Biomechanical Analysis of Serious Neck Injuries Resulting from Judo

Video Biomechanical Analysis of Shoulder Impact Kinematics in Tai-Otoshi and Morote-Seoi-Nage Judo Throws: A Cross-Sectional Study

Background: Shoulder injuries in judo are common as the falling player (uke) lands. Two throws implicated in shoulder injury are tai-otoshi and morote-seoi-nage. Kinematic investigation can provide insight into possible shoulder injury mechanisms and allow for appropriate preventative measures to be suggested. We used two-dimensional (2D) video analysis to measure and compare: (a) the peak acceleration and (b) the peak velocity of uke’s shoulder when tai-otoshi and morote-seoi-nage were performed by elite adult judoka. Methods: Eight male participants were recruited from the Budokwai Judo Club in London, UK. The mean age, height, and weight of participants were 25.4 ± 5.2 years (18–34), 1.7 ± 0.0 m (1.7–1.8), and 75.0 ± 5.2 kg (66–80), respectively. Throws were recorded using an iPhone 6S camera and uploaded onto Kinovea for subsequent processing. Results: The peak acceleration (m/s2) was greater in tai-otoshi (71.6 ± 12.4) compared to morote-seoi-nage (67.9 ± 9.9), although this was statistically insignificant. The peak velocity (m/s) was significantly greater (p = 0.030) in tai-otoshi (5.1 ± 0.8) than in morote-seoi-nage (4.5 ± 0.6). Conclusions: A greater peak velocity in tai-otoshi suggests that the shoulder is subjected to increased loads upon impact. This may indicate that tai-otoshi carries a greater risk of shoulder injury. Nage-komi (repetitive throwing) practices in training should follow gradual loading principles—beginning with morote-seoi-nage, before moving to tai-otoshi, for example. We must be aware of any assumptions made in estimations of impact force, and future in vivo research is required to provide more definitive values. Meanwhile, coaches must continue to ensure that correct ukemi (breakfall) technique is displayed by athletes before performing throws.

A Systematic Review on the Biomechanics of Breakfall Technique (Ukemi) in Relation to Injury in Judo within the Adult Judoka Population

Objectives: To investigate the biomechanics of Ukemi in relation to head and neck injury in adult judokas with varying skill sets. Design: Narrative systematic review. Methods: An extensive literature search was performed using PubMed, Google Scholar, Science direct and EMBASE from inception to April 2021. Studies were included if they: (1) reported biomechanical analysis of judo throws and Ukemi; (2) were on adult judoka populations; (3) discussed injury related to judo technique. The included studies were assessed for risk of bias using a five-part modified STROBE checklist. A narrative synthesis was performed due to the heterogeneity of included studies. Results: 173 titles and abstracts were screened with 16 studies (158 judokas, 9 of which were female) included. All studies used 3D biomechanical analysis to assess Ukemi. Ukemi implementation produced reduced kinematic data in comparison to direct occipital contact, which was always below the injury threshold. Analysis of lower limb and trunk kinematics revealed variances in Ukemi between novice and experienced judoka. Whilst no significant differences were seen in neck flexion angles, hip, knee and trunk angle time plots revealed greater extension angles in experienced judokas. Conclusions: Ukemi is essential in preventing head and neck injuries; however, technique differs between experienced and novice judoka. Larger flexion angles of the hip, knee and trunk are seen in novice judoka, which correlate with increased kinematic data. The association of greater neck muscle strength with improved Ukemi is weak. However, a negative correlation was established between fatigue and breakfall skill by one study.

A biomechanics analysis of the judo osoto-gari technique: comparison of black belt and white belt judokas

The purpose of this study was to determine biomechanical factors for the effective execution of the osoto-gari technique by comparing differences between black belt and white belt judokas. Twenty-two male judokas (12 black belts; 10 white belts) performed osoto-gari, and the motion data were recorded using a Mac3D motion analysis system (250 Hz). The peak angular momentums of the trunk and leg of the uke were larger in the black belts than in the white belts, suggesting that the black belts rotated the uke's body more effectively than the white belts. During the swing phase, the peak angular velocities of the arms and trunk twist in the black belts were larger compared to the white belts. During the throwing phase, the black belts had substantially greater peak angular velocities of the arms, upper torso, and trunk twist. Additionally, the timing of the peak value of the upper torso and trunk twist of the black belts was closer to sweeping leg contact than that of the white belts. The results can provide coaches with suggestions for improving training protocol design when teaching osoto-gari and for helping novices more efficiently master the technique.