2015, Volume 11, Issue 1

The use of k-means method for assessment of training and differences in motor abilities indices in judo contestants at different age



Grzegorz Lech1, Tomasz Pałka2, Wanda Pilch3, Tadeusz Ambroży4, Wiesław Chwała5, Janusz Jaworski5, Anna Tyka6, Dariusz Mucha2

1Department of Theory and Methodology of Combat Sports, University School of Physical Education, Cracow, Poland
2Institute of Human Physiology, University School of Physical Education, Cracow, Poland
3Institute of Human Physiology, University School of Physical Education, Cracow, Poland, Poland
4Department of Theory and Methodology of Gymnastics, University School of Physical Education, Cracow, Poland
5Department of Antropometrics, University School of Physical Education, Cracow, Poland
6Department of Recreation and Biological Regeneration, University School of Physical Education, Cracow, Poland


Author for correspondence: Anna Tyka; Department of Recreation and Biological Regeneration, University School of Physical Education, Cracow, Poland; email: aniatyka[at]yahoo.co.uk


Full text

Abstract

Background and Study Aim: Elementary coordinated motor abilities usually exhibit typical stages of development i.e. the progressive stage, relative stabilization and regression. Dynamic development occurs until 16-18 years of age, followed by a long period of relative stabilization that takes until the age of 40 to 50 years. These regularities relate to the population which is not actively involved in physical activity (sports). It remains unknown what is the dynamics of changes in the above abilities in elite judo athletes. The aim of the study was the usefulness of the k-means method (taxonomy) in identifying the differences in motor abilities indices’ profile in judo contestants at different age.
Material and Methods: Twenty five judo contestants were examined. The selection of the subjects considered their age, competition experience, weight category and sports level.
During the final phase of the competitive season laboratory tests were used to measure the level of coordinated motor abilities (a battery of computer tests and balance measurement), speed (Wingate test), strength (muscle torque measurements) and endurance (graded exercise test). 
Results: Interpretation of the results revealed that three cadets had a profile and level of motor abilities typical of junior competitors. Level of motor abilities in one cadet was evaluated as corresponding to senior level. One junior athlete exhibited motor abilities typical of cadets’ level. When comparing the methods of determination the differences in the level of motor abilities indices, the method of k-means showed 19 statistically significant differences. One-way analysis of variance with age as an independent variable revealed statistically significant differences in 16 cases. The statistically significant differences in both methods were found in the same 14 indices. However, only 6 cases showed the same correlation. 
Conclusions: The method of k-means differentiates the athletes to higher extent than the analysis of variance with age as an independent variable. This method allows to evaluate motor development (specifity of training) in individual athletes.


Key words: competition experience, ontogenesis, sports level, taxonomy