درخت حوزه‌های تخصصی

Introduction: This research was conducted to determine whether professional athletes with Chronic Ankle Instability (CAI) exhibit differences in maintaining balance under conditions of with and without visual informationMaterials and Methods: Forty-five elite players with CAI were classified into soccer, volleyball, and basketball groups (n=15 each). All participants performed a static single-leg balance test in conditions wherein visual information was provided and withheld. Also, their center of pressure (CoP) oscillation parameters was measured. The data were examined through an analysis of variance (ANOVA) and the Tukey test.Results: A significant difference was found between the soccer and volleyball players (P=0.034) in anteroposterior CoP displacement. Furthermore, there was a significant difference between soccer compared with volleyball (P=0.001) and basketball (P=0.02) groups regarding mediolateral sway and sway area (P=0.003 and P=0.03, respectively) when they performed the test with their eyes open. A significant difference occurred between the soccer and volleyball players concerning anteroposterior and mediolateral sway (P=0.002 and P=0.04, respectively) and sway area (P=0.004) when they performed the test with their eyes closed.Conclusion: Given the necessity of maintaining a good balance in sports, volleyball coaches should design practices that reduce players’ reliance on visual information. These practices should strengthen their proprioceptive abilities through an increased challenge to their proprioceptive senses.

This paper proposes a categorization of sport that is based on the system of rules that a sport must adhere to. We focus on these systems of rules to examine how a winner is produced in different sports. The rules of a sport dictate the gameplay and the direction it takes. We propose to break down the gameplay into Events. At this junction, we observe two kinds of events – ones that follow sequential logic and ones that do not. Our focus is pertained to sports that comprise sequential events. To examine these events further, to understand how a winner emerges, we take the help of Finite State Automaton from theory of computation (Automata theory). We showcase how sequential sports are eligible to be represented as Finite State Machines. We depict these Finite State Machines as State Diagrams. We examine these State Diagrams to observe how a team/player reaches the final states of the sport, with special focus on one final state – the final state which determines the winner. This exercise has been carried out for the following sports: Hurdles, Track, Shot Put, Long Jump, Bowling, Badminton, Pacman, Weightlifting (Snatch). Based on our observations of how this final State of winning is achieved, we propose a categorization of sports.

Background : Volleyball is known as sport that requires high physical fitness, including muscle power, agility and reaction; hence, body composition and anthropometric features play important roles in this field. The purpose of this study was to investigate the relationship between anthropometric and body composition indices with lower limb explosive power in female volleyball players. Material and method : This correlational study was conducted in which 16 semi-professional female volleyball players with an average age of 20.4 ± 1.34 years and BMI of 22.09 ± 3.42 kg/m2 voluntarily participated. All volleyball players had a history of participation in the Tehran province volleyball league. First, data were collected and recorded by demographic questionnaire. Then, the body composition (fat percentage, muscle mass, visceral fat) was measured and recorded in the 3-hours fasting condition by body analysis device (OMRUN Bf511). Finally, Sargent Vertical Jump Test was used to evaluate explosive power of the lower limb muscles. Results :  Pearson correlation coefficient was used at the significant level p Conclusion: The results of this study show that resistance training along with volleyball specific power training can increase the muscle mass as well as it is at the same time.

Purpose: the etiology of children obesity can be varied. Adipose tissue is an active tissue that secretes proteins such as TNF-α, IL-6, leptin, and adiponectin. The purpose of this study was to investigate the effect of short-term sprint interval training on serum levels of adiponectin, leptin, TNF-α, IL-6, insulin, and lipid profile in overweight boys. Method: a number of 30 overweight male students (with a mean age of 9.93±0.2 and BMI of 27.73±0.2) were randomly assigned to the control group (n=15) and sprint interval training (n=15). The subjects of the experimental group did the training for eight weeks, as the control group was engaged in doing their daily activities without intervention. Measurement of anthropometric indices and fasting blood collection were performed (to measure insulin, leptin, adiponectin, TNF-α, IL-6, cholesterol, LDL, HDL and TG) one day before and one day after the training program. Results: the results of the present study indicated that 8 weeks of sprint interval training significantly decreased weight and BMI in overweight children (P<0.001). In addition to weight and BMI reduction, levels of TNF-α, IL-6, leptin, insulin, cholesterol, triglyceride, and LDL significantly reduce the following eight weeks of the sprint interval workout (P< 0.001 for all), while adiponectin and HDL levels increase (P<0.001, P<0.01, respectively). Conclusions: in general, the present study demonstrate that sprint interval training which is a new way of physical activity exerted a positive effect on most of components contributing to children obesity.