It is generally accepted that proper learning of the breakfall technique during early judo training is essential for attenuating the risk of judo-related head injury. Therefore, it is critical to understand the kinematics and head injury risks of breakfall motion to design a more safe and effective judo teaching paradigm that results in reduction of injury risk. We aimed to investigate the biomechanics of judo backward breakfalls by comparing osoto-gari and ouchi-gari in novice judokas. Twelve male novice judokas (age: 21.3 years, SD = 0.6 years; height: 1.74 m, SD = 0.04 m; body weight: 71.3, SD = 6.4 kg; body mass index: 23.5, SD = 2.3) volunteered to participate in this study. The kinematic data of the breakfall motion for both osoto-gari and ouchi-gari were collected using a three-dimensional motion analysis technique (200 Hz). We observed significant differences between the movement patterns for the two techniques, especially in the lower extremity movements. In addition, a significantly greater peak extension momentum (osoto-gari: 1.29, SD = 0.23 kg m2 s-1; ouchi-gari: 0.84, SD = 0.29 kg m2 s-1) and lower head position along the vertical axis (osoto-gari: 0.18, SD = 0.05 m; ouchi-gari: 0.31, SD = 0.08 m) with a large effect size were found in the breakfall for osoto-gari. Our results suggest that a different paradigm is needed for effectively teaching each breakfall technique that will enable us to substantially lower the risk of judo-related head injuries in novice judokas.
Keywords: Biomechanics; coaching; injury and prevention.