Abstract

SANTOS, Saray G. dos et al. Acceleration and impact time on judo's athlete body segmets during ukemi movement on different tatame types . Rev. Port. Cien. Desp. [online]. 2007, vol.7, n.2, pp.156-166. ISSN 1645-0523.

This exploratory study was conducted to detect and compare the accelerations and the time intervals of impacts suffered by different body segments of a judoka (wrist, hip, and ankle) using different types of tatami. In order to accomplish this study, seven different types of tatami were selected intentionally (six of them synthetic and one natural - straw). We had the help of two judoka to execute the "Ipon-Seoi-Nague" technique and the respective "Zempo-Kaiten-Ukemi" reduction. A Bruel&Kjaer triaxial accelerometer was used for the measurements. It was connected through cables to preamplifiers linked to a system of terminals with divisors where the signal was acquired. For the data collection, the accelerometer was fastened on the wrist, on the hip, and on the ankle. The device measured the accelerations of 10 impacts of every segment in each of the seven types of tatami, totaling 210 measures. The results obtained allow us to state, based on tolerance criteria, that the values of the impacts received by the judoka, mainly in the fist and ankle body segments, exceed the limits considered safe. Even though these impacts were of short duration, they are in limits considered causer of severe injuries (acceleration >200g). From the results of this work, the more appropriate for Judo falls damping were the tatami "A", "B" and "F".

Keywords : Impact; ukemi; tatami.

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