Sports Research Articles

Differences in athlete's left ventricular morphology by sex and sports discipline categories in elite Japanese athletes.

The cardiac morphology of elite athletes is related to sports disciplines and race; however, no studies have examined the effects of sports discipline on East Asian athletes. Therefore, this study aimed to assess left ventricular (LV) remodeling using transthoracic echocardiography in elite Japanese athletes and establish standard values for the indicators of the cardiac morphology of elite athletes in East Asia, considering the influence of body size. We retrospectively evaluated 1,363 elite Japanese athletes who underwent electrocardiography and transthoracic echocardiography between January 2011 and December 2021. The athletes were assigned to four sports discipline categories (skill, power, mixed, and endurance). We evaluated the differences in LV volume and mass between the groups for each sex. The LV end-diastolic volume (LVEDV) and LV mass indexed to the body surface area (BSA) in the endurance group (LVEDV/BSA: 72.3 ± 11.4 mL/m2 in males and 68.7 ± 11.0 mL/m2 in females, LV mass/BSA: 121.1 ± 19.1 g/m2 in males and 106.5 ± 18.0 g/m2 in females) were significantly larger than those of any other groups. Both values were affected by sex, BSA, and endurance sport type, whereas only LV mass was affected by age. Cardiac remodeling is proportional to the sport type, with a significantly greater effect in athletes playing endurance sports. The remodeling is particularly evident in the left ventricle; however, the corresponding remodeling is also observed in other heart chambers. Cardiac remodeling in elite Japanese athletes is similar to that observed in elite athletes of other races, except for the changes in LV wall thickness.

Gender-specific improvements incognitive resources : Impact of a multidimensional exercise program on healthy physically inactive older adults.

Neuroanatomical parameters deteriorate with age and this process varies among individuals. Gender differences in these parameters have been documented but their effects on cognition remain unclear. Physical activity, continuous learning and social interactions are recognized strategies to prevent cognitive decline. This study investigated the effects of multidimensional training on selective attention and reaction speed in physically inactive but healthy older adults, exploring gender-specific differences in cognitive abilities. The study employed apre-post design and included a24-week exercise program. A total of 60 participants (30male, 30female) aged 65-69years completed the program, which consisted of 90 min of fitness and 90 min of recreational sports each week. Cognitive performance was assessed using the STROOP (a visual test for selective attention) and reaction time (RT) tests administered through the Vienna Test System. Significant gender differences were observed. Women were initially slower than men but significantly improved their reaction speed after the training (p < 0.001, d = 1.144). Conversely, men showed significant improvements in controlled and automated actions (p = 0.021, d = 0.5). Multidimensional training enhances cognitive performance in physically inactive older adults. Gender-specific differences in reaction time were confirmed, while differences in other cognitive domains were revealed. The underlying causes of these differences are still unclear, raising the question of whether training programs should be tailored differently for men and women.

Evaluation of the Perceptions of Fitness Sports Center Members Towards Service Quality

This research aimed to evaluate the perceptions of members of fitness sports centers regarding service quality. A relational screening model was used in the research. The universe of the study consists of individuals who are members of sports centers affiliated with Bornova Municipality Sports Affairs Directorate of Izmir Province and who exercise regularly. The sample consists of 395 individuals who are members of these centers and voluntarily participated in the study. "Personal Information Form" and Perceived Service Quality in Sports and Fitness Centers scale developed by Uçan (2007) were used as data collection tools. In addition to descriptive statistics, independent groups t-test and One-way ANOVA methods were used in the analysis of the data. When the research findings were examined, it was observed that there were statistically significant differences in perceived service quality scores according to factors such as gender, educational status, occupational status, purpose of going to the sports center, exercise duration, and preferred sports center (p. 05). As a result, it was determined that service quality factors vary depending on different demographic and personal characteristics.

