Hitosashiyubi ipponken (人差し指一本拳)

Introduction

Hitosashiyubi ipponken (人差し指一本拳) is a fist form in which the projecting second joint of the index finger forms the striking surface. It is used in thrusts and downward strikes.

Definition

The second joint of the index finger projects forward as a concentrated contact point.

Terminology

Japanese: 人差し指一本拳
Romaji: hitosashiyubi ipponken
English: index-finger one-knuckle fist

Structure / Form

• close the hand into a compact fist with the back of the hand facing upward
• project the second joint of the index finger
• press the thumb against the side of the index fingernail to lock the structure
• keep wrist and forearm aligned

Striking surface

Primary: projecting second joint of the index finger.
Avoid the other knuckles, fingers and palm.

Basic principles

Keep the hand compact and the contact point clearly supported. Transfer force through the whole body and apply kime at impact.

Execution and use

Drive the fist toward the target on a controlled path, contact with the projecting joint and retract immediately. The form is used in thrusting and downward striking actions.

Training

Use kihon, controlled repetitions and precision practice. Focus on the correct joint, thumb lock, wrist alignment and structural stability.

Common errors

• striking with the wrong knuckle
• incorrect thumb position
• collapsing hand structure
• bent wrist

Summary

Hitosashiyubi ipponken concentrates force through the projecting second joint of the index finger in a compact, locked fist.