I know a few people who carry a knife for defense as well as utility. For the longest time, I did not find the value in it. After attending some seminars, I now understand why people would use it as a defense item. I still would not, because I am not proficient in the techniques and in a defense situation a poorly understood technique can be more dangerous than no technique.
Many of the people that say they would use their knife for defense never train in it. The closest they come is cutting an apple or a piece of twine. I believe that they are putting themselves in more danger by carrying a tool that they don’t know how to use or would have trouble using when they are under stress.
Many knife holders think that the act of carrying is a defense strategy. If people do not train with the tool, they are setting themselves up for disappointment. A knife is not a shield. Just having it on your person or even holding it in your hand will not save you. You need to know how to use it and more importantly you need to be able to use it in a stressful situation.
To become proficient in defense, you need to train against other people. The touch and fight back factors are where the rubber hits the road. If you do not have another person in front of you for at least some of your training, you are not ready to defend yourself, especially if you are expecting to defend yourself with some kind of weapon. Many people who carry a weapon don’t practice with it and if they do, they do not practice with it in a defense scenario.
At this point in my training I use the knife for fun and education. I do not carry a blade but I am beginning to understand why some of my training partners do. If used properly, the knife can be a great defense weapon. The problem is that you can go from defense to excessive force with one wrong move. You need to be cognizant of how you are using your tools in self-defense. Without proper training, you can kill someone or hurt them beyond the bounds of self-defense.
Just like a weapon, a self-defense plea is not a shield. You need to mind your response. Excessive force can put you in jail along with your attacker. Remember that self-defense is also keeping yourself out of jail. You need to be thoroughly trained and you need to practice with any weapons system you want to employ for defense.
I went to an interesting weapons seminar. It was based on the zombie apocalypse. Since zombies move slowly, we were able to practice our techniques at a slower speed. After working the techniques in drills, we practiced against live attackers, first a single attacker, then multiple attackers. It gave you a real feel for person on person conflict. They were suited up with protective gear so we could realistically strike with training blades rather than just simulating the strike.
Working with aggressive attackers (suited up training partners) and having the ability to execute realistic strikes was an eye-opening experience. But even this was not fully realistic because we started with the training blade in our hands. A knife in a sheath or folded in your pocket adds more complication in a defense situation. Retrieving the blade also needs to be trained if you are going to use a knife in defense. A knife is not a good defense option if it is stuck in your pocket or somewhere else where you cannot reasonably access it.
I am lucky that I live and work in areas that have lower chances for violent attack. I feel comfortable enough with my open hand techniques that I do not feel the need to carry a knife. For those who do feel the need, find a good teacher to teach you the proper techniques, practice in realistic situations regularly and remember that excessive force can put you, the victim, in jail along with your attacker.