Seiken (正拳)

Introduction

Seiken (正拳) is the primary striking surface of the fist in Kyokushin karate.

It is used mainly in thrusts and punches (tsuki, 突き), where contact is made with the two front knuckles of a compact closed fist.

Definition

Seiken (正拳)
A striking surface in which contact is made with the two front knuckles of a closed fist.

Terminology

Japanese: 正拳
Romaji: seiken
English: forefist

Structure / Form

Starting position

• the hand is open
• the fingers are naturally extended

Fingers

The fingers fold in this order:

• little finger
• ring finger
• middle finger
• index finger

The fingertips are pulled firmly into the palm so the fist closes compactly.

Thumb

• the thumb is placed over the fingers
• it presses across the index- and middle-finger joints to lock the fist

Wrist

• the wrist is kept straight
• the back of the hand and forearm remain aligned

Striking surface

Primary contact

• index-finger knuckle
• middle-finger knuckle

Secondary contact to avoid

• ring-finger knuckle
• little-finger knuckle
• thumb

Basic principles

Structure

The fist is closed compactly so the striking surface remains stable.

Body connection

Force is transferred through the body to the striking surface.

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

Japanese / romaji:
jimen (地面) → ashi (足) → koshi (腰) → dōtai (胴体) → kata (肩) → ude (腕) → datotsu-bu (打突部)

Kime (決め)

Force is concentrated at the moment of impact.

Execution

Movement

• in the basic form, the fist starts with the palm facing upward
• the hand travels straight forward from the side toward the target
• during the thrust, the fist rotates so the palm finishes facing downward

Impact

• contact is made with the two front knuckles
• wrist, back of the hand and forearm stay in one straight line
• impact occurs just before full extension

Recovery

• the opposite hand retracts into hikite (引き手)
• the working arm retracts immediately after impact

Use

Seiken is used, among other techniques, in:

• seiken jōdan tsuki (正拳上段突き)
• seiken chūdan tsuki (正拳中段突き)
• seiken gedan tsuki (正拳下段突き)
• seiken mawashi uchi (正拳回し打ち)
• seiken ago uchi (正拳顎打ち)

Training

Seiken is trained through:

• kihon
• repeated tsuki
• makiwara
• knuckle push-ups
• controlled striking practice

Focus on:

• correct fist formation
• straight wrist
• correct striking surface
• coordination between the body and impact

Common errors

Incorrect thumb position

• the fist is not locked correctly
• the thumb may be injured

Weak little-finger closure

• the fist becomes unstable
• the structure opens on impact

Bent wrist

• breaks alignment
• increases the risk of wrist injury

Incorrect striking surface

• contact occurs on the ring- or little-finger knuckles
• force transfer is reduced
• the hand may be injured

Full extension at impact

• the punch becomes rigid
• force transfer deteriorates
• injury risk increases

Summary

Seiken (正拳) is the front striking surface of the closed fist.

It is defined by:

• the two front knuckles
• a compact closed fist
• correct thumb lock
• straight alignment through wrist and forearm