Ukemi Technique Prevents the Elevation of Head Acceleration of a Person Thrown by the Judo Technique ‘Osoto-gari’

Abstract

Biomechanical analysis was performed to evaluate the effectiveness of mastering ukemi in preventing severe head injury in judo. One judo expert (tori) threw another judo expert (uke) with a skilled breakfall (ukemi) four times. We obtained kinematic data of uke with a digital video camera. Both translational and rotational accelerations were measured with a six-degree-of-freedom sensor affixed to uke's forehead. When Osoto-gari was performed, uke fell backward and his arm made contact with the tatami; the translational and rotational accelerations rose to peak values. The peak resultant translational and rotational accelerations were respectively 10.3 ± 1.6 G and 679.4 ± 173.6 rad/s 2 (mean ± standard deviation). Furthermore, when comparing the values obtained for the judo experts with those obtained using an anthropomorphic test device (ATD: the POLAR dummy) that did not perform ukemi, both the peak resultant translational (P = 0.021) and rotational (P = 0.021) accelerations of uke were significantly lower than those for the ATD, whose head struck the tatami. Additionally, there was no significant difference among the three axis directions for either translational (a x : 7.4 ± 0.2, a y : 8.5 ± 2.1, a z : 7.2 ± 0.8 G) or rotational (`x: 576.7 ± 132.7, `y: 401.0 ± 101.6, `z: 487.8 ± 66.6 rad/s 2 ) acceleration. We confirmed that performing correct ukemi prevented the elevation of head acceleration by avoiding head contact with the tatami when a judoka is thrown by Osoto-gari. Judoka should therefore undertake intensive practice after they have acquired ukemi skills.

Use of a Simulation Model to Investigate the Mechanisms of Sports-related Head Injuries

“…Furthermore, brain behavior along with whole-body movement with variable neck stiffness is another issue, though Murayama et al have already delineated the relationship between body actions and head acceleration in judo. 15,16) Although simulations are only theoretical, digitalized model investigations, they offer the only means of exploring the mechanism of sports-related brain injury at present. In the present study, impacts were simulated with an energy corresponding to HIC = 1000, the level at which serious brain injury occurs more than half the time, but by investigating the threshold for impacts that actually causes concussion in sports, 17) it may be possible to confirm the response to increasing and decreasing energy levels and identify the anatomical changes in corresponding simulations more practically.…”

Biomechanical Analysis of Serious Neck Injuries Resulting from Judo

“…The need for young or inexperienced practitioners to master ukemi before participating in throwing technique practice is emphasized. Because correct ukemi prevents high head accelerations [ 10 ], measurement of head acceleration would be useful for evaluating acquired break-fall technique skills in judo practitioners.…”

“…A biomechanical examination of the mechanisms of head injuries during judo and proposal of effective preventive measures have previously been performed [ 6 , 7 , 8 , 9 , 10 ]. However, no studies have been performed to analyze the mechanisms of serious neck injuries in judo.…”

Assessment of the efficacy and safety of a Judo exercise program in improving the quality of life among elderly patients

“…Judo is a common form of martial arts practiced in many countries. Before practicing throwing techniques or engaging in matches, judo founder Jigoro Kano pointed out that it is imperative to master a technique called ukemi to prevent | | doi: 10.2185/jrm.2021-008 2021; 16(4): 229-235 the damaging effects of falls 10) .…”