Learn oi-zuki in karate: combining step, hips and punch. With milestones, typical mistakes, a competition link and safety tips for beginners.
The honest answer: oi-zuki is the punch you deliver at the end of a forward step with the fist on the same side as the front leg. It is the first kihon technique (basics) in which step, hips and punch fuse into a single movement. If choku-zuki is the punch in stance, oi-zuki is the punch in motion.
Under the WKF kumite rules a cleanly executed punch to the body scores one point. The condition is that it is controlled and delivered with good form, speed and power, correct timing and the right distance [1]. The technique you practise here trains exactly those things, just in slow motion and without a partner.
What happens during the movement is interesting. In a measurement on 14 elite and national-level karateka with 165 gyaku-zuki punches, the time order of hand acceleration, body movement and peak speed differed between fast and slow punches [2]. That means it is not only power but the timing of the individual parts that decides. That it already runs better after a few weeks is a practical estimate, not a study result.
Begin in zenkutsu-dachi, left leg forward. The right fist is at the hip (hikite); the left fist is the guarding hand in front or also at the hip, depending on the exercise in your dojo. Milestone: stance and posture are calm before you move.
The rear (right) leg is brought forward just above the floor and lands in front of the left foot. The hips stay low and do not rise and fall. Your head stays at the same height, as if you were gliding along a rail. Milestone: a partner does not see your head bob up and down during the step.
The punch begins when the foot is almost down and ends exactly as it lands. The fist on the side of the front leg punches (right leg forward means right fist). The pulling hand returns to the hip at the same time. The body stays facing the front. Milestone: foot and fist arrive at the same moment.
At the end you tense briefly and exhale. The rear leg is straight and the front knee sits over the ankle. Then relax immediately. Milestone: the punch ends with a clearly visible stop.
Step forward and back several times in a row. The target is chudan (stomach height) or jodan (chin height). Only train jodan once chudan runs cleanly. Milestone: five punches in a row with the same rhythm and a stable head.
Practise oi-zuki in the air first. Partner exercises such as gohon-kumite come in only once distance and control are in place. In competition, for hits to the head: at most a light touch, and for children under 14 no skin contact to the head at all [1]. Never punch at a partner at full intent without an instructor.
During the step the deep stances load the knees. A survey among Shotokan karateka found the knee to be the most frequently affected region [4]. That is a cross-sectional survey without proof of cause, but a good reason to warm up. This guide explains and motivates and does not replace supervised training.
Put a towel or a sheet of paper in front of the front foot and glide your heel just over it during the step without touching it. This forces you to stay low, and you notice immediately when the hips bob.
How to practise sensibly: walk a distance of five steps forward and back, first with the step only and no punch so that hips and head height stay calm. Then with the punch, but at half speed. Only in the third pass do you go to normal tempo. Two to three such runs per session are enough. This is a practical estimate, not a study. Film one run per week and compare it with the previous week.
"Oi" means to chase or follow and "zuki" means punch. It describes the following punch during the forward step. In training you practise it as a kihon basis for later partner drills and kata.
With the fist on the side of the front leg. When stepping with the right foot, the right fist punches. The other hand pulls to the hip at the same time.
Long enough that you end in zenkutsu-dachi with a stable stance. This is standard practice and depends on your height. Your instructor corrects the measure best live.
As a basis for attacks with reach. In competition a controlled punch to the body scores one point [1]. You learn how to use distance and timing in a fight later in kumite training.
Because in oi-zuki step and punch use the same side. The punch of the opposite side is called gyaku-zuki and follows a different hip logic. Both belong to the basic programme, and you learn them one after the other.
Age-uke: How to Perform the Rising Block in Karate