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Speed of Visual Sensorimotor Processes and Conductivity of Visual Pathway in Volleyball Players Volleyball is a dynamic game which requires a high level of visual skills. The first aim of this study was to investigate the several aspects of reaction times (RT) to visual stimuli in volleyball players (12) compared to non-athletic subjects (12). By using the tests included in the Vienna Test System (Schuhfried, Austria), simple reaction time (SRT), choice reaction time (CRT) and peripheral reaction time (PRT) were examined. The second aim of this study was to assess the neurophysiological basis of early visual sensory processing in both examined groups. We measured two sets of pattern-reversal visual evoked potentials (VEPs) during monocular central field stimulation (Reti Scan, Roland Consult, Germany). The latencies of waves N75, P100 and N135 were determined. We observed significantly shorter (p<0.05) total reaction time to stimuli appearing in the central and peripheral field of vision in the volleyball players compared to non-athletes. With regard to SRT and CRT the main differences between the groups appeared in pre-motor reaction times. Volleyball players had shorter VEPs P100 wave latencies (p<0.05) than the non-athlete group. The results indicate faster signal transmission in visual pathways in athletes than in non-athletes. This fact can be attributed to the effect of rapid visual-activity-demanding sports on the central nervous system.

The purpose of this study was to assess the effect of 18-week Tai Chi training on body balance in dynamic trial among elderly men. The study covered 49 subjects from age 60 to 82.1 years, who had osteopenia or osteoporosis. The subjects were recruited from the community by direct mailings and community efforts to participate in studies. The participants were randomly assigned to either the exercise intervention (n = 25) or control groups (n = 24). The Tai Chi group participated in an 18-week exercise class held for 45 min, twice a week. Body balance was assessed using a Computer Posturographic System PE 90 produced by the Military Institute of Aviation Medicine in Warsaw with modified software made in Pro-Med. During the measurement of body balance, the capacity to perform specific tasks was analyzed (deflections in the set scope and direction). In the Tai Chi group, an increase (p < or = 0.01) in effectiveness of balance task performance was noted from 80.95% to 84.45% after the training. In the control group, no statistically significant improvement in the level of body balance was found in the same period. Thus, an 18-week period of Tai Chi exercises twice a week for 45 min is beneficial for dynamic balance. It can be important for reducing fall risk factors.

The aim of the study was to investigate the relationship between body image and prevalence of underweight, normal weight, and overweight in adolescents. The study included 1702 girls and 1547 boys, aged 14-16 years, who completed questionnaire assessing body satisfaction. The participants' BMI status: underweight, normal weight or overweight was determined on the basis of BMI cut-off values. Results revealed that more girls (p < .001) showed low body satisfaction (44.8%) and fewer girls (p < .001) had high body satisfaction (17.6%) compared to boys (28.5% and 29.0%, respectively). A two-way ANOVA revealed a significant interaction between BMI status and gender on body satisfaction F(2, 3243) = 4.10, p = .017, η2 = .003. In boys, body satisfaction was higher in normal weight and underweight in comparison to overweight individuals (p < .001). Underweight girls presented higher body satisfaction than those who were normal weight and overweight (p < .001). Our findings indicated that, in relation to gender, BMI status can be associated with different body satisfaction in adolescents. This should be taken into consideration when designing programs aimed at obesity and disordered eating prevention and body image improvement. Due to the fact that underweight girls and boys have high body satisfaction, this can lead to behaviors that maintain low body weight in adolescents and in turn this may have negative health consequences.

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