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.

Principles of Judo Training as an Organised Form of Physical Activity for Children.

When organising judo training for children, it is essential to ensure maximum safety, and use an appropriate training methodology adapted to the age of the youngest judo athletes. This paper aims to review the current literature containing judo training principles and safety-related considerations for preschool (4-6 years) and school-age (7-12 years) children as an organised physical activity. Data were collected until October 2021 from eight international scientific databases (PubMed, Scopus, UpToDate, Web of Science, Cochrane, EBSCOhost, ScienceDirect, Google Scholar). In the overviews, we found various times and frequencies of judo training for children. In preschool, the training time was 30-60 min with a frequency of 2-3 times per week, whereas in the school-age group, the training time was extended from 45 to 90 min 3-4 times per week. The most common injuries included upper arm injuries, followed by those of the lower limbs. In the future, it would be an advantage to systematise the methodology of judo training as an organised form of physical activity that can complement the daily dose of exercises recommended by the World Health Organization for maintaining children's general health.

Rotational head acceleration and traumatic brain injury in combat sports: a systematic review.

BACKGROUND: Traumatic brain injury (TBI) in combat sports is relatively common, and rotational acceleration (RA) is a strong biomechanical predictor of TBI. This review summarizes RA values generated from head impacts in combat sport and puts them in the context of present evidence regarding TBI thresholds. SOURCES OF DATA: PubMed, EMBASE, Web of Science, Cochrane Library and Scopus were searched from inception to 31st December 2021. Twenty-two studies presenting RA data from head impacts across boxing, taekwondo, judo, wrestling and MMA were included. The AXIS tool was used to assess the quality of studies. AREAS OF AGREEMENT: RA was greater following direct head strikes compared to being thrown or taken down. RA from throws and takedowns was mostly below reported injury thresholds. Injury thresholds must not be used in the absence of clinical assessment when TBI is suspected. Athletes displaying signs or symptoms of TBI must be removed from play and medically evaluated immediately. AREAS OF CONTROVERSY: Methodological heterogeneity made it difficult to develop sport-specific conclusions. The role of headgear in certain striking sports remains contentious. GROWING POINTS: RA can be used to suggest and assess the effect of safety changes in combat sports. Gradual loading of training activities based on RA may be considered when planning sessions. Governing bodies must continue to work to minimize RA generated from head impacts. AREAS TIMELY FOR DEVELOPING RESEARCH: Prospective research collecting real-time RA data is required to further understanding of TBI in combat sports.

Association Analysis of Polymorphic Variants of the BDNF Gene in Athletes.

As BDNF is one of the group of neurotrophins highly influencing the processes happening in the brain, such as the processes of learning and personality creation, we decided to look closer at its genetic variations in association with the personality of a group of athletes and their controls. The study group consisted of 305 volunteers: martial arts athletes (n = 153; mean age = 24.06) and healthy non-athletes as controls (n = 152; mean age = 22.23). Thirty-eight percent of the martial arts group achieved the championship level. Both the martial arts and control subjects were examined using the NEO Five-Factor Personality Inventory (NEO-FFI) and the State-Trait Anxiety Inventory (STAI) scales. The results of the NEO-FFI and STAI inventories were given as sten scores. The conversion of the raw score to the sten scale was performed according to Polish norms for adults. Genomic DNA was extracted from blood leukocytes and then genotyped using a PCR method for the following polymorphisms: BDNF rs10767664 and BDNF rs2030323. We observed statistical significance for both polymorphisms when comparing martial arts athletes with the control group in relation to the conscientiousness and extraversion scales. However, since few extant articles consider this association, our results still require further analysis, probably by considering a larger group.

Characteristics of Technical and Tactical Preparation of Elite Judokas during the World Championships and Olympic Games.

The basis for achieving success in sport is technical preparation supported by adequate level of physical fitness. During judo competitions, athletes use technique to meet tactical objectives aimed to achieve victory. The modification of the rules of combat in judo that has been carried out in recent years has changed the course of competition. It seems to be interesting if there are relations between technical and tactical preparation expressed by means of indices and modification of the course of the fight caused by changes in the rules. The purpose of the paper was to determine the values of technical and tactical preparation of judokas during competition at the elite level. A hundred and twenty bouts during the Olympic Games in London in 2012 as well as 136 bouts fought during the World Championships in Rio de Janeiro in 2013 were analyzed. Verification was performed by calculating indicators of technical and tactical preparation. The results show a significant correlation between the indicators of technical and tactical preparation and the ranking in the general classification of the analyzed competitions. There were no statistically significant correlations between the change of fighting rules and the level of the examined indices of technical and tactical preparation. The results of the study verified the appropriate method of preparation for the competitions analyzed.

