Scenario: you have a knife and you’re in a fight. Somebody grabs your knife hand. What do you do?
If you’re like most people, your immediate focus is to free your knife. The unsophisticated reflex is to try to use your other hand to pry the grab free; the trained reflex might be some form of grab-escape technique, like a wrist lock.
While you’re doing that, what are you not doing? Well, you’re not striking. You’re not improving your position. You’re not making any progress towards winning the fight, all you’re doing is trying to recover the status quo.
When someone has a weapon, they tend to get very focused on the weapon. The weapon is usually by far the most powerful tool available, and so it certainly makes sense to prioritize it. In combat you don’t have very much attention to spare, however, and in the process of prioritizing the weapon people often neglect the rest of their available weapons.
When someone grabs your wrist or hand, think about what they’ve done – they’ve established a mechanical connection between their body and yours. They’ve used one of their hands (or, if you’re really lucky, both of their hands) to immobilize one of your hands. This is exactly the same thing that would happen if you grabbed them instead: you’d establish more or less the same mechanical connection, and you’d remove the same set of weapons from the fight.
Now, they presumably chose their trade in a way that seemed advantageous: if they grab your knife hand with their empty hand, that’s a win for them. All they’ve done, though, is to remove your advantage and brought the fight to an equal plane – they haven’t gained an advantage of their own.
I mentioned grab-escape techniques above, and I was thinking about, for example, turning your wrist through their fingers, locking their wrist, peeling a finger, all of that sort of thing that always gets taught in self-defense classes. That’s all fine, but it doesn’t accomplish anything other than escaping the grab. Turns out, breaking someone’s nose will usually also make them let go, and as a side effect now they have a broken nose. In the words of literally every teacher I’ve ever had: “if you can just hit them, just hit them.”
If they do something like grab your shirt, that’s even better: they’ve taken away one of their weapons in exchange for none of yours. By all means, please hang onto my shirt, I’d be delighted to use my free hand to hit you until you decide it was a bad idea. You presumably grabbed me with the intention of pushing or pulling me, but if my structure is good, nothing stops me from moving you instead.
So, how do you train this? The reflex to fight the grab is a strong one, and it takes practice to respond with offense instead of trying to escape. The first step is just to practice using multiple weapons (punches, kicks, headbutts, grabs, throws, etc.) This can be a bit counterintuitive – “I have a sword, why am I kicking them in the shins?” By doing this, however, if your sword is unavailable for whatever reason you’ll more easily and automatically fall back on your other weapons without that tunnel vision. It’s also never a bad thing to introduce some secondary strikes into your attacks – as a distraction, if nothing else.
Once you’ve done that, then you can train for the grab itself. Ideally you’d do this with a partner, of course, but failing that you can hold a weapon in your primary hand as if had been grabbed and then work through responses. Hit the attacker several times with whatever weapons appeal to you and then break the grab and use the weapon to finish them. Odds are that if you’ve hit them effectively, you won’t need to break the grab, they’ll let go on their own.
You can also practice attacking the grab itself. This is a bit different from trying to escape from the grab, because the goal here is to damage the limb that’s holding you. Elbow breaks, wrist locks, finger breaks, muscle-body strikes, nerve strikes, they’re all options. By the way, I’m not a big fan of nerve strikes in general because they’re really difficult to pull off at speed, but they’re a whole lot easier when the limb you’re hitting is attached to your own body! Attacking the grab may or may not make it let go, but the damage done will stick after it does let go so at least you’re making progress.
Having a weapon is a powerful advantage in a fight; that’s why there have been so few people throughout history who voluntarily went into battle unarmed. That said, it’s important not to let your weapon become a weak spot by over-emphasizing it.