This first video is self-protection and edged weapons expert Michael Janich demonstrating the effects of a small blade attack on flesh. From his Paladin Press Video, "Martial Blade Concepts."
http://www.youtube.com/watch?feature=player_detailpage&v=9PWmRWjDhYw
This next video is of Jeet Kune Do expert and trainer to more than 18 Federal Agencies, Paul Vunak showing the effects of a blade attack against flesh. From his PFS video, "Street Safe2."
http://www.youtube.com/watch?feature=player_detailpage&v=Nqy95dWUFO8
Self-protection expert and Edged Weapons expert Steve Tarani demonstrating the effects of a curved blade against flesh. From his em3Video, "Mastering the Curved Blade."
http://www.youtube.com/watch?feature=player_detailpage&v=tG_7mz-Qsv8
And a little more from that video:
http://www.youtube.com/watch?feature=player_detailpage&v=QWAzGBLYxzE
And some real world examples: (Warning, Graphic images of actual wounds)
http://www.youtube.com/watch?feature=player_detailpage&v=I0d46oSJhq4
Now, while I don't agree with the last statement in the last video where they say that knives don't protect, I will say this: Knives are extremely dangerous. Hand a knife to a 12 year old and you have a 50th degree black belt. Knife attacks are extremely serious. And, the majority of what's taught in Martial Arts Schools as defenses against knife attacks is not only ludicrous, but could easily get someone killed.
The key is to learn how criminals actually use their blades during an actual attack, and then use that to figure out what to focus on in your training.
Now, go out and train hard and I'll talk with you all later.
Yours in peace,
Brett Stepan
P.S. I'm not making any money recommending the above videos, but I'd personally recommend each of the videos that Mr. Janich, Mr. Vunak, and Mr. Tarani all offer. It's more than worth your investment.