In Episode 1 of the Making An Impact series, we looked at how Pressure affects our striking ability. We learned that pressure is a measurement of the relationship between Force and Area, and that by decreasing the surface area of the impact site, either by using a more precise tool or by choosing a more precise target, we can increase the pressure of our strike. In this article we will discuss the second factor in the equation: Force.
When we think of Force, we often think about how hard we have to push something to get it to move, or how hard we have to hit something to get an effect. But Force, like so many other scientific measurements we use so loosely in every day speech, has a specific definition. Just to reiterate before we begin, the definitions we use in this series go much deeper than we will perhaps delve, and we will be focusing on understandable examples as they relate to our martial arts. So, what exactly IS Force? Just as area was calculated in our last article by multiplying two measurements (length and width), Force is calculated by multiplying the object in question’s Mass by its Acceleration. We express this with the formula F=ma.
In Episode 1 we learned that Pressure equals Force divided by Area. By decreasing Area, we increased Pressure. The opposite is true when trying to increase Pressure by manipulating our Force measurements. Assuming the Area of the strike remains constant, in order to increase Pressure, we must also increase Force. In common speech, if we want our strikes to have a greater impact, we must simply hit harder. Based on the above formula for Force, we can see that there are two ways to increase the amount of Force in our punch: we can either add more mass to the strike or we can add greater acceleration.
How can we accomplish this? Well, let us look at each variable in turn. First, let us define Mass. In every day usage, Mass is referred to as “weight” and is measured in kilograms. While this is not strictly scientifically correct, it is sufficient for our understanding. All other things being equal, would you rather have a penny dropped on your foot or a car? Obviously, the penny has less mass and therefore has less effect on our delicate little piggies than Uncle Joe’s Oldsmobile. In the same way, all other things being equal, you would probably rather be punched by a 90 pound grandmother with osteoporosis than by a 200 pound bricklayer.
There are several ways we can increase Mass. We can begin a training regimen that will increase our muscle mass (which will have added benefit when we discuss Acceleration), we can include resistance training and skeletal stressors (such as working the makiwara) that will cause our bones to become more dense, or we can simply wrap a roll of quarters in duct tape and use it to weight the fist. More Mass, however, makes it a bit harder to maintain or increase the other factor we want to develop: Acceleration.
In this case, the object we are most directly looking to accelerate is our striking appendage (the fist, for example), which will in turn transfer that energy to the item being struck (the nose, perhaps), causing it to accelerate as well. There are few shortcuts to increasing the rate of acceleration. While we can increase mass by using the roll of quarters, we must actively seek to build our body in order to realize any real gains in the acceleration department. We must build lean muscle mass with appropriate ratios of quick twitch and slow twitch muscle fibers (the methods for this are beyond the scope of this article, but a quick internet search should get you started). We must decrease tension in opposing muscles. we can make subtle changes in our stance or technical execution of a strike that will allow us to move more efficiently while recruiting multiple muscle groups. In short, the only real way to increase your rate of acceleration is through training.
Also worth noting are two other formulae that relate directly to our topic. The first is Momentum. When learning to strike effectively, we are often taught to visualize a point behind our target, and to punch through the actual target toward that point. This allows the strike to harness the Force we have worked so hard to build for a greater period of time by allowing the Momentum of the technique to carry through the full range of motion before opposing musculature kicks in for braking and recovery. Technically speaking, Momentum equals Mass (which we’ve already discussed) times Velocity. (Again, while this may not be precisely how we are using the term, it fits for our purposes.) Velocity, the second equation, is equal to the speed of an object times the direction of the motion. We want the most amount of Mass behind the strike, having Accelerated as quickly as possible to as high a Velocity as possible and to land in as direct a fashion as possible, with minimal angle for deflection, which would waste all of this fancy math and intense effort (for more on deflection and angles, check out our next episode in the series).
In review, we have learned in this episode that we can increase our impact by increasing the amount of Mass behind the punch, and by increasing the speed of the punch as it makes contact. This explains how an ultra fast welterweight can hit with devastating consequences, and how the slower yet bulkier super heavyweight can generate so much power (yes, power, because now you know what it means).
Up next — Making an Impact (Episode 3: Angles)