The Science Behind a Punch

Tungod, Inabanga, Bohol – A punch is often associated by boxing experts and aficionados with the concept of force and power. We regularly hear these terms mentioned by boxing commentators in their blow by blow account of a boxing match, though technically, their definitions of force and power aren’t exactly what they mean in physics, strictly speaking. Nevertheless, it is most certainly refreshing to incorporate a little bit of physics into some aspects of boxing. After all, boxing is also science in itself – the so-called sweet science.

But worry not because in this article, I won’t subject you to mind-boggling calculations; much less force you into a state of induced headache.

Anyway, I believe that there is an easier way to make comparisons between punches than through the concept of force… and that is through the concept of momentum. Simply put, momentum p is the product of a moving object’s mass m and its velocity v. In this particular case, the object referred to is the fist.

p = mv        (momentum = mass x velocity)

Keeping all other factors constant, the bigger the momentum, the bigger the force of impact and consequently, the bigger the damage inflicted as well. This is probably the reason why big punchers like Roberto “Hands of Stone” Duran are called heavy-handed, while boxers like Malignaggi are called feather-fisted. In addition, this is also the reason why boxers in the heavier weight class tend to hurt those in the lower weight class more effectively than the other way around. Therefore, this makes the creation of weight divisions necessary. Mass and velocity (or speed) are two parameters that affect momentum. For people of the same weight, speed is the determining factor. However, please take note that these general statements only consider a stationary target, to save ourselves from the more complicated concept of impulse (change in momentum), and make things a whole lot simpler. Nonetheless, for those who are interested, this concept is discussed a little bit later in the article.

We can also use the concept of momentum in differentiating the impact of a jab and a power-punch. A jab only utilizes the weight (or mass, to be technically correct) of the fist and the arm, while a power punch utilizes the weight of the whole body, which translates to a bigger momentum upon impact and more damage inflicted.