european college of sport science

Wednesday, June 24th, 2009
Chiodo S. et al. 13th Congress of the European College of Sport Sciences p. 457.
Melhim A.F. Br. J. Sports Med. 2001; 35: 231-234.
Shin Y.W. et al. Am. J. Sports Med 2008; 36: 158-61.
Yard E.E. et al. J. Sci. Med. Sport 2007; 10: 219-226.
TECHNIQUE AND BALANCE IN ELITE JUDO
RODRÍGUEZ-ROMO, G., STIRLING, J., ZAKYNTHINAKI, M., LÓPEZ DÍAZ DE DURANA, A., CORDENTE MARTÍNEZ, C., SILLERO
QUINTANA, M., SAMPEDRO MOLINUEVO, J.
TECHNICAL UNIVERSITY OF MADRID (UPM)
Introduction: Balance is fundamental in judo, both in attack when trying to break the opponent’s balance and in the defense of such
attacks. Tools from dynamical systems have recently been used to model the process of regaining balance following a perturbation form
quiet stance (Zakynthinaki et al, 2008; Stirling and Zakynthinaki, 2004). The aim of this study was to apply the model of Stirling and Zakynthinaki
(2004) to look at the connection between the balance of elite judokas and their technique both in attack and defense.
Methods: 5 judokas of the Spanish National Team were studied. The ground reaction forces resulting from the judoka being perturbed
from quiet upright stance, for the two legged and single legged condition (Zakynthinaki et al, 2008; Stirling et al, 2007) were modeled and
analyzed. With the use of a force platform the maximum correctable angles between the resultant ground reaction forces and the vertical
in the anteroposterior and mediolateral directions were obtained. A closed critical curve (Stirling and Zakynthinaki, 2004) was then fit
through the maximum correctable angles (for greater angles than these the judoka falls over). The curve was analyzed to find asymmetries.
Each judoka also completed a questionnaire regarding their preferred techniques, with video being taken both of these techniques
and also all the experiments.
Results: It was observed that the favored side (in the case of the two legged experiment) or leg (in the case of one legged experiment) for
balance was connected with technical features of the preferred techniques of the judokas. In some of the judokas this preference was
shown to be strong.
Discussion: Non-symmetric behavior caused by muscle imbalances, postural problems, structural problems and differences in the
ranges of motion on either side of the body have been identified via the critical curve (Zakynthinaki et al, 2008; Stirling and Zakynthinaki,
2004). Our research has shown how these methods can be used to identify competitive strengths and weaknesses for addressing and
correcting via training in elite judo (Stirling and Zakynthinaki, 2005; A. López Díaz de Durana, 2009).
References
López Díaz de Durana A (2009). PhD thesis UCLM.
Stirling JR, Cordente Martínez CA, López Díaz de Durana A, Sillero Quintana M (2007). Technical Report, Consejo Superior de Deportes
07/UPB10/07.
Stirling JR, Zakynthinaki MS (2004). Chaos, 14(1), 96-105.
Stirling JR, Zakynthinaki MS (2005). Lecture notes of the ICB Seminar, Mechanical loads of the human motor system - Injury prevention, A.
Wit and F. Vaverka (Eds.) 64, 39-47.
Zakynthinaki MS, Stirling JR, López Díaz de Durana A, Cordente Martínez CA, Sillero Quintana M, Sampedro Molinuevo J (2008). Comp
Phys Comm, 179(8), 562-568.
BALANCE IN ELITE JUDO AND ITS RELATIONSHIP WITH INJURIES
LOPEZ DIAZ DE DURANA, A., STIRLING, J.R., ZAKYNTHINAKI, M.S., RODRÍGUEZ-ROMO, G., CORDENTE MARTINEZ, C., SILLERO
QUINTANA, M., SAMPEDRO MOLINUEVO, J., REFOYO, I.
TECHNICAL UNIVERSITY OF MADRID
Introduction: Balance and posture in general is often affected by the history of injuries: different injuries affecting the balance or movement
pattern of the individual in different ways. The converse of this is also true, in as much as irregularities in an individual’s posture and
balance can increase the likelihood of particular injuries. The aim of this study was to apply the model Stirling and Zakynthinaki (2004)
and the tools presented in Zakynthinaki et al (2008) to examine the connection between injuries and the asymmetries in the balance of
elite judokas.
Methods: 5 elite judokas took part in the study. Each judoka stood on a force platform and was perturbed from quiet upright stance, for
the two legged and single legged position (Zakynthinaki et al, 2008; Stirling et al, 2007). The maximum correctable angles between the
resultant ground reaction forces and the vertical in both the anteroposterior and mediolateral directions were obtained. A closed critical
curve (Stirling and Zakynthinaki, 2004) was fit through the maximum correctable angles at which the judoka could lean. This critical curve
was analyzed for asymmetries and the judokas completed a questionnaire regarding their history of injuries. Video was also taken of all
the experiments in both the anteroposterior and mediolateral directions so as to allow us to observe some of the basic irregularities in
the posture and movement patterns.
Results: A connection between the asymmetries in the critical curve and both the history of injuries and the current injuries was observed.
In particular very strong asymmetries in the critical curve were shown to exist for those judokas who were injured when they completed
the test.
Discussion: Injuries can result in muscle imbalances, postural problems, structural problems and hence as a result can cause asymmetric
movement patterns which lead to differences in the ranges of motion on either side of the body. Such differences have been identified
via the critical curve (Zakynthinaki et al, 2008; Stirling and Zakynthinaki, 2004). Our research has shown how these methods can be used
to identify both current injuries and those which have occurred in the past (Stirling and Zakynthinaki, 2005).
References
Zakynthinaki MS, Stirling JR, Lopez Diaz de Durana A, Cordente Martinez CA, Sillero Quintana M, Sampedro Molinuevo J (2008). Comp
Phys Comm, 179(8), 562-568.
Stirling JR, Cordente Martinez CA, Lopez Diaz de Durana A, Sillero Quintana M (2007) Technical Report, Consejo Superior de Deportes
07/UPB10/07.
Stirling JR, Zakynthinaki MS (2005). Lecture notes of the ICB Seminar, Mechanical loads of the human motor system - Injury prevention, A.
Wit and F. Vaverka (Eds.) 64, 39-47.
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