The reality of pressure ulcers: an exploratory sequential mixed design study in coaches and Paralympic athletes

ABSTRACT Objectives This study aims to explore and understand the knowledge and attitudes of Paralympic athletes and their coaches toward pressure ulcers. By focusing on this underserved population, the study seeks to improve awareness, recognition, and management practices to minimize the health and performance impacts of pressure ulcers in Paralympic sports. Methods Paralympic athletes and their coaches were contacted. Volunteers were included in the exploratory sequential mixed design study. In the quantitative phase, a digital survey was used to evaluate Paralympic athletes’ and coaches’ awareness of pressure ulcers. To gain a deeper understanding of the factors deemed significant in the quantitative analyses, the researcher conducted one-on-one semi-structured interviews with athletes and coaches. The data was analyzed using the SPSS package program and MAXQDA program. Results Ten coaches and 82 Paralympic athletes participated in the study. The sports disciplines were wheelchair basketball (40%), Paralympic table tennis (40%), Paralympic court tennis (10%), and athletics (10%). Coaches’ knowledge about pressure ulcers was low, and athletes’ knowledge was even lower. It was concluded that coaches should improve their attitudes toward pressure ulcers, particularly in the areas of competence and responsibility sharing. During the interviews with the participants, several themes emerged. Conclusion To address pressure ulcers’ significance, it is essential to increase the knowledge level of both athletes and the entire team and adopt a positive attitude. It has been concluded that different areas of expertise in the fields of health and sports should work with a more organized structure and team awareness.

Protein Intake, Physical Performance and Body Composition in Master Athletes—A Short Scoping Review

Sufficient protein intake has been shown to be advantageous for developing muscle mass, muscle strength, muscle quality, as well as for improving recovery from strenuous exercise, all of which are essential for athletic performance. Aging athletes, so-called master athletes, would benefit from evidence-based recommendations; however, studies investigating the role of their protein intake on muscle quality or performance are diverse and rare. Consequently, existing recommendations for this subpopulation of aging athletes are non-existent or speculative in nature. The aim of this short scoping review is to summarize available reports, identify common outcomes, and suggest future research directions. Literature research was carried out in PubMedMedline, SPORTDiscuss, and ScienceDirect without any restrictions regarding year of publication, type of research or sports discipline. Only observational and interventional studies with data on protein intake linked with body composition or performance outcomes were included for further analyses. We identified 12 suitable reports on master athletes with very diverse age-ranges, a broad variety of sports, and very heterogeneous outcome parameters. Seven studies investigated endurance athletes, four studies investigated multi-sports athletes, and only one study reported on strength-trained athletes. Average protein intake ranged between 1.0 and 1.9 g/kg/d. Within the few available studies, evidence tends to point towards a benefit of higher protein intakes for muscle mass and function; however, the low number of studies, combined with heterogeneity in study design and methods, limits their generalizability. Future studies are needed to build the evidence base for clear dietary recommendations respecting the specific needs of aging athletes.

Patterns of left ventricular remodeling according to the type of sport in a cohort of elite athletes assessed by speckle tracking echocardiography

Abstract Background Athletic training is associated with hemodynamic demands leading to physiological cardiac changes referred to as athlete’s heart. Whilst some studies support the hypothesis with predicted eccentric left ventricular hypertrophy (LVH) from endurance training, data confirming concentric-type effects of resistance training are inconsistent. Also, whether specific geometric adaptations are associated with specific changes of LV myocardial performance is undefined. Purpose To assess patterns of LV remodeling in relation to the type of sport, using speckle tracking echocardiography (STE) in a cohort of elite athletes (EA). Methods 132 EA (23±5 years) referred for resting echocardiography during annual check-up were prospectively enrolled.They were involved in competitive sports for &amp;gt;10 hours/week for over 3 years and had no history of cardiac/non-cardiac disease or sudden cardiac death. A control group of 15 healthy volunteers (25±3 years), either sedentary or engaged in &amp;lt;6 h of non-competitive training/week, was enrolled. An echocardiogram was performed in all subjects. Global myocardial work (MW) indices - work index (GWI), constructive work (GCW), work efficiency (GWE) and wasted work (GWW)- were calculated using a software able to construct a noninvasive LV pressure-strain loop based on STE-derived global longitudinal strain (GLS) and LV pressure from systolic cuff pressure. Analysis was performed by an experienced investigator blinded to the sport history of each subject. Results Four subgroups of EA were defined according to the sports disciplines: power (n=27), endurance (n=30), mixed (n=62) and skill (n=13). Mean values of LV volumes, wall thickness and mass were significantly higher in EA compared with controls. Normal LV geometry was present in &amp;gt;50% of EA in each group and &amp;gt;70% of power and skill EA. LVH was more prevalent in endurance (23.3%) and mixed (19.4%) as compared to skill (7.7%) and power (7.4%) EA. Eccentric hypertrophy was found only in endurance and mixed EA (&amp;lt;15% each group). Including age, BSA, gender, sport discipline, duration and intensity of training in binary logistic regression to predict LVH, increasing age was the only significant predictor (p=0.01). Conventional and advanced parameters of LV systolic and diastolic function were within normal range in all subjects. The one-way ANOVA revealed no significant differences between groups of EA and controls regarding mean values of GLS, LV ejection fraction and MW indices. However, among EA, endurance EA exhibited the highest values of GCW(2075±228 mmHg%), GWI(1767±222 mmHg%) and GWE(95.5±1.7%) and lowest GWW(76±35 mmHg%) with statistic significance for GWW(p=0.03) and marginally for GWE(p=0.05). Conclusion In our study, the type of sport was not related to the presence of LVH. The most significant LV remodeling was observed in EA, as expected, associated with a resting myocardial work profile characterized by highest values of GWI, GCW and GWE and lowest GWW. MW parameters and the type of sport

