Quantifying Judo Performance---An Attempt to Judge the Effectiveness of Throwing Attacks (original) (raw)
An Analysis Model for Studying the Determinants of Throwing Scoring Actions During Standing Judo
Sports, 2019
In judo, the attacking system is grounded on several determinants of the chances to throw. In our study, data regarding four determinants of the attacking system were collected in order to classify the standing scoring actions: the attacking type (direct/counter-attack), the throwing area (forward/backward), the technique’s category (based on motor criteria), and the lateral structure of fighting (contenders with a symmetrical/asymmetrical position). To study the usefulness of such an analysis, the standing scoring actions of the 2013 Judo World Championship were analyzed as an example of elite judo’s attacking system (n = 775). The Pearson’s chi-squared test and Cramér’s V were used to analyze the hypothesis of a uniform distribution or the association between variables and the strength of such an association, respectively. The scoring actions (p < 0.001) were mostly direct attacks (82.6%), in the forward throw area (57.5%), and in an asymmetrical position (67.2%). All of the va...
2006
Four black belt throwers (tori) and one black belt faller (uke) were filmed and analyzed in threedimensions using two video cameras (JVC 60 Hz) and motion analysis software. Average linear momentum in the anteroposterior (x), vertical (y), and mediolateral (z) directions and average resultant impulse of uke’s center of mass (COM) were investigated for three different throwing techniques; harai-goshi (hip throw), seoi-nage (hand throw), and osoto-gari (leg throw). Each throw was broken down into three main phases; kuzushi (balance breaking), tsukuri (fit-in), and kake (throw). For the harai-goshi and osoto-gari throws, impulse measurements were the largest within kuzushi and tsukuri phases (where collision between tori and uke predominantly occurs). Both throws indicated an importance for tori to create large momentum prior to contact with uke. The seoi-nage throw demonstrated the lowest impulse and maintained forward momentum on the body of uke throughout the entire throw. The harai...
Journal of sports science & medicine, 2007
The purpose of this study was to compare the kinematics of kuzushi/tsukuri (KT) phases of the harai-goshi throw under competitive and non-competitive conditions. A third degree black belt subject served as the tori (thrower) for both conditions. Two black belt participants ranked as first degree and fourth degree served as the uke (faller) for the competitive and non-competitive conditions, respectively. Two video cameras (JVC 60 Hz) and a three dimensional motion analysis system (Vicon-Peak Performance Technologies, Inc., Englewood, CO) were used to collect and analyze peak velocity for the center of mass (COM) of uke and tori and peak angular velocity of tori's trunk (TAV). Data were smoothed using a 4(th) order zero lag Butterworth filter with a cut-off frequency set by the Peak software optimization technique. All variables were normalized by time as a percentage of the KT phase. In general, the COM directional velocity patterns were similar between conditions. Uke's def...
Three-dimensional assessment of the judo throwing techniques frequently used in competition
Background Although the judo throwing techniques are not considered as injurious to the attacker, repetition of these techniques might cause repetitive strain type injuries. The goal of the study was knowledge about the degrees of flexion and extension and abduction and adduction of the main locomotive joints, performing the most employed throwing techniques in high-level competition.
Judo Combat: Time-Motion Analysis And Biomechanical Approach
IJF Academy, 2021
The aim of this work is to connect time-motion analysis of judo combats and biomechanical classification of throwing techniques differenced as lever based and couple-based techniques. The connection of time contest analysis and biomechanical approach made this study punctual, nomothetic and useful for training input. The study sample included 104 judo combats and the collection of 6 time-motion indicators, namely: average combat time, locomotion, technique, ne waza, defense in standing, defense in groundwork phases. The study results showed that the locomotion phase is longer than the other combat phases, while technique phase is the shortest one. Average time durations increased after first round till to final combats. Lever based techniques were used a little bit more than couple-based techniques and this may be taken into account in training process. The semifinal combats, and combats for bronze medal lasted longer than other rounds. Also, the majority of the combats ended before regular time and 19% of the combats finished with golden score. The results of this work give information about time-motion characters of the judo contests that could be connected to the order of magnitude of the energy demands of the real judo competitions, by one heuristic combating equation, for example. The judo coaches may use these findings to plan their training process and improve strategic skills of judokas.
