Stanislaw Sterkowicz

Injuries in judo: a systematic literature review including suggestions for prevention

Background There is limited knowledge on epidemiological injury data in judo. Objective To systematically review scientific literature on the frequency and characteristics of injuries in judo. Methods The available literature up to June 2013 was searched for prospective as well as retrospective studies on injuries in judo. Data extraction and presentation focused on the incidence rate, injury risk, types, location and causes of injuries. Results During the Olympic Games in 2008 and 2012, an average injury risk of about 11–12% has been observed. Sprains, strains and contusions, usually of the knee, shoulder and fingers, were the most frequently reported injuries, whereas being thrown was the most common injury mechanism. Severe injuries were quite rare and usually affected the brain and spine, whereas chronic injuries typically affected the finger joints, lower back and ears. The most common types of injuries in young judo athletes were contusions/abrasions, fractures and sprains/strains. Sex-differences data on judo injuries were mostly inconsistent. Some studies suggested a relationship between nutrition, hydration and/or weight cycling and judo injuries. Also, psychological factors may increase the risk of judo injuries. Conclusions The present review provides the latest knowledge on the frequency and characteristics of injuries in judo. Comprehensive knowledge about the risk of injury during sport activity and related risk factors represents an essential basis to develop effective strategies for injury prevention. Thus, the introduction of an ongoing injury surveillance system in judo is of utmost importance.

TECHNICAL VARIATION IN A SAMPLE OF HIGH LEVEL JUDO PLAYERS

Technical actions performed by two groups of judokas who won medals at World Championships and Olympic Games during the period 1995–2001 were analyzed. In the Super Elite group (n = 17) were the best athletes in each weight category. The Elite group (n = 16) were medal winners who were not champions and did not win more than three medals. Super Elite judokas used a greater number of throwing techniques which resulted in scores, even when expressed relative to the total number of matches performed, and these techniques were applied in more directions than those of Elite judokas. Further, the number of different throwing techniques and the variability of directions in which techniques were applied were significantly correlated with number of wins and the number of points and ippon scored. Thus, a greater number of throwing techniques and use of directions for attack seem to be important in increasing unpredictability during judo matches.

Techniques frequently used during London Olympic judo tournaments: A biomechanical approach

Feedback between training and competition should be considered in athletic training.The aim of the study was contemporary coaching tendencies in women s and men s judo with particular focus on a biomechanical classification of throws and grappling actions. Throwing technique frequencies grouped in the seven biomechanical classes were dependent on gender. A significant difference was found between frequencies of variable arm of physical lever technique scored by males and females as compared to the techniques counts. Significant differences between men who competed in extra lightweight and heavy weight concerned the frequency of the techniques used with maximum arm or variable arm of physical lever and a couple of forces applied by trunk and legs.In females a tendency to higher frequency of techniques that used couple of forces applied by arm or arms and leg was observed in extra lightweight compared to the heavy weight. Because the technique preferred in the fight depends on a gender and weight category of a judoka, the relationships found in this study, which can be justified by the biomechanics of throws, should be taken into consideration in technical and tactical coaching of the contestants. A method used in this study can be recommended for future research concerning coaching tendencies

Tracking 10-year competitive winning performance of judo athletes across age groups.

Little information is available concerning early specialization and competitive success in judo across the early training years. Thus, the present objective was to verify the stability of individual competitive performance of a state-level championship for judo athletes who had been previously successful. For this, 406 athletes from six age groups (9 to 20+ years old) of each sex were followed for 10 years. Using recorded data from the São Paulo State Judo Federation beginning in 1999, the scores and standings for these judo players were analyzed. The proportion of medal winners during this period was not constant, differing from the grand mean in all groups of both 204 males and 202 females. At the end of this period, only 7% of the male and 5% of the female athletes had maintained their competitive levels. Successful competitive performance in early judo competition was not associated with success later in adulthood.

Coordination motor abilities of judo contestants at different age

Results of judo competition represent a combination of a variety of factors, connected with both natural aptitudes as current body abilities [1]. A vital (and multi-faceted) element is the ability of performing efficient movements of the body while controlling balance and ensuring quick and precise reactions to unexpected attack of the opponent. Combined with a variety of requirements, this control over movement represents the essence of a global motor coordination [2,3]. Attempts to find judo-specific coordination motor abilities (CMA) reveal that a considerable place in this structure is taken by: balance, reaction time and spatial orientation. Ability to control balance helps maintain a stable body position (static balance) or maintaining/regaining this state (dynamic balance) during or after completion of an activity. Judo is a sport that requires a high level of dynamic balance [4]. The main criteria of optimum level of the ability discussed are the elements determined by a number of factors in body build and function of the nervous system, such as precision, speed, purposefulness and resourcefulness that ensure maintaining or regaining the stability [5]. The most intensive development of balance control is observed at the age of from 7 to 12 years [6], but an improvement of 11.9% [7] is also observed in boys aged 15 to 17 years. The best age for development of balance abilities is from 9 to 14 years [8]. Abilities of spatial orientation and kina esthetic differentiation are based primarily on orientation and kinaesthetic information of the process of controlling movements, with the decisive role played by sensory functions. Furthermore, the ability of quick reaction is a property which is characterized by more complex sensory functions and complicated executive motor operations [9]. A complex reaction assumes making a choice out of a selection of several available patterns which are closely related to particular stimuli. In judo fight, these decisions are actually made throughout the fight. Reaction time is determined by speed aptitudes, which can be effectively developed in the period of human life between 11 and 15 years of age, whereas at the age of 16, a gradual regress in this ability is observed [10,11].

