Recently,many instructors have been teaching kirikaeshi without taiatari, as they feel that its inclusion leads to bad posture. This is particularly true for less experienced players who tend to lean forward and use the strength of their shoulders and arms when they make body-contact with their opponent. On the other hand learning taiatari equips the student to aim for the centre, to make successful hiki waza and when the chance allows, give their opponent an extra shove to gain hansoku in shiai.
The clue is in the name. Taiatari means “body strike”, not “push”. To do it successfully you simply drop your hands to the height of your navel, engage your opponent’s shinai in correct tsubazeriai (omote side to omote) and push down using the strength of your back and hips. You should hit just once with the forward momentum of your attack. Your hands and arms should be relaxed, your posture should be upright and your left foot should be in the correct position following hikitsuke from the preceding strike.
Taiatari almost always follows an unsuccessful strike when you are directly in front of your opponent. By dropping your hands you also ensure that you do not put him or her in danger by pushing forward with your hands at throat height, potentially causing neck injury.
In shiai the rule is that a “one hit” body strike that pushes your opponent over the line, results in a hansoku in your favour; a repeated or concerted push which is not connected to a valid attempt to strike a target, could result in the penalty being awarded against you.
The intention of taiatari is not necessarily to push your opponent back. With heavier opponents it may be that your aim is to gain distance by bouncing off them. It is however possible for a lighter person to gain ground with the strength of their taiatari. I have seen 45kg female player move a 100kg male opponent with a well-timed body strike.
To practice taiatari we use butsukarigeiko, where we follow a forward strike with taiatari and a hikiwaza. So a possible sequence might be – men, taiatari, hiki-men; men, taiatari, hiki-gote; men, taiatari, hiki-dou. Or of course you can practise by introducing correct taiatari into kirikaeshi; which brings us back to where we started.