There is a lot of talk about Fairbairn's 'gutter-fighting' knife system, but you must keep in mind a lot of that was about having an appropriate knife and stabbing the other person somewhere deadly. In the scheme of things, these systems are not really for fighting unarmed, hence these portions are typically questionable. There is a reliance on mindset and action. There has always been a lot of mystique surrounding military knife systems however when you think about it they are rightly inappropriate solutions in other situations and are probably most useful in considering the actions of an attacker in a civilian or policing context.
Puukko (Knife)
As always the stance is the same, like the pistol the knife is brought back to the hip:
The blade is shown as being held in an inverted position, with a sabre type thumb configuration:
No other offensive advice is given, from here it is from the point of being unarmed against the knife:
Possibly one of the worst demonstrations I've seen of this particular set up, one gets the feeling the demonstrator has had minimal training himself:
Unusually here the classic commando inside armlock goes to a bent arm variation:
