The Foundation – Why Mechanics Matter
Author's Note This article represents my personal understanding and interpretation of traditional karate as taught by Hidetaka Nishiyama Sensei and followed by Avi Rokah Sensei. While I have endeavoured to accurately represent their teachings and methodology, any errors, misinterpretations, or misunderstandings are entirely my own. The insights and principles discussed here reflect my current level of comprehension as a student of this art, not the definitive word of my teachers. Andrzej
Beyond the Language of Guesswork
In the dojo, we often find ourselves using terms like “power,” “force,” “speed,” or “strength” as if they mean the same thing, when they describe completely different physical phenomena. For someone training in traditional karate as taught by Nishiyama Sensei and continued by Rokah Sensei, this vagueness may create real problems. If our goal is to develop a technique that relies on efficiency rather than chance, then guesswork is our enemy.
Without understanding the underlying mechanics, students default to raw muscular power or rely on being faster, younger, or stronger than their opponent. These advantages are temporary and unreliable – the body ages, opponents vary, and conditions change. This is why clarity about mechanics matters. It provides an objective physical standard that cannot be faked or argued with. Either your joints are aligned with the floor’s reaction force, or they are not. Either your technique generates the impact needed for Todome (“finishing blow” in Nishiyama Sensei terms), or it does not.
We often hear claims that traditional karate is “superior” and that it somehow magically instills “good” character traits and humility (only because we train the art). There is no magic. The humbling nature of this path comes from pursuing a physical perfection that is, by definition, impossible to fully reach. This pursuit forces you to confront your ego every day in the dojo. If you cannot align your body with the floor, no amount of “spirit” will bridge the gap.
The difference between traditional karate (as practiced by followers of Nishiyama Sensei and Avi Sensei) and many other styles and combat sports is one of fundamental purpose. Sport competition is built around winning within a ruleset—accumulating points, exploiting speed or “size” advantages, outlasting an opponent. Traditional karate is built around Todome—the single, decisive finishing blow. These are not the same goals. To make Todome a reality rather than a hollow assertion, we must move beyond speculation and train with a clear understanding of the specific physical quantity we are manipulating at any given moment [1].
We begin with potential energy—the “loaded” state of the body, the pressure we store through internal compression before movement begins. When we release that compression into movement, we convert it to kinetic energy, the energy of our body mass in motion [2]. However, the effectiveness of the strike depends on how that energy is transitioned into impact force.
This final variable, force, is what creates the impact required for Todome. While energy can be shifted and recycled, force at the moment of impact always follows a specific vector [3]. Whether the technique is linear or rotational, the body acts as a structural conduit directing the ground’s reaction toward the target. If the joints are not aligned, the force built from the ground will “leak” into your own structure. To achieve Todome, the kinetic chain must be solid at impact, ensuring force travels through a pressurized, unified body structure [4].
The Architecture of the Two Pushes
Sensei Avi Rokah described Nishiyama Sensei as “very pragmatic and a philosopher at the same time.” Nishiyama Sensei sought to prove the “why” of karate through the laws of Newtonian physics, teaching that “karate is the art of using the floor.” He emphasized that true effectiveness is a product of the reaction force received from the ground rather than a product of isolated muscular tension [1, 12]. Sensei required that “body unity” coincide exactly with the maximum ground reaction.
To help students understand this concept, Sensei Avi explains the process through the “two pushes.” The first push is the initiation—the moment you engage with the floor to launch your centre of mass toward the target. This might be a drive from the back foot in stepping techniques, a twist of the hips in rotation, or any movement that uses ground reaction to move your centre. Many students move without truly connecting to the floor, becoming light and losing power. Properly done, according to Rokah Sensei’s teachings, the first push is a trigger that sends your centre toward the target with the full weight of your body behind it [23].
The second push occurs at the time of impact. It is a sharp, strong pressure to the floor that “connects” your body into the ground [3, 25]. This creates what we call total body contraction (kime). This is the act of rooting yourself so that the reaction from the opponent’s body travels through you and into the floor, rather than pushing you backward. In this moment of total body contraction, your “effective mass” includes the ground itself. Without this second push, your technique is weak, and you will find yourself being pushed away (bounced back) by the force of your own strike [13, 19]. The technique remains “hollow” and cannot achieve Todome.
In Part 2, we'll explore how the body becomes a conduit for this ground force — the role of stances, internal pressure, and what Sensei Avi calls the "water balloon" effect. The floor provides the force, but the body must be structured to transmit it without leaking power.