Muscle torque and its relation to technique, tactics, sports level and age group in judo contestants.

Abstract The aim of this study was to perform a comparative analysis of maximal muscle torques at individual stages of development of athletes and to determine the relationship between muscle torques, fighting methods and the level of sports performance. The activity of 25 judo contestants during judo combats and the effectiveness of actions were evaluated. Maximum muscle torques in flexors/extensors of the body trunk, shoulder, elbow, hip and knee joints were measured. The level of significance was set at p≤0.05; for multiple comparisons the Mann-Whitney U test, p≤0.016, was used. Intergroup differences in relative torques in five muscle groups studied (elbow extensors, shoulder flexors, knee flexors, knee extensors, hip flexors) were not significant. In cadets, relative maximum muscle torques in hip extensors correlated with the activity index (Spearmans r=0.756). In juniors, maximum relative torques in elbow flexors and knee flexors correlated with the activity index (r=0.73 and r=0.76, respectively). The effectiveness of actions correlated with relative maximum torque in elbow extensors (r=0.67). In seniors, the relative maximum muscle torque in shoulder flexors correlated with the activity index during the second part of the combat (r=0.821).

The effects of training and creatine malate supplementation during preparation period on physical capacity and special fitness in judo contestants

The purpose of the study was to determine the effect of 6-weeks training and creatine malate supplementation demonstrated in anaerobic capacity and aerobic power and in special judo fitness test performance (Throws in Total and Index in SJFT).

Stress in sport situations experienced by people who practice karate

Background Sport situations can be difficult. Stress can be a factor which decreases the quality of sports performance, especially during competition. The aim of this study was to identify situations which generate the highest stress levels in karate contestants. Material/Methods: Polish National Kyokushin team members (n=22) participated in the study. Questions concerning training and competitions were answered on a 10 – point scale. Cronbach alfa for questionnaire items were 0.84–0.97. Stress demand level was determined by sports motivation questionnaire. Mean values of males and females were compared by non-parametric tests (p£0.05). Results: Competitions generated higher stress than training. Importance of competition and presence of audience increased stress intensity. Quality of fighting activities modified stress intensity. Stress intensity at the end of karate match remained lower in men than women. Stress during the first selection match and semi-final fight exceeded athletes’ general demand for stress. Stress intensity was lower than the demand for stress during tactical and technical training, free of audience. The dissonance between stress intensity and demand for stress in women in final fights, against stronger opponent, exposed them to psychological discomfort. Conclusions: Psychological and tactical preparations correlate. This manifests by development and realization of a fight plan and reaction to unexpected situation. Differences in reactions between men and women in stressful situations suggest the need for individual approach to training process and at each stage of competition.

Rule change and Olympic judo scores, penalties and match duration

Abstract In judo, between 2009 and 2013, many changes were added, especially after London 2012 Olympics to promote “positive” actions/score instead of “negative” actions/penalties. This study compared the total match duration, frequency of scores (ippon, wazari, yuko) and penalties (shido) between Rio 2016 and London 2012 (before and after rules change), considering weight categories and competition phases. Data from 470 male athletes and 307 female athletes who disputed, respectively, 1022 and 698 matches in both Olympic Games were analysed. Three-way ANOVA was used to compare sexes, weight categories, Olympic Games edition, with Tukey test as post hoc. The association between Olympic Games edition and percentage of matches without any score was tested via Chi-square and Cramer’s – V effect size was used. Significance level was set at 5%. Eta squared (η2) was used as effect size. Results (Rio 2016 vs. London 2012) suggest in no change in ippon and wazari scores, while decreasing the number of yuko and increasing the number of penalties. Females scored more yuko and received less penalties than males. Females matches in Rio were shorter than matches for all other groups. For scores and penalties, no difference was found concerning weight categories, but half-heavyweight matches were shorter than lightweight ones.

Judo rules: searching for a wind of changes

Abstract After 2016, the International Judo Federation changed rules to promote the “positive” judo. This study compared two World Championships editions before and after the rules changes: Astana-2015 and Budapest-2017. Data from matches disputed in Astana (765) and Budapest (768) were analysed concerning: total match duration, frequency of scores and penalties, association between edition and extra-time, disqualifications and matches without penalties. Three-way ANOVA was used to compare sexes, weight categories and World Championships edition, with Fisher’s Least Significant Difference (LSD) test as post hoc. The associations between World Championships edition and matches finished in extra-time, disqualifications and matches without any score were tested via Chi-square. Results were: (a) no change in number of ippon when the same sex and weight category were considered across years; (b) number of waza-ari increased from Astana to Budapest; (c) number of penalties decreased from Astana to Budapest. Females in Budapest received less penalties than females in Astana and males in both competitions. Extra-lightweights received less penalties than lightweights upwards; heavyweights received more penalties than all other weight categories from middleweights downwards; (d) occurrence of extra-time and hansoku-make increased for females, males and all groups together; (e) males’ matches were longer than females ones. Thus, the new rules partially achieved the goal proposed.