1. Introduction
Today, sports for the disabled have become one of the most critical categories in the world of sports. Sports for the blind and visually impaired are of particular importance. According to the International Blind Sports Federation (IBSA), 115 countries currently have national federations active in this field. And Goalball participated in the Toronto Paralympic Games since 1976 [1]. Identifying the role of body physics dimensions (body type) and anthropometric dimensions in the optimal implementation of sports skills or designing training programs is attractive to athletes, coaches, and researchers.
The research that has been done so far in the field of goalball sports were mainly in the field of evaluation of functional, morphological, and anthropometric aspects, evaluation of aerobic parameters in field tests [5, 6], technical and tactical functions [7, 8] and physiological responses [9]. And only one study whose data was collected during the 2012 London Olympics examined the relationship between anthropometric dimensions and the performance of elite goalball players [14].
However, it is important to know that the first study was conducted to examine the morphological characteristics of elite goalball athletes in Iran. Therefore, assuming the effect of anthropometric dimensions and body type on the performance of elite goalball players, this study aimed to investigate the relationship between structural profile and sports performance of elite goalball players.
2. Materials and Methods
To carry out the research steps, the researcher, after the necessary coordination with the National Blind Sports Federation and Visually Impaired, attended the site of the Goalball National Championships. The statistical population of this study was 48 players from 8 national goalball leagues. 30 subjects with Mean±SA age: 27.30±5.40 years, Mean±SA height: 1.78±0.04 m, Mean±SA weight: 82.83±11.62 kg, Mean±SA body mass index: 26.07±3.74 kg square meters were purposefully selected.
Inclusion criteria included participating in at least two matches and attending the game for at least twenty-two minutes (average minutes when all 48 players were on the field). Before receiving the consent to announce the readiness of the subjects to participate in this study, the necessary information for the players and the team leader about the purpose and manner of conducting this research and the points that the subjects should observe to participate in this study were stated.
After completing the consent form, personal information and medical and sports records were collected through a questionnaire and interview. A researcher performed all measurements with a tool based on the standard methods recommended by the International Association for the Advisory Anthropometric Advancement (ISAK). At the end of the evaluations, the Shapiro-Wilk test was used to check the normality of data distribution. Due to the non-normality of data distribution, non-parametric Spearman correlation coefficient tests were used to test the hypotheses.
None of the measurements were performed before and after the match, and all stages of the research were completed in the players’ free time. In this study, a wall scaler (Seca) made in Germany with an accuracy of 1 mm was used to measure the height of the subjects, a digital scale (Seca) made in Germany with an accuracy of 0.01 kg was used to measure the weight of the subjects, the Lufkin tape meter with an accuracy of 1 mm was used to measure the circumference of the limbs and the length of the two open arms (Arm Span), Mitutoyo calipers with a precision of 1 mm made in Japan were used to measure arm and thigh bone widths, a caliper (Lafayette) with an accuracy of 1 mm made in the USA was used to measure the thickness of subcutaneous fat and an Iranian segment meter with an accuracy of 1 mm was used to measure the length of the limbs.
3. Results
Descriptive statistics including age, weight, height, and body mass index (BMI) of the subjects were measured before the test, the results of which are summarized in the Table 1. 



The results of examining the hypotheses showed no significant relationship between body composition and somatotype with functional indicators (P>0.05). However, between the efficiency of defenses with weight (P=0.03) and body mass index (P=0.03) and between the efficiency of shots in the penalty with the length of the defense height (P=0.005), the total length of the hand (P=0.02) and the length of the two open hands (P=0.02) a significant relationship was observed.
Also, this relationship between the length of the sole and the efficiency of shots leading to the goal (P=0.009) and the efficiency of shots in the penalty (P=0.001) was significant. However, no significant relationship was observed between other anthropometric features and dimensions of athletic performance.
4. Conclusion
In this study, the structural characteristics of elite goalball players were examined, the efficiency of defenses indicated high-quality defense, and the player saved the ball in the area where the shot was taken. The player does this with a dive and grabs the ball. One of the factors that can cause such a quality in the defensive performance of players is anthropometric dimensions such as height and weight [10-14], and the relationship between defense efficiency with weight and body mass index in this study can confirm this. Thus, taller height covers more ground area, and more muscle mass and lower fat percentage also cause agility and faster performance during the defense.
Another indicator was the effectiveness of the penalty shootout, which examined the goals scored on penalties. In this study, the relationship between shots in the penalty with the total length of the hand and the length of the two open arms and the height was significant. And it can be confirmed that goalball players throw the ball to the opponent ground more quickly when attacking with higher height and hand [10-24]. According to the results, the structural profile is very important in the success of goalball players and reaching national levels.
But at the elite level, factors such as experience, basic training, technical factors, and spatial orientation are more effective factors in the success of elite players. Dingley et al. believe that after developing compensatory motor skills, trainers can consider body size for specific disabilities as a secondary measure of improving power production and, consequently, speed [27].

Ethical Considerations
Compliance with ethical guidelines
This study was approved by the Ministry of Physical Education and Sports Science (Code: IR.SSRI.REC.1400.994).
Funding
This study was extracted by the MA. thesis of the first author at Department of Sport Injuries and Corrective Exercises, Faculty of Physical Education and Sport Sciences, University of Guilan, Rasht.
Authors' contributions
All authors equally contributed to preparing this article.
Conflicts of interest
The authors declared no conflict of interest.
Acknowledgements
The authors want to thank the cooperation of the Sports Federation of the Blind of the Islamic Republic of Iran.
 

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