Die voorkoms van morfologiese asimmetrie by eliteinternasionale manlike spiesgooiers

Abstract

The aim of this study was to determine the degree (percentage) of upper body morphological asymmetry amongst elite international male javelin throwers, as it could possibly negatively affect the health of athletes and hinder optimal sporting performances. Nineteen javelin throwers with an average age of 26.4 ±4.4 years, were measured on both the dominant and non-dominant sides of the upper body. Twelve anthropometrical variables (three skinfolds, five girths, three segment lengths and one breadth) were measured according to the methods described by Norton et al. (1996). The percentage of morphological asymmetry was determined by making use of Wolañski's Relative Indices of Asymmetry (RIA) as used by Copley (1980). The dominant and non-dominant side measurements were compared by means of dependant t-tests. Statistically significant differences between the dominant and nondominant sides were found for the relaxed arm (p<0.05), forearm (p<0.001) and half-chest girths (p<0.001), acromial-radial (humerus) and midstilion-dactilion (hand) lengths (p<0.05). For thirteen of the fourteen measured (and calculated) variables, larger values were found on the dominant side, compared to those on the non-dominant side. The greatest degree of asymmetrical development occurred at the triceps skinfold (5.9%), half-chest girth (4.9%), forearm girth (3.9%), subscapular skinfold (-2.9%), biceps skinfold (2.5%), sum of three skinfolds (2.2%) and the relaxed arm girth (1.8%). The conclusion is therefore that a significant degree of morphological asymmetry occurs in the upper body of javelin throwers, with possible health detrimental and performance limiting effects. Further research is however needed.

South African Journal for Research in Sport, Physical Education and Recreation Vol. 27(2) 2005: 47-55