This is part of a series of articles providing insight into concepts used in Kenpo to increase power and make techniques more effective.
Borrowed force is a Kenpo principle of using your opponent’s force and momentum against them by using it to add power to your own technique. While there are several variations of this principle, the easiest to understand is the direct attack in which you meet your opponent’s forward motion with your own forward motion (picture two cars in a head-on collision – This generates more force than if you hit a parked car or a car traveling the same direction). An example of this is meeting a stepping punch by stepping in, parrying the punch, and striking with a knee. The attacker’s forward motion amplifies the power of your knee strike.
Similar to the direct attack, you can use your opponent’s force and channel it through your body to add power to your strike. Examples include turning the power of an attacker’s forward push into torque power to deliver a more powerful strike. Since in Kenpo, we can attack at any angle, we can take that same push and deliver a more powerful groin kick by going with the attacker’s push and lifting our leg.
To maximize the power of borrowed force, it is important that you do not interrupt or prematurely stop your opponent’s momentum. You want his energy to continue until you meet his momentum with your own strike moving opposite to the direction of their force. Of course, you can redirect their energy and use that as borrowed force, but that’s a topic for another day.