Akiresu-ken undo
Jumbi Undō 11¶
1. Name of exercise¶
Akiresu-ken no undō
(Achilles tendon exercise)
2. Romaji instruction¶
Hai, akiresu-ken no undō.
Hai, obi no yoko o motte.
Ichi, ni, san, shi, go, roku, shichi, hachi, kyū, jū.
Jū wa kiai.
3. Translation¶
Achilles tendon exercise.
Hold the sides of the belt.
One, two, three, four, five, six, seven, eight, nine, ten.
Ten with kiai.
4. Counting¶
Ichi – Ni – San – Shi – Go – Roku – Shichi – Hachi – Kyū – Jū
(Jū with kiai)
5. Short description¶
The practitioner stands with the feet approximately shoulder width apart and holds the sides of the belt (obi no yoko).
The knees bend slightly forward. From this position the heels rise so the body lifts onto the balls of the feet (chūsoku) while the knees remain bent.
The heels are then lowered back to the floor while the legs extend more fully. When the heels touch the floor the Achilles tendon and calf muscles are stretched.
The movement repeats rhythmically:
- rise onto chūsoku with bent knees
- lower to kakato while the legs extend
On the final count (jū) the movement is performed with kiai.
6. Purpose¶
The purpose of the exercise is to:
- strengthen the calf muscles
- increase elasticity in the Achilles tendon
- improve ankle stability
- prepare the body for explosive push-offs, footwork, and kicks
In Kyokushin training methodology the different parts of the foot – such as chūsoku (ball of the foot) and kakato (heel) – are essential both as support points and as striking surfaces in techniques.
Alternating between these positions develops structural control of the foot while gradually loading the Achilles tendon, reducing injury risk before more dynamic training.
This exercise therefore acts as a transition between basic joint mobilization and more dynamic leg movements later in the Jumbi Undō sequence.
Comments¶
1. Romaji
The term akiresu-ken is the Japanese adaptation of the word Achilles tendon and is commonly used in martial arts warm-ups.
2. Terminology
The terms chūsoku (ball of the foot) and kakato (heel) are fundamental in karate when describing both support and striking surfaces.