Being able to generate power is important, but just as important is being able to do something with it.
When you look at the physics equations that describe motion, particularly force – mass is a major component.
- Force equals Mass time Acceleration
- Kinetic Energy equals 1/2 Mass times Velocity Squared
In both instances, more mass means more energy. With martial arts we want to get as much mass behind our hits as possible.
If you punch with just your first, you’re not going to get a lot force. You need to get your whole body behind your hits.
There’s an imaginary line that bisects (cuts it in half) your body. The closer you can get to your centerline being behind your strikes the more mass they’ll have behind them.
You have to be judicious in contracting your muscles, to generate speed. But you need something solid to transmit the force into your target. Your skeleton is nice and rigid, but if the bones in your hands or feet aren’t lined up properly you can easily hurt yourself on impact.
The basic rule is to create a straight line between what you’re connecting with and your spine.
In the case of a fist, you want to connect with your two big knuckles the bones in your hand, you want to line up with your radius and your ulna, then your humerus into your shoulder – which connects with your spine through your clavicle and and your scapula.
Kevlar, one of the major materials in modern body armor is particularly effective at stopping hollow-point defensive rounds, meanwhile, it can’t stop a sewing needle – even though the sewing needle is moving much more slowly than the hollow-point.
The difference between the two is the amount of area the force is spread out over. In imperial units, we use Pounds per Square Inch (PSI) express how much force is being exerted over a given area.
If you halve the surface area over which a given force is applied, the force applied over that area is doubled.
This is why tight weapons are important, if using a punch concentrate the force over the two larger knuckles as opposed to the face of the fist.