Biomechanics and Medicine in Swimming XI

BiomechanicsandmedicineinswimmingXi
Models for Assessing General Horizontal Swimming
Abilities of Junior Water Polo Players According to
Playing Position
Özkol, Z. 1 , dopsaj, M. 2 , Thanopoulos, V. 3 , Bratusa, Z. 2
1Ege University Physical Education and Sport Department, Izmir, Türkiye.
2University of Belgrade Faculty of Sport and Physical Education, Belgrade,
Serbia.
3University of Athens Faculty of Physical Education and Sports Sciences,
Athens, Greece.
The aim of this study was to identify general level of horizontal swim
abilities of junior water polo players according to playing position. The
subjects were 71 players, members of national junior teams. The players
were divided in three main playing position groups; peripherals (P), center
defenders (CD) and center players (C). The following six swimming
tests were performed, crawl; 15m, 25m, 50m, 200m, 25m crawl with
head up and 25m crawl with ball. The results of these tests were analyzed
using a confirmative model of factor analysis for the determination of
the factor scores and mathematical multidimensional procedures were
determined for creating models. There were no statistical differences
(p>0.05) between general level of basic horizontal swim abilities according
to position.
Key words: Waterpolo, playing position, junior, model assessment,
swim test.
IntroductIon
Tactical, technical, physical demands and also playing position differences
of water polo players are very important factors for competitive
success. For the planning of water polo training, the primary informative
sources need to be taken into consideration, the physiological demands
of the game, based on the differences in game duration, the period of the
game, the level of competitiveness of the players, the level of competitiveness
of the teams and the different player positions (Lozovina, 1983;
Lozovina et al., 2009; Platanou, 2009; Tsekouras et al., 2005).
Certain activities are performed more frequently and with an increased
overall duration by the center forwards compared to attackers
and defenders (Platanou, 2009). However, very few studies have been
published about the anthropometrical, physical and physiological parameters
of water polo players at various ages. Bratusa (2000) found that
water polo training affects basic motor skill improvement in prepubescent
children. Matković et al. (1999) suggest using specific tests on land
and in the water. Through training and selection, an early specialization
takes place and those boys who are more skillful in specific situations
stand out. Falk et al. (2004) recommend using fewer swimming tests in
the selection process of young water polo players. In high profile water
polo, using manifest anthropometric and motor skills variables, it is possible
to make a prognosis of how successful any defense/offence will be
(Lozovina, 1983).
However, there is little data about horizontal swimming abilities
according to playing position in the younger categories, especialy cross
culturally. There is also a lack of research on how to identify horizontal
swimming abilities according to playing position differences of water
polo players. Therefore the aim of this study was to identify the general
level of horizontal swim abilities of junior water polo players according
to playing position and to improve our understanding of the positional
differences of water polo players.
Methods
The subjects consisted of 71 players aged 15-16, members of national
junior teams from: Slovenia, Türkiye, Serbia and Greece. For the play-
276
ing positions, players were divided three main playing position group,
peripherals (P, n=41), center defenders (CD, n=20) and center players
(C, n=13). Each team has been tested using by the same procedures
(3) and in the same training period at the start of the national precompetition
period.
The following six swimming tests were performed: 15m crawl, 25m
crawl, 50mcrawl, 200m crawl, 25m crawl with head up and 25m crawl
with ball (25mcrawlHUP, 25mcrawlWB). All tests were performed in a
50m swimming pool. The players started from in the water at the signal
of the timekeeper, and tracks of 25m were measured by stopping the
stopwatch when the head crossed the imaginary line of the finish.
Data obtained were processed by standard descriptive statistics, calculations
included arithmetic mean (X), standard deviation (SD) and
coefficient of variation (cV%). Multivariate tests were performed to determine
the level of statistical significance between the playing positions.
Then results of these tests were analyzed using confirmative models
of factor analysis for the determination of the factor scores. Following
this analysis, the mathematical multi-dimensional procedures were determined
for creating models for assessing the horizontal swim score
(HSS) equations for three different playing positions; for the peripherals
HSS (P) , for the central defenders HSS (CD) and for the center players
HSS (C) . The results of HSS for three different playing positions was
expressed numerically (from a hypothetical minimum of zero to a hypothetical
maximum of 100, where 50 represents an average swim score).
For this process, multiple regression model analysis has been used to
determine predictor system influence on the criterion variable. The level
of significance was set at p0.05 (p=0.305), there are no statistical
Wilks’ differences Lambda between statistics basic horizontal found swim that abilities the according p was >0.05 to position. (p=0.305), It seems that there
are the no process statistical of specialization differences is not yet between strong in basic 16 yrs horizontal old water polo swim players abilities from these ac-
four countries (Slovenia, Türkiye, Serbia and Greece).
cording to position. It seems that the process of specialization is not
yet strong in 16 yrs old water polo players from these four countries
(Slovenia, Türkiye, Serbia and Greece).
Table 2. The results of tests of between-subjects effects.
Dependent Variable Type III Sum of Squares df Mean Square F Sig.
m15crawl .043 2 .022 .078 .925
m25crawl .363 2 .181 .209 .812
m50crawl 1.434 2 .717 .253 .777
m200crawl 61.343 2 30.671 .641 .530
m25crawlHUP .626 2 .313 .390 .678
m25crawlWB .068 2 .034 .027 .974
Beside the fact that statistically significant differences were not found (Table 2)
between these observed groups (P,CD,C) for the variables (Table 2); 15m crawl
(F=0.078, p=0.925), 25m crawl (F=0.209, p=0.812), 50m crawl (F=0.253, p=0.777),
200m crawl (F=0.641, p=0.530), 25m crawlHUP (F=0.390, p=0.678), 25m crawlWB
(F=0.027, p=0.974) three different multidimensional models for prediction of basic
horizontal swimming abilities for 16 yrs old water polo players were created, as
Horizontal Swim Score (HSS).
The ANOVA regression analysis results show that the separated set of 6 predicting