Dimitrova N.
EQOL (2009) 38-41
BIODYNAMIC ANALYSIS OF THE UKI GOSHI
TECHNIQUE IN JUDO
Nikolina Dimitrova
National Sports Academy “Vassil Levski”, Sofia, Bulgaria
Abstract
Active experiment for analysis of movement activities dinamographic structure of “Uki Goshi”, one of
the main ku-dan system judo techniques has been performed. The hypothesis that there are much more
complicated interrelations between kinematical and dynamical structures has been proved. With the
means of reacting dummy, the uke counter attack in the specific points of dynamic function development
has been modeled. The untenability of classic biodynamic analysis conclusions, where the uke reaction is
not modeled was proved. This study has also relation to the creation of individual training process for
highly qualified competitors.
Introduction
It is known that the sport technique is very multidimensional quantity and have
different aspects regarding the specific function and applicable sport-technical
rules. A set of criteria for quantity evaluation referring to volume, stability, variety
and effectiveness of sport-technical actions are developed in the theoretic
biomechanics2,4. There is a principle difference between sport disciplines with
individual and group character. In cases of two persons combat (judo, sambo,
wrestling etc.) the classic biomechanics criteria for force impulse, linear
acceleration etc., are compromised by the fact, that upon the attacking system exist
an uncontrolled external force reactions influence (uke).
As working hypothesis of this study, we accept, that performed so far dynamographic records
carry only superficial information about the movement system possibilities. Because of the sophisticated
interdependence between kinematical and dynamical structures in the highly changeable external
situational field, the adaptation and correction potential possibilities in the process of the execution of the
technique remains concealed1,5.
Method
The main aim of this study is construction of controlled active experiment for quantitative biodynamic
evaluation of the compensative possibilities for opponent’s force reactions overcoming.
In order to achieve the aim the following purposes had to be resolved:
Development of specific software for special points evaluation
(in real time from the
dynamographic curve record achieved from tri-dimensional strain-measurement platform).
Hardware development of reacting dummy.
The laboratory experiment was held with 10 judo players with sport-technical mastership above
1st dan. The sport technique Uki Goshi was investigated, because it is in the basis of all hip techniques of
the ku-dan system.
The laboratory task provided implementation of dynamographic analysis on the support reaction
vector of tori at performance with dummy, with consecutive determination of all dynamographic curve
specific points3.
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Dimitrova N.
EQOL (2009) 38-41
The next set of dynamographic analyses was performed with standard force reaction releasing by
the uke in direction opposite to the throw direction. The reaction moment was selected by the random
numbers law in the area of the main specific points.
In order to standardise the experiment the same reaction force F=100N was used in all cases.
Results and Discussion
Regardless of individual peculiarities in performance of the technique, because of the kinematical
structure similarity of the movement system the dynamographic curves family has the same progress
logic.
Summarised expression of the dynamographic record type is presented on the figure 1. Here are
presented the main global extremes and multiple local extremes are smoothen as carriers of the
information peculiarities.
1600
F
Fy
1400
1200
1000
800
600
F
E
400
B
C
200
A
0
t
0
0,1
0,2
0,3
0,4
0,5
0,6
0,7
0,8
0,9
1
-200
Fig. 1
The classic biodynamic analysis would determined as main critical point D from the curve of the
horizontal component, as it would suggest that with smaller effort in this area the attack could be
overcome. We deliberately did not perform analysis of the dynamographic curve after E, because after
this moment the vertical component became bigger than the combined weight of the tori and uke and it is
presumed that there is no contact with mat and the influence of uke on the technique have rather
kinematical than dynamic characteristics. In table 1 are presented the results illustrating in statistical
scope the experiments with reacting dummy model effect. The deeper structural relations in the whole
movement system are obvious. In general scope at all examined persons it appears that biomechanical
system have considerable potential for overcoming of the counter attack in the global minimum area. This
is valid even to competitor №5 who have “paradox” negative values for the horizontal component of the
support reaction force in the global minimum point (D).
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Dimitrova N.
EQOL (2009) 38-41
Char
acteri
A
B
C
D
E
stic
Fav S V Fav S V Fav S V Fav S V Fav S V
1
75
42
56
72
24.1
33
48
10.1
21
38
8.2
22
300
42
14
2
96
32
33
78
19.2
25
54
11.8
22
42
6.1
15
360
39
11
3
36
26
72
116
15.3
13
54
12.2
23
57
4.2
7.3
420
58
14
4
124
38
30
88
16.1
18
68
14.1
21
59
3.4
5.8
280
48
17
5
121
39
32
84
21.4
29
82
11
12
72
1.9
2.6
390
21
5
Table 1
Especially important for the analysis is the fact, that application of external to the movement
system force is not explained with algebraic subjection. This means that the internal dynamographic
structure is far dense than external manifestation and the researcher should not be attempted to analyse
such type of dynamographic records.
As long as variation coefficient could be interpreted as system stability, most destroying effect on
it have the reactions in extreme points A and C, or this moments are most appropriate for performance of
counter actions.
In individual scope the test person №3 obviously have problem in the beginning of the attack and
the training process should accent on the first or “kudzushi” phase.
Surprisingly clear are the final phases of the test person №5. Consequent deep analysis of the
cause-effect relations between kinematical and dynamical structures ensuring this stability would be of
interest. We emphasise again that this competitor at normal, not influenced by the reactions performance,
global minimum D has negative value (F (D)=-16.2N).
By the individual peculiarities analysis in the behaviour of the influenced dynamograms became
clear that used experimental methodic could be applied with success for modeling and improving of
deeper structures of sport-technical mastership.
Conclusion
1. Performed laboratory experiment undisputedly proves the untenability of sport-technical mastership
evaluation based on classic (or simple) dynamographic record of the tori force vector.
2. With the means of developed
“passive” or
“active” experiment simulating uke reactions are
determined some general regularities as well as a set of individual ones bearing quantitative
information for sport-technical mastership.
3. As most significant conclusion we consider the fact of proving of the cogency of the hypothesis about
significant differences in the interpretation and analysis of dinamographic curves recorded in
“passive” and “active” experiment conditions. Thus is proved not only the multidimensionality of
sport-technical mastership, but also it hierarchic structure in depth. Of course remains open the
question about realisation of larger scale experiments for evaluation of interdependence between
parameters of the tri-dimensional spatial attack and defense force vectors.
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