Data mining for psychological profiling of track and field athletes and runners

Psychological factors in sports have been widely studied in scientific literature. However, only a few studies have used data mining techniques for athletic profile analysis. The main goal of this study was to analyze motivation, self-confidence, flow, and psychological skills in athletics to build differentiated profiles through clustering techniques. The sample size was 470 participants (ages 14–70 years old; M = 32.1; SD = 13.5). The Sports Motivation Scale (SMS), Task and Ego Orientation in Sport Questionnaire (TEOSQ), Self-confidence in Sport Questionnaire (CACD), Flow Dispositional Scale-2 (FDS-2), and Psychological Inventory of Sport Performance (IPED) were used to analyze the psychological profile of the sample. A data clustering analysis was carried out to check the study’s purpose. Results show different behavior patterns according to specific profiles. Similarly, there have been differences between men and women, online and face-to-face participants, federated athletes and runners, categories, or sports disciplines. In conclusion, the understanding of each athlete’s psychological profile is essential to improve his/her performance. The results of this study could be used to implement changes and adjustments in athlete psychological training to run several intervention programs that focus on each group’s needs.

Enhancing individuals’ engagement in marine recreational sport activities: from an institutional perspective

IntroductionEncouraging consumer participation in marine recreational sport activities is recognized as a key strategy for boosting both local and regional economies. However, compared to other traditional outdoor activities, participation rates in marine recreation remain relatively low. Two major barriers to participation are consumers' concerns about whether marine recreational sport activities are interesting and suitable for themselves, which can be summarized into product quality uncertainty and product fit uncertainty.MethodsTo address this issue, this paper, grounded in institutional theory, investigates how different institutional environments influence consumers' product certainty and their behavioral engagement in marine recreational sport activities—an area previously underexplored in the literature.Results and discussionsBy collecting 292 survey responses and utilizing ordinary least squares (OLS) regression analysis, we found that both product quality certainty and product fit certainty have a significant positive effect on consumers' behavioral engagement. Additionally, both the regulatory-normative and cognitive institutional environments were shown to significantly enhance consumers' product quality and fit certainty. Moreover, age was found to moderate these effects, with a positive influence on the relationship between the regulatory-normative environment and product certainty, while only affecting the relationship between the cognitive institutional environment and product fit certainty.

Digital Transformation in Voluntary Sports Organizations: A Scoping Review on Multi-Level Drivers, Promoting Factors, Forms and Consequences