Significant Predictors of Sports Performance in Elite Men Judo Athletes Based on Multidimensional Regression Models.

BACKGROUND: This research aimed to identify the most significant predictors of sports level using regression modeling. METHODS: This study examined 16 judokas (aged 23 (±2.5)) from four weight categories, with four athletes in each category (66 kg, 73 kg, 81 kg and 90 kg). Each athlete was a member of the Polish National Team, an international master class (IM) or national master class (M). The tests were carried out twice (every two weeks) during the pre-competitive season in the morning, after a 10-min warm-up. The tests were performed according to the following protocol: Explosive Strength Lower Limbs (ExSLL) [W], Strength Endurance Lower Limbs (SELL) [%], Explosive Strength Upper Limbs (ExSUL) [W], Strength Endurance Upper Limbs (SEUL) [%]. The relationships between the dependent variable (ranking score) and the other analyzed variables (predictors) were estimated using the one-factor ridge regression analysis. RESULTS: There were significant intergroup and intragroup differences in the results of explosive strength and strength endurance of the lower and upper limbs. The best predictors were identified using regression modeling: ExSLL, SELL, and SEUL. CONCLUSIONS: Increasing the value of these predictors by a unit should significantly affect the scores in the ranking table. Correlation analysis showed that all variables that are strongly correlated with the Polish Judo Association (PJA) ranking table scores may have an effect on the sports performance.

Nonspecific Low Back Pain among Kyokushin Karate Practitioners.

Background and objective: Spinal pain is a common and growing problem, not only in the general population but also among athletes. Lifestyle, occupation, and incorrectly exerted effort have a significant impact on low back pain. To assess the prevalence of low back pain among those practicing Kyokushin karate, we take into account age, body weight, sex, length of karate experience, level of skill, and occupation. Materials and Methods: The study involved 100 people practicing Kyokushin karate, aged 18 to 44. A questionnaire developed for this study and the Oswestry Disability Index (ODI) were used. Results: The research showed the prevalence of low back pain among karate practitioners (55%), depending on age (R = -0.24; p = 0.015), body weight (χ2 = 16.7; p = 0.002), occupation (χ2 = 18.4; p = 0.0004), and overall length of karate experience (R = -0.28; p = 0.04). A correlation was also found between sex (χ2 = 22.3; p = 0.001), occupation (χ2 = 51; p = 0.0000), length of experience (R = -0,28; p = 0.04), karate skill level (R = 0.39; p = 0.003), and the intensity of pain defined using the Visual Analogue Scale (VAS). Subjects with low back pain showed minimal (71%) and moderate (29%) disability according to the Oswestry index. Conclusions: Low back pain is common in karate practitioners and depends on age, weight, occupation, and length of karate experience. The intensity of low back pain is influenced by sex, occupation, overall length of training experience, and one's level of karate skill. Lumbar spine ailments reduce functionality and quality of life to a small degree. Karate practitioners seldom seek treatment for spinal pains, and only few use physiotherapy and pharmacology.

Functional connectivity between core and shoulder muscles increases during isometric endurance contractions in judo competitors.

PURPOSE: The aim of this study was to assess the surface electromyogram (SEMG) changes within and between muscles of the torso and shoulder region during static endurance contraction in elite judokas. We hypothesized an increased functional connectivity of muscles from the shoulder and torso regions during sustained isometric contraction. METHODS: Twelve healthy, right-handed judo competitors participated in the study. The SEMG signals from the dominant trapezius (upper, middle and lower part), deltoideus anterior, serratus anterior, and pectoralis major muscles were recorded during isometric endurance contraction consisting of bilateral arm abduction at 90°. The normalized mutual information (NMI) was computed between muscle pairs as an index indicating functional connectivity. RESULTS: The NMIs increased significantly during endurance test for 10 of the 15 muscle pairs (P < 0.001). CONCLUSION: We concluded that the increases in NMIs highlighted functional changes in the interplay between core and shoulder muscles during an endurance contraction in elite judokas.