Visual restriction on crawl swimming skill influence the variant and invariant aspects of swimming techinque

Perceptual manipulation in the visual field, when observing the effect of retinal manipulation, can be extremely important in creating changes in the swimmer's body perception and technique. The aim of this study was to observe and understand the role restriction has in swimming ability (Partial glasses occlusion - restriction in the body) and can influence the variant and invariant aspects of crawl swimming. Beginners swimmers of both genders (13 to 15 years old, n=20) were evaluated in a 50-meter stretch in both underwater and air phase without visual restrictions and, later, with visual restrictions (Convergent Foramen, Divergent Foramen, Upper Field, Lower Field). The results were analyzed in both absolute and relative values. The biological maturation was obtained through the somatic maturation indicator. The variable that showed significant difference between the type with restriction and without restriction was the Converged Foramen (CF), both for relative (p= 0.023) and absolute values (p= 0.006). However, both differences, although significant, had a very small sized effect (d= -0.029 and d= -0.142 respectively) as well as negative. In conclusion the restriction by CF may cause significant changes in the technique of young swimmers.