Introduction: Digital transformation, as the implementation of information technologies, is increasingly embraced among voluntary sports organizations, including sports federations and clubs (Thompson et al., 2024). These organizations are central pillars of organized sports in Switzerland, playing a critical role in fulfilling the socio-political functions of sports, such as promoting public health, social integration, and civic engagement (Nagel et al., 2020). Despite the increasing adoption of digital technologies, little is known about the drivers, promoting factors, and forms of digital transformation in these organizations (Ehnold et al., 2021; Merten et al., 2022). Furthermore, it remains unclear whether digital transformation helps to effectively address common challenges of voluntary sports organizations, such as recruiting and retaining members and volunteers. Therefore, this review aims to analyse the existing research on digital transformation in voluntary sports organizations to reconcile current approaches in the field of sport management research and identify research gaps. Methods: A scoping review methodology is employed to explore the current evidence and highlight knowledge gaps regarding digital transformation in voluntary sports organizations. Scoping reviews are particularly suited for this purpose, as they allow the scope of diverse research approaches (Arksey &amp; O’Malley, 2005). Results: While final results are pending, preliminary findings indicate that digital transformation in voluntary sports organizations is driven by external pressures (e.g., mandates from umbrella federations) and internal evaluations of its benefits, such as improved service quality and operational efficiency. The most adopted tools support communication, data management, and administration, while tools affecting sports practices remain underutilized. Key promoting factors include access to organizational capacity, digital transformation strategies, leadership commitment, and digital literacy. Regarding the consequences, digital transformation enhances organizational efficiency primarily through standardization, while challenges appear regarding initial costs and information technology skills. Discussion/Conclusion: Detailed results will be presented at the conference. This review clarifies the multi-level drivers, enabling factors, forms, and consequences of digital transformation in voluntary sports organizations. The findings provide a conceptual foundation for future research in sport management, addressing both practical applications and theoretical advancements.

Risk control of sports flooring in athletic activities from the perspective of inertia mechanics

From the perspective of inertia mechanics, sports flooring plays a critical role in controlling safety risks in athletic activities. Firstly, high-quality flooring materials and structural designs can effectively absorb impact forces generated during exercise, thereby reducing the physical burden on athletes and lowering the risk of injury. Secondly, flooring materials with good resilience can provide appropriate rebound properties, offering better support and reaction forces for athletes, thus improving both performance and safety. Additionally, high-quality flooring materials possess high durability and stability, maintaining their performance over prolonged use and minimizing safety hazards caused by material degradation. Lastly, flooring design should account for the characteristics of different sports, providing suitable coefficients of friction and elasticity to meet the needs of various athletes and reduce the likelihood of accidents during sports activities. Therefore, the design and material selection of sports flooring play an essential role in ensuring athlete safety and enhancing athletic performance. The findings of this study have significant implications for future research and practical applications, as they provide a scientific basis for the development of safer, more effective sports flooring solutions that can be tailored to meet the specific needs of different sports disciplines.

Frequency of Physical Activity-Related Injuries Among Adolescents: An Umbrella Review

ObjectivesThe aim of this umbrella review was to investigate the frequency of physical activity-related injuries (PARI) among adolescents. Our secondary objective was to describe the available reviews of injuries in three settings: organized sports, leisure time physical activity (PA), and school physical education (PE).MethodsWe conducted an overview of reviews consistent with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement guidelines on the frequency of physical activity related injuries in adolescents.ResultsWe identified 19 systematic reviews with at least moderate quality to include in the review. We were not able to pool data from reviews and conduct meta-analysis due to heterogeneity of injury definitions, exposure times, and sample demographics. All reviews included studies of injuries sustained in organized sports, and injury incidence was higher during matches than training. No systematic reviews were found focusing on leisure time or school-based PA injuries.ConclusionHigh-quality research is essential to understand the frequency of various types of physical activity related injuries among adolescents in organized sports, PE, and leisure time activities to develop more effective prevention strategies.

Sports behaviour and adherence to sports and exercise recommendations in patients with myocarditis

AimIn the clinical setting of acute myocarditis, existing guidelines recommend refraining from moderate-intensity to high-intensity sports for 3–6 months, yet the extent to which these recommendations are implemented by clinicians...

The key roles of teammates, coaches, and instrumental support in adolescent sports participation: a one-year prospective study.

Sports participation is important for promoting lifelong health and well-being. However, it often declines during adolescence, highlighting the need to understand the factors related to adolescent sports participation. This prospective study examines the associations between different sources (e.g., family, peers, coaches, teachers) and types (e.g., emotional, instrumental, co-participation) of social support and hours of organized sports participation among secondary school students (N = 294). It also explores whether these associations change from the second to the third year of secondary education. Data were collected using questionnaires and anthropometric measurements in October/November 2021 and October/November 2022. Multilevel linear fixed effects regression models were used to analyze relationships between sources and types of social support and sports participation. Additionally, scatterplots illustrated individual variability in these associations. Results showed significant associations for various sources and types of social support with organized sports participation. Social support from teammates and coaches and instrumental support emerged as the strongest predictors of hours of participation. Additionally, we found that the relationships remained stable over time. Yet, substantial individual variability in how social support related to sports participation was also observed. These findings emphasize the importance to promote social support from within the sports environment and to encourage instrumental support. Tailored approaches addressing individual differences are recommended to enhance adolescent sports participation.