Classification of judo motor skills: tactical and motor criteria approach
The so-called combat sports involving a grip in general, and judo in particular, represent a complex reality of disciplines with common structural features. Such sports, particulary judo, require a great number of skills and techniques, which are used for sporting objectives; to facilitate understanding and simplify their organization, numerous classifications have been proposed. Studying a sport through the analysis of its motor skills involves, in the first place, organizing and classifying its different movements based on relevant and pertinent criteria, and relating them to the main objective. This work aims to present a proposal for the classification and organization of specific judo skills, based on the establishment of motor and tactical criteria, to analyse and optimize learnig and training processes, and applied research, enabling a new perspective on sporting analysis. Our main intention is to organize judo motor skills in order to: a) facilitate the acquisition of a large amount of movements (techniques) and to design a tool for acquiring a significative learning through a classificaction based on motor criteria; b) use this proposal as a resource to design, control and optimize the training process; and c) analyse the sport of judo from a tactical perspective by studying the relationship between the different components of the struggle.
Ido Movement for Culture. Journal of Martial Arts Anthropology, 2019
Background. Judo throwing techniques are traditionally classified as ashi-waza (leg techniques), te-waza (arm techniques), koshiwaza (hip techniques) and sutemi-waza (sacrifice techniques). However, this classification has recently been criticised, and instead a 9-group classification system based on action characteristics (movement type, base of support, throw direction, and position of attack) has been proposed. Problem and aim. To determine the throwing techniques that resulted in score using this classification and compare weight categories, sexes and medal/non-medal winners during the 2017 Senior Judo World Championship. Method. The analysis included 756 throwing techniques that resulted in a score (over 601 matches) across the competition. Results. There was an association between technique classification and sex (c 2 = 15.64; p = 0.048; Cramer`s V = 0.144): females scored more frequently using the techniques from group 3 compared with males (c 2 = 6.93; p = 0.009), whereas males scored more often using the techniques from group 8 compared with females (c 2 = 5.55; p = 0.019). A significant relationship between technique classification and weight category (c 2 = 106.19; p < 0.001; Cramer`s V = 0.153) was observed, but there was no association between technique classification and World Championship classification (c 2 = 9.55; p = 0.298; Cramer`s V = 0.112). Additionally, a limited number of throwing techniques resulted in more than half of all scoring situations during this competition. Conclusions. Techniques types utilised by athletes differed according to sex and weight category, and that a few number of techniques were utilised in this top-level judo competition.
A three-dimensional analisis of the Center of mass for three different judo throwing techiniques
Journal of sports science & medicine
Four black belt throwers (tori) and one black belt faller (uke) were filmed and analyzed in three-dimensions using two video cameras (JVC 60 Hz) and motion analysis software. Average linear momentum in the anteroposterior (x), vertical (y), and mediolateral (z) directions and average resultant impulse of uke's center of mass (COM) were investigated for three different throwing techniques; harai-goshi (hip throw), seoi-nage (hand throw), and osoto-gari (leg throw). Each throw was broken down into three main phases; kuzushi (balance breaking), tsukuri (fit-in), and kake (throw). For the harai-goshi and osoto-gari throws, impulse measurements were the largest within kuzushi and tsukuri phases (where collision between tori and uke predominantly occurs). Both throws indicated an importance for tori to create large momentum prior to contact with uke. The seoi-nage throw demonstrated the lowest impulse and maintained forward momentum on the body of uke throughout the entire throw. The ...
Judo: how to enhance tactics in competition, biomechanics of combination and action reaction
This paper is an ideal continuation of the previous one - How to enhance effectiveness of Direct Attack Judo throws -in it there are analyzed the two following parts of Judo tactics in high level competitions: combination, and action-reaction. The paper start with a review of the Japanese approach to Initiative ( Sen) and follows by the biomechanical view of the same subject. High level competitions are the main argument not only of coaches match analysis , but also of a lot of scientific researches. However the connection between these two field that analyze the same subject is very hard . A lot of information are not easily transfer to coaching area. In this paper the effort to give coaching useful information is the primary aspect also at detriment of some formal mechanical information. After a new Operative Classification of throwing techniques , the biomechanical analysis of combination and action-reaction tricks flows in easy way singling out some interesting finding, useful f...