In 2021, heel-hook joint-locks (HHJL), effective and controversial techniques known for forcing opponents to quit, were introduced in Brazilian jiu-jitsu (BJJ) no-gi tournaments. However, the effects of these rule changes on no-gi match dynamics remain unknown. This study aimed to investigate the effects of HHJL legalization on the match dynamics of high-level male BJJ no-gi athletes. One hundred and eighty-five matches were categorized following HHJL legalization (Pre x Post) and into five subdivisions: extra-lightweight, lightweight, middleweight, heavyweight, and absolute. Post-HHJL, the number of matches ending by leg-based submission increased (Pre: 6 x Post: 19, p = 0.02), especially by HHJLs (n = 15). Minor changes were observed in time-motion analysis across combat phases. However, in heavyweight, high-intensity actions (attack-and-defense) decreased after HHJL legalization (median [first and third interquartiles]; Pre: 98s [59-112s] x Post: 47s [29-96s], p = 0.02). Moreover, total points scored were reduced in extra-lightweight (Pre: 7 [4-10] x Post: 0 [0-8], p = 0.02) and heavyweight (Pre: 8 [2-11] x Post: 2 [0-6], p = 0.01) after HHJL, while the number of applied techniques during matches were reduced in middleweight (Pre: 7 [5-8] x Post: 3 [2-6.5], p = 0.01) and heavyweight (Pre: 7 [5-10] x Post: 5 [3-7], p = 0.03), respectively. Total match duration did not change after HHJL legalization. HHJL legalization increased the occurrences of leg-based submissions. However, only minor changes were observed in the time structure of BJJ no-gi matches, with heterogeneous effects across weight divisions.
‘Martial arts’ is a stable phrase but a contested and analytically variable category in scholarship and practice. This article develops a pragmatic reporting framework for classification without requiring prior agreement on whether a final definition of martial arts is possible. Essentialist, contextual, genealogical, and institutional approaches are considered, with particular attention to the distinction between practical classifications made by practitioners and organisations and scholarly classifications made for analytical purposes. A scope box is proposed for declaring the intended extension and level of analysis, together with a five-step diaeretic protocol for handling borderline cases in a public and revisable manner. The framework is demonstrated through mini-cases on taekwondo, wing chun, and mixed martial arts, treated as stress tests for classificatory reasoning rather than as proof that the general category is indefinable. The output is a reporting standard that supports comparison, dispute resolution, and cumulative research while remaining compatible with competing positions on definition, historical change, and conceptual classification.
This study aimed to ascertain whether penalty situations and the types of shido are associated with the sex, regardless of when the contest ends, whether penalty situations and the types of shido are associated with when the contest ends, and whether this association is influenced by sex. Data from 2340 contests (3178 penalties) from the 2018, 2019, and 2021 World Judo Championships were analyzed. Chi-square tests with standardized residuals and Cramer’s V were used to examine associations. Three-way log-linear models were applied to assess interaction effects, multinomial logistic regression models were used to estimate the probability of penalty situations, and multilevel logistic regression models were conducted to analyze shido types while accounting for within-contest clustering. Penalty situations were associated with sex (p < 0.001, V = 0.10) and with contest-ending condition (p < 0.001, V = 0.30). A significant interaction (p = 0.021) indicated that the association between penalty situations and contest-ending condition differs depending on sex. Contests extending beyond regular time were strongly associated with penalty situations. Male athletes showed higher probabilities of shido plus score contests, whereas female contests were more frequently resolved without penalties. Shido types were also associated with sex (p < 0.001, V = 0.09), although the magnitude of this association was small. Variation in shido types across contest-ending conditions was observed only in female contests (p < 0.001, V = 0.11), while no significant interaction between shido type, contest-ending condition, and sex was found (p = 0.181). Multilevel analyses indicated that contest-ending condition had a more consistent influence on shido type distribution than sex. Overall, penalty situations and shido types are associated with contest-ending conditions in elite judo, with sex-related differences present but generally small in magnitude. Data included 2.340 contests (3.178 penalties) from the 2018, 2019, and 2021 World Judo Championships. Analyses employed chi-square tests with standardized residuals and Cramer’s V, three-way log-linear models for moderation effects, and multilevel multinomial and binary logistic regressions with random intercepts to account for clustering within contests. Penalty situations were associated with sex (p<0.001, V=0.10) and strongly related to when the contest ends (p<0.001, V=0.30). A modest interaction (p=0.021) indicated that sex slightly moderates the link between penalties and when the contest ends. Men were more likely to accumulate penalties, especially in contests ending before regular time, while women more often competed without penalties. Shido types were associated with sex (p<0.001, V=0.09), with defensive posture and sleeve-hold penalties more frequent among men. Variation in shido types by when the contest ends occurred only in female contests (p<0.001, V=0.11). No significant three-way interaction was found. Overall, penalty situations and shido types influence contest when the contest ends, with sex-related differences present but small in magnitude.