Sports participation as a reflection of social inclusion in youth: a holistic exploration of sport within young people’s lives

ABSTRACT The positive statistical outcomes associated with participation in sport for young people are commonly used to support claims that sport has the potential to promote social policy goals, especially those related to social inclusion. In this paper, we examine this claim by drawing on interview data from the Norwegian qualitative longitudinal study Inequality in Youth. We investigate how young people’s organized sports participation is related to social inclusion and overall security by focusing on three common sport participation trajectories: not participating, opting out and participating continuously. We find that those who did not participate constituted a particularly selected group that more often was characterized by a situation of struggle related to structural issues such as class and ethnicity; organized sports participation seemed to be less viable in their situation. For ethnic-majority non-participators, this was due to struggles with a complex set of challenges related to family, school, and health, which made sport participation difficult, whereas ethnic-minority non-participators often thrived in other arenas of life but struggled to find activities within traditional sports organizations that suited their preferences. In contrast, the young people in the study who participated continuously and those who opted out of sport had a life situation characterized by an overall sense of security and belonging, with sport first and foremost being a part of their overall life situation. Generally, they shared a sense of security and optimism and a strong degree of social inclusion that their sports participation easily fit into. On the basis of our findings, we concluded that in Norway, where organized sports’ cultural standing is strong, rather than young people’s sport participation promoting social inclusion, their sport participation is a reflection of their life situation in general, and in particular whether they already are socially included.

The Effects of the Mamanet Cachibol League Intervention Program on Perceived Health Status, Mental Health, and Healthy Lifestyle Among Arab Women.

Background: The Israeli Mamanet Cachibol League (MCL) is a community-oriented athletic program serving mothers through non-competitive recreational sports participation. This study aimed to assess the effects of the MCL on perceived health status, mental health (happiness, depression, social capital), and healthy lifestyle behaviors (physical activity and nutrition). Methods: This is an experimental study with a sample of 231 women (174 in the experimental group and 57 in the control). Participants completed questionnaires in November 2023 (T1) and then in August 2024 (T2). The questionnaire included questions on sociodemographic characteristics, perceived health status, mental health (happiness, depression, social capital), and healthy lifestyle behaviors (physical activity and nutrition). Results: At T1, the MCL participants reported better mental health (higher subjective happiness and social capital and lower depressive symptoms) than the control group. Over time, participation in the MCL led to significant improvements in mental health (reductions in depression and increases in subjective happiness and social capital). The participants showed substantial improvements in healthy lifestyle behaviors, with moderate effect sizes (effects size > 0.5) observed across these areas. Sociodemographic factors influenced the outcomes, with variations in health perception and physical activity linked to marital status and education level. Conclusions: Participation in the MCL program was associated with better mental health at baseline and significantly improved over time compared to the control group. The MCL participants also showed gains in healthy lifestyle behaviors, highlighting the importance of tailored interventions.

The Effects of Endurance Training and High-Intensity Resistance Training on Pulse Wave Velocity and QT Dispersion.

Objectives: This study aimed to examine the effects of endurance and high-intensity resistance training on arterial stiffness and ventricular repolarization in elite athletes. Methods: A total of 50 male athletes from different sports disciplines (volleyball, football, judo, and wrestling) and a sedentary group of 30 males participated in this study. Data collected from all participants included age, height, body weight, cardiovascular hemodynamic parameters, arterial stiffness parameters, and ECG measurements. Results: There was no significant age difference between the athlete group (20.42 ± 1.903 years) and the control group (20.97 ± 1.771 years) (p > 0.05). However, body mass index (BMI) values in the control group (24.83 ± 2.22 kg/m2) were significantly different from those in the athlete group (22.39 ± 2.663 kg/m2) (p < 0.05). Significant differences were found between the athlete and control groups in QT dispersion, systolic blood pressure, pulse pressure, and central pulse pressure values (p < 0.05), while similar results were obtained for arterial stiffness parameters (p > 0.05). Conclusions: The lack of a difference in pulse wave velocity and augmentation index (AIx) values between the athletes and the control group suggests that athletes do not bear additional risks regarding arterial stiffness. However, increased systolic blood pressure, pulse pressure, and central pulse pressure, among the hemodynamic parameters, indicate potential variations in vascular wall compliance and hemodynamic responses in the cardiovascular system. The increase in QT dispersion suggests that athletes may exhibit a heterogeneous repolarization process and an elevated risk of ventricular arrhythmias compared to the general population.

