hit as hard as other strikes, like a stomp on an attacker whose on the ground. I don't know if an upward knee hits harder than a kick or puch. Each kind of strike has prefered targets though, and a woman can probably hurt a male attacker worst with a knee to the groin than a forearm blow to the chest (figuring the woman is shorter and will have a harder time hitting the attacker up high in the chin or nose.)

[ican'tbelieveit]

Actually, if the woman were shorter than her attacker, the elbow swing (assuming he is behind her) is going to strike the attacker in the stomach region. That could definitely make an attacker double over.

[Doctor Stochastic]

High heel on the top of the foot isn't ineffective.

[BlueNgold]

The knee, while effecive, is more easily blocked or avoided, and cannot be aimed as well or repeated as quickly as the elbow. Additionally, the impact force of the elbow is greater (small surface area to high power ratio) than even the forearm. Also, the elbow strike techniques generally follow with a 'push away and run' protocol of some sort.