The aim of this study was to verify whether there is similarity in medalist judo athletes’ age peak, at the Olympic Games from 2004 to 2024, between the different male and female weight categories and according to the countries’ competitive level and their geographic locations. We collected data on the medalists’ ages, related to male (N=168) and female (N=168) judo categories, of Athens 2004, Beijing 2008, London 2012, Rio 2016, Tokyo 2020 and Paris 2024 Olympic Games. They were grouped per country and separated per sex, forming three analysis categories: a) weight category; b) groups, according to the number of Olympic medals of each nation, and c) world geographic region. A Bayesian ANOVA was performed for each of the categories of analysis, with order of comparison from the null model, to determine probability of similarity (BF01). One verified that the probability of medalist judo athletes in 2004 (26.2 ± 3.3), 2008 (25.6 ± 3.9), 2012 (26.2 ± 3.6), 2016 (26.1 ± 2.6), 2020 (26.1 ± 2.8) and 2024 (26.7 ± 3.2) Olympic Games to present age similarity varies between 77% and 84%. About the different weight categories, it is possible to say that Olympic medalists’ age are one to three times more likely to be similar than different and the probability of similarity of Olympic medalists’ age is not influenced of competitive relevance or geographic region. It can be concluded no differences were found in relation to the medalist judo athletes’ age, regardless of sex, weight categories, country competitive tradition, or the geographic region.
This study aimed to investigate the behavioral strategies employed during critical moments of judo matches by athletes with visual impairments, comparing performance across sport classes (J1 and J2), sexes, and weight categories at the Paris 2024 Paralympic Games. A descriptive time-motion analysis was conducted using video footage from 195 official matches, of which 93 featured critical moments, defined as situations in the final 60 seconds where the score difference was one score or less. Performance was evaluated using time-motion variables (e.g., effective combat time, time from threat onset) and frequency-based metrics (e.g., number of attacks). Statistical analyses included Student's t-tests, Chi-square tests, and two-way analysis of variance (ANOVA) (Sport class × Weight category) with Tukey's post hoc test (p < 0.05). The main results indicated that J2 athletes performed significantly more attacks from the critical situation (t-test, p = 0.009; Cohen's d = 0.19) and had a higher frequency of initiating attacks (χ² test, p = 0.006; Cramer's V = 0.27) than J1 athletes, reflecting more proactive tactical behavior. However, no significant differences were found in time-motion variables between sport classes, nor were there differences across weight categories. Furthermore, critical moments predominantly served to consolidate an existing lead rather than facilitate comebacks. In conclusion, strategic behavior under pressure is primarily driven by perceptual input and strategic intent rather than match duration or athlete body mass. These findings highlight the need for class-specific training interventions focusing on decision-making and attack frequency, particularly for athletes with residual vision, to optimize performance under extreme competitive pressure.
