Abstract
Ukemi has great weight with judo. It is an effective technique of keeping ourselves safe when we are hurled, it is indispensable for protecting us from pain or injury.
This research deals with “the effacement of the impact by the use of the arm”which is one of the theories of ukemi.
We have examined the effect on diminishing the impact by giving a tatami a sharp touch in comparison with the case of not using the arm.
We have made experiments on each kind of nagewaza to see the impact, the order in which each part (the flat of the hand, the middle joint of the arm, the shoulder, and the hip) keeps in touch with a tatami and the intervals among them.
This is the outcome of scientific research:
(I) Concerning the effacement of the impact by the use of ukemi; the effect of ukemi is apparent to us judging from the maximum and impulse per second of ipponseoinage when it is the time for doing ukemi or not doing it.
(II) We get the impulse of each nagewaza lined up in an order based on how large they are; (1) ipponseoinage (2) osotogari (3) haraigoshi and (4) sasaetsurikomiashi.
(III) Concerning the impulse per second; (1) haraigoshi (2) ipponseoinage (3)sasaetsurikomiashi and (4) osotogari. Concerning three parts. (1) the part of hip (2) the part of back and (3) the part of arm.
(IV) Concerning the time when ukemi is finished; ipponseoinage (0.204 sec.), osotogari (0.260 sec.), haraigoshi (0.191 sec.), sasaetsurikomiashi (0.174 sec.) and ouchigari (0.126 sec.).
