Koken (弧拳)

Introduction

Koken (弧拳) is a hand form that uses the exposed outer area of the wrist as the striking surface. It is used in strikes and, in advanced practice, in some blocks.

Definition

Contact is made with the exposed outer wrist while the hand is held in a compact curved form.

Terminology

Japanese: 弧拳
Romaji: koken
English: arc fist / wrist striking surface

Structure / Form

• keep the hand compact
• flex the wrist forward
• place the thumb near the base of the middle finger
• expose the outer wrist as the contact area

Striking surface

Primary: exposed outer wrist.
Avoid contact with the fingers, palm or forearm.

Basic principles

Maintain a stable curved structure and connect the strike through the whole body:

ground → legs → hips → trunk → shoulder → arm → striking surface

Use kime at impact.

Execution and use

Keep the wrist flexed through impact. Koken may be delivered downward, upward, inward or outward and can also have defensive applications at an advanced level.

Training

Use controlled repetitions and controlled blocking/striking practice. Focus on wrist angle, thumb position and a clear contact zone.

Safety: the wrist area is sensitive; do not condition this technique against hard objects.

Common errors

• insufficient wrist flexion
• incorrect thumb position
• contact with fingers, palm or forearm
• hard-surface conditioning

Summary

Koken (弧拳) uses the outer wrist as the contact surface with a compact, clearly flexed hand form.