Martial arts are not just about technique and discipline—they are deeply rooted in the principles of physics. Understanding the physics behind martial arts can improve performance, efficiency, and even safety.

I will start with the simple stuff and cover more advanced ‘physics’ in future posts.

Newton’s Laws of Motion

First Law (Inertia)

– A body at rest stays at rest, and a body in motion stays in motion unless acted upon by an external force.

Application: Martial artists must overcome inertia to initiate movement. This is why in fighters there is usually movement when not in contact – side-to-side swaying or jumping around, for example. Being static requires more ‘force’ to move, than if already in some form of motion.

Second Law (Force)

Force equals mass times acceleration.

(F = ma)

Application: Increasing speed (acceleration) or mass (body weight behind the strike) increases force.

This is important if you want to know how much force you will feel when hit.

• The force will be proportional to the mass behind the strike, the heavier the blow the worse it is.
• The force will be proportional to the deceleration experienced by the strike when it hits you. When you are hit, you are the cause of the speed reduction, and you are the barrier that absorbs the energy. Therefore, the higher initial speed of the strike – the more damage done.
• The less time taken to stop the blow, the more damage done. This is the reason that fighters try to ‘ride’ the punch – so the deceleration takes longer with a lower peak value of the force felt.

Third Law (Action-Reaction)

Every action has an equal and opposite reaction.

Application: When striking, the opponent’s body exerts an equal force back on the striker’s body. Proper stance and balance prevent the martial artist from being pushed backward. Taking this the other way around means that pressing into the ground will enable a force to be generated away from the ground. This is also the reason that ‘punch from the floor’ is often quoted in martial arts.

Additionally, the joints are a very good shock absorbing mechanism meaning that all that power being generated is partly being absorbed by you and not being transferred to the attacker. This is why having good structure is important to negate the natural way of preventing harm to yourself (by dissipating energy in the joints).

---

It is one thing to use physics to determine the best way to strike, but at some point, practical measurements are necessary. One of the most comprehensive studies was done for the TV series ‘Fight Science’ which aired on the National Geographic Channel.

There are some clips on YouTube but you need a subscription to view the complete series:

I will examine the results in future posts.