Tettsui (鉄槌)

Introduction

Tettsui (鉄槌) is a striking surface using the thick area at the base of the little-finger side of the fist.

The fist is formed as in seiken, but the striking surface is on the little-finger edge. Tettsui is used in strikes (uchi, 打ち), mainly from the side or from above.

Definition

Tettsui (鉄槌)
A striking surface in which contact is made with the thick, fleshy area at the base of the little-finger side of a closed fist.

Terminology

Japanese: 鉄槌
Romaji: tettsui
English: hammerfist

Structure / Form

Starting position

• the hand is closed as for seiken
• the fingers are held tightly together
• the thumb locks the fist over the fingers

Position

• the fist is oriented so the little-finger side forms the striking surface
• the thick base of the fist is directed toward the target

Wrist

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

Striking surface

Primary contact

• the thick area at the base of the little-finger side of the fist

Secondary contact to avoid

• knuckles
• wrist
• forearm

Basic principles

Structure

The fist is kept compact as in seiken.

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 impact.

Execution

Movement

• the strike begins without unnecessary tension
• movement is driven by coordinated body action
• the strike travels mainly from the side or from above

Impact

• contact is made with the thick area at the base of the little-finger side
• wrist and forearm remain aligned

Recovery

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

Use

Tettsui is used, among other techniques, in:

• tettsui komekami uchi (鉄槌こめかみ打ち)
• tettsui oroshi uchi (鉄槌下ろし打ち)
• tettsui yoko uchi (鉄槌横打ち)
• tettsui hizō uchi (鉄槌脾臓打ち)

Training

Tettsui is trained through:

• kihon
• repetitions
• controlled striking practice
• makiwara in suitable forms

Focus on:

• correct striking surface
• compact fist
• straight wrist
• clear strike direction

Common errors

Incorrect striking surface

• contact is made with the knuckles or wrist
• force transfer is reduced
• the hand may be injured

Bent wrist

• breaks alignment
• weakens the impact

Loose fist

• the structure opens on impact
• the striking surface becomes unstable

Missing body connection

• the strike is driven only by the arm
• force is not transferred correctly

Summary

Tettsui (鉄槌) uses the thick area at the base of the little-finger side of the fist.

It is defined by:

• the same basic fist as seiken
• impact with the base of the little-finger side
• a straight wrist
• compact structure