Sadly I can’t embed this one: http://youtu.be/QHSXZnxLZ0I
An interesting illustration (on a ballistic gel dummy) of why most “knife defences” won’t work. There is no way most of what is taught within the martial arts will work when an aggressive attacker means it. No “stabbing and standing” in the style of a classical lunge punch here; just lots of damage done very quickly.
All the best,