Individuals with disabilities in grassroots football clubs: volunteering and social capital

Abstract Volunteering might be a leisure activity that supports the development of social capital of individuals with disabilities in organized sports. This study investigates the link between having a disability (i.e., physical, mental, or both), the likelihood and extent of volunteering, and the level of social capital in grassroots football clubs. We further examine a moderating effect of volunteering hours on the relationship between having a disability and social capital. Drawing on leisure constraints theory, individuals with disabilities are assumed to have a lower probability to volunteer than able-bodied individuals. Also, we hypothesize that individuals with disabilities perceive their social capital as lower than able-bodied individuals. Based on the motivational model, we assume that sport volunteers with disabilities perceive a higher social capital if they volunteer more hours. Data were collected via an online survey in seven European countries and targeted at adult volunteers and members in football clubs (n = 16,989 volunteers). Results of regressions show that having a physical disability is significantly negatively associated with the probability to volunteer in a football club. Further, having either a physical or mental disability is significantly negatively related to an individuals’ social capital level. The moderation analyses indicate that volunteers having both types of disabilities perceive a higher social capital if they volunteer more hours per month.

Comparing some the Tripartite Consequences of Leisure-Recreational Sports among Selected University Students in Iran and Iraq

The purpose of this study was to compare the triple consequences of recreational sports among selected Iranian and Iraqi university students. and then thematic analysis was used to analyze the data. In the quantitative part, the Kendall W and independent t-tests were used. Based on the findings of the qualitative part, out of a total of 202 identified basic themes, 43 themes constituted physical outcomes, including the development of individual skills and abilities, reduction of injuries and illnesses, physical vitality, and contribution to the proper functioning of body organs; 75 themes constituted psycho-emotional outcomes, including individual growth, moral-behavioral development, emotional-trait development, and life development; and 84 themes constituted social outcomes, including social growth, communication development, improvement of social status, and social life development. In the quantitative part, it was also found that there is a significant priority between the triple consequences of recreational sports from the perspective of Iraqi and Iranian students, so that "psycho-emotional outcomes" from the perspective of Iraqi students and "physical outcomes" from the perspective of Iranian students were the first priority. Also, it was found that there is a significant difference between the triple consequences in the two groups of students, and this difference in all cases is higher in favor of Iraqi students.

The Use of Reinforced Concrete for Durable and Aesthetic Sports and Recreational Sports

This study focuses on the design and construction of durable recreational seating using reinforced concrete, addressing the limitations of traditional materials such as wood and metal, which are prone to environmental degradation and high maintenance costs. Reinforced concrete is known for its durability, strength, and resistance to harsh weather conditions, making it an ideal material for public seating in outdoor environments. Several key tests were conducted to assess the performance of the concrete mix used in this project. Sieve analysis confirmed that the fine and coarse aggregates were well-graded, ensuring optimal compaction and strength. The slump test,conducted with a water-cement ratio of 0.6, produced a slump value of 150 mm, indicating medium workability. This level of workability is suitable for concrete that requires easy placement and proper compaction without segregation or excessive bleeding. The compressive strength test at 7 days yielded a compressive strength of 15.81 MPa, demonstrating the early strength development of the concrete. However, compressive strength results for the 14-day and 28-day tests are still pending, as the remaining cubes are currently in the curing tank. These results will provide further insights into the long-term strength and performance of the concrete once the curing process is completed. Preliminary findings suggest that reinforced concrete is an excellent choice for recreational seating due to its ability to provide long-lasting durability and reduced maintenance. The combination of well-graded aggregates, an optimal water-cement ratio, and promising early compressive strength indicates that this material will perform well under both static and dynamic loads typically encountered in public seating.

Assessment of the occurrence of postural abnormalities in children aged 10-12 practicing various sports disciplines

Assessment of the occurrence of postural abnormalities in children aged 10-12 practicing various